Canadian Patents Database / Patent 2920246 Summary

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(12) Patent Application: (11) CA 2920246
(54) English Title: THERAPEUTIC COMPOSITIONS INCLUDING CHROMAN DERIVATIVES AND USES THEREOF TO TREAT AND PREVENT MITOCHONDRIAL DISEASES AND CONDITIONS
(54) French Title: COMPOSITIONS THERAPEUTIQUES RENFERMANT DES DERIVES DE CHROMANE ET LEURS UTILISATIONS EN VUE DE TRAITER ET PREVENIR LES MALADIES ET TROUBLES MITOCHONDRIAUX
(51) International Patent Classification (IPC):
  • A61K 31/353 (2006.01)
  • A61K 31/4162 (2006.01)
  • A61P 3/00 (2006.01)
(72) Inventors :
  • WILSON, D. TRAVIS (United States of America)
(73) Owners :
  • STEALTH BIOTHERAPEUTICS CORP (Not Available)
(71) Applicants :
  • STEALTH BIOTHERAPEUTICS CORP (Cayman Islands)
(74) Agent: OSLER, HOSKIN & HARCOURT LLP
(74) Associate agent:
(45) Issued:
(22) Filed Date: 2016-02-09
(41) Open to Public Inspection: 2016-08-13
(30) Availability of licence: N/A
(30) Language of filing: English

(30) Application Priority Data:
Application No. Country/Territory Date
62/115,942 United States of America 2015-02-13

English Abstract


Disclosed herein are methods and compositions related to the treatment and/or
amelioration of diseases and conditions comprising administration of chroman
derivatives
and/or analogues, or pharmaceutically acceptable salts thereof. In particular,
the present
technology relates to administering an effective amount of chroman derivatives
to a
subject in need thereof to prevent or treat a disease or medical condition,
reduce risk
factors associated with a disease or medical condition, and/or reducing the
severity of a
medical disease or condition.


Note: Claims are shown in the official language in which they were submitted.

CLAIMS
What is claimed is:
1. A method for treating or preventing a mitochondrial disease or disorder
in a subject
in need thereof, comprising administering to the subject a therapeutically
effective
amount of a chroman derivative or a pharmaceutically acceptable salt thereof,
in
combination with one or more additional therapeutic agents selected from the
group consisting of: vitamins, cofactors, antibiotics, hormones,
antineoplastic
agents, steroids, immunomodulators, dermatologic drugs, antithrombotic,
antianemic, and cardiovascular agents.
2. The method of claim 1, wherein the mitochondrial disease or disorder is
selected
from the group consisting of Alexander disease, Alpers Syndrome, Alpha-
ketoglutarate dehydrogenase (AKDGH) deficiency, ALS-FTD, Sideroblastic
anemia with spinocerebellar ataxia, Pyridoxine-refractory sideroblastic
anemia,
GRACILE Syndrome, Björnstad Syndrome, Leigh Syndrome, mitochondrial
complex III deficiency nuclear type 1 (MC3DN1), combined oxidative
phosphorylation deficiency 18 (COXPD18), Thiamine-responsive megaloblastic
anemia syndrome (TRMA), Pearson Syndrome, HAM Syndrome, Ataxia, Cataract,
and Diabetes Syndrome, MELAS/MERRF Overlap Syndrome, combined oxidative
phosphorylation deficiency-14 (COXPD14), Infantile cerebellar-retinal
degeneration (ICRD), Charlevoix-Saguenay spastic ataxia, Primary coenzyme Q10
deficiency-1 (C0Q10D1), ataxia oculomotor apraxia type 1 (A0A1), Autosomal
recessive spinocerebellar ataxia-9/ coenzyme Q10 deficiency-4 (C0Q10D4),
Ataxia, Pyramidal Syndrome, and Cytochrome Oxidase Deficiency, Friedreich's
ataxia, Infantile onset spinocerebellar ataxia (IOSCA)/ Mitochondrial DNA
Depletion Syndrome-7, Leukoencephalopathy with brainstem and spinal cord
involvement and lactate elevation (LBSL), Autosomal recessive spastic ataxia-3

(SPAX3), MIRAS, SANDO, mitochondrial spinocerebellar ataxia and epilepsy
(MSCAE), spastic ataxia with optic atrophy (SPAX4), progressive external
ophthalmoplegia with mitochondrial DNA deletions autosomal dominant type 5
(PEOA5), mitochondrial complex III deficiency nuclear type 2 (MC3DN2),
episodic encephalopathy due to thiamine pyrophosphokinase deficiency/Thiamine
Metabolism Dysfunction Syndrome-5 (THMD5), Spinocerebellar ataxia-28
231

(SCA28), autosomal dominant cerebellar ataxia, deafness, and narcolepsy (ADCA-
DN), Dominant Optic Atrophy (DOA), cerebellar ataxia, areflexia, pes cavus,
optic
atrophy, and sensorineural hearing loss (CAPOS) Syndrome, spinocerebellar
ataxia
7 (SCA7), Barth Syndrome, Biotinidase deficiency, gyrate atrophy, Syndromic
Dominant Optic Atrophy and Deafness (Syndromic DOAD), Dominant Optic
Atrophy plus (D0Aplus), Leber's hereditary optic neuropathy (LHON), Wolfram
Syndrome-1 (WFS1), Wolfram Syndrome-2 (WFS2), Age-related macular
degeneration (ARMD), Brunner Syndrome, Left ventricular noncompaction-1
(LVNC1), histiocytoid cardiomyopathy, Familial Myalgia Syndrome,
Parkinsonism, Fatal infantile cardioencephalomyopathy due to cytochrome c
oxidase (COX) deficiency-1 (CEMCOX1), Sengers Syndrome,
Cardiofaciocutaneous Syndrome-1 (CFC1), Mitochondrial trifunctional protein
(MTP) deficiency, infantile encephalocardiomyopathy with cytochrome c oxidase
deficiency, cardiomyopathy + encephalomyopathy, mitochondrial phosphate
carrier deficiency, infantile cardioencephalomyopathy due to cytochrome c
oxidase
(COX) deficiency (CEMCOX2), P-Hydroxyisobutyryl CoA Deacylase (HIBCH)
deficiency, ECHS1) deficiency, Maternal Inheritance Leigh Syndrome (MILS),
dilated cardiomyopathy with ataxia (DCMA), Mitochondrial DNA Depletion
Syndrome-12 (MTDPS12), cardiomyopathy due to mitochondrial tRNA
deficiencies, mitochondrial complex V (ATP synthase) deficiency nuclear type 1

(MC5DN1), combined oxidative phosphorylation deficiency-8 (COXPD8),
progressive leukoencephalopathy with ovarian failure (LKENP), combined
oxidative phosphorylation deficiency-10 (COXPD10), combined oxidative
phosphorylation deficiency-16 (COXPD16), combined oxidative phosphorylation
deficiency-17 (COXPD17), combined oxidative phosphorylation deficiency-5
(COXPD5), combined oxidative phosphorylation deficiency-9 (COXPD9),
carnifine acetyltransferase (CRAT) deficiency, carnitine palmitoyltransferase
I
(CPT I) deficiency, myopathic carnitine deficiency, primary systemic carnitine

deficiency (CDSP), carnitine palmitoyltransferase II (CPT II) deficiency,
carnitine-
acylcarnitine translocase deficiency (CACTD), cartilage-hair hypoplasia,
cerebrotendinous xanthomatosis (CTX), congenital adrenal hyperplasia (CAH),
megaconial type congenital muscular dystrophy, cerebral creatine deficiency
syndrome-3 (CCDS3), maternal nonsyndromic deafness, maternal nonsyndromic
deafness, autosomal dominant deafness-64 (DFNA64), Mohr-Tranebjaerg
232

Syndrome, Jensen Syndrome, MEGDEL, reticular dysgenesis, primary coenzyme
Q10 deficiency-6 (COQ10D6), CAGSSS, diabetes, Dimethylglycine
dehydrogenase deficiency (DMGDHD), Multiple Mitochondrial Dysfunctions
Syndrome-1 (MMDS1), Multiple Mitochondrial Dysfunctions Syndrome-2
(MMDS2), Multiple Mitochondrial Dysfunctions Syndrome-3 (MMDS3),
childhood leukoencephalopathy associated with mitochondrial Complex II
deficiency, encephalopathies associated with mitochondrial Complex I
deficiency,
encephalopathies associated with mitochondrial Complex III deficiency,
encephalopathies associated with mitochondrial Complex IV deficiency,
encephalopathies associated with mitochondrial Complex V deficiency,
hyperammonemia due to carbonic anhydrase VA deficiency (CA5AD), early
infantile epileptic encephalopathy-3 (EIEE3), 2,4-Dienoyl-CoA reductase
deficiency (DECRD), infection-induced acute encephalopathy-3 (IIAE3),
ethylmalonic encephalopathy (EE), hypomyelinating leukodystrophy (HLD4),
exocrine pancreatic insufficiency, dyserythropoietic anemia and calvarial
hyperostosis, Glutaric aciduria type 1 (GA-1), glycine encephalopathy (GCE),
hepatic failure, 2-hydroxyglutaric aciduria, 3-hydroxyacyl-CoA dehydrogenase
deficiency, familial hyperinsulinemic hypoglycemia (FHH), hypercalcemia
infantile, hyperornithinemia-hyperammonemia-homocitrullinuria (HHH)
Syndrome, Immunodeficiency with hyper-IgM type 5 (HIGM5), Inclusion Body
Myositis (IBM), polymyositis with mitochondrial pathology, IM-Mito,
granulomatous myopathies with anti-mitochondrial antibodies, necrotizing
myopathy with pipestem capillaries, myopathy with deficient chondroitin
sulfate C
in skeletal muscle connective tissue, benign acute childhood myositis,
idiopathic
orbital myositis, masticator myopathy, hemophagocytic Iymphohistiocytosis,
infection-associated myositis, Facioscapulohumeral dystrophy (FSH), familial
idiopathic inflammatory myopathy, Schmidt Syndrome (Diabetes mellitus,
Addison disease, Myxedema), TNF receptor-associated Periodic Syndrome
(TRAPS), focal myositis, autoimmune fasciitis, Spanish toxic oil-associated
fasciitis, Eosinophilic fasciitis, Macrophagic myofasciitis, Graft-vs-host
disease
fasciitis, Eosinophilia-myalgia Syndrome, perimyositis, isovaleric acidemia
(IVA),
Kearnes-Sayre Syndrome (KSS), 2-oxoadipic aciduria, 2-aminoadipic aciduria,
Limb-girdle Muscular Dystrophy Syndromes, leukodystrophy, Maple syrup urine
disease (MSUD), 3-Methylcrotonyl-CoA carboxylase (MCC), Methylmalonic
233

aciduria (MMA), Miller Syndrome, Mitochondrial DNA Depletion Syndrome-2
(MTDPS2), spinal muscular atrophy syndrome, rigid spine syndrome, severe
myopathy with motor regression, Mitochondrial DNA Depletion Syndrome-3,
MELAS Syndrome, camptocormia, MNGIE, MNGIM Syndrome, Menkes
Disease, Occipital Horn Syndrome, X-linked distal spinal muscular atrophy-3
(SMAX3), methemoglobinemia, MERRF, progressive external ophthalmoplegia
with myoclonus, deafness and diabetes (DD), multiple symmetric lipomatosis,
Myopathy with Episodic high Creatine Kinase (MIMECK), Epilepsia Partialis
Continua, malignant hyperthermia syndromes, glycogen metabolic disorders,
fatty
acid oxidation and lipid metabolism disorders, medication-, drug- or toxin-
induced
myoglobinuria, mitochondrial disorder-associated myoglobinuria, hypokalemic
myopathy and rhabdomyolysis, muscle trauma-associated myoglobinuria,
ischemia-induced myoglobinuria, infection-induced myoglobinuria, immune
myopathies associated with myoglobinuria, Myopathy, lactic acidosis, and
sideroblastic anemia (MLASA), infantile mitochondrial myopathy due to
reversible COX deficiency (MMIT), Myopathy, Exercise intolerance,
Encephalopathy and Lactic acidemia Syndrome, myoglobinuria and exercise
intolerance syndrome, exercise intolerance, proximal weakness ~ myoglobinuria
syndrome, encephalopathy and seizures syndrome, septo-optic dysplasia,
exercise
intolerance mild weakness, myopathy exercise intolerance, growth or CNS
disorder, maternally-inherited mitochondrial myopathies, myopathy with lactic
acidosis, myopathy with rhabdomyolysis, Myopathy with cataract and combined
respiratory chain deficiency, myopathy with abnormal mitochondrial
translation,
Fatigue Syndrome, myopathy with extrapyramidal movement disorders (MPXPS),
glutaric aciduria II (MADD), primary CoQ10 deficiency-1 (C0Q10D1), primary
CoQ10 deficiency-2 (C0Q10D2), primary CoQ10 deficiency-3 (C0Q10D3),
primary CoQ10 deficiency-5 (C0Q10D5), secondary CoQ10 deficiency,
autosomal dominant mitochondrial myopathy, myopathy with focal depletion of
mitochondria, mitochondrial DNA breakage syndrome (PEO + Myopathy), lipid
type mitochondrial myopathy, multiple symmetric lipomatosis (MSL), N-
acetylglutamate synthase (NAGS) deficiency, Nephronophthisis (NPHP), ornithine

transcarbamylase (OTC) deficiency, neoplasms, NARP Syndrome, paroxysmal
nonkinesigenic dyskinesia (PNKD), sporadic PEO, maternally-inherited PEO,
autosomal dominant progressive external ophthalmoplegia with mitochondrial
234

DNA deletions-3 (PEOA3), autosomal dominant progressive external
ophthalmoplegia with mitochondrial DNA deletions-2 (PEOA2), autosomal
dominant progressive external ophthalmoplegia with mitochondrial DNA
deletions-1 (PEOA1), PEO+ demyelinating neuropathy, PEO + hypogonadism,
autosomal dominant progressive external ophthalmoplegia with mitochondrial
DNA deletions-4 (PEOA4), distal myopathy, cachexia & PEO, autosomal
dominant progressive external ophthalmoplegia-6 (PEOA6), PEO + Myopathy and
Parkinsonism, autosomal recessive progressive external ophthalmoplegia (PEOB),

Mitochondrial DNA Depletion Syndrome-11 (MTDPS11), PEO with
cardiomyopathy, PEPCK deficiency, Perrault Syndromes (PRLTS), propionic
acidemia (PA), pyruvate carboxylase deficiency, pyruvate dehydrogenase El-
alpha
deficiency (PDHAD), pyruvate dehydrogenase El-beta deficiency (PDHBD),
dihydrolipoamide dehydrogenase (DLD) deficiency, pyruvate dehydrogenase
phosphatase deficiency, pyruvate dehydrogenase E3-binding protein deficiency
(PDHXD), mitochondrial pyruvate carrier deficiency (MPYCD), Schwartz-Jampel
Syndrome type 1 (SJS1), selenium deficiency, short-chain acyl-CoA
dehydrogenase (SCAD) deficiency, succinyl CoA:3-oxacid CoA transferase
(SCOT) deficiency, Stuve-Wiedemann Syndrome (STWS), thrombocytopenia
(THC), Very long-chain acyl-CoA dehydrogenase deficiency (VLCADD), Vitamin
D-dependent rickets type 1 A (VDDR1A), Wilson's disease, Zellweger Syndrome
(PBD3A), arsenic trioxide myopathy, myopathy and neuropathy resulting from
nucleoside analogues, germanium myopathy, Parkinsonism and mitochondrial
Complex I neurotoxicity due to trichloroethylene, valproate-induced hepatic
failure, neurodegeneration with brain iron accumulation-4 (NBIA4), Complex I
deficiency, Complex II deficiency, Complex III deficiency, Complex IV
deficiency, Complex V deficiency, Cytochrome c oxidase (COX) deficiency,
combined complex I, II, IV, V deficiency, combined complex I, II, and III
deficiency, combined oxidative phosphorylation deficiency-1 (COXPD1),
combined oxidative phosphorylation deficiency-2 (COXPD2), combined oxidative
phosphorylation deficiency-3 (COXPD3), combined oxidative phosphorylation
deficiency-4 (COXPD4), combined oxidative phosphorylation deficiency-6
(COXPD6), combined oxidative phosphorylation deficiency-7 (COXPD7),
combined oxidative phosphorylation deficiency-9 (COXPD9), combined oxidative
phosphorylation deficiency-11 (COXPD11), combined oxidative phosphorylation
235

deficiency-12 (COXPD12), combined oxidative phosphorylation deficiency-13
(COXPD13), combined oxidative phosphorylation deficiency-15 (COXPD15),
combined oxidative phosphorylation deficiency-16 (COXPD16), combined
oxidative phosphorylation deficiency-19 (COXPD19), combined oxidative
phosphorylation deficiency-20 (COXPD20), combined oxidative phosphorylation
deficiency-21 (COXPD21), fumarase deficiency, HMG-CoA synthase-2
deficiency, hyperuricemia, pulmonary hypertension, renal failure, and
alkalosis
(HUPRA) Syndrome, syndromic microphthalmia-7, pontocerebellar hypoplasia
type 6 (PCH6), Mitochondrial DNA Depletion Syndrome-9 (MTDPS9P), and
Sudden infant death Syndrome (SIDS).
3. The method of any one of claims 1-2, wherein the chroman derivative in
combination with one or more additional therapeutic agents is administered
daily
for one, two, three, four or five weeks.
4. The method of any one of claims 1-3, wherein the chroman derivative in
combination with one or more additional therapeutic agents is administered
daily
for 6 weeks or more.
5. The method of claim 1, wherein the subject displays abnormal levels of
one or
more energy biomarkers compared to a normal control subject.
6. The method of claim 5, wherein the energy biomarker is selected from the
group
consisting of lactic acid (lactate) levels; pyruvic acid (pyruvate) levels;
lactate/pyruvate ratios; total, reduced or oxidized glutathione levels; total,
reduced
or oxidized cysteine levels; reduced/oxidized glutathione ratios;
reduced/oxidized
cysteine ratios; phosphocreatine levels; NADH (NADH+H30) or NADPH
(NADPH+H3O ) levels; NAD or NADP levels; ATP levels; reduced coenzyme Q
(CoQred) levels; oxidized coenzyme Q (CoQox) levels; total coenzyme Q
(CoQtot) levels; oxidized cytochrome C levels; reduced cytochrome C levels;
oxidized cytochrome C/reduced cytochrome C ratio; acetoacetate levels; beta-
hydroxy butyrate levels; acetoacetate/ beta-hydroxy butyrate ratio; 8-hydroxy-
2'-
deoxyguanosine (8-OHdG) levels; levels of reactive oxygen species; oxygen
consumption (VO2), carbon dioxide output (Van), and respiratory quotient
(VCO2/VO2).
7. The method of any one of claims 1-6, wherein the subject is human.
236

8. The method of any one of claims 1-7, wherein the chroman derivative is
administered orally, intranasally, intrathecally, intraocularly,
intradermally,
transmucosally, iontophoretically, topically, systemically, intravenously,
subcutaneously, intraperitoneally, or intramuscularly.
9. The method of claim 1, wherein the symptoms of the mitochondrial disease
or
disorder comprises one or more of poor growth, loss of muscle coordination,
muscle weakness, neurological deficit, seizures, autism, autistic spectrum,
autistic-
like features, learning disabilities, heart disease, liver disease, kidney
disease,
gastrointestinal disorders, severe constipation, diabetes, increased risk of
infection,
thyroid dysfunction, adrenal dysfunction, autonomic dysfunction, confusion,
disorientation, memory loss, failure to thrive, poor coordination, sensory
(vision,
hearing) problems, reduced mental functions, hypotonia, disease of the organ,
dementia, respiratory problems, hypoglycemia, apnea, lactic acidosis,
seizures,
swallowing difficulties, developmental delays, movement disorders (dystonia,
muscle spasms, tremors, chorea), stroke, and brain atrophy.
10. The method of any one of claims 1-8, comprising separately,
sequentially or
simultaneously administering the additional therapeutic agent to the subject.
11. A method for modulating the expression of one or more energy biomarkers
in a
mammalian subject in need thereof, the method comprising: administering to the

subject a therapeutically effective amount of a chroman derivative or a
pharmaceutically acceptable salt thereof, in combination with one or more
additional therapeutic agents selected from the group consisting of: vitamins,

cofactors, antibiotics, hormones, antineoplastic agents, steroids,
immunomodulators, dermatologic drugs, antithrombotic, antianemic, and
cardiovascular agents.
12. The method of claim 11, wherein the energy biomarker is selected from
the group
consisting of lactic acid (lactate) levels; pyruvic acid (pyruvate) levels;
lactate/pyruvate ratios; total, reduced or oxidized glutathione levels; total,
reduced
or oxidized cysteine levels; reduced/oxidized glutathione ratios;
reduced/oxidized
cysteine ratios; phosphocreatine levels; NADH (NADH+H30) or NADPH
(NADPH+H30 ) levels; NAD or NADP levels; ATP levels; reduced coenzyme Q
(CoQred) levels; oxidized coenzyme Q (CoQox) levels; total coenzyme Q
237

(CoQtot) levels; oxidized cytochrome C levels; reduced cytochrome C levels;
oxidized cytochrome C/reduced cytochrome C ratio; acetoacetate levels; beta-
hydroxy butyrate levels; acetoacetate/ beta-hydroxy butyrate ratio; 8-hydroxy-
2'-
deoxyguanosine (8-OHdG) levels; levels of reactive oxygen species; oxygen
consumption (VO2), carbon dioxide output (VCO2), and respiratory quotient
(VCO2/VO2).
13. The method of any one of claims 11-12, wherein the chroman derivative
in
combination with one or more additional therapeutic agents is administered
daily
for one, two, three, four or five weeks.
14. The method of any one of claims 11-13, wherein the chroman derivative
in
combination with one or more additional therapeutic agents is administered
daily
for 6 weeks or more.
15. The method of any one of claims 11-14, wherein the subject has been
diagnosed
has having, is suspected of having, or is at risk of having a mitochondrial
disease
or disorder.
16. The method of claim 15, wherein symptoms of the mitochondrial disease
or
disorder comprises one or more of poor growth, loss of muscle coordination,
muscle weakness, neurological deficit, seizures, autism, autistic spectrum,
autistic-
like features, learning disabilities, heart disease, liver disease, kidney
disease,
gastrointestinal disorders, severe constipation, diabetes, increased risk of
infection,
thyroid dysfunction, adrenal dysfunction, autonomic dysfunction, confusion,
disorientation, memory loss, failure to thrive, poor coordination, sensory
(vision,
hearing) problems, reduced mental functions, hypotonia, disease of the organ,
dementia, respiratory problems, hypoglycemia, apnea, lactic acidosis,
seizures,
swallowing difficulties, developmental delays, movement disorders (dystonia,
muscle spasms, tremors, chorea), stroke, and brain atrophy. .
17. The method of any one of claims 11-16, wherein the subject is human.
18. The method of any one of claims 11-17, wherein the chroman derivative
is
administered orally, intranasally, intrathecally, intraocularly,
intradermally,
transmucosally, iontophoretically, topically, systemically, intravenously,
subcutaneously, intraperitoneally, or intramuscularly.
238

19. The
method of any one of claims 11-18, wherein the additional therapeutic agent is
administered sequentially or simultaneously to the subject.
239

Note: Descriptions are shown in the official language in which they were submitted.

CA 02920246 2016-02-09
THERAPEUTIC COMPOSITIONS INCLUDING CHROMAN
DERIVATIVES AND USES THEREOF TO TREAT AND
PREVENT MITOCHONDRIAL DISEASES AND
CONDITIONS
TECHNICAL FIELD
[0001] Disclosed herein are methods and compositions related to the treatment
and/or
amelioration of diseases and conditions comprising administration of chroman
derivatives,
analogues, or pharmaceutically acceptable salts thereof.
BACKGROUND
[0002] The following description is provided to assist the understanding of
the reader.
None of the information provided or references cited is admitted to be prior
art to the
present technology.
[0003] Mitochondria are sometimes described as cellular "power plants" because
among
other things, mitochondria are responsible for creating more than 90% of the
energy
needed by the body to sustain life and support growth. Mitochondria are
organelles found
in almost every cell in the body. In addition to making energy, mitochondria
are also
deeply involved in a variety of other activities, such as making steroid
hormones and
manufacturing the building blocks of DNA. Mitochondrial failure causes cell
injury that
leads to cell death.
[0004] Mitochondrial diseases are nearly as common as childhood cancer.
Approximately one in 4,000 children born in the United States every year will
develop a
mitochondrial disorder by age 10. In adults, many diseases of aging have been
found to
have defects of mitochondrial function. These include, but are not limited to,
type 2
diabetes, Parkinson's disease, Alzheimer's disease, and cancer. In addition,
select drugs
can injure the mitochondria.
[0005] There are multiple forms of mitochondrial disease. Mitochondrial
disease can
manifest as a chronic, genetic disorder that occurs when the mitochondria of
the cell fails
to produce enough energy for cell or organ function. Indeed, for many
patients,
mitochondrial disease is an inherited condition that runs in families
(genetic).
Mitochondrial disease is inherited in a number of different ways. There is
autosomal
inheritance, mtDNA inheritance as well as a combination thereof. For example,
mutations
1

CA 02920246 2016-02-09
of genes encoding Complex I ¨ Complex V can contribute to mitochondrial
disease in
humans. An uncertain percentage of patients acquire symptoms due to other
factors,
including mitochondrial toxins.
[0006] Mitochondrial disease presents very differently from individual to
individual.
There is presently no cure for mitochondrial-based disease. Treatment is
generally
palliative to improve disease symptoms.
SUMMARY
[0007] In one aspect, the present disclosure provides a method for treating or
preventing
a mitochondrial disease or disorder in a subject in need thereof, comprising
administering
to the subject a therapeutically effective amount of a chroman derivative or a

pharmaceutically acceptable salt thereof. In some embodiments, the chroman
derivative is
selected from:
2,2,7,8-Tetramethy1-5-phenyl-chroman-6-ol;
4-(6-Hydroxy-2,2,7,8-tetramethyl-chroman-5-ye-benzoic acid methyl ester;
4-(6-Hydroxy-2,2,7,8-tetramethyl-chroman-5-y1)-benzoic acid;
2,2,7,8-Tetramethy1-5-pyridin-4-yl-chroman-6-ol;
2,2,7,8-Tetramethy1-5-pyridin-3-yl-chroman-6-ol;
5-(4-Methanesulfonyl-phenyl)-2,2,7,8-tetramethyl-chroman-6-ol;
5-(4-Dimethylamino-pheny1)-2,2,7,8-tetramethyl-chroman-6-ol;
5-(4-Chloro-pheny1)-2,2,7,8-tetramethyl-chroman-6-ol;
4-(6-Hydroxy-2,2,7,8-tetramethyl-chroman-5-y1)-benzenesulfonamide;
5-(4-Methoxy-phenyl)-2,2,7,8-tetramethyl-chroman-6-ol;
(6-Hydroxy-2,2,7,8-tetramethyl-chroman-5-ylmethyl)-1-hydroxyurea;
2,2,7,8-Tetramethy1-5-(3-nitro-pheny1)-chroman-6-01;
2,2,7,8-Tetramethy1-5-(4-trifluoromethyl-pheny1)-chroman-6-ol;
5-(4-tert-Butyl-phenyl)-2,2,7,8-tetramethyl-chroman-6-ol;
2,2,7,8-Tetramethy1-5-(3,4,5-trimethoxy-pheny1)-chroman-6-ol;
4-(6-Hydroxy-2,2,7,8-tetramethyl-chroman-5-y1)-benzonitrile;
5-(2,5-Dimethoxy-3,4-dimethyl-pheny1)-2,2,7,8-tetramethyl-chroman-6-ol;
5-(6-Hydroxy-2,2,7,8-tetramethyl-chroman-5-y1)-benzene-1,2,3-triol;
5-(6-Hydroxy-2,2,7,8-tetramethyl-chroman-5-y1)-2,3-dimethyl-benzene-1,4-diol;
5-(2-Chloro-phenyl)-2,2,7,8-tetramethyl-chroman-6-ol;
2

CA 02920246 2016-02-09
5-Furan-2-y1-2,2,7,8-tetramethyl-chroman-6-ol;
5-Allylsulfanylmethy1-2,2,8-trimethyl-7-(3-methyl-buty1)-chroman-6-ol;
5-Cyclopentylsulfanylmethy1-2,2,7,8-tetramethyl-chroman-6-ol;
5-Hex ylsulfanylmethy1-2,2,7,8-tetramethyl-chroman-6-ol;
5-Allylsulfanylmethy1-2,2,7,8-tetramethyl-chroman-6-ol;
5-(4,6-Dimethyl-pyrimidin-2-ylsulfanylmethyl)-2,2,7,8-tetramethyl-chroman-6-
ol;
1-[3-(6-Hydroxy-2,2,7,8-tetramethyl-chroman-5-ylmethylsulfany1)-2-methyl-
propionyl[-pyrrolidine-2-carboxylic acid;
4-(6-Hydroxy-2,2,7,8-tetramethyl-chroman-5-ylmethylene)-5-methy1-2-phenyl-
2,4-dihydro-pyrazol-3-one;
4-(6-Hydroxy-2,2,7,8-tetramethyl-chroman-5-ylmethylene)-3-pheny1-4H-isoxazol-
5-one;
4-[4-(6-Hydroxy-2,2,7,8-tetramethyl-chroman-5-ylmethylene)-3-methy1-5-oxo-
4,5-dihydro-pyrazol-1-y11-benzoic acid;
4-(6-Hydroxy-2,2,7,8-tetramethyl-chroman-5-ylmethylene)-2-methy1-5-propy1-
2,4-dihydro-pyrazol 3-one;
5-Hydroxy-3-(6-hydroxy-2,2,7,8-tetramethyl-chroman-5-ylmethylene)-3H-
benzofuran-2-one;
2,5,7,8-Tetramethy1-2-thiophen-2-yl-chroman-6-ol;
2-(2,5-Dimethyl-thiophen-3-y1)-2,5,7,8-tetramethyl-chroman-6-ol;
2-(2,5-Dimethyl-thiophen-3-y1)-2,7,8-trimethyl-chroman-6-ol;
8-Chloro-2-(2,5-dimethyl-thiophen-3-y1)-2,5,7-trimethyl-chroman-6-- ol;
5-Chloro-2,7,8-trimethy1-2-thiophen-2-yl-chroman-6-ol;
5-[3-(6-Methoxymethoxy-2,7,8-trimethyl-chroman-2-y1)-propylidenel-
thiazolidine-2,4-dione;
513-(6-Hydroxy-2,7,8-trimethyl-chroman-2-y1)-propylideneHhiazolidine-2,4-
dione;
3-[6-Hydroxy-2,7,8-trimethy1-2-(4,8,12-trimethyl-tridec y1)-chroman-5-
ylmethylsulfany1]-2-methyl-propionic acid;
2,7,8-Trimethy1-5 -(5-methyl- 1H-benzoimidazol-2-ylsulfan ylmethyl)-2-(4,8, 12-

trimethyl-tridec y1)-chroman-6-ol;
2- [6-Hydroxy-2,7,8-trimethy1-2-(4,8, 1 2-trimethyl-tridecy1)-chroman-5-
ylmethylsulfanyl]-ethanesulfonic acid;
3

CA 02920246 2016-02-09
5-(4,6-Dimethyl-pyrimidin-2-ylsulfanylmethyl)-2,7,8-trimethyl-2-(4,8,12-
trimethyl-tridecy1)-chroman-6-ol;
4-[2-(4,8-Dimethyl-tridecy1)-6-hydroxy-2,7,8-trimethyl-chroman-5-
ylmethylsulfanyl]-benzoic acid;
1- 3 -[6-Hydroxy-2,7,8-trimethy1-2-(4,8,12-trimethyl-tridecy1)-chroman-5 -
ylmethylsulfany1]-2-methyl-propionyl } -pyrrolidine-2-carboxylic acid;
2-(2,2-Dichloro-vinyl)-2,5,7,8-tetramethyl-chroman-6-ol;
2-(2,2-Dibromo-vinyl)-2,5,7,8-tetramethyl-chroman-6-ol;
5-(5-Chloro-3-methyl-pent-2-eny1)-2,2,7,8-tetramethyl-chroman-6-ol;
5-Chloro-2-(2,5-dimethyl-thiophen-3-y1)-2,7,8-trimethyl-chroman-6-ol;
2-(3-Chloro-propy1)-5,7-dimethyl-2-thiophen-2-yl-chroman-6-ol;
5-Chloro-2-(2,5-dimethyl-thiazol-4-y1)-2,7,8-trimethyl-chroman-6-ol;
5-Chloro-2-(2,5-dimethyl-thiazol-4-y1)-2,7,8-trimethy1-2H-chromen-6-ol; and
5-Chloro-2-(2,5-dimethyl-thiazol-4-y1)-2,7,8-trimethyl-chroman-6-ol.
[0008] In some embodiments, the chroman derivative is selected from:
3-(6-Hydroxy-2-methy1-3,4,7,8,9,10-hexahydro-7,10-methano-2H-
benzo[h]chromen-2-y1)-propionic acid methyl ester;
3-(6-Hydroxy-2-methy1-3,4,7,8,9,10-hexahydro-7,10-methano-2H-
benzo[h]chromen-2-y1)-propionic acid;
3-(6-Hydroxy-2-methyl-3,4,7,8,9,10-hexahydro-7,10-propano-2H-
benzo[h]chromen-2-y1)-propionic acid methyl ester;
2-Methy1-2-[3-(thiazol-2-ylsulfany1)-propyl]-3,4,7,8,9,10-hexahydro-7,10-
methano-2H-benzo[h]chromen-6-ol;
[3-(6-Hydroxy-2-methy1-3,4,7,8,9,10-hexahydro-7,10-methano-2H-
benzo[h]chromen-2-y1)-propyll-phosphonic acid dimethyl ester;
[3-(6-Hydroxy-2-methy1-3,4,7,8,9,10-hexahydro-7,10-methano-2H-
benzo[h]chromen-2-y1)-propy1}-phosphonic acid;
4-(6-Hydroxy-2-methy1-3,4,7,8,9,10-hexahydro-7,10-methano-2H-
benzo[h]chromen-2-y1)-butane-1-sulfonic acid dimethylamide;
2- (3-Hydroxy-propy1)-2-methyl-3 ,4,7, 8,9, 10-hexahydro-7, 10-methano-2H-
benzo[h]chromen-6-ol;
3- [7-(2-Methoxycarbonypethy1-2,7-dimethy1-2,7 ,9, 10, 1 1 , 1 2-hexahydro- 1,
8-dioxa-
9:12-methano-triphenylen-2-yl]-propionic acid methyl ester;
4

CA 02920246 2016-02-09
3-[6-Hydroxy-2-methy1-5-(3-methyl-but-2-eny1)-3,4,7,8,9,10-hexahydro-7,10-
methano-2H-benzo[h]chromen-2-A-propionic acid;
2-(3-Hydroxy-propy1)-2-methyl-3,4,7,8,9,10-hexahydro-7,10-propano-2H-
benzo[h]chromen-6-ol;
3-(6-Hydroxy-2-methy1-3,4,7,8,9,10-hexahydro-7,10-propano-2H-
benzo[h]chromen-2-y1)-propionic acid;
3-(6-Hydroxy-2-methy1-3,4,7,8,9,10-hexahydro-7,10-methano-2H-
benzo[h]chromen-2-y1)-1-morpholin-4-yl-propan-1-one;
2-Methy1-2-(3-piperidin-1-yl-propy1)-3,4,7,8,9,10-hexahydro-7,10-methano-2H-
benzo[h]chromen-6-ol;
2-(3-Chloro-propy1)-2-methy1-3,4,7,8,9,10-hexahydro-7,10-methano-2H-
benzo[h]chromen-6-ol;
1- { 3-[3-(6-Hydroxy-2-methy1-3,4,7,8,9,10-hexahydro-7,10-methano-2H-
benzo[h]chromen-2-y1)-propylsulfanyl[-2-methyl-propionyl I -pyrrolidine-2-
carboxylic
acid;
243-(Benzothiazol-2-ylsulfany1)-propy1F2-methyl-3,4,7,8,9,10-hexahydro-7,10-
methano-2H-benzo[h]chromen-6-ol;
213-(2-Hydroxy-ethylamino)-propy1]-2-methy1-3,4,7,8,9,10-hexahydro-7,10-
methano-2H-benzo[h]chromen-6-ol;
2- [3-(2-Dimethylamino-ethylamino)-propy11-2-methy1-3,4,7,8,9,10-hexahydro-
7,10-methano-2H-benzo[h]chromen-6-ol;
2,6:9,12-Dimethano-9,10,11,12-tetrahydro-2-methylnaphtho[1,2-b]oxocan-8-ol;
2-(2-Chloro-ethyl)-2-methy1-3,4,7,8,9,10-hexahydro-7,10-methano-2H-
benzo[h]chromen-6-ol;
2-Methy1-2-[3-(pyridine-4-ylsulfany1)-propyl]-3,4,7,8,9,10-hexahydro-7,10-
methano-2H-benzo[h]chromen-6-ol;
2-(3-isobutylsulfanyl-propy1)-2-methy1-3,4,7,8,9,10-hexahydro-7,10-methano-2H-
benzo[h]chromen-6-ol;
2-Methy1-2-thiophen-2-y1-3,4,7,8,9,10-hexahydro-7,10-methano-2H-
benzo[h]chromen-6-ol;
2-Methy1-2-thiazol-2-y1-3,4,7,8,9,10-hexahydro-7,10-methano-2H-
benzo[h]chromen-6-ol;
3-(6-Hydroxy-2-methy1-3,4,7,8,9,10-hexahydro-7,10-ethano-2H-
benzo[h]chromen-2-y1)-propionic acid;

CA 02920246 2016-02-09
3-(6-Hydroxy-2-methy1-3,4,7,8,9,10-hexahydro-7,10-ethano-2H-
benzo[h]chromen-2-y1)-propionic acid methyl ester;
2-(3-Chloro-propy1)-2-methy1-3,4,7,8,9,10-hexahydro-7,10-ethano-2H-
benzo[h]chromen-6-ol;
2-(3-Chloro-propy1)-2,5-dimethyl-3,4,7,8,9,10-hexahydro-7,10-ethano-2H-
benzo[h]chromen-6-ol;
2-[3-(Benzothiazol-2-ylsulfany1)-propyl]-2-methyl-3,4,7,8,9,10-hexahydro-7,10-
ethano-2H-benzo[h]chromen-6-ol;
3-(6-Hydroxy-2-methy1-3,4,7,8,9,10-hexahydro-7,10-methano-2H-
benzo[h]chromen-2-y1)-propionic acid, sodium salt;
3-[6-Hydroxy-2-methy1-5-(3-methyl-but-2-eny1)-3,4,7,8,9,10-hexahydro-7,10-
ethano-2H-benzo[h]chromen-2-y11-propionic acid;
Sodium salt of 3-(6-Hydroxy-2-methy1-3,4,7,8,9,10-hexahydro-7,10-ethano-2H-
benzo[h]chromen-2-y1)-propionic acid;
3-(6-Hydroxy-2-methy1-3,4,7,8,9,10-hexahydro-7,10-ethano-2H-
benzo[h]chromen-2-y1)-propionic acid benzyl ester;
3-(5-Bromo-6-hydroxy-2-methy1-3,4,7,8,9,10-hexahydro-7,10-ethano-2H-
benzo[h]chromen-2-y1)-propionic acid;
5-Bromo-2-methy1-2-(3-piperidin-1-yl-propy1)-3,4,7,8,9,10-hexahydro-7,10-
ethano-2H-benzo[h]chromen-6-ol;
5-Methoxy-2,2-dimethy1-3,4,7,8,9,10-hexahydro-7,10-methano-2H-
benzo[h]chromen-6-ol;
3-(6-Hydroxy-2-methy1-3,4,7,8,9,10-hexahydro-7,10-ethano-2H-
benzo[h]chromen-2-y1)-1-piperidin-1-yl-propan-1-one;
N-(2-Dimethylamino-ethyl)-3 -(6-hydroxy-2-methyl-3 ,4,7,8 ,9, 10-hex ahydro-7,
10-
ethano-2H-benzo [h]chromen-2-y1)-propionamide;
2-Methyl-2-(3-piperidin- 1-yl-propy1)-3,4,7,8,9,10-hexahydro-7,10-ethano-2H-
benzo[h]chromen-6-ol;
3-(6-Hydroxy-2-methy1-3,4,7,8,9,10-hexahydro-7,10-ethano-2H-
benzo[h]chromen-2-y1)-1-morpholin-4-yl-propan-1-one;
213-(2-Dimethylamino-ethylamino)-propy1]-2-methy1-3,4,7,8,9,10-hexahydro-
7,10-ethano-2H-benzo[h]chromen-6-ol;
2-Methy1-243-(pyridine-4-sulfony1)-propyl]-3,4,7,8,9,10-hexahydro-7,10-
methano-2H-benzo[h]chromen-6-ol;
6

CA 02920246 2016-02-09
2,2,-Dimethy1-3,4,7,8,9,10-hexahydro-7,10-methano-2H-benzo[h]chromen-6-ol;
2,2-Dimethy1-3,4,7,8,9,10-hexahydro-7,10-methano-2H-benzo[h]chromen-6-ol;
2,2-Dimethy1-5-(3-methyl-but-2-eny1)-3,4,7,8,9,10-hexahydro-7,10-methano-2H-
benzo[h]chromen-6-ol;
Acetic acid 2,2-dimethy1-5-(3-methyl-but-2-eny1)-3,4,7,8,9,10-hexahydro-7,10-
methano-2H-benzo[h]chromen-6-y1 ester;
2,2-Dimethy1-5-(3-methyl-buty1)-3,4,7,8,9,10-hexahydro-7,10-methano-2H-
benzo[h]chromen-6-ol;
5-Bromo-2,2-dimethy1-3,4,7,8,9,10-hexahydro-7,10-methano-2H-
benzo[h]chromen-6-ol;
Acetic acid 2,2-dimethy1-5-(3-methyl-buty1)-3,4,7,8,9,10-hexahydro-7,10-
methano-2H-benzo[h]chromen-6-y1 ester;
2,2-Dimethy1-3,4,7,10-tetrahydro-7,10-methano-2H-benzo[h]chromen-6-ol;
2,2-Dimethy1-3,4,7,8,9,10-hexahydro-7,10-ethano-2H-benzo[h]chromen-6-ol;
2,2-Dimethy1-5-(3-methyl-but-2-eny1)-7,8,9,10-tetrahydro-7,10-methano-2H-
benzo[h]chromen-6-ol;
2,2-Dimethy1-5-(3-methyl-but-2-eny1)-3,4,7,10-tetrahydro-7,10-ethano-2H-
benzo[h]chromen-6-ol;
2,2,7,7-Tetramethy1-9, 12-ethano-2,3 ,4,5 ,6,7,9, 1 0, 1 1 , 12-decahydro- 1
,8-dioxa-
triphenylene;
Acetic acid 2,2-dimethy1-3,4,7,8,9,10-hexahydro-7,10-ethano-2H-
benzo[h]chromen-6-y1 ester;
Phosphoric acid mono-(2,2-dimethy1-3,4,7,8,9,10-hexahydro-7,10-methano-2H-
benzo[h]chromen--6-y1) ester, disodium salt;
2,2-Dimethy1-7,8,9,10-tetrahydro-7,10-ethano-2H-benzo[h]chromen-6-ol;
Phosphoric acid mono-(2,2-dimethy1-3,4,7,8,9,10-hexahydro-7,10-ethano-2H-
benzo[h]chromen-6-y1) ester, disodium salt;
2,2-Dimethy1-5-(3-methyl-butyl)-3,4,7,8,9,10-hexahydro-7,10-ethano-2H-
benzo[h]chromen-6-ol;
2,2,5-Trimethy1-3,4,7,8,9,10-hexahydro-7,10-ethano-2H-benzo[h]chromen-6-ol;
6-Hydroxy-2,2-dimethy1-3,4,7,8,9,10-hexahydro-7,10-methano-2H-
benzo[h]chromene-5-carbonitrile;
2,2-Dimethy1-5-(3-methyl-but-2-eny1)-3,4,7,8,9, 10-hexahydro-7,10-ethano-2H-
benzo[h]chromen-6-ol;
7

CA 02920246 2016-02-09
5-Hydroxymethy1-2,2-dimethy1-3,4,7,8,9,10-hexahydro-7,10-methano-21-1-
benzo[h]chromen-6-ol;
5-Bromo-2,2-dimethy1-3,4,7,8,9,10-hexahydro-7,10-ethano-2H-benzo[h]chromen-
6-01;
2,2-Dimethy1-5-[2-(tetrahydro-pyran-4-ylidene)-ethy1]-3,4,7,8,9,10-hexahydro-
7,10-ethano-2H-benzo[h]chromen-6-ol;
5-(2-Cyclohexylidene-ethyl)-2,2-dimethy1-3,4,7,8,9,10-hexahydro-7,10-ethano-
2H-benzo[h]chromen-6-ol;
1-(6-Hydroxy-2,2-dimethy1-3,4,7,8,9,10-hexahydro-7,10-ethano-2H-
benzo[h]chromen-5-y1)-ethanone;
4-(6-Acetoxy-2,2-dimethy1-3,4,7,8,9,10-hexahydro-2H-benzo[h]chromen-5-y1)-4-
oxo-butyric acid;
2,2-Dimethy1-5-nitro-3,4,7,8,9,10-hexahydro-7,10-methano-2H-benzo[h]chromen-
6-ol;
Acetic acid 2,2-dimethy1-5-(3-methyl-but-2-eny1)-7,8,9,10-tetrahydro-7,10-
methano-2H- benzo[h]chromen-6-y1 ester;
5-(6-Hydroxy-2,2-dimethy1-3,4,7,8,9,10-hexahydro-7,10-methano-2H-
benzo[h]chromen-5-ylmethylene)-thiazolidine-2,4-dione;
5-Hydroxy-3-(6-hydroxy-2,2-dimethy1-3,4,7,8,9,10-hexahydro-7,10-methano-2H-
benzo[h]chromen-5-ylmethylene)-3H-benzofuran-2-one;
Phosphoric acid dibenzyl ester 2,2-dimethy1-3,4,7,8,9,10-hexahydro-7,10-
methano-2H-benzo[h]chromen-6-y1 ester;
Phosphoric acid dibenzyl ester 2,2-dimethy1-3,4,7,8,9,10-hexahydro-7,10-ethano-

2H-benzo[h]chromen-6-y1 ester;
10-Methoxy-2,2-dimethy1-3,4,7,8,9,10-hexahydro-7,10-ethano-2H-
benzo[h]chromen-6-ol;
4-[4-(6-Hydroxy-2,2-dimethy1-3,4,7,8,9,10-hexahydro-7,10-methano-2H-
benzo[h]chromen-5-ylmethylene)-3-methy1-5-oxo-4,5-dihydro-pyrazol- 1 -yl] -
benzoic acid;
4-(6-Hydroxy-2,2-dimethy1-3,4,7,8,9,10-hexahydro-7,10-methano-2H-
benzo[h]chromen-5-ylmethylene)-2-methyl-5-propy1-2,4-dihydro-pyrazol-3-one;
(6-Hydroxy-2,2-dimethy1-3,4,7,8,9,10-hexahydro-7,10-methano-2H-
benzo[h[chromen-5-y1methy1)- 1 -hydroxyurea;
5-(1-1-Iydroxy-ethyl)-2,2-dimethy1-3,4,7,8,9,10-hexahydro-7,10-methano-2H-
benzo[h]chromen-6-ol;
8

CA 02920246 2016-02-09
Dimethylamino-acetic acid 2,2-dimethy1-3,4,7,8,9,10-hexahydro-7,10-ethano-2H-
benzo[h]chromen-6-y1 ester; and
stereoisomers, mixture of stereoisomers or pharmaceutically acceptable salts
thereof.
[0009] In some embodiments of the method, the mitochondrial disease or
disorder is
selected from the group consisting of Alexander disease, Alpers Syndrome,
Alpha-
ketoglutarate dehydrogenase (AKDGH) deficiency, ALS-FTD, Sideroblastic anemia
with
spinocerebellar ataxia, Pyridoxine-refractory sideroblastic anemia, GRACILE
Syndrome,
Bjornstad Syndrome, Leigh Syndrome, mitochondrial complex III deficiency
nuclear type
1 (MC3DN1), combined oxidative phosphorylation deficiency 18 (COXPD18),
Thiamine-
responsive megaloblastic anemia syndrome (TRMA), Pearson Syndrome, HAM
Syndrome, Ataxia, Cataract, and Diabetes Syndrome, MELAS/MERRF Overlap
Syndrome, combined oxidative phosphorylation deficiency-14 (COXPD14),
Infantile
cerebellar-retinal degeneration (ICRD), Charlevoix-Saguenay spastic ataxia,
Primary
coenzyme Q10 deficiency-1 (C0Q10D1), ataxia oculomotor apraxia type 1 (A0A1),
Autosomal recessive spinocerebellar ataxia-9/ coenzyme Q10 deficiency-4
(C0Q10D4),
Ataxia, Pyramidal Syndrome, and Cytochrome Oxidase Deficiency, Friedreich's
ataxia,
Infantile onset spinocerebellar ataxia (IOSCA)/ Mitochondrial DNA Depletion
Syndrome-
7, leukoencephalopathy with brainstem and spinal cord involvement and lactate
elevation
(LBSL), Autosomal recessive spastic ataxia-3 (SPAX3), MIRAS, SANDO,
mitochondrial
spinocerebellar ataxia and epilepsy (MSCAE), spastic ataxia with optic atrophy
(SPAX4),
progressive external ophthalmoplegia with mitochondrial DNA deletions
autosomal
dominant type 5 (PEOA5), mitochondrial complex III deficiency nuclear type 2
(MC3DN2), episodic encephalopathy due to thiamine pyrophosphokinase
deficiency/Thiamine Metabolism Dysfunction Syndrome-5 (THMD5), Spinocerebellar

ataxia-28 (SCA28), autosomal dominant cerebellar ataxia, deafness, and
narcolepsy
(ADCA-DN), Dominant Optic Atrophy (DOA), cerebellar ataxia, areflexia, pes
cavus,
optic atrophy, and sensorineural hearing loss (CAPOS) Syndrome,
spinocerebellar ataxia 7
(SCA7), Barth Syndrome, Biotinidase deficiency, gyrate atrophy, Syndromic
Dominant
Optic Atrophy and Deafness (Syndromic DOAD), Dominant Optic Atrophy plus
(D0Aplus), Leber's hereditary optic neuropathy (LHON), Wolfram Syndrome-1
(WFS1),
Wolfram Syndrome-2 (WFS2), Age-related macular degeneration (ARMD), Brunner
Syndrome, Left ventricular noncompaction-1 (LVNC1), histiocytoid
cardiomyopathy,
Familial Myalgia Syndrome, Parkinsonism, Fatal infantile
cardioencephalomyopathy due
9

CA 02920246 2016-02-09
to cytochrome c oxidase (COX) deficiency-1 (CEMCOX1), Sengers Syndrome,
Cardiofaciocutaneous Syndrome-1 (CFC1), Mitochondrial trifunctional protein
(MTP)
deficiency, infantile encephalocardiomyopathy with cytochrome c oxidase
deficiency,
cardiomyopathy + encephalomyopathy, mitochondrial phosphate carrier
deficiency,
infantile cardioencephalomyopathy due to cytochrome c oxidase (COX) deficiency

(CEMCOX2), P-Hydroxyisobutyryl CoA Deacylase (HIBCH) deficiency, ECHS1)
deficiency, Maternal Inheritance Leigh Syndrome (MILS), dilated cardiomyopathy
with
ataxia (DCMA), Mitochondrial DNA Depletion Syndrome-12 (MTDPS12),
cardiomyopathy due to mitochondrial tRNA deficiencies, mitochondrial complex V
(ATP
synthase) deficiency nuclear type 1 (MC5DN1), combined oxidative
phosphorylation
deficiency-8 (COXPD8), progressive leukoencephalopathy with ovarian failure
(LKENP),
combined oxidative phosphorylation deficiency-10 (COXPD10), combined oxidative

phosphorylation deficiency-16 (COXPD16), combined oxidative phosphorylation
deficiency-17 (COXPD17), combined oxidative phosphorylation deficiency-5
(COXPD5),
combined oxidative phosphorylation deficiency-9 (COXPD9), carnitine
acetyltransferase
(CRAT) deficiency, carnitine palmitoyltransferase I (CPT I) deficiency,
myopathic
carnitine deficiency, primary systemic carnitine deficiency (CDSP), carnitine
palmitoyltransferase II (CPT II) deficiency, carnitine-acylcarnitine
translocase deficiency
(CACTD), cartilage-hair hypoplasia, cerebrotendinous xanthomatosis (CTX),
congenital
adrenal hyperplasia (CAH), megaconial type congenital muscular dystrophy,
cerebral
creatine deficiency syndrome-3 (CCDS3), maternal nonsyndromic deafness,
maternal
nonsyndromic deafness, autosomal dominant deafness-64 (DFNA64), Mohr-
Tranebjaerg
Syndrome, Jensen Syndrome, MEGDEL, reticular dysgenesis, primary coenzyme Q10
deficiency-6 (C0Q10D6), CAGSSS, diabetes, Dimethylglycine dehydrogenase
deficiency
(DMGDHD), Multiple Mitochondrial Dysfunctions Syndrome-1 (MMDS1), Multiple
Mitochondrial Dysfunctions Syndrome-2 (MMDS2), Multiple Mitochondrial
Dysfunctions Syndrome-3 (MMDS3), childhood leukoencephalopathy associated with

mitochondrial Complex II deficiency, encephalopathies associated with
mitochondrial
Complex I deficiency, encephalopathies associated with mitochondrial Complex
III
deficiency, encephalopathies associated with mitochondrial Complex IV
deficiency,
encephalopathies associated with mitochondrial Complex V deficiency,
hyperammonemia
due to carbonic anhydrase VA deficiency (CA5AD), early infantile epileptic
encephalopathy-3 (EIEE3), 2,4-Dienoyl-CoA reductase deficiency (DECRD),
infection-
induced acute encephalopathy-3 (IIAE3), ethylmalonic encephalopathy (EE),

CA 02920246 2016-02-09
hypomyelinating leukodystrophy (HLD4), exocrine pancreatic insufficiency,
dyserythropoietic anemia and calvarial hyperostosis, Glutaric aciduria type 1
(GA-1),
glycine encephalopathy (GCE), hepatic failure, 2-hydroxyglutaric aciduria, 3-
hydroxyacyl-CoA dehydrogenase deficiency, familial hyperinsulinemic
hypoglycemia
(FHH), hypercalcemia infantile, hyperornithinemia-hyperammonemia-
homocitrullinuria
(HHH) Syndrome, Immunodeficiency with hyper-IgM type 5 (HIGM5), Inclusion Body

Myositis (IBM), polymyositis with mitochondrial pathology, IM-Mito,
granulomatous
myopathies with anti-mitochondrial antibodies, necrotizing myopathy with
pipestem
capillaries, myopathy with deficient chondroitin sulfate C in skeletal muscle
connective
tissue, benign acute childhood myositis, idiopathic orbital myositis,
masticator myopathy,
hemophagocytic lymphohistiocytosis, infection-associated myositis,
Facioscapulohumeral
dystrophy (FSH), familial idiopathic inflammatory myopathy, Schmidt Syndrome
(Diabetes mellitus, Addison disease, Myxedema), TNF receptor-associated
Periodic
Syndrome (TRAPS), focal myositis, autoimmune fasciitis, Spanish toxic oil-
associated
fasciitis, Eosinophilic fasciitis, Macrophagic myofasciitis, Graft-vs-host
disease fasciitis,
Eosinophilia-myalgia Syndrome, perimyositis, isovaleric acidemia (IVA),
Kearnes-Sayre
Syndrome (KSS), 2-oxoadipic aciduria, 2-aminoadipic aciduria, Limb-girdle
Muscular
Dystrophy Syndromes, leukodystrophy, Maple syrup urine disease (MSUD), 3-
Methylcrotonyl-CoA carboxylase (MCC), Methylmalonic aciduria (MMA), Miller
Syndrome, Mitochondrial DNA Depletion Syndrome-2 (MTDPS2), spinal muscular
atrophy syndrome, rigid spine syndrome, severe myopathy with motor regression,

Mitochondrial DNA Depletion Syndrome-3, MELAS Syndrome, camptocormia, MNGIE,
MNGIM Syndrome, Menkes Disease, Occipital Horn Syndrome, X-linked distal
spinal
muscular atrophy-3 (SMAX3), methemoglobinemia, MERRF, progressive external
ophthalmoplegia with myoclonus, deafness and diabetes (DD), multiple symmetric

lipomatosis, Myopathy with Episodic high Creatine Kinase (MIMECK), Epilepsia
Partialis Continua, malignant hyperthermia syndromes, glycogen metabolic
disorders,
fatty acid oxidation and lipid metabolism disorders, medication-, drug- or
toxin-induced
myoglobinuria, mitochondrial disorder-associated myoglobinuria, hypokalemic
myopathy
and rhabdomyolysis, muscle trauma-associated myoglobinuria, ischemia-induced
myoglobinuria, infection-induced myoglobinuria, immune myopathies associated
with
myoglobinuria, Myopathy, lactic acidosis, and sideroblastic anemia (MLASA),
infantile
mitochondrial myopathy due to reversible COX deficiency (MMIT), Myopathy,
Exercise
intolerance, Encephalopathy and Lactic acidemia Syndrome, myoglobinuria and
exercise
11

CA 02920246 2016-02-09
intolerance syndrome, exercise intolerance, proximal weakness myoglobinuria
syndrome, encephalopathy and seizures syndrome, septo-optic dysplasia,
exercise
intolerance mild weakness, myopathy exercise intolerance, growth or CNS
disorder,
maternally-inherited mitochondrial myopathies, myopathy with lactic acidosis,
myopathy
with rhabdomyolysis, Myopathy with cataract and combined respiratory chain
deficiency,
myopathy with abnormal mitochondrial translation, Fatigue Syndrome, myopathy
with
extrapyramidal movement disorders (MPXPS), glutaric aciduria II (MADD),
primary
CoQ10 deficiency-1 (C0Q10D1), primary CoQ10 deficiency-2 (C0Q10D2), primary
CoQ10 deficiency-3 (C0Q10D3), primary CoQ10 deficiency-5 (C0Q10D5), secondary
CoQ10 deficiency, autosomal dominant mitochondria' myopathy, myopathy with
focal
depletion of mitochondria, mitochondrial DNA breakage syndrome (PEO +
Myopathy),
lipid type mitochondrial myopathy, multiple symmetric lipomatosis (MSL), N-
acetylglutamate synthase (NAGS) deficiency, Nephronophthisis (NPHP), ornithine

transcarbamylase (OTC) deficiency, neoplasms, NARP Syndrome, paroxysmal
nonkinesigenic dyskinesia (PNI(D), sporadic PEO, maternally-inherited PEO,
autosomal
dominant progressive external ophthalmoplegia with mitochondria' DNA deletions-
3
(PEOA3), autosomal dominant progressive external ophthalmoplegia with
mitochondrial
DNA deletions-2 (PEOA2), autosomal dominant progressive external
ophthalmoplegia
with mitochondrial DNA deletions-1 (PEOA1), PEO+ demyelinating neuropathy, PEO
+
hypogonadism, autosomal dominant progressive external ophthalmoplegia with
mitochondrial DNA deletions-4 (PEOA4), distal myopathy, cachexia & PEO,
autosomal
dominant progressive external ophthalmoplegia-6 (PEOA6), PEO + Myopathy and
Parkinsonism, autosomal recessive progressive external ophthalmoplegia (PEOB),

Mitochondrial DNA Depletion Syndrome-11 (MTDPS11), PEO with cardiomyopathy,
PEPCK deficiency, Perrault Syndromes (PRLTS), propionic acidemia (PA),
pyruvate
carboxylase deficiency, pyruvate dehydrogenase El-alpha deficiency (PDHAD),
pyruvate
dehydrogenase El-beta deficiency (PDHBD), dihydrolipoamide dehydrogenase (DLD)

deficiency, pyruvate dehydrogenase phosphatase deficiency, pyruvate
dehydrogenase E3-
binding protein deficiency (PDHXD), mitochondrial pyruvate carrier deficiency
(MPYCD), Schwartz-Jampel Syndrome type 1 (SJS1), selenium deficiency, short-
chain
acyl-CoA dehydrogenase (SCAD) deficiency, succinyl CoA:3-oxacid CoA
transferase
(SCOT) deficiency, Stuve-Wiedemann Syndrome (STWS), thrombocytopenia (THC),
Very long-chain acyl-CoA dehydrogenase deficiency (VLCADD), Vitamin D-
dependent
rickets type lA (VDDR1A), Wilson's disease, Zellweger Syndrome (PBD3A),
arsenic
12

CA 02920246 2016-02-09
trioxide myopathy, myopathy and neuropathy resulting from nucleoside
analogues,
germanium myopathy, Parkinsonism and mitochondrial Complex I neurotoxicity due
to
trichloroethylene, valproate-induced hepatic failure, neurodegeneration with
brain iron
accumulation-4 (NBIA4), Complex I deficiency, Complex II deficiency, Complex
III
deficiency, Complex IV deficiency, Complex V deficiency, Cytochrome c oxidase
(COX)
deficiency, combined complex I, II, IV, V deficiency, combined complex I,
II, and III
deficiency, combined oxidative phosphorylation deficiency-1 (COXPD1), combined

oxidative phosphorylation deficiency-2 (COXPD2), combined oxidative
phosphorylation
deficiency-3 (COXPD3), combined oxidative phosphorylation deficiency-4
(COXPD4),
combined oxidative phosphorylation deficiency-6 (COXPD6), combined oxidative
phosphorylation deficiency-7 (COXPD7), combined oxidative phosphorylation
deficiency-9 (COXPD9), combined oxidative phosphorylation deficiency-11
(COXPD11),
combined oxidative phosphorylation deficiency-12 (COXPD12), combined oxidative

phosphorylation deficiency-13 (COXPD13), combined oxidative phosphorylation
deficiency-15 (COXPD15), combined oxidative phosphorylation deficiency-16
(COXPD16), combined oxidative phosphorylation deficiency-19 (COXPD19),
combined
oxidative phosphorylation deficiency-20 (COXPD20), combined oxidative
phosphorylation deficiency-21 (COXPD21), fumarase deficiency, HMG-CoA synthase-
2
deficiency, hyperuricemia, pulmonary hypertension, renal failure, and
alkalosis (HUPRA)
Syndrome, syndromic microphthalmia-7, pontocerebellar hypoplasia type 6
(PCH6),
Mitochondrial DNA Depletion Syndrome-9 (MTDPS9P), and Sudden infant death
Syndrome (SIDS).
[0010] Additionally or alternatively, in some embodiments of the method, the
chroman
derivative composition is administered one, two, three, four, or five times
per day. In
some embodiments of the method, the chroman derivative composition is
administered
more than five times per day.
[0011] Additionally or alternatively, in some embodiments of the method, the
chroman
derivative composition is administered every day, every other day, every third
day, every
fourth day, every fifth day, or every sixth day. In some embodiments of the
method, the
chroman derivative composition is administered weekly, bi-weekly, tri-weekly,
or
monthly.
[0012] In some embodiments, the chroman derivative composition is administered
for a
period of one, two, three, four, or five weeks. In some embodiments, the
chroman
13

CA 02920246 2016-02-09
derivative is administered for six weeks or more. In some embodiments, the
chroman
derivative is administered for twelve weeks or more. In some embodiments, the
chroman
derivative is administered for a period of less than one year. In some
embodiments, the
chroman derivative is administered for a period of more than one year.
[0013] Additionally or alternatively, in some embodiments of the method, the
chroman
derivative is administered daily for one, two, three, four or five weeks. In
some
embodiments of the method, the chroman derivative is administered daily for
less than 6
weeks. In some embodiments of the method, the chroman derivative is
administered daily
for 6 weeks or more. In other embodiments of the method, the chroman
derivative is
administered daily for 12 weeks or more.
[0014] In some embodiments of the method, the subject displays abnormal levels
of one
or more energy biomarkers compared to a normal control subject. In some
embodiments,
the energy biomarker is selected from the group consisting of lactic acid
(lactate) levels;
pyruvic acid (pyruvate) levels; lactate/pyruvate ratios; total, reduced or
oxidized
glutathione levels; reduced/oxidized glutathione ratios; total, reduced or
oxidized cysteine
levels; reduced/oxidized cysteine ratios; phosphocreatine levels; NADH
(NADH+H30) or
NADPH (NADPH+H30 ) levels; NAD or NADP levels; ATP levels; reduced coenzyme Q
(CoQred) levels; oxidized coenzyme Q (CoQox) levels; total coenzyme Q (CoQtot)
levels;
oxidized cytochrome C levels; reduced cytochrome C levels; oxidized cytochrome

C/reduced cytochrome C ratio; acetoacetate levels; beta-hydroxy butyrate
levels;
acetoacetate/ beta-hydroxy butyrate ratio; 8-hydroxy-2'-deoxyguanosine (8-
0HdG) levels;
levels of reactive oxygen species; oxygen consumption (V02), carbon dioxide
output
(VCO2), and respiratory quotient (VCO2/V02). In some embodiments of the
method, the
lactate levels of one or more of whole blood, plasma, cerebrospinal fluid, or
cerebral
ventricular fluid are abnormal compared to a normal control subject. In some
embodiments of the method, the pyruvate levels of one or more of whole blood,
plasma,
cerebrospinal fluid, or cerebral ventricular fluid are abnormal compared to a
normal
control subject. In some embodiments of the method, the lactate/pyruvate
ratios of one or
more of whole blood, plasma, cerebrospinal fluid, or cerebral ventricular
fluid are
abnormal compared to a normal control subject. In some embodiments of the
method, the
total, reduced or oxidized glutathione levels of one or more of whole blood,
plasma,
lymphocytes, cerebrospinal fluid, or cerebral ventricular fluid are abnormal
compared to a
normal control subject. In some embodiments of the method, the total, reduced
or
14

CA 02920246 2016-02-09
oxidized cysteine levels of one or more of whole blood, plasma, lymphocytes,
cerebrospinal fluid, or cerebral ventricular fluid are abnormal compared to a
normal
control subject. In some embodiments of the method, the reduced/oxidized
glutathione
ratios of one or more of whole blood, plasma, lymphocytes, cerebrospinal
fluid, or
cerebral ventricular fluid are abnormal compared to a normal control subject.
In some
embodiments of the method, the reduced or oxidized cysteine ratios of one or
more of
whole blood, plasma, lymphocytes, cerebrospinal fluid, or cerebral ventricular
fluid are
abnormal compared to a normal control subject.
[0015] Additionally or alternatively, in some embodiments of the method, the
chroman
derivative is administered orally, intranasally, intrathecally, intraocularly,
intradermally,
transmucosally, iontophoretically, topically, systemically, intravenously,
subcutaneously,
intraperitoneally, or intramuscularly. In some embodiments of the method, the
subject is
human.
[0016] Additionally or alternatively, in some embodiments of the method, the
symptoms
of the mitochondrial disease or disorder comprises one or more of poor growth,
loss of
muscle coordination, muscle weakness, neurological deficit, seizures, autism,
autistic
spectrum, autistic-like features, learning disabilities, heart disease, liver
disease, kidney
disease, gastrointestinal disorders, severe constipation, diabetes, increased
risk of
infection, thyroid dysfunction, adrenal dysfunction, autonomic dysfunction,
confusion,
disorientation, memory loss, failure to thrive, poor coordination, sensory
(vision, hearing)
problems, reduced mental functions, hypotonia, disease of the organ, dementia,
respiratory
problems, hypoglycemia, apnea, lactic acidosis, seizures, swallowing
difficulties,
developmental delays, movement disorders (dystonia, muscle spasms, tremors,
chorea),
stroke, and brain atrophy.
[0017] Additionally or alternatively, in some embodiments, the method further
comprises separately, sequentially or simultaneously administering an
additional
therapeutic agent to the subject. In certain embodiments, the additional
therapeutic agent
is selected from the group consisting of: vitamins, cofactors, antibiotics,
hormones,
antineoplastic agents, steroids, immunomodulators, dermatologic drugs,
antithrombotic,
antianemic, and cardiovascular agents.
[0018] In another aspect, the present disclosure provides a method for
modulating the
expression of one or more energy biomarkers in a mammalian subject in need
thereof, the

CA 02920246 2016-02-09
method comprising: administering to the subject a therapeutically effective
amount of a
chroman derivative or a pharmaceutically acceptable salt thereof.
[0019] In some embodiments of the method, the energy biomarker is selected
from the
group consisting of lactic acid (lactate) levels; pyruvic acid (pyruvate)
levels;
lactate/pyruvate ratios; total, reduced or oxidized glutathione levels;
reduced/oxidized
glutathione ratios; total, reduced or oxidized cysteine levels;
reduced/oxidized cysteine
ratios; phosphocreatine levels; NADH (NADH+H30) or NADPH (NADPH+H30 ) levels;
NAD or NADP levels; ATP levels; reduced coenzyme Q (CoQred) levels; oxidized
coenzyme Q (CoQox) levels; total coenzyme Q (CoQtot) levels; oxidized
cytochrome C
levels; reduced cytochrome C levels; oxidized cytochrome C/reduced cytochrome
C ratio;
acetoacetate levels; beta-hydroxy butyrate levels; acetoacetate/ beta-hydroxy
butyrate
ratio; 8-hydroxy-2'-deoxyguanosine (8-0HdG) levels; levels of reactive oxygen
species;
oxygen consumption (V02), carbon dioxide output (VCO2), and respiratory
quotient
(VCO2NO2). In some embodiments of the method, the lactate levels of one or
more of
whole blood, plasma, cerebrospinal fluid, or cerebral ventricular fluid are
abnormal
compared to a normal control subject. In some embodiments of the method, the
pyruvate
levels of one or more of whole blood, plasma, cerebrospinal fluid, or cerebral
ventricular
fluid are abnormal compared to a normal control subject. In some embodiments
of the
method, the lactate/pyruvate ratios of one or more of whole blood, plasma,
cerebrospinal
fluid, or cerebral ventricular fluid are abnormal compared to a normal control
subject. In
some embodiments of the method, the total, reduced or oxidized glutathione
levels of one
or more of whole blood, plasma, lymphocytes, cerebrospinal fluid, or cerebral
ventricular
fluid are abnormal compared to a normal control subject. In some embodiments
of the
method, the total, reduced or oxidized cysteine levels of one or more of whole
blood,
plasma, lymphocytes, cerebrospinal fluid, or cerebral ventricular fluid are
abnormal
compared to a normal control subject. In some embodiments of the method, the
reduced/oxidized glutathione ratios of one or more of whole blood, plasma,
lymphocytes,
cerebrospinal fluid, or cerebral ventricular fluid are abnormal compared to a
normal
control subject. In some embodiments of the method, the reduced or oxidized
cysteine
ratios of one or more of whole blood, plasma, lymphocytes, cerebrospinal
fluid, or
cerebral ventricular fluid are abnormal compared to a normal control subject.
[0020] Additionally or alternatively, in some embodiments of the method, the
chroman
derivative composition is administered one, two, three, four, or five times
per day. In
16

CA 02920246 2016-02-09
some embodiments of the method, the chroman derivative composition is
administered
more than five times per day.
[0021] Additionally or alternatively, in some embodiments of the method, the
chroman
derivative composition is administered every day, every other day, every third
day, every
fourth day, every fifth day, or every sixth day. In some embodiments of the
method, the
chroman derivative composition is administered weekly, bi-weekly, tri-weekly,
or
monthly.
[0022] In some embodiments, the chroman derivative composition is administered
for a
period of one, two, three, four, or five weeks. In some embodiments, the
chroman
derivative is administered for six weeks or more. In some embodiments, the
chroman
derivative is administered for twelve weeks or more. In some embodiments, the
chroman
derivative is administered for a period of less than one year. In some
embodiments, the
chroman derivative is administered for a period of more than one year.
[0023] Additionally or alternatively, in some embodiments of the method, the
chroman
derivative is administered daily for one, two, three, four or five weeks. In
some
embodiments of the method, the chroman derivative is administered daily for
less than 6
weeks. In some embodiments of the method, the chroman derivative is
administered daily
for 6 weeks or more. In other embodiments of the method, the chroman
derivative is
administered daily for 12 weeks or more.
[0024] In some embodiments of the method, the subject has been diagnosed has
having,
is suspected of having, or is at risk of having a mitochondrial disease or
disorder. In a
further embodiment of the method, the subject is human.
[0025] In some embodiments of the method, the symptoms of the mitochondrial
disease
or disorder comprises one or more of poor growth, loss of muscle coordination,
muscle
weakness, neurological deficit, seizures, autism, autistic spectrum, autistic-
like features,
learning disabilities, heart disease, liver disease, kidney disease,
gastrointestinal disorders,
severe constipation, diabetes, increased risk of infection, thyroid
dysfunction, adrenal
dysfunction, autonomic dysfunction, confusion, disorientation, memory loss,
failure to
thrive, poor coordination, sensory (vision, hearing) problems, reduced mental
functions,
hypotonia, disease of the organ, dementia, respiratory problems, hypoglycemia,
apnea,
lactic acidosis, seizures, swallowing difficulties, developmental delays,
movement
disorders (dystonia, muscle spasms, tremors, chorea), stroke, and brain
atrophy.
17

CA 02920246 2016-02-09
[0026] In some embodiments of the method, the chroman derivative is
administered
orally, intranasally, intrathecally, intraocularly, intradermally,
transmucosally,
iontophoretically, topically, systemically, intravenously, subcutaneously,
intraperitoneally,
or intramuscularly.
[0027] Additionally or alternatively, in some embodiments, the method further
comprises separately, sequentially or simultaneously administering an
additional
therapeutic agent to the subject. In certain embodiments of the method, the
additional
therapeutic agent is selected from the group consisting of: vitamins,
cofactors, antibiotics,
hormones, antineoplastic agents, steroids, immunomodulators, dermatologic
drugs,
antithrombotic, antianemic, and cardiovascular agents.
[0028] In another aspect, the present technology provides methods for
treating,
ameliorating or preventing the disruption of mitochondrial oxidative
phosphorylation in a
subject in need thereof, by administering chroman derivatives as disclosed
herein, the
method comprising administering to the subject a therapeutically effective
amount of a
chroman derivative or a pharmaceutically acceptable salt thereof, thereby
preventing,
ameliorating, or treating mitochondrial oxidative phosphorylation, and/or
signs or
symptoms thereof. In one embodiment, the method further comprises the step
administering one or more additional therapeutic agents to the subject.
[0029] In some embodiments of the method, the subject is suffering from or is
at
increased risk of a disruption of mitochondrial oxidative phosphorylation. In
some
embodiments, the subject is suffering from or is at increased risk of a
disease or conditions
characterized by a genetic mutation which affects mitochondrial function.
BRIEF DESCRIPTION OF THE DRAWINGS
[0030] Figure 1 shows the effect that various dysfunctions can have on energy
biomarkers as well as biochemical events that occur within the body. It also
indicates the
physical effect (such as a disease symptom or other effect of the dysfunction)
typically
associated with a given dysfunction. It should be noted that any of the energy
biomarkers
listed in the table, in addition to energy biomarkers enumerated elsewhere,
can also be
modulated, enhanced, or normalized by the chroman derivatives of the present
technology.
RQ=respiratory quotient; BMR=basal metabolic rate; HR (C0)=heart rate (cardiac

output); T=body temperature (preferably measured as core temperature);
AT=anaerobic
threshold; pH=blood pH (venous and/or arterial).
18

CA 02920246 2016-02-09
[0031] Figure 2 shows exemplary structures (1)-(18) of bicycloalkyl chroman
derivatives of the present technology.
DETAILED DESCRIPTION
[0032] It is to be appreciated that certain aspects, modes, embodiments,
variations and
features of the present technology are described below in various levels of
detail in order
to provide a substantial understanding of the present technology. The
definitions of
certain terms as used in this specification are provided below. Unless defined
otherwise,
all technical and scientific terms used herein generally have the same meaning
as
commonly understood by one of ordinary skill in the art to which the present
technology
belongs.
[0033] All numerical designations, e.g., pH, temperature, time, concentration
and
molecular weight, including ranges, are approximations which are varied (+) or
(-) by
increments of 1.0 or 0.1, as appropriate, or alternatively by a variation of
+/- 10%, or
alternatively 5% or alternatively 2%. It is to be understood, although not
always explicitly
stated, that all numerical designations are preceded by the term "about".
[0034] As used in this specification and the appended claims, the singular
forms "a",
"an" and "the" include plural referents unless the content clearly dictates
otherwise. For
example, reference to "a cell" includes a combination of two or more cells,
and the like.
[0035] As used herein, the term "about" encompasses the range of experimental
error
that may occur in a measurement and will be clear to the skilled artisan.
[0036] As used herein, the "administration" of an agent, drug, or compound to
a subject
includes any route of introducing or delivering to a subject a compound to
perform its
intended function. Administration can be carried out by any suitable route,
including
orally, intranasally, intrathecally, parenterally (intravenously,
intramuscularly,
intraperitoneally, or subcutaneously), intraocularly, intradermally,
transmucosally,
iontophoretically, or topically. Administration includes self-administration
and the
administration by another.
[0037] As used herein, the term "amino acid" includes naturally-occurring
amino acids
and synthetic amino acids, as well as amino acid analogs and amino acid
mimetics that
function in a manner similar to the naturally-occurring amino acids. Naturally-
occurring
amino acids are those encoded by the genetic code, as well as those amino
acids that are
later modified, e.g., hydroxyproline, y-carboxyglutamate, and 0-phosphoserine.
Amino
19

CA 02920246 2016-02-09
acid analogs refers to compounds that have the same basic chemical structure
as a
naturally-occurring amino acid, i.e., an a-carbon that is bound to a hydrogen,
a carboxyl
group, an amino group, and an R group, e.g., homoserine, norleucine,
methionine
sulfoxide, methionine methyl sulfonium. Such analogs have modified R groups
(e.g.,
norleucine) or modified peptide backbones, but retain the same basic chemical
structure as
a naturally-occurring amino acid. Amino acid mimetics refers to chemical
compounds
that have a structure that is different from the general chemical structure of
an amino acid,
but that functions in a manner similar to a naturally-occurring amino acid.
Amino acids
can be referred to herein by either their commonly known three letter symbols
or by the
one-letter symbols recommended by the IUPAC-TUB Biochemical Nomenclature
Commission.
[0038] The term "acyl" refers to the groups ¨C(0)¨H, ¨C(0)-(optionally
substituted
alkyl), ¨C(0)-(optionally substituted cycloalkyl), ¨C(0)-(optionally
substituted
alkenyl), ¨C(0)-(optionally substituted cycloalkenyl), ¨C(0)-(optionally
substituted
aryl), and ¨C(0)-(optionally substituted heterocyclyl). This term is
exemplified with
groups as formyl, acetyl, 4-oxo-4-yl-butyric acid.
[0039] The term "alkenyl" refers to a monoradical branched or unbranched,
unsaturated
or polyunsaturated hydrocarbon chain, having from about 2 to 20 carbon atoms
or about 2
to 10 carbon atoms. This term is exemplified by groups such as ethenyl, but-2-
enyl, 3-
methyl-but-2-enyl (also referred to as "prenyl"), octa-2,6-dienyl, 3,7-
dimethyl-octa-2,6-
dienyl (also referred to as "geranyl"), and the like.
[0040] The term "substituted alkenyl" refers to an alkenyl group in which 1 or
more (up
to about 5 or up to about 3) hydrogen atoms is replaced by a substituent
independently
selected from the group: =0, =S, acyl, acyloxy, optionally substituted alkoxy,
optionally
substituted amino (wherein the amino group may be a cyclic amine), azido,
carboxyl,
(optionally substituted alkoxy)carbonyl, (optionally substituted
amino)carbonyl, cyano,
optionally substituted cycloalkyl, optionally substituted cycloalkenyl,
optionally
substituted heteroaryl, halogen, hydroxyl, nitro, sulfamoyl, sulfanyl,
sulfinyl, sulfonyl, and
sulfonic acid. Preferred examples of substituted alkenyl are 5-vinyl-
thiazolidine-2,4-dione,
3-vinyl-3-H-benzofuran-2-one, 3-methyl-4-vinyl-5-oxo-4,5-dihydropyrazol-1-yl-
benzoic
acid, tetrahydropyran-4-ylidene-ethyl, 2-methy1-4-viny1-5-propyl-2,4-dihydro-
pyrazol-3-
one and cyclohexylidene-ethyl.

CA 02920246 2016-02-09
[0041] The term "acyloxy" refers to the moiety ¨0-acyl, including, for
example, ¨0¨
C(0)-alkyl.
[0042] The term "alkoxy" refers to the groups ¨0-alkyl, ¨0-alkenyl, ¨0-
cycloalkyl,
¨0-cycloalkenyl, and ¨0-alkynyl. In some embodiments, alkoxy groups are ¨0-
alkyl
and include, by way of example, methoxy, ethoxy, n-propoxy, iso-propoxy, n-
butoxy, tert-
butoxy, sec-butoxy, n-pentoxy, n-hexoxy, 1,2-dimethylbutoxy, and the like.
[0043] The term "substituted alkoxy" refers to the groups ¨0-(substituted
alkyl), ¨0-
(substituted alkenyl), ¨0-(substituted cycloalkyl), ¨0-(substituted
cycloalkenyl), ¨0-
(substituted alkynyl) and ¨0-(optionally substituted alkylene)-alkoxy.
[0044] The term "alkyl" refers to a monoradical branched or unbranched
saturated
hydrocarbon chain having from about 1 to 20 carbon atoms, or about 1 to 10
carbon
atoms, or about 1 to 6 carbon atoms. The term "alkyl" also means a combination
of linear
or branched and cyclic saturated hydrocarbon radical consisting solely of
carbon and
hydrogen atoms. This term is exemplified by groups such as methyl, ethyl, n-
propyl, iso-
propyl, n-butyl, iso-butyl, n-hexyl, n-decyl, tetradecyl, and the like. The
term "lower alkyl
refers to a monoradical branched or unbranched saturated hydrocarbon chain of
1 to 6
atoms.
[0045] The term "substituted alkyl" refers to an alkyl group in which 1 or
more (up to
about 5, or up to about 3) hydrogen atoms is replaced by a substituent
independently
selected from the group: =0, =5, acyl, acyloxy, optionally substituted alkoxy,
optionally
substituted amino (wherein the amino group may be a cyclic amine), azido,
carboxyl,
(optionally substituted alkoxy)carbonyl, (optionally substituted
amino)carbonyl, cyano,
optionally substituted cycloalkyl, optionally substituted cycloalkenyl,
halogen, hydroxyl,
nitro, sulfamoyl, sulfanyl, sulfinyl, sulfonyl, and sulfonic acid. One of the
optional
substituents for alkyl is hydroxy, exemplified by hydroxyalkyl groups, such as
2-
hydroxyethyl, 3-hydroxypropyl, 3-hydroxybutyl, 4-hydroxybutyl, and the like;
dihydroxyalkyl groups (glycols); such as 2,3-dihydroxypropyl, 3,4-
dihydroxybutyl, 2,4-
dihydroxybutyl, and the like; aminoalkyl groups such as dimethyl aminoalkyl,
piperidinylalkyl, morpholinylalkyl, and those compounds known as polyethylene
glycols,
polypropylene glycols and polybutylene glycols, and the like. Another optional

substituent for alkyl is sulfanyl exemplified by allylsulfanyl,
carboxypropylsulfanyl, 2-
methyl-propionyl-pyrrolidine-2-carboxylic acid, 5-methyl-l-H-benzimidazol-2-yl-

21

CA 02920246 2016-02-09
sulfanyl, sulfoxyethylsulfanyl, 4,6-dimethyl-pyrimidin-2-ylsulfanyl, 4 carboxy-
benzyl-
sulfanyl, isobutylsulfanyl, and the like. Other optional substituents for
alkyl are ¨N-
hydroxyureidyl, ¨N-hydroxythioureidyl or ¨N-hydroxyacetamide. Other alkyl
substituents are halogen exemplified by chloro and bromo, acyl exemplified by
methylcarbonyl, alkoxy, and heterocyclyl exemplified by morpholino and
piperidino.
[0046] The term "alkylene" refers to a diradical derived from the above-
defined
monoradical, alkyl. This term is exemplified by groups such as methylene
(¨CH2¨),
ethylene (¨CH2CH2¨), the propylene isomers [e.g., ¨CH2CH2CH2¨ and ¨
CH(CH3)CH2--] and the like.
[0047] The term "substituted alkylene" refers to a diradical derived from the
above-
defined monoradical, substituted alkyl. Examples of substituted alkylenes are
chloromethylene (¨CH(C1)¨), aminoethylene (¨CH(N112)CH2¨),
methylaminoethylene (¨CH(NHMe)CH2¨), 2-carboxypropylene isomers (¨
CH2CH(CO2H)CH2¨), ethoxyethylene (¨CH2CH2O¨CH2CH2¨), ethyl(N-
methyl)aminoethylene (¨CH2CH2N(CH3)CH2CH2¨), 1-ethoxy-2-(2-ethoxy-
ethoxy)ethylene (¨CH2CH2O¨CH2CH2-0CH2CH2-0CH2CH2¨), and the like.
[0048] The term "amino" refers to the group ¨NH2 as well as to the groups ¨NHR
or
¨NRR where each R is independently selected from the group: optionally
substituted
alkyl, optionally substituted cycloalkyl, optionally substituted alkenyl,
optionally
substituted cycloalkenyl, optionally substituted alkynyl, optionally
substituted aryl,
optionally substituted heterocyclyl, acyl, optionally substituted alkoxy,
carboxy and
alkoxycarbonyl, and where ¨NRR may be a cyclic amine.
[0049] The term "aromatic" refers to a cyclic or polycyclic moiety having a
conjugated
unsaturated (4n+2) it electron system (where n is a positive integer),
sometimes referred to
as a delocalized IC electron system.
[0050] The term "aryl" refers to an aromatic cyclic hydrocarbon group of from
6 to 20
carbon atoms having a single ring (e.g., phenyl) or multiple condensed (fused)
rings (e.g.,
naphthyl or anthryl). In some embodiments, aryls include phenyl, naphthyl and
the like.
[0051] The term "substituted aryl" refers to an aryl group as defined above,
which unless
otherwise constrained by the definition for the aryl substituent, is
substituted with from 1
to 5 substituents, or 1 to 3 substituents, independently selected from the
group consisting
of: hydroxy, thiol, acyl, acyloxy, optionally substituted alkenyl, optionally
substituted
22

CA 02920246 2016-02-09
alkoxy, optionally substituted alkyl (such as tri-halomethyl), optionally
substituted
alkynyl, optionally substituted amino, optionally substituted aryl, optionally
substituted
aryloxy, azido, carboxyl, (optionally substituted alkoxy)carbonyl, (optionally
substituted
amino)carbonyl, cyano, optionally substituted cycloalkyl, optionally
substituted
cycloalkenyl, halogen, optionally substituted heterocyclyl, optionally
substituted
heterocyclooxy, hydroxyl, nitro, sulfanyl, sulfinyl, sulfanyl, and sulfonic
acid. In some
embodiments, aryl substituents include alkyl, alkenyl, alkoxy, halo, cyano,
nitro, haloalkyl
(e.g., trihalomethyl), carboxy, amino, amido, sulfonamido, and sulfinyl.
[0052] The term "carbonyl" refers to the di-radical "¨C(=0)¨", which is also
illustrated as "¨C(0)
[0053] The term "(optionally substituted alkoxy)carbonyl" refers to the
groups: ¨
C(0)0-(optionally substituted alkyl), ¨C(0)0-(optionally substituted
cycloalkyl), ¨
C(0)0-(optionally substituted alkenyl), and ¨C(0)0-(optionally substituted
alkynyl).
These moieties are also referred to as esters.
[0054] The term "(optionally substituted amino)carbonyl" refers to the group
¨C(0)-
(optionally substituted amino). This moiety is also referred to as a primary,
secondary or
tertiary carboxamide.
[0055] The term "carboxy' or "carboxyl" refers to the moiety "¨C(0)0H", which
is
also illustrated as "¨COOH".
[0056] The term "cycloalkyl" refers to non-aromatic cyclic hydrocarbon groups
of
having about 3 to 40 (or about 4 to 15) carbon atoms having a single ring or
multiple
condensed or bridged rings. Such cycloalkyl groups include, by way of example,
single
ring structures such as cyclopropyl, cyclobutyl, cyclopentyl, cyclooctyl, and
the like, or
multiple ring structures such as adamantanyl, and the like. The term
"cycloalkyl"
additionally encompasses Spiro systems wherein the cycloalkyl ring has a
carbon ring
atom in common with another ring.
[0057] The term "substituted cycloalkyl" refers to a cycloalkyl group
substituted with
from 1 to 5 substituents, or 1 to 3 substituents, independently selected from
the group
consisting of: =0, =S, acyl, acyloxy, optionally substituted alkenyl,
optionally substituted
alkoxy, optionally substituted alkyl (such as tri-halomethyl), optionally
substituted
alkynyl, optionally substituted amino, optionally substituted aryl, optionally
substituted
aryloxy, azido, carboxyl, (optionally substituted alkoxy)carbonyl, (optionally
substituted
23

CA 02920246 2016-02-09
amino)carbonyl, cyano, optionally substituted cycloalkyl, optionally
substituted
cycloalkenyl, halogen, optionally substituted heterocyclyl, optionally
substituted
heterocyclooxy, hydroxyl, nitro, sulfanyl, sulfinyl, sulfanyl, and sulfonic
acid. A
cycloalkyl ring substituted with an alkyl group is also referred as
"alkylcycloalkyl".
[0058] As used herein, a "control" is an alternative sample used in an
experiment for
comparison purpose. A control can be "positive" or "negative." For example,
where the
purpose of the experiment is to determine a correlation of the efficacy of a
therapeutic
agent for the treatment for a particular type of disease, a positive control
(a compound or
composition known to exhibit the desired therapeutic effect) and a negative
control (a
subject or a sample that does not receive the therapy or receives a placebo)
are typically
employed.
[0059] As used herein, the term "effective amount" refers to a quantity
sufficient to
achieve a desired therapeutic and/or prophylactic effect, e.g., an amount
which results in
the prevention of, or amelioration of a disease or medical condition described
herein or
one or more symptoms associated with a disease or medical condition described
herein. In
the context of therapeutic or prophylactic applications, the amount of a
composition
administered to the subject will depend on the type and severity of the
disease and on the
characteristics of the individual, such as general health, age, sex, body
weight and
tolerance to drugs. It will also depend on the degree, severity and type of
disease. The
skilled artisan will be able to determine appropriate dosages depending on
these and other
factors. The compositions can also be administered in combination with one or
more
additional therapeutic compounds. In some embodiments, an effective amount of
a
compound is an amount of the compound sufficient to modulate, normalize, or
enhance
one or more energy biomarkers (where modulation, normalization, and
enhancement are
defined herein). In the methods described herein, the compositions of the
present
technology may be administered to a subject having one or more signs or
symptoms of a
disease or medical condition described herein. For example, a "therapeutically
effective
amount" of the chroman derivatives is meant levels at which the physiological
effects of a
particular disease or medical condition are, at a minimum, ameliorated. A
therapeutically
effective amount can be given in one or more administrations. By way of
example only,
in some embodiments, the disease or medical condition is a mitochondrial
disease or
disorder. In some embodiments, signs, symptoms or complications of a
mitochondrial
disease or disorder include, but are not limited to: poor growth, loss of
muscle
24

CA 02920246 2016-02-09
coordination, muscle weakness, neurological deficit, seizures, autism,
autistic spectrum,
autistic-like features, learning disabilities, heart disease, liver disease,
kidney disease,
gastrointestinal disorders, severe constipation, diabetes, increased risk of
infection, thyroid
dysfunction, adrenal dysfunction, autonomic dysfunction, confusion,
disorientation,
memory loss, failure to thrive, poor coordination, sensory (vision, hearing)
problems,
reduced mental functions, hypotonia, disease of the organ, dementia,
respiratory problems,
hypoglycemia, apnea, lactic acidosis, seizures, swallowing difficulties,
developmental
delays, movement disorders (dystonia, muscle spasms, tremors, chorea), stroke,
brain
atrophy, or any other sign or symptom of a mitochondrial disease state
disclosed herein.
In other embodiments of the method, the disease or medical condition is
selected from the
group consisting of vitiligo, porphyria, Alport Syndrome, and IPF.
[0060] As used herein, the terms "enhancement" of, or to "enhance," energy
biomarkers
means to improve the level of one or more energy biomarkers in a direction
that results in
a beneficial or desired physiological outcome in a subject (compared to the
values
observed in a normal control subject, or the value in the subject prior to
treatment with a
composition or compound). For example, in a situation where significant energy
demands
are placed on a subject, it may be desirable to increase the level of ATP in
that subject to a
level above the ATP level observed in a normal control subject. Enhancement
can also be
of beneficial effect in a subject suffering from a disease or pathology such
as a
mitochondrial disease, in that normalizing an energy biomarker may not achieve
the
optimum outcome for the subject; in such cases, enhancement of one or more
energy
biomarkers can be beneficial, for example, higher-than-normal levels of ATP,
or lower-
than normal levels of lactic acid (lactate) can be beneficial to such a
subject.
[0061] As used herein, "expression" refers to the process by which
polynucleotides are
transcribed into mRNA and/or the process by which the transcribed mRNA is
subsequently being translated into peptides, polypeptides, or proteins. If the

polynucleotide is derived from genomic DNA, expression may include splicing of
the
mRNA in an eukaryotic cell. The expression level of a gene may be determined
by
measuring the amount of mRNA or protein in a cell or tissue sample. In one
aspect, the
expression level of a gene from one sample may be directly compared to the
expression
level of that gene from a control or reference sample. In another aspect, the
expression
level of a gene from one sample may be directly compared to the expression
level of that
gene from the same sample following administration of a chroman derivative.

CA 02920246 2016-02-09
[0062] The term "halo" or "halogen" refers to fluoro, chloro, bromo and iodo.
[0063] The terms "heterocycle", "heterocyclic", "heterocyclo", and
"heterocycly1" refer
to a monovalent, saturated, partially unsaturated or unsaturated (aromatic),
carbocyclic
radical having one or more rings incorporating one, two, three or four
heteroatoms within
the ring (chosen from nitrogen, oxygen, and/or sulfur). In some embodiments,
heterocycles include morpholine, piperidine, piperazine, thiazole,
thiazolidine, isothiazole,
oxazole, isoxazole, pyrazole, pyrazolidine, pyrazoline, imidazole,
imidazolidine,
benzothiazole, pyridine, pyrazine, pyrimidine, pyridazine, pyrrole,
pyrrolidine, quinoline,
quinazoline, purine, carbazole, benzimidazole, pyrimidine, thiophene,
benzothiophene,
pyran, tetrahydropyran, benzopyran, furan, tetrahydrofuran, indole, indoline,
indazole,
xanthene, thioxanthene, acridine, quinuclidine, and the like.
[0064] The terms "substituted heterocycle", "substituted heterocyclic",
"substituted
heterocyclo" and "substituted heterocycly1" refer to a heterocycle group as
defined above,
which unless otherwise constrained by the definition for the heterocycle, is
substituted
with from 1 to 5 substituents, or 1 to 3 substituents, independently selected
from the group
consisting of: hydroxy, thiol, acyl, acyloxy, optionally substituted alkenyl,
optionally
substituted alkoxy, optionally substituted alkyl (such as tri-halomethyl),
optionally
substituted alkynyl, optionally substituted amino, optionally substituted
aryl, optionally
substituted aryloxy, azido, carboxyl, (optionally substituted alkoxy)carbonyl,
(optionally
substituted amino)carbonyl, cyano, optionally substituted cycloalkyl,
optionally
substituted cycloalkenyl, halogen, optionally substituted heterocyclyl,
optionally
substituted heterocyclooxy, hydroxyl, nitro, sulfanyl, sulfinyl, and sulfonic
acid. In some
embodiments, substituted heterocycles include pyrrolidine 2-carboxylic acid,
thiazolidine-
2,4-dione and 3-methyl-5-oxo-4,5-dihydro-1H-pyrazol.
[0065] The term "isomers" or "stereoisomers" relates to compounds that have
identical
molecular formulae but that differ in the arrangement of their atoms in space.

Stereoisomers that are not mirror images of one another are termed
"diastereoisomers" and
stereoisomers that are non-superimposable mirror images are termed
"enantiomers", or
sometimes optical isomers. A carbon atom bonded to four non-identical
substituents is
termed a "chiral center". Certain compounds of the present technology have one
or more
chiral centers and therefore may exist as either individual stereoisomers or
as a mixture of
stereoisomers. The present technology includes all possible stereoisomers as
individual
stereoisomers or as a mixture of stereoisomers.
26

CA 02920246 2016-02-09
[0066] As used herein, the term "mitochondrial disease or disorder" refers to
any disease
or disorder that results from the perturbation of any biological/physiological
process in the
mitochondria. Non-limiting examples of mitochondrial disease include but are
not limited
to Alexander disease, Alpers Syndrome, Alpha-ketoglutarate dehydrogenase
(AKDGH)
deficiency, ALS-FTD, Sideroblastic anemia with spinocerebellar ataxia,
Pyridoxine-
refractory sideroblastic anemia, GRACILE Syndrome, Bjornstad Syndrome, Leigh
Syndrome, mitochondrial complex III deficiency nuclear type 1 (MC3DN1),
combined
oxidative phosphorylation deficiency 18 (COXPD18), Thiamine-responsive
megaloblastic
anemia syndrome (TRMA), Pearson Syndrome, HAM Syndrome, Ataxia, Cataract, and
Diabetes Syndrome, MELAS/MERRF Overlap Syndrome, combined oxidative
phosphorylation deficiency-14 (COXPD14), Infantile cerebellar-retinal
degeneration
(ICRD), Charlevoix-Saguenay spastic ataxia, Primary coenzyme Q10 deficiency-1
(C0Q10D1), ataxia oculomotor apraxia type 1 (A0A1), Autosomal recessive
spinocerebellar ataxia-9/ coenzyme Q10 deficiency-4 (C0Q10D4), Ataxia,
Pyramidal
Syndrome, and Cytochrome Oxidase Deficiency, Friedreich's ataxia, Infantile
onset
spinocerebellar ataxia (IOSCA)/ Mitochondrial DNA Depletion Syndrome-7,
Leukoencephalopathy with brainstem and spinal cord involvement and lactate
elevation
(LBSL), Autosomal recessive spastic ataxia-3 (SPAX3), MIRAS, SANDO,
mitochondrial
spinocerebellar ataxia and epilepsy (MSCAE), spastic ataxia with optic atrophy
(SPAX4),
progressive external ophthalmoplegia with mitochondrial DNA deletions
autosomal
dominant type 5 (PEOA5), mitochondrial complex III deficiency nuclear type 2
(MC3DN2), episodic encephalopathy due to thiamine pyrophosphokinase
deficiency/Thiamine Metabolism Dysfunction Syndrome-5 (THMD5), Spinocerebellar

ataxia-28 (SCA28), autosomal dominant cerebellar ataxia, deafness, and
narcolepsy
(ADCA-DN), Dominant Optic Atrophy (DOA), cerebellar ataxia, areflexia, pes
cavus,
optic atrophy, and sensorineural hearing loss (CAPOS) Syndrome,
spinocerebellar ataxia 7
(SCA7), Barth Syndrome, Biotinidase deficiency, gyrate atrophy, Syndromic
Dominant
Optic Atrophy and Deafness (Syndromic DOAD), Dominant Optic Atrophy plus
(D0Aplus), Leber's hereditary optic neuropathy (LHON), Wolfram Syndrome-1
(WFS1),
Wolfram Syndrome-2 (WFS2), Age-related macular degeneration (ARMD), Brunner
Syndrome, Left ventricular noncompaction-1 (LVNC1), histiocytoid
cardiomyopathy,
Familial Myalgia Syndrome, Parkinsonism, Fatal infantile
cardioencephalomyopathy due
to cytochrome c oxidase (COX) deficiency-1 (CEMCOX1), Sengers Syndrome,
Cardiofaciocutaneous Syndrome-1 (CFC1), Mitochondrial trifunctional protein
(MTP)
27

CA 02920246 2016-02-09
deficiency, infantile encephalocardiomyopathy with cytochrome c oxidase
deficiency,
cardiomyopathy + encephalomyopathy, mitochondrial phosphate carrier
deficiency,
infantile cardioencephalomyopathy due to cytochrome c oxidase (COX) deficiency

(CEMCOX2), P-Hydroxyisobutyryl CoA Deacylase (HIBCH) deficiency, ECHS1)
deficiency, Maternal Inheritance Leigh Syndrome (MILS), dilated cardiomyopathy
with
ataxia (DCMA), Mitochondrial DNA Depletion Syndrome-12 (MTDPS12),
cardiomyopathy due to mitochondrial tRNA deficiencies, mitochondrial complex V
(ATP
synthase) deficiency nuclear type 1 (MC5DN1), combined oxidative
phosphorylation
deficiency-8 (COXPD8), progressive leukoencephalopathy with ovarian failure
(LKENP),
combined oxidative phosphorylation deficiency-10 (COXPD10), combined oxidative

phosphorylation deficiency-16 (COXPD16), combined oxidative phosphorylation
deficiency-17 (COXPD17), combined oxidative phosphorylation deficiency-5
(COXPD5),
combined oxidative phosphorylation deficiency-9 (COXPD9), carnitine
acetyltransferase
(CRAT) deficiency, carnitine palmitoyltransferase I (CPT I) deficiency,
myopathic
carnitine deficiency, primary systemic carnitine deficiency (CDSP), carnitine
palmitoyltransferase II (CPT II) deficiency, carnitine-acylcarnitine
translocase deficiency
(CACTD), cartilage-hair hypoplasia, cerebrotendinous xanthomatosis (CTX),
congenital
adrenal hyperplasia (CAH), megaconial type congenital muscular dystrophy,
cerebral
creatine deficiency syndrome-3 (CCDS3), maternal nonsyndromic deafness,
maternal
nonsyndromic deafness, autosomal dominant deafness-64 (DFNA64), Mohr-
Tranebjaerg
Syndrome, Jensen Syndrome, MEGDEL, reticular dysgenesis, primary coenzyme Q10
deficiency-6 (C0Q10D6), CAGSSS, diabetes, Dimethylglycine dehydrogenase
deficiency
(DMGDHD), Multiple Mitochondrial Dysfunctions Syndrome-1 (MMDS1), Multiple
Mitochondrial Dysfunctions Syndrome-2 (MMDS2), Multiple Mitochondrial
Dysfunctions Syndrome-3 (MMDS3), childhood leukoencephalopathy associated with

mitochondrial Complex II deficiency, encephalopathies associated with
mitochondrial
Complex I deficiency, encephalopathies associated with mitochondrial Complex
III
deficiency, encephalopathies associated with mitochondrial Complex IV
deficiency,
encephalopathies associated with mitochondrial Complex V deficiency,
hyperammonemia
due to carbonic anhydrase VA deficiency (CA5AD), early infantile epileptic
encephalopathy-3 (EIEE3), 2,4-Dienoyl-CoA reductase deficiency (DECRD),
infection-
induced acute encephalopathy-3 (IIAE3), ethylmalonic encephalopathy (EE),
hypomyelinating leukodystrophy (HLD4), exocrine pancreatic insufficiency,
dyserythropoietic anemia and calvarial hyperostosis, Glutaric aciduria type 1
(GA-1),
28

CA 02920246 2016-02-09
glycine encephalopathy (GCE), hepatic failure, 2-hydroxyglutaric aciduria, 3-
hydroxyacyl-CoA dehydrogenase deficiency, familial hyperinsulinemic
hypoglycemia
(FHH), hypercalcemia infantile, hyperornithinemia-hyperammonemia-
homocitrullinuria
(HHH) Syndrome, Immunodeficiency with hyper-IgM type 5 (HIGM5), Inclusion Body

Myositis (IBM), polymyositis with mitochondrial pathology, IM-Mito,
granulomatous
myopathies with anti-mitochondrial antibodies, necrotizing myopathy with
pipestem
capillaries, myopathy with deficient chondroitin sulfate C in skeletal muscle
connective
tissue, benign acute childhood myositis, idiopathic orbital myositis,
masticator myopathy,
hemophagocytic lymphohistiocytosis, infection-associated myositis,
Facioscapulohumeral
dystrophy (FSH), familial idiopathic inflammatory myopathy, Schmidt Syndrome
(Diabetes mellitus, Addison disease, Myxedema), TNF receptor-associated
Periodic
Syndrome (TRAPS), focal myositis, autoimmune fasciitis, Spanish toxic oil-
associated
fasciitis, Eosinophilic fasciitis, Macrophagic myofasciitis, Graft-vs-host
disease fasciitis,
Eosinophilia-myalgia Syndrome, perimyositis, isovaleric acidemia (IVA), Keames-
Sayre
Syndrome (KSS), 2-oxoadipic aciduria, 2-aminoadipic aciduria, Limb-girdle
Muscular
Dystrophy Syndromes, leukodystrophy, Maple syrup urine disease (MSUD), 3-
Methylcrotonyl-CoA carboxylase (MCC), Methylmalonic aciduria (MMA), Miller
Syndrome, Mitochondrial DNA Depletion Syndrome-2 (MTDPS2), spinal muscular
atrophy syndrome, rigid spine syndrome, severe myopathy with motor regression,

Mitochondrial DNA Depletion Syndrome-3, MELAS Syndrome, camptocormia, MNGIE,
MNGIM Syndrome, Menkes Disease, Occipital Horn Syndrome, X-linked distal
spinal
muscular atrophy-3 (SMAX3), methemoglobinemia, MERRF, progressive external
ophthalmoplegia with myoclonus, deafness and diabetes (DD), multiple symmetric

lipomatosis, Myopathy with Episodic high Creatine Kinase (MIMECK), Epilepsia
Partialis Continua, malignant hyperthermia syndromes, glycogen metabolic
disorders,
fatty acid oxidation and lipid metabolism disorders, medication-, drug- or
toxin-induced
myoglobinuria, mitochondrial disorder-associated myoglobinuria, hypokalemic
myopathy
and rhabdomyolysis, muscle trauma-associated myoglobinuria, ischemia-induced
myoglobinuria, infection-induced myoglobinuria, immune myopathies associated
with
myoglobinuria, Myopathy, lactic acidosis, and sideroblastic anemia (MLASA),
infantile
mitochondrial myopathy due to reversible COX deficiency (MMIT), Myopathy,
Exercise
intolerance, Encephalopathy and Lactic acidemia Syndrome, myoglobinuria and
exercise
intolerance syndrome, exercise intolerance, proximal weakness myoglobinuria
syndrome, encephalopathy and seizures syndrome, septo-optic dysplasia,
exercise
29

CA 02920246 2016-02-09
intolerance mild weakness, myopathy exercise intolerance, growth or CNS
disorder,
maternally-inherited mitochondrial myopathies, myopathy with lactic acidosis,
myopathy
with rhabdomyolysis, Myopathy with cataract and combined respiratory chain
deficiency,
myopathy with abnormal mitochondria' translation, Fatigue Syndrome, myopathy
with
extrapyramidal movement disorders (MPXPS), glutaric aciduria II (MADD),
primary
CoQ10 deficiency-1 (C0Q10D1), primary CoQ10 deficiency-2 (C0Q10D2), primary
CoQ10 deficiency-3 (C0Q10D3), primary CoQ10 deficiency-5 (C0Q10D5), secondary
CoQ10 deficiency, autosomal dominant mitochondrial myopathy, myopathy with
focal
depletion of mitochondria, mitochondria' DNA breakage syndrome (PEO +
Myopathy),
lipid type mitochondrial myopathy, multiple symmetric lipomatosis (MSL), N-
acetylglutamate synthase (NAGS) deficiency, Nephronophthisis (NPHP), ornithine

transcarbamylase (OTC) deficiency, neoplasms, NARP Syndrome, paroxysmal
nonkinesigenic dyskinesia (PNKD), sporadic PEO, maternally-inherited PEO,
autosomal
dominant progressive external ophthalmoplegia with mitochondrial DNA deletions-
3
(PEOA3), autosomal dominant progressive external ophthalmoplegia with
mitochondrial
DNA deletions-2 (PEOA2), autosomal dominant progressive external
ophthalmoplegia
with mitochondrial DNA deletions-1 (PEOA1), PEO+ demyelinating neuropathy, PEO
+
hypogonadism, autosomal dominant progressive external ophthalmoplegia with
mitochondria' DNA deletions-4 (PEOA4), distal myopathy, cachexia & PEO,
autosomal
dominant progressive external ophthalmoplegia-6 (PEOA6), PEO + Myopathy and
Parkinsonism, autosomal recessive progressive external ophthalmoplegia (PEOB),

Mitochondrial DNA Depletion Syndrome-11 (MTDPS11), PEO with cardiomyopathy,
PEPCK deficiency, Perrault Syndromes (PRLTS), propionic acidemia (PA),
pyruvate
carboxylase deficiency, pyruvate dehydrogenase El-alpha deficiency (PDHAD),
pyruvate
dehydrogenase El-beta deficiency (PDHBD), dihydrolipoamide dehydrogenase (DLD)

deficiency, pyruvate dehydrogenase phosphatase deficiency, pyruvate
dehydrogenase E3-
binding protein deficiency (PDHXD), mitochondria] pyruvate carrier deficiency
(MPYCD), Schwartz-Jampel Syndrome type 1 (SJS1), selenium deficiency, short-
chain
acyl-CoA dehydrogenase (SCAD) deficiency, succinyl CoA:3-oxacid CoA
transferase
(SCOT) deficiency, Stuve-Wiedemann Syndrome (STWS), thrombocytopenia (THC),
Very long-chain acyl-CoA dehydrogenase deficiency (VLCADD), Vitamin D-
dependent
rickets type 1A (VDDR1A), Wilson's disease, Zellweger Syndrome (PBD3A),
arsenic
trioxide myopathy, myopathy and neuropathy resulting from nucleoside
analogues,
germanium myopathy, Parkinsonism and mitochondrial Complex I neurotoxicity due
to

CA 02920246 2016-02-09
trichloroethylene, valproate-induced hepatic failure, neurodegeneration with
brain iron
accumulation-4 (NBIA4), Complex I deficiency, Complex II deficiency, Complex
III
deficiency, Complex IV deficiency, Complex V deficiency, Cytochrome c oxidase
(COX)
deficiency, combined complex I, II, IV, V deficiency, combined complex I,
II, and III
deficiency, combined oxidative phosphorylation deficiency-1 (COXPD1), combined

oxidative phosphorylation deficiency-2 (COXPD2), combined oxidative
phosphorylation
deficiency-3 (COXPD3), combined oxidative phosphorylation deficiency-4
(COXPD4),
combined oxidative phosphorylation deficiency-6 (COXPD6), combined oxidative
phosphorylation deficiency-7 (COXPD7), combined oxidative phosphorylation
deficiency-9 (COXPD9), combined oxidative phosphorylation deficiency-11
(COXPD11),
combined oxidative phosphorylation deficiency-12 (COXPD12), combined oxidative

phosphorylation deficiency-13 (COXPD13), combined oxidative phosphorylation
deficiency-15 (COXPD15), combined oxidative phosphorylation deficiency-16
(COXPD16), combined oxidative phosphorylation deficiency-19 (COXPD19),
combined
oxidative phosphorylation deficiency-20 (COXPD20), combined oxidative
phosphorylation deficiency-21 (COXPD21), fumarase deficiency, HMG-CoA synthase-
2
deficiency, hyperuricemia, pulmonary hypertension, renal failure, and
alkalosis (HUPRA)
Syndrome, syndromic microphthalmia-7, pontocerebellar hypoplasia type 6
(PCH6),
Mitochondrial DNA Depletion Syndrome-9 (MTDPS9P), and Sudden infant death
Syndrome (SIDS).
[0067] As used herein, the "modulation" of, or to "modulate," an energy
biomarker
means to change the level of the energy biomarker towards a desired value, or
to change
the level of the energy biomarker in a desired direction (e.g., increase or
decrease).
Modulation can include, but is not limited to, normalization and enhancement
as defined
herein.
[0068] As used herein, the terms "normalization" of, or to "normalize," an
energy
biomarker is defined as changing the level of the energy biomarker from a
pathological
value towards a normal value, where the normal value of the energy biomarker
can be 1)
the level of the energy biomarker in a healthy person or subject, or 2) a
level of the energy
biomarker that alleviates one or more undesirable symptoms in the person or
subject. That
is, to normalize an energy biomarker which is depressed in a disease state
means to
increase the level of the energy biomarker towards the normal (healthy) value
or towards a
value which alleviates an undesirable symptom; to normalize an energy
biomarker which
31

CA 02920246 2016-02-09
is elevated in a disease state means to decrease the level of the energy
biomarker towards
the normal (healthy) value or towards a value which alleviates an undesirable
symptom.
[0069] The term "optional" or "optionally" means that the subsequently
described event
or circumstance may or may not occur, and that the description includes
instances where
said event or circumstance occurs and instances in which it does not. For
example,
"optionally substituted alkyl" means either "alkyl" or "substituted alkyl," as
defined below.
[0070] It will be understood by those skilled in the art with respect to any
group
containing one or more substituents that such groups are not intended to
introduce any
substitution or substitution patterns that are sterically impractical and/or
physically non-
feasible.
[0071] As used herein, the terms "polypeptide," "peptide," and "protein" are
used
interchangeably herein to mean a polymer comprising two or more amino acids
joined to
each other by peptide bonds or modified peptide bonds, i.e., peptide
isosteres. Polypeptide
refers to both short chains, commonly referred to as peptides, glycopeptides
or oligomers,
and to longer chains, generally referred to as proteins. Polypeptides may
contain amino
acids other than the 20 gene-encoded amino acids. Polypeptides include amino
acid
sequences modified either by natural processes, such as post-translational
processing, or
by chemical modification techniques that are well known in the art.
[0072] As used herein, "prevention" or "preventing" of a disease or medical
condition
refers to a compound that, in a statistical sample, reduces the occurrence of
the disease or
medical condition in the treated sample relative to an untreated control
sample, or delays
the onset of one or more symptoms of the disease or medical condition relative
to the
untreated control sample.
[0073] As used herein, the term "simultaneous" therapeutic use refers to the
administration of at least two active ingredients by the same route and at the
same time or
at substantially the same time.
[0074] As used herein, the term "separate" therapeutic use refers to an
administration of
at least two active ingredients at the same time or at substantially the same
time by
different routes.
[0075] As used herein, the term "sequential" therapeutic use refers to
administration of
at least two active ingredients at different times, the administration route
being identical or
different. More particularly, sequential use refers to the whole
administration of one of
32

CA 02920246 2016-02-09
the active ingredients before administration of the other or others commences.
It is thus
possible to administer one of the active ingredients over several minutes,
hours, or days
before administering the other active ingredient or ingredients. There is no
simultaneous
treatment in this case.
[0076] As used herein, the terms "subject," "individual," or "patient" can be
an
individual organism, a vertebrate, a mammal, or a human.
[0077] The term "sulfanyl" or "thiol" refers to the groups: ¨S-(optionally
substituted
alkyl), ¨S-(optionally substituted aryl), ¨S-(optionally substituted
heterocyclyl). In
some embodiments, sulfanyl groups include, by way of example, allylsulfanyl (¨
SCHCH2=CH2), n-(iso-butylsulfanyl (¨SCH2CH(CH3)2), 3-thiazol-2-ylsulfanyl,
captopril, 3-carboxy-2-methylpropylsulfanyl, and the like.
[0078] The term "sulfonic acid" refers to the group: ¨S(02)-0H.
[0079] As used herein, a "synergistic therapeutic effect" refers to a greater-
than-additive
therapeutic effect which is produced by a combination of at least two agents,
and which
exceeds that which would otherwise result from the individual administration
of the
agents. For example, lower doses of one or more agents may be used in treating
a disease
or disorder, resulting in increased therapeutic efficacy and decreased side-
effects.
[0080] "Treating" or "treatment" as used herein covers the treatment of a
disease or
medical condition described herein, in a subject, such as a human, and
includes: (i)
inhibiting a disease or disorder, i.e., arresting its development; (ii)
relieving a disease or
disorder, i.e., causing regression of the disorder; (iii) slowing progression
of the disorder;
and/or (iv) inhibiting, relieving, or slowing progression of one or more
symptoms of the
disease or medical condition.
[0081] It is also to be appreciated that the various modes of treatment or
prevention of
medical diseases and conditions as described are intended to mean
"substantial," which
includes total but also less than total treatment or prevention, and wherein
some
biologically or medically relevant result is achieved. The treatment may be a
continuous
prolonged treatment for a chronic disease or a single, or few time
administrations for the
treatment of an acute condition.
33

CA 02920246 2016-02-09
Chroman Derivatives
[0082] As used herein, chroman derivatives include any of the compounds
described
below in Formulas Ia-Hc. In some aspects, chroman derivatives include the
compounds
represented by a general Formula Ia:
R.3
R40 A
a
R.2
R4
Formula Ia
wherein:
-A-B¨ is ¨CH2¨CH2¨; ¨CH=CH¨; ¨CH2-0¨; ¨CH2¨S¨; or ¨
CL¨N¨;
n is 0;
RI is C1-4 alkyl;
R2 is C1-4 alkyl;
R3 is
¨ (CR2),,,C(0)0Ra;
¨ (CR2).N(OH)C(0)NRbRc;
¨ (CR2),,,NRbRe;
¨ (CR2)n,NRb¨S02¨Ra;
¨ (CR2),,S02NRbRc;
¨ (CR2).P(0)(0R)2;
¨ CR=Het, wherein Het is a saturated, partially unsaturated or unsaturated
heterocyclyl optionally substituted with one or more substituents selected
from alkyl,
haloalkyl, hydroxy, alkoxy, halogen, oxo, cyano, nitro, amino, ¨SO2NR2, and ¨
C(0)0R;
cycloalkyl, aryl, or saturated, partially unsaturated or unsaturated
heterocyclyl, all rings optionally substituted with one or more substituents
selected from
alkyl, haloalkyl, hydroxy, alkoxy, halogen, oxo, cyano, nitro, amino, ¨SO2NR2,
and ¨
C(0)0R, with the proviso that the heterocyclyl is not 4,5-dihydro-isoxazol-3-
y1 or
34

CA 02920246 2016-02-09
chroman; or
haloalkenyl;
R4 is hydrogen; optionally substituted C1-4 alkyl; C2-12 alkenyl;
hydroxyalkyl;
acyl; glucoside; phosphoryl; phosphoryloxyalkyl; carboxyalkylcarbonyl;
aminoalkylcarbonyl; or alkylketocarbonyl;
R5 and R6 are independently of each other C1_6 alkyl, C2-12 alkenyl, or
halogen;
m is 0 to 3;
R is hydrogen or C1_4 alkyl;
Ra is hydrogen; optionally substituted C1-4 alkyl; optionally substituted C2-
12
alkenyl; optionally substituted aryl; optionally substituted cycloalkyl; or
optionally
substituted saturated, partially unsaturated or unsaturated heterocyclyl;
RI) and RC are independently of each other hydrogen; C1-4 alkyl; hydroxyalkyl;

aminoalkyl; optionally substituted aryl; optionally substituted benzyl; or
optionally
substituted heterocyclyl; with the proviso that if R5 or R6 are halogen, then
R3 is not
hydrogen or methyl; or
single stereoisomers, mixtures of stereoisomers, or pharmaceutically
acceptable
salts thereof.
[0083] In some aspects, chroman derivatives of the present disclosure include
the
compounds represented by a general Formula lb:
R3
R40 A
Rs RI
=
R6 Formula lb
wherein:
-A-B¨ is ¨CH2¨CH2¨; ¨CH=CH¨; ¨CH2-0¨; ¨CH2¨S¨; or ¨
CH2¨N¨;
n is 0 to 5;
RI is C1-4 alkyl or halo-(C1_4)-alkyl;
R2 is
¨C(0)0Ra;

CA 02920246 2016-02-09
halogen or dihalovinyl;
aryl optionally substituted with one or more substituents selected from alkyl,
haloalkyl, hydroxy, alkoxy, halogen, oxo, cyano, nitro, amino, ¨SO2NR2, and ¨
C(0)0R; or
¨Het, ¨CH-(Het)2; or ¨CH=Het; where Het is saturated, partially unsaturated
or unsaturated heterocyclyl optionally substituted with one or more
substituents selected
from alkyl, haloalkyl, hydroxy, alkoxy, halogen, oxo, cyano, nitro, amino,
¨SO2NR2, and
¨C(0)0R;
R3 is
hydrogen;
halogen;
optionally substituted C1_6 alkyl;
C2-20 alkenyl;
nitro;
¨OR;
¨ (CR2),,,C(0)0Ra;
¨ (CR2)mC(0)NR6Rc;
¨ (CR2),,N(OH)C(0)NleRc;
¨(CR2),nNieRc;
¨(CR2),,Nle¨SCO2¨Ra;
¨ (CR2).S(0)0_2Ra;
¨ (CR2).S02NR6Rc;
¨CR=Het, wherein Het is a saturated, partially unsaturated or unsaturated
heterocyclyl optionally substituted with one or more substituents selected
from alkyl,
haloalkyl, hydroxy, alkoxy, halogen, oxo, cyano, nitro, amino, ¨SO2NR2, and ¨
C(0)0R; or
cycloalkyl, aryl or saturated, partially unsaturated or unsaturated
heterocyclyl,
all rings optionally substituted with C1_6 alkyl, hydroxy, alkoxy, nitro,
amino, or ¨
C(0)0R;
R4 is hydrogen; optionally substituted C1_4 alkyl, C2-12 alkenyl,
hydroxyalkyl,
acyl, glucoside, phosphoryl, phosphoryloxyalkyl, carboxyalkylcarbonyl,
aminoalkylcarbonyl, or alkylketocarbonyl;
R5 and R6 are independently of each other C1-6 alkyl, C2-20 alkenyl, or
halogen;
m is 0 to 3;
36

CA 02920246 2016-02-09
R is hydrogen or C1_4 alkyl;
Ra is hydrogen, optionally substituted C1-4 alkyl, optionally substituted C2-
12
alkenyl, optionally substituted aryl, optionally substituted cycloalkyl, or
optionally
substituted heterocyclyl;
Rb and RC are independently of each other hydrogen, C1-4 alkyl, hydroxyalkyl,
aminoalkyl, optionally substituted aryl, optionally substituted benzyl, or
optionally
substituted heterocyclyl; or Rb and RC taken together with the atom to which
they are
attached may form a 5 to 8 membered aromatic, saturated or unsaturated ring,
optionally
incorporating one additional atom chosen from N, 0, or S and optionally
substituted with
a substituent selected from the group consisting of lower alkyl, halo, cyano,
alkylthio,
lower alkoxy, oxo, phenyl, benzyl and carboxy; with the proviso that if -A-B¨
is ¨
CH2¨Cf2¨ or ¨CH=CH¨, and R3, R5, or R6 are hydrogen or C1_3-alkyl then R2 is
not
¨C(0)0R, halogen, or aryl;
further provided that if R2 is -Het and R3 is C1_6-alkyl, then n=0 and Het is
not
2,2-dimethy111,3]dioxolan-4-yl, oxiran-2-yl, thiazole-2-yl, oxazole-2-yl,
thiazole-4-y1 or
benzofuran-2-y1; and further provided that if R2 is aryl, then R3 is not
optionally
substituted alkyl; or
single stereoisomers, mixtures of stereoisomers, or pharmaceutically
acceptable
salts thereof.
[0084] In some aspects, chroman derivatives of the present disclosure include
the
compounds represented by a general Formula Ic:
R.'
R40soi
A ......õ
13
RI .
lk.
RI; 0 n
R6 Formula Ic
wherein:
-A-B¨ is ¨CH2¨CH/¨; ¨CH=CH¨; ¨CH2-0¨; ¨CH2¨S¨; or ¨
CH2¨N¨;
n is 0;
RI is C1_4 alkyl;
37

CA 02920246 2016-02-09
R2 is C1-20 alkyl or C2-20 alkenyl;
R3 is ¨(CR2).S(0)0_2Ra; wherein Ra is hydrogen; C1-4 alkyl; ¨(CR2).C(0)0R; ¨
(CR2)mC(0)NRbRc; optionally substituted C2-12 alkenyl; optionally substituted
aryl;
optionally substituted cycloalkyl; or optionally substituted saturated,
partially saturated, or
unsaturated heterocyclyl, with the proviso that Ra is not ethyl or
¨(CR2)2C(0)0C2H5, if
RI and R2 are methyl;
R4 is hydrogen; optionally substituted C1-4 alkyl; C2-12 alkenyl;
hydroxyalkyl; acyl;
glucoside; phosphoryl; phosphoryloxyalkyl; carboxyalkylcarbonyl;
aminoalkylcarbonyl;
or alkylketocarbonyl;
R5 and R6 are independently of each other C1-6 alkyl or C2_12 alkenyl;
m is 0 to 3;
R is hydrogen or C1_4 alkyl;
Rb and RC are independently of each other hydrogen, C1-4 alkyl, hydroxyalkyl,
aminoalkyl, optionally substituted aryl, optionally substituted benzyl or
optionally
substituted heterocyclyl; or Rb and RC taken together with the atom to which
they are
attached may form a 5 to 8 membered aromatic, saturated or unsaturated ring,
optionally
incorporating one additional atom chosen from N, 0, or S and optionally
substituted with
a substituent selected from the group consisting of lower alkyl, halo, cyano,
alkylthio,
lower alkoxy, oxo, phenyl, benzyl and carboxy; or single stereoisomers,
mixtures of
stereoisomers, or pharmaceutically acceptable salts thereof.
[0085] In some embodiments, the compound is selected from Formula Ia, and
single
stereoisomers, mixtures of stereoisomers, or pharmaceutically acceptable salts
thereof. In
certain embodiments, R5 and R6 are C1-4 alkyl and R4 is hydrogen. In one
embodiment,
RI, R2, R5 and R6 are methyl and R4 is hydrogen. In another embodiment, R3 is
aryl or
saturated, partially saturated or unsaturated heterocyclyl both optionally
substituted with
one or more substituents selected from alkyl, haloalkyl, hydroxy, alkoxy,
halogen, oxo,
cyano, nitro, amino, ¨SO2NR2 and ¨C(0)0R. In another embodiment, R3 is ¨CR=Het

and Het is an unsaturated heterocyclyl optionally substituted with one or more
substituents
selected from alkyl, haloalkyl, hydroxy, alkoxy, halogen, oxo, cyano, nitro,
amino, ¨
SO2NR2, and ¨C(0)0R.
[0086] In other embodiments, the compound is selected from Formula lb, and in
another
embodiment, R2 is ¨Het selected from furanyl, thienyl, imidazolyl, thiazolyl,
thiazolidine, pyrazolyl, oxazolyl, and thiadiazol-2-yl, optionally substituted
with one or
38

CA 02920246 2016-02-09
more substituents selected from alkyl, haloalkyl, hydroxy, alkoxy, halogen,
oxo, cyano,
nitro, amino, ¨SO2NR2, and ¨C(0)0R. In another embodiment, R2 is ¨CH-(Het)2 or

¨CH=Het, optionally substituted with one or more substituents selected from
alkyl,
haloalkyl, hydroxy, alkoxy, halogen, oxo, cyano, nitro, amino, ¨SO2NR2, and ¨
C(0)0R, particularly R2 is 2,4-dioxo thiazolidin-5-methylene; 2,4-dioxo-
thiazolidin-5-
methyl; 3-methy1-5-oxo-4,5-dihydro-1H-pyrazol-4-y1)-methyl; or di-(3-methy1-5-
oxo-4,5-
dihydro-1H-pyrazol-4-y1)-methyl. In another embodiment n is 0 and R2 is
dihalovinyl.
[0087] In some embodiments, the compound is selected from Formula Ic. In some
embodiments, RI is methyl and R2 is C16 alkyl or C16 alkenyl and R3 is
¨(CR2),SRa; and
in another embodiment RI and R2 are C1-4 alkyl and R3 is ¨(CR2),,,SRa.
[0088] In some embodiments, the compound is selected from:
2,2,7,8-Tetramethy1-5-phenyl-chroman-6-ol;
4-(6-Hydroxy-2,2,7,8-tetramethyl-chroman-5-y1)-benzoic acid methyl ester;
4-(6-Hydroxy-2,2,7,8-tetramethyl-chroman-5-y1)-benzoic acid;
2,2,7,8-Tetramethy1-5-pyridin-4-yl-chroman-6-ol;
2,2,7,8-Tetramethy1-5-pyridin-3-yl-chroman-6-ol;
5-(4-Methanesulfonyl-phenyl)-2,2,7,8-tetramethyl-chroman-6-ol;
5-(4-Dimethylamino-phenyl)-2,2,7,8-tetramethyl-chroman-6-ol;
5-(4-Chloro-phenyl)-2,2,7,8-tetramethyl-chroman-6-ol;
4-(6-Hydroxy-2,2,7,8-tetramethyl-chroman-5-y1)-benzenesulfonamide;
5-(4-Methoxy-phenyl)-2,2,7,8-tetramethyl-chroman-6-ol;
(6-Hydroxy-2,2,7,8-tetramethyl-chroman-5-ylmethyl)-1-hydroxyurea;
2,2,7,8-Tetramethy1-5-(3-nitro-pheny1)-chroman-6-ol;
2,2,7,8-Tetramethy1-5-(4-trifluoromethyl-phenyl)-chroman-6-ol;
5-(4-tert-Butyl-phenyl)-2,2,7,8-tetramethyl-chroman-6-ol;
2,2,7,8-Tetramethy1-5-(3,4,5-trimethoxy-pheny1)-chroman-6-ol;
4-(6-Hydroxy-2,2,7,8-tetramethyl-chroman-5-y1)-benzonitrile;
5-(2,5-Dimethoxy-3,4-dimethyl-pheny1)-2,2,7,8-tetramethyl-chroman-6-ol;
5-(6-Hydroxy-2,2,7,8-tetramethyl-chroman-5-y1)-benzene-1,2,3-triol;
5-(6-Hydroxy-2,2,7,8-tetramethyl-chroman-5-y1)-2,3-dimethyl-benzene-1,4-diol;
5-(2-Chloro-phenyl)-2,2,7,8-tetramethyl-chroman-6-ol;
5-Furan-2-y1-2,2,7,8-tetramethyl-chroman-6-ol;
5-Allylsulfanylmethy1-2,2,8-trimethyl-7-(3-methyl-buty1)-chroman-6-ol;
39

CA 02920246 2016-02-09
5-Cyclopentylsulfanylmethy1-2,2,7,8-tetramethyl-chroman-6-ol;
5-Hexylsulfanylmethy1-2,2,7,8-tetramethyl-chroman-6-ol;
5-Allylsulfanylmethy1-2,2,7,8-tetramethyl-chroman-6-ol;
5-(4,6-Dimethyl-pyrimidin-2-ylsulfanylmethyl)-2,2,7,8-tetramethyl-chroman-6-
ol;
1-[3-(6-Hydroxy-2,2,7,8-tetramethyl-chroman-5-ylmethylsulfany1)-2-methyl-
propionyl[-pyrrolidine-2-carboxylic acid;
4-(6-Hydroxy-2,2,7,8-tetramethyl-chroman-5-ylmethylene)-5-methy1-2-pheny1-
2,4-dihydro-pyrazol-3-one;
4-(6-Hydroxy-2,2,7,8-tetramethyl-chroman-5-ylmethylene)-3-pheny1-4H-isoxazol-
5-one;
4-[4-(6-Hydroxy-2,2,7,8-tetramethyl-chroman-5-ylmethylene)-3-methy1-5-oxo-
4,5-dihydro-pyrazol-1-y1[-benzoic acid;
4-(6-Hydroxy-2,2,7,8-tetramethyl-chroman-5-ylmethylene)-2-methy1-5-propy1-
2,4-dihydro-pyrazol 3-one;
5-Hydroxy-3-(6-hydroxy-2,2,7,8-tetramethyl-chroman-5-ylmethylene)-3H-
benzofuran-2-one;
2,5,7,8-Tetramethy1-2-thiophen-2-yl-chroman-6-ol;
2-(2,5-Dimethyl-thiophen-3-y1)-2,5,7,8-tetramethyl-chroman-6-ol;
2-(2,5-Dimethyl-thiophen-3-y1)-2,7,8-trimethyl-chroman-6-ol;
8-Chloro-2-(2,5-dimethyl-thiophen-3-y1)-2,5,7-trimethyl-chroman-6-- ol;
5-Chloro-2,7,8-trimethy1-2-thiophen-2-yl-chroman-6-ol;
5-[3-(6-Methoxymethoxy-2,7,8-trimethyl-chroman-2-y1)-propylidene]-
thiazolidine-2,4-dione;
5-[3-(6-Hydroxy-2,7,8-trimethyl-chroman-2-ye-propylidene]-thiazolidine-2,4-
dione;
3-[6-Hydroxy-2,7,8-trimethy1-2-(4,8,12-trimethyl-tridecy1)-chroman-5-
ylmethylsulfany11-2-methyl-propionic acid;
2,7,8-Trimethy1-5-(5-methy1-1H-benzoimidazol-2-ylsulfanylmethyl)-2-(4,8,12-
trimethyl-tridecy1)-chroman-6-ol;
2-[6-Hydroxy-2,7,8-trimethy1-2-(4,8,12-trimethyl-tridecy1)-chroman-5-
ylmethylsulfanyl]-ethanesulfonic acid;
5-(4,6-Dimethyl-pyrimidin-2-ylsulfanylmethyl)-2,7,8-trimethyl-2-(4,8,12-
trimethyl-tridecy1)-chroman-6-ol;

CA 02920246 2016-02-09
4-[2-(4,8-Dimethyl-tridecy1)-6-hydroxy-2,7,8-trimethyl-chroman-5-
ylmethylsulfany1]-benzoic acid;
1-13-[6-Hydroxy-2,7,8-trimethy1-2-(4,8,12-trimethyl-tridecy1)-chroman-5-
ylmethylsulfanyl]-2-methyl-propionyll-pyrrolidine-2-carboxylic acid;
2-(2,2-Dichloro-vinyl)-2,5,7,8-tetramethyl-chroman-6-ol;
2-(2,2-Dibromo-vinyl)-2,5,7,8-tetramethyl-chroman-6-ol;
5-(5-Chloro-3-methyl-pent-2-eny1)-2,2,7,8-tetramethyl-chroman-6-ol;
5-Chloro-2-(2,5-dimethyl-thiophen-3-y1)-2,7,8-trimethyl-chroman-6-ol;
2-(3-Chloro-propy1)-5,7-dimethy1-2-thiophen-2-yl-chroman-6-ol;
5-Chloro-2-(2,5-dimethyl-thiazol-4-y1)-2,7,8-trimethyl-chroman-6-ol;
5-Chloro-2-(2,5-dimethyl-thiazol-4-y1)-2,7,8-trimethy1-2H-chromen-6-ol; and
5-Chloro-2-(2,5-dimethyl-thiazol-4-y1)-2,7,8-trimethyl-chroman-6-ol.
[0089] In some aspects, chroman derivatives of the present disclosure include
compounds represented by Formula II:
R4
R30A,
16 3 B
17 2 RI 2
VIP R
Formula II
wherein:
-A-B- is ¨CH2¨(CH2)0_2¨; ¨CH=CH¨; ¨CH2-0¨; ¨CH2¨S¨; or ¨
CH2¨N¨;
n is 0 to 5;
V is C7_12-bicyclo[a.b.c]alkyl; C7_12-bicyclo[a.b.c]alkenyl; C7-12-
heterobicyclo[a.b.c]alkyl; or C7_12-heterobicyclo[a.b.c]alkenyl; and a, b, and
c are 0 to 6;
and wherein the bicyclo ring is optionally substituted with one or more
substituents
selected from C1-6 alkyl, halogen, haloalkyl, carboxy, alkoxycarbonyl, cyano,
hydroxy,
alkoxy, thiol, and oxo;
RI is C1_6 alkyl;
41

CA 02920246 2016-02-09
R2 is C1-20 alkyl; optionally substituted C2-20 alkenyl; halogen; hydroxy;
alkoxy;
acyl; ¨C(0)0R; ¨S(0)20R; ¨NR'R"; ¨NH¨C(=NH2)¨NR'R"; ¨N¨SO2R; ¨
NHC(0)NR'R"; ¨N(OH)C(0)NR'R"; ¨SO2NR'R"; ¨C(0)NR'R"; ¨S(0) 0_2R"'; ¨
PO(OR)2; triphenylphosphonium; trialkylphosphonium; optionally substituted
aryl;
optionally substituted heterocyclyl;
R3 is hydrogen; optionally substituted C1-20 alkyl; C2-20 alkenyl;
hydroxyalkyl;
acyl; glucoside; phosphoryl; phosphoryloxyalkyl; carboxyalkylcarbonyl;
aminoalkylcarbonyl; or alkylketocarbonyl;
R4 is hydrogen; halogen; nitro; cyano; optionally substituted alkyl; aryl,
aralkyl,
heterocyclyl or heterocyclylalkyl, all optionally substituted with alkyl,
hydroxy, alkoxy,
nitro, acyl, amino, oxo, or ¨C(0)0R; optionally substituted alkenyl; hydroxy;
alkoxy;
nitro; ¨C(0)0R; ¨C(0)NR'R"; ¨NR'R"; ¨NHC(0)NR'R"; ¨NR'¨S02¨R; ¨NH¨
C(=NH2)¨NR'R"; ¨SO2NR'R", or ¨P(0)(0R)2; or
R3 and R4 taken together with the atoms to which they are attached may form a
heterocyclic ring;
R is hydrogen; optionally substituted alkyl; optionally substituted aryl;
optionally
substituted arylalkyl; optionally substituted cycloalkyl; or optionally
substituted
heterocyclyl;
R' and R" are independently of each other hydrogen; C1_6 alkyl; hydroxyalkyl;
aminoalkyl; optionally substituted aryl; or optionally substituted benzyl; or
R' and R"
taken together with the atom to which they are attached may form a 5 to 8
membered
aromatic, saturated or unsaturated ring, optionally incorporating one
additional atom
chosen from N, 0, or S and optionally substituted with a substituent selected
from the
group consisting of C1_6 alkyl, halo, cyano, alkylthio, lower alkoxy, phenyl,
benzyl and
carboxy; and
R'" is optionally substituted C1-6 alkyl; optionally substituted aryl; or
optionally
substituted heterocyclyl;
or single stereoisomers and mixtures of stereoisomers, or the pharmaceutically

acceptable salts thereof.
[0090] In one embodiment, R3 is hydrogen. In another embodiment, R4 is
hydrogen, C1_
6 alkyl optionally substituted with halogen, haloalkyl, hydroxy, alkoxy,
amino, sulfanyl,
carboxy, nitro or cyano; or C2-12 alkenyl optionally substituted with halogen,
haloalkyl,
hydroxy, alkoxy, amino, sulfanyl, carboxy, nitro or cyano.
42

CA 02920246 2016-02-09
[0091] In another embodiment, V is a bicyclo[2.2.1]heptane ring and the
compound is
represented by Formula Ha:
R4
R30 A
4 10...,
0 11
RI
nR2
(10:n
Formula Ha
wherein -A-B- is ¨CH2¨CI-2¨ or ¨CH=CH¨; RI, R2, R3, R4, and n are as defined
in
Formula II;
m is in each occurrence independently 0-3;
and R5 is selected from optionally substituted C1_6-alkyl, halogen, haloalkyl,

carboxy, alkoxycarbonyl, cyano, hydroxy, alkoxy, thiol, and oxo. In some
embodiments,
V is a bicyclo[2.2.1]heptane ring and R2 is C1-6 alkyl; halogen; hydroxy;
alkoxy; ¨
C(0)0R; ¨SO2NR'R"; ¨C(0)NR'R"; ¨SR; ¨PO(OR)2; triphenylphosphonium;
trialkylphosphonium; phenyl optionally substituted with C1_6 alkyl, halogen,
haloalkyl,
carboxy, alkoxycarbonyl, cyano, hydroxy, alkoxy, thiol, and oxo; or
heterocyclyl selected
from morpholine, piperidine, piperazine, thiazole, thiazolidine, isothiazole,
oxazole,
isoxazole, pyrazole, pyrazolidine, pyrazoline, imidazole, imidazolidine,
benzothiazole,
pyridine, pyrazine, pyrimidine, pyridazine, pyrrole, pyrrolidine, quinoline,
quinazoline,
purine, carbazole, benzimidazole, thiophene, benzothiophene, pyran,
tetrahydropyran,
benzopyran, furan, tetrahydrofuran, indole, indoline, indazole, xanthene,
thioxanthene,
acridine, and quinuclidine, optionally substituted with C1_6 alkyl, halogen,
haloalkyl,
carboxy, alkoxycarbonyl, cyano, hydroxy, alkoxy, thiol, and oxo. In certain
embodiments,
V is a bicyclo[2.2.1]heptane ring, R2 is ¨COOR and R is hydrogen or C1_6
alkyl. In
another embodiment, V is a bicyclo[2.2.1]heptane ring, RI and R2 are C1-6
alkyl and m and
n are 0.
[0092] In another embodiment, V is a bicyclo[2.2.2]octane ring and the
compound is
represented by Formula Ifb:
43

CA 02920246 2016-02-09
R4
R30
B
R1
IF 0"-----<("--- (R5). 1104
(R5). Formula IIb
wherein -A-B- is ¨CH2¨CH2¨ or ¨CH=CH¨; RI, R2, R3, R4, and n are as defined in

Formula II;
m is in each occurrence independently 0-3; and
R5 is selected from optionally substituted C1_6-alkyl, halogen, haloalkyl,
carboxy,
alkoxycarbonyl, cyano, hydroxy, alkoxy, thiol, and oxo. In certain
embodiments, V is a
bicyclo[2.2.2]octane ring and R2 is C1_6 alkyl; halogen; hydroxy; alkoxy;
¨C(0)0R; ¨
SO2NR'R"; ¨C(0)NR'R"; ¨SR"; ¨PO(OR)2; triphenylphosphonium;
trialkylphosphonium; phenyl optionally substituted with C1_6 alkyl, halogen,
haloalkyl,
carboxy, alkoxycarbonyl, cyano, hydroxy, alkoxy, thiol, and oxo; or
heterocyclyl selected
from morpholine, piperidine, piperazine, thiazole, thiazolidine, isothiazole,
oxazole,
isoxazole, pyrazole, pyrazolidine, pyrazoline, imidazole, imidazolidine,
benzothiazole,
pyridine, pyrazine, pyrimidine, pyridazine, pyrrole, pyrrolidine, quinoline,
quinazoline,
purine, carbazole, benzimidazole, thiophene, benzothiophene, pyran,
tetrahydropyran,
benzopyran, furan, tetrahydrofuran, indole, indoline, indazole, xanthene,
thioxanthene,
acridine, and quinuclidine, optionally substituted with C1_6 alkyl, halogen,
haloalkyl,
carboxy, alkoxycarbonyl, cyano, hydroxy, alkoxy, thiol, and oxo. In some
embodiments,
V is a bicyclo[2.2.2]octane ring, R2 is ¨COOR, and R is hydrogen or C1_6
alkyl. In
another embodiment, V is a bicyclo[2.2.2]octane ring and Rl and R2 are
independently of
each other C1-6 alkyl and m and n are 0.
[0093] In another embodiment, V is a bicyclo[3.2.2]nonane ring and the
compound is
represented by Formula IIc:
44

CA 02920246 2016-02-09
R4
R30 A
31
0
(Obi ______
\
Formula Ile:
wherein -A-B- is ¨CH2¨CH2¨ or ¨CH=CH¨; RI, R2, R3, R4, and n are as defined in

Formula II;
m is in each occurrence independently 0-3; and
R5 is selected from optionally substituted C1_6-alkyl, halogen, haloalkyl,
carboxy,
alkoxycarbonyl, cyano, hydroxy, alkoxy, thiol, and oxo. In some embodiments, V
is a
bicyclo[3.2.2]nonane ring and R2 is C1_6 alkyl; halogen; hydroxy; alkoxy;
¨C(0)0R; ¨
SO2NR'R"; ¨C(0)NRR"; ¨SW"; ¨PO(OR)2; triphenylphosphonium;
trialkylphosphonium; phenyl optionally substituted with C1_6 alkyl, halogen,
haloalkyl,
carboxy, alkoxycarbonyl, cyano, hydroxy, alkoxy, thiol, and oxo; or
heterocyclyl selected
from morpholine, piperidine, piperazine, thiazole, thiazolidine, isothiazole,
oxazole,
isoxazole, pyrazole, pyrazolidine, pyrazoline, imidazole, imidazolidine,
benzothiazole,
pyridine, pyrazine, pyrimidine, pyridazine, pyrrole, pyrrolidine, quinoline,
quinazoline,
purine, carbazole, benzimidazole, thiophene, benzothiophene, pyran,
tetrahydropyran,
benzopyran, furan, tetrahydrofuran, indole, indoline, indazole, xanthene,
thioxanthene,
acridine, and quinuclidine, optionally substituted with C1_6 alkyl, halogen,
haloalkyl,
carboxy, alkoxycarbonyl, cyano, hydroxy, alkoxy, thiol, and oxo. In some
embodiments,
V is a bicyclo[3.2.2]nonane ring, R2 is ¨COOR, and R is hydrogen or C I -6
alkyl. In
another embodiment, V is a bicyclo[3.2.2]nonane ring, RI and R2 are
independently of
each other C1-6 alkyl and n is 0.
[0094] In another embodiment, -A-B- is ¨CH2¨CH2¨ and n is 2 or 3, and in a
further
embodiment, -A-B- is ¨CH2¨CH2¨; n is 2 or 3 and V is a bicyclo[2.2.1]heptane
ring, a
bicyclo[2.2.2]octane ring, or a bicyclo[3.2.2]nonane ring. In another
embodiment, -A-B-
is ¨CH2=CH2¨ and n is 2 or 3, and in a further embodiment -A-B- is ¨CH2=CH1¨
and
n is 2 or 3, and V is a bicyclo[2.2.1Theptane ring, a bicyclo[2.2.2]octane
ring, or a
bicyclo[3.2.2]nonane ring.

CA 02920246 2016-02-09
[0095] In another embodiment -A-B- is ¨CH2¨CH2¨; n is 2 or 3; R2 is ¨C(0)0R,
and R is hydrogen or C1-6 alkyl. In another embodiment, -A-B- is ¨CH2=CR2¨, n
is 2 or
3; R2 is ¨C(0)0R, and R is hydrogen or C1_6 alkyl.
[0096] In another embodiment RI and R2 are independently of each other C1-6
alkyl and
n is 0, particularly RI and R2 are independently of each other C1_6 alkyl, n
is 0, and -A-B-
is ¨CH2¨CH2¨. In another embodiment, RI and R2 are independently of each other
C1-
6 alkyl, n is 0, and -A-B- is ¨CH2=CH2¨.
[0097] In another embodiment the present disclosure relates to a
pharmaceutical
composition comprising a chroman derivative compound of Formula II or
stereoisomers,
mixtures of stereoisomers or pharmaceutically acceptable salts thereof,
admixed with a
pharmaceutically acceptable excipient, wherein the compound is selected from
the group
consisting of:
HO 40
lei 0
HO io
likill, 0 N.
0
.-
HO
,
-.. COOR and
0 -,
Jo,
' ithõ.
HO
W.
0
wherein R is hydrogen or C1-4 alkyl.
46

CA 02920246 2016-02-09
[0098] In some embodiments, the compound of Formula II is selected from:
3-(6-Hydroxy-2-methy1-3,4,7,8,9,10-hexahydro-7,10-methano-2H-
benzo[h]chromen-2-y1)-propionic acid methyl ester;
3-(6-Hydroxy-2-methy1-3,4,7,8,9,10-hexahydro-7,10-methano-2H-
benzo[h]chromen-2-y1)-propionic acid;
3-(6-Hydroxy-2-methy1-3,4,7,8,9,10-hexahydro-7,10-propano-2H-
benzo[h]chromen-2-y1)-propionic acid methyl ester;
2-Methy1-2-[3-(thiazol-2-ylsulfany1)-propyl]-3,4,7,8,9,10-hexahydro-7,10-
methano-2H-benzo[h]chromen-6-ol;
[3-(6-Hydroxy-2-methy1-3,4,7,8,9,10-hexahydro-7,10-methano-2H-
benzo[h]chromen-2-y1)-propyll-phosphonic acid dimethyl ester;
[3-(6-Hydroxy-2-methy1-3,4,7,8,9,10-hexahydro-7,10-methano-2H-
benzo[h]chromen-2-y1)-propyl]-phosphonic acid;
4-(6-Hydroxy-2-methy1-3,4,7,8,9,10-hexahydro-7,10-methano-2H-
benzo[h]chromen-2-y1)-butane-1-sulfonic acid dimethylamide;
2-(3-Hydroxy-propy1)-2-methyl-3,4,7,8,9,10-hexahydro-7,10-methano-2H-
benzo[h]chromen-6-ol;
3- [7-(2-Methoxycarbonyeethy1-2,7-dimethy1-2,7,9, 10, 1 1 , 1 2-hexahydro- 1,8-
dioxa-
9:12-methano-triphenylen-2-A-propionic acid methyl ester;
3-[6-Hydroxy-2-methy1-5-(3-methyl-but-2-eny1)-3,4,7,8,9,10-hexahydro-7,10-
methano-2H-benzo[h]chromen-2-y1]-propionic acid;
2-(3-Hydroxy-propy1)-2-methyl-3,4,7,8,9,10-hexahydro-7,10-propano-2H-
benzo[h]chromen-6-ol;
3-(6-Hydroxy-2-methy1-3,4,7,8,9,10-hexahydro-7,10-propano-2H-
benzo[h]chromen-2-y1)-propionic acid;
3-(6-Hydroxy-2-methy1-3,4,7,8,9,10-hexahydro-7,10-methano-2H-
benzo[h]chromen-2-y1)-1-morpholin-4-yl-propan-1-one;
2-Methy1-2-(3-piperidin-1-yl-propy1)-3,4,7,8,9,10-hexahydro-7,10-methano-2H-
benzo[h[chromen-6-ol;
2-(3-Chloro-propy1)-2-methy1-3,4,7,8,9,10-hexahydro-7,10-methano-2H-
benzo[h[chromen-6-ol;
47

CA 02920246 2016-02-09
1-13-[3-(6-Hydroxy-2-methy1-3,4,7,8,9,10-hexahydro-7,10-methano-2H-
benzo[h]chromen-2-y1)-propylsulfany11-2-methyl-propionyl } -pyrrolidine-2-
carboxylic
acid;
243-(Benzothiazol-2-ylsulfany1)-propyl]-2-methyl-3,4,7,8,9,10-hexahydro-7,10-
methano-2H-benzo[h]chromen-6-ol;
2-[3-(2-Hydroxy-ethylamino)-propy1]-2-methy1-3,4,7,8,9,10-hexahydro-7,10-
methano-2H-benzo[h]chromen-6-ol;
2-[3-(2-Dimethylamino-ethylamino)-propy1]-2-methy1-3,4,7,8,9,10-hexahydro-
7,10-methano-2H-benzo[h]chromen-6-ol;
2,6:9,1 2-Dimethano-9, 1 0, 1 1 , 1 2-tetrahydro-2-methylnaphtho [1 ,2-
b]oxocan-8-ol;
2-(2-Chloro-ethyl)-2-methy1-3,4,7,8,9,10-hexahydro-7,10-methano-2H-
benzo[h]chromen-6-ol;
2-Methy1-2-[3-(pyridine-4-ylsulfany1)-propyl]-3,4,7,8,9,10-hexahydro-7,10-
methano-2H-benzo[h]chromen-6-ol;
2-(3-isobutylsulfanyl-propy1)-2-methy1-3,4,7,8,9,10-hexahydro-7,10-methano-2H-
benzo[h]chromen-6-ol;
2-Methy1-2-thiophen-2-y1-3,4,7,8,9,10-hexahydro-7,10-methano-2H-
benzo[h]chromen-6-ol;
2-Methy1-2-thiazol-2-y1-3,4,7,8,9,10-hexahydro-7,10-methano-2H-
benzo[hichromen-6-ol;
3-(6-Hydroxy-2-methy1-3,4,7,8,9,10-hexahydro-7,10-ethano-2H-
benzo[h]chromen-2-y1)-propionic acid;
3-(6-Hydroxy-2-methy1-3,4,7,8,9,10-hexahydro-7,10-ethano-2H-
benzo[h[chromen-2-y1)-propionic acid methyl ester;
2-(3-Chloro-propy1)-2-methy1-3,4,7,8,9,10-hexahydro-7,10-ethano-2H-
benzo[h]chromen-6-ol;
2-(3-Chloro-propy1)-2,5-dimethy1-3,4,7,8,9,10-hexahydro-7,10-ethano-2H-
benzo[h]chromen-6-ol;
2-[3-(Benzothiazol-2-ylsulfany1)-propyl]-2-methyl-3,4,7,8,9,10-hexahydro-7,10-
ethano-2H-benzo[hichromen-6-ol;
3-(6-Hydroxy-2-methy1-3,4,7,8,9,10-hexahydro-7,10-methano-2H-
benzo[h]chromen-2-y1)-propionic acid, sodium salt;
3-[6-Hydroxy-2-methy1-5-(3-methyl-but-2-eny1)-3,4,7,8,9,10-hexahydro-7,10-
ethano-2H-benzo[h]chromen-2-A-propionic acid;
48

CA 02920246 2016-02-09
Sodium salt of 3-(6-Hydroxy-2-methy1-3,4,7,8,9,10-hexahydro-7,10-ethano-2H-
benzo[h]chromen-2-y1)-propionic acid;
3-(6-Hydroxy-2-methy1-3,4,7,8,9,10-hexahydro-7,10-ethano-2H-
benzo[h]chromen-2-ye-propionic acid benzyl ester;
3-(5-Bromo-6-hydroxy-2-methy1-3,4,7,8,9,10-hexahydro-7,10-ethano-2H-
benzo[h]chromen-2-y1)-propionic acid;
5-Bromo-2-methy1-2-(3-piperidin-1-yl-propy1)-3,4,7,8,9,10-hexahydro-7,10-
ethano-2H-benzo[h]chromen-6-ol;
5-Methoxy-2,2-dimethy1-3,4,7,8,9,10-hexahydro-7,10-methano-2H-
benzo[h]chromen-6-ol;
3-(6-Hydroxy-2-methy1-3,4,7,8,9,10-hexahydro-7,10-ethano-2H-
benzo[h]chromen-2-y1)-1-piperidin-1-yl-propan-1-one;
N-(2-Dimethylamino-ethyl)-3-(6-hydroxy-2-methy1-3,4,7,8,9,10-hexahydro-7,10-
ethano-2H-benzo[h]chromen-2-y1)-propionamide;
2-Methy1-2-(3-piperidin-1-yl-propy1)-3,4,7,8,9,10-hexahydro-7,10-ethano-2H-
benzo[h]chromen-6-ol;
3-(6-Hydroxy-2-methy1-3,4,7,8,9,10-hexahydro-7,10-ethano-2H-
benzo[h]chromen-2-y1)-1-morpholin-4-yl-propan-1-one;
2-[3-(2-Dimethylamino-ethylamino)-propy1]-2-methyl-3,4,7,8,9,10-hexahydro-
7,10-ethano-2H-benzo[h]chromen-6-ol;
2-Methy1-243-(pyridine-4-sulfony1)-propyll-3,4,7,8,9,10-hexahydro-7,10-
methano-2H-benzo[h]chromen-6-ol;
2,2,-Dimethy1-3,4,7,8,9,10-hexahydro-7,10-methano-2H-benzo[h]chromen-6-ol;
2,2-Dimethy1-3,4,7,8,9,10-hexahydro-7,10-methano-2H-benzo[h]chromen-6-ol;
2,2-Dimethy1-5-(3-methyl-but-2-eny1)-3,4,7,8,9,10-hexahydro-7,10-methano-2H-
benzo[h]chromen-6-ol;
Acetic acid 2,2-dimethy1-5-(3-methyl-but-2-eny1)-3,4,7,8,9,10-hexahydro-7,10-
methano-2H-benzo[h]chromen-6-y1 ester;
2,2-Dimethy1-5-(3-methyl-buty1)-3,4,7,8,9,10-hexahydro-7,10-methano-2H-
benzo[h]chromen-6-ol;
5-Bromo-2,2-dimethy1-3,4,7,8,9,10-hexahydro-7,10-methano-2H-
benzo[h]chromen-6-ol;
Acetic acid 2,2-dimethy1-5-(3-methyl-buty1)-3,4,7,8,9,10-hexahydro-7,10-
methano-2H-benzo[h]chromen-6-y1 ester;
49

CA 02920246 2016-02-09
2,2-Dimethy1-3,4,7,10-tetrahydro-7,10-methano-2H-benzo[h]chromen-6-ol;
2,2-Dimethy1-3,4,7,8,9,10-hexahydro-7,10-ethano-2H-benzo[h]chromen-6-ol;
2,2-Dimethy1-5-(3-methyl-but-2-eny1)-7,8,9,10-tetrahydro-7,10-methano-2H-
benzo[h]chromen-6-ol;
2,2-Dimethy1-5-(3-methyl-but-2-eny1)-3,4,7,10-tetrahydro-7,10-ethano-2H-
benzo[h]chromen-6-ol;
2,2,7 ,7-Tetramethy1-9,12-ethano-2,3,4 ,5,6,7,9,10,11,12-decahydro-1,8-dioxa-
triphenylene;
Acetic acid 2,2-dimethy1-3,4,7,8,9,10-hexahydro-7,10-ethano-2H-
benzo[h]chromen-6-y1 ester;
Phosphoric acid mono-(2,2-dimethy1-3,4,7,8,9,10-hexahydro-7,10-methano-2H-
benzo[h]chromen--6-y1) ester, disodium salt;
2,2-Dimethy1-7,8,9,10-tetrahydro-7,10-ethano-2H-benzo[h]chromen-6-ol;
Phosphoric acid mono-(2,2-dimethy1-3,4,7,8,9,10-hexahydro-7,10-ethano-2H-
benzo[h]chromen-6-y1) ester, disodium salt;
2,2-Dimethy1-5-(3-methyl-buty1)-3,4,7,8,9,10-hexahydro-7,10-ethano-2H-
benzo[h]chromen-6-ol;
2,2,5-Trimethy1-3,4,7,8,9,10-hexahydro-7,10-ethano-2H-benzo[h]chromen-6-ol;
6-Hydroxy-2,2-dimethy1-3,4,7,8,9,10-hexahydro-7,10-methano-2H-
benzo[h]chromene-5-carbonitrile;
2,2-Dimethy1-5-(3-methyl-but-2-eny1)-3,4,7,8,9,10-hexahydro-7,10-ethano-2H-
benzo[h]chromen-6-ol;
5-Hydroxymethy1-2,2-dimethy1-3,4,7,8,9,10-hexahydro-7,10-methano-2H-
benzo[h]chromen-6-ol;
5-Bromo-2,2-dimethy1-3,4,7,8,9,10-hexahydro-7,10-ethano-2H-benzo[h]ehromen-
6-01;
2,2-Dimethy1-542-(tetrahydro-pyran-4-ylidene)-ethy11-3,4,7,8,9,10-hexahydro-
7,10-ethano-2H-benzo[h]chromen-6-ol;
5-(2-Cyclohexylidene-ethyl)-2,2-dimethy1-3,4,7,8,9,10-hexahydro-7,10-ethano-
2H-benzo[h]chromen-6-ol;
1-(6-Hydroxy-2,2-dimethy1-3,4,7,8,9,10-hexahydro-7,10-ethano-2H-
benzo[h]chromen-5-y1)-ethanone;
4-(6-Acetoxy-2,2-dimethy1-3,4,7,8,9,10-hexahydro-2H-benzo[h]chromen-5-y1)-4-
oxo-butyric acid;

CA 02920246 2016-02-09
2,2-Dimethy1-5-nitro-3,4,7,8,9,10-hexahydro-7,10-methano-2H-benzo[h]chromen-
6-01;
Acetic acid 2,2-dimethy1-5-(3-methyl-but-2-eny1)-7,8,9,10-tetrahydro-7,10-
methano-2H- benzo[h]chromen-6-y1 ester;
5-(6-Hydroxy-2,2-dimethy1-3,4,7,8,9,10-hexahydro-7,10-methano-2H-
benzo[h]chromen-5-ylmethylene)-thiazolidine-2,4-dione;
5-Hydroxy-3-(6-hydroxy-2,2-dimethy1-3,4,7,8,9,10-hexahydro-7,10-methano-2H-
benzo[h]chromen-5-ylmethylene)-3H-benzofuran-2-one;
Phosphoric acid dibenzyl ester 2,2-dimethy1-3,4,7,8,9,10-hexahydro-7,10-
methano-2H-benzo[h]chromen-6-y1 ester;
Phosphoric acid dibenzyl ester 2,2-dimethy1-3,4,7,8,9,10-hexahydro-7,10-ethano-

2H-benzo[h]chromen-6-y1 ester;
10-Methoxy-2,2-dimethy1-3,4,7,8,9,10-hexahydro-7,10-ethano-2H-
benzo[h]chromen-6-ol;
4-[4-(6-Hydroxy-2,2-dimethy1-3,4,7,8,9,10-hexahydro-7,10-methano-2H-
benzo[h]chromen-5-ylmethylene)-3-methy1-5-oxo-4,5-dihydro-pyrazol- 1 -yl] -
benzoic acid;
4-(6-Hydroxy-2,2-dimethy1-3,4,7,8,9,10-hexahydro-7,10-methano-2H-
benzo[h]chromen-5-ylmethylene)-2-methy1-5-propy1-2,4-dihydro-pyrazol-3-one;
(6-Hydroxy-2,2-dimethy1-3,4,7,8,9,10-hexahydro-7,10-methano-2H-
benzo[h]chromen-5-ylmethyl)-1-hydroxyurea;
5-(1-Hydroxy-ethyl)-2,2-dimethy1-3,4,7,8,9,10-hexahydro-7,10-methano-2H-
benzo[h]chromen-6-ol;
Dimethylamino-acetic acid 2,2-dimethy1-3,4,7,8,9,10-hexahydro-7,10-ethano-2H-
benzo[h]chromen-6-y1 ester; and
stereoisomers, mixture of stereoisomers or pharmaceutically acceptable salts
thereof.
[0099] Figure 2 shows exemplary structures of bicycloalkyl chroman derivatives
of the
present technology.
[0100] In some embodiments, the chroman derivative compounds of the present
technology are capable of forming acid and/or base salts by virtue of the
presence of
amino and/or carboxyl groups or groups similar thereto. Pharmaceutically
acceptable base
addition salts can be prepared from inorganic and organic bases. Salts derived
from
inorganic bases, include by way of example only, sodium, potassium, lithium,
ammonium,
51

CA 02920246 2016-02-09
calcium and magnesium salts. Salts derived from organic bases include, but are
not
limited to, salts of primary, secondary and tertiary amines, such as alkyl
amines, dialkyl
amines, trialkyl amines, substituted alkyl amines, di(substituted alkyl)
amines,
tri(substituted alkyl) amines, alkenyl amines, dialkenyl amines, trialkenyl
amines,
substituted alkenyl amines, di(substituted alkenyl) amines, tri(substituted
alkenyl) amines,
cycloalkyl amines, di(cycloalkyl) amines, tri(cycloalkyl) amines, substituted
cycloalkyl
amines, disubstituted cycloalkyl amine, trisubstituted cycloalkyl amines,
cycloalkenyl
amines, di(cycloalkenyl) amines, tri(cycloalkenyl) amines, substituted
cycloalkenyl
amines, disubstituted cycloalkenyl amine, trisubstituted cycloalkenyl amines,
aryl amines,
diary) amines, triaryl amines, heterocyclic amines, diheterocyclic amines,
triheterocyclic
amines, mixed di- and tri-amines where at least two of the substituents on the
amine are
different and are selected from the group consisting of alkyl, substituted
alkyl, alkenyl,
substituted alkenyl, cycloalkyl, substituted cycloalkyl, cycloalkenyl,
substituted
cycloalkenyl, aryl, heterocyclic, and the like. Also included are amines where
the two or
three substituents, together with the amino nitrogen, form a heterocyclic
group. Specific
examples of suitable amines include, by way of example only, isopropylamine,
trimethyl
amine, diethyl amine, tri(iso-propyl) amine, tri(n-propyl) amine,
ethanolamine, 2-
dimethylaminoethanol, tromethamine, lysine, arginine, histidine, caffeine,
procaine,
hydrabamine, choline, betaine, ethylenediamine, glucosamine, N-
alkylglucamines,
theobromine, purines, piperazine, piperidine, morpholine, N-ethylpiperidine,
and the like.
[0101] Pharmaceutically acceptable acid addition salts may be prepared from
inorganic
and organic acids. Salts derived from inorganic acids include hydrochloric
acid,
hydrobromic acid, sulfuric acid, nitric acid, phosphoric acid, and the like.
Salts derived
from organic acids include acetic acid, propionic acid, glycolic acid, pyruvic
acid, oxalic
acid, malic acid, malonic acid, succinic acid, maleic acid, fumaric acid,
tartaric acid, citric
acid, benzoic acid, cinnamic acid, mandelic acid, methanesulfonic acid,
ethanesulfonic
acid, p-toluene-sulfonic acid, salicylic acid, and the like.
Mitochondrial Diseases
[0102] Mitochondrial dysfunction plays a role both in the pathogenesis of late-
onset
neurodegenerative disorders, including Parkinson disease (PD), Huntington
disease (HD),
Alzheimer disease (AD), and amyotrophic lateral sclerosis (ALS), and in the
pathogenesis
of aging.
52

CA 02920246 2016-02-09
[0103] Mitochondrial diseases are a clinically heterogeneous group of
disorders that
arise as a result of dysfunction of the mitochondrial respiratory chain. The
mitochondrial
respiratory chain is the only metabolic pathway in the cell that is under the
dual control of
the mitochondrial genome (mtDNA) and the nuclear genome (nDNA). While some
mitochondrial disorders only affect a single organ (e.g., the eye in Leber
hereditary optic
neuropathy [LHON]), many involve multiple organ systems and often present with

prominent neurologic and myopathic features. Mitochondrial disorders may
present at any
age.
[0104] Mutations in mtDNA can be divided into those that impair mitochondrial
protein
synthesis in toto and those that affect any one of the 13 respiratory chain
subunits encoded
by mtDNA.
(i) Heteroplasmy and threshold effect. Each cell contains hundreds or
thousands of
mtDNA copies, which, at cell division, distribute randomly among daughter
cells. In
normal tissues, all mtDNA molecules are identical (homoplasmy). Deleterious
mutations
of mtDNA usually affect some but not all mtDNAs within a cell, a tissue, or an
individual
(heteroplasmy). The clinical expression of a pathogenic mtDNA mutation is
largely
determined by the relative proportion of normal and mutant mtDNA genomes in
different
tissues. A minimum critical number of mutant mtDNAs is required to cause
mitochondrial dysfunction in a particular organ or tissue (threshold effect).
(ii) Mitotic segregation. At cell division, the proportion of mutant mtDNAs in

daughter cells may shift and the phenotype may change accordingly. This
phenomenon,
called mitotic segregation, explains how certain patients with mtDNA-related
disorders
may actually manifest different mitochondrial diseases at different stages of
their lives.
(iii) Maternal inheritance. At fertilization, all mtDNA derives from the
oocyte.
Therefore, the mode of transmission of mtDNA and of mtDNA point mutations
(single
deletions of mtDNA are usually sporadic events) differs from Mendelian
inheritance. A
mother carrying a mtDNA point mutation will pass it on to all her children
(males as well
as females), but only her daughters will transmit it to their progeny. A
disease expressed
in both sexes but with no evidence of paternal transmission is strongly
suggestive of a
mtDNA point mutation.
[0105] Many individuals with a mutation of mtDNA display a cluster of clinical
features
that fall into a discrete clinical syndrome, such as the Kearns-Sayre syndrome
(KSS),
chronic progressive external ophthalmoplegia, mitochondrial encephalomyopathy
with
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lactic acidosis and stroke-like episodes (MELAS), myoclonic epilepsy with
ragged-red
fibers (MERRF), neurogenic weakness with ataxia and retinitis pigmentosa
(NARP), or
Leigh syndrome (LS). However, considerable clinical variability exists and
many
individuals do not fit neatly into one particular category, which is well-
illustrated by the
overlapping spectrum of disease phenotypes (including mitochondrial recessive
ataxia
syndrome (MIRAS) resulting from mutation of the nuclear gene POLG, which has
emerged as a major cause of mitochondrial disease.
[0106] Disorders due to mutations in nDNA are more abundant not only because
most
respiratory chain subunits are nucleus-encoded but also because correct
assembly and
functioning of the respiratory chain require numerous steps, all of which are
under the
control of nDNA. These steps (and related diseases) include: (i) synthesis of
assembly
proteins; (ii) intergenomic signaling; (iii) mitochondrial importation of nDNA-
encoded
proteins; (iv) synthesis of inner mitochondrial membrane phospholipids; (v)
mitochondrial
motility and fission.
[0107] Common clinical features of mitochondrial disease ¨ whether involving a

mitochondrial or nuclear gene ¨ include ptosis, external ophthalmoplegia,
proximal
myopathy and exercise intolerance, cardiomyopathy, sensorineural deafness,
optic
atrophy, pigmentary retinopathy, and diabetes mellitus. Common central nervous
system
findings are fluctuating encephalopathy, seizures, dementia, migraine, stroke-
like
episodes, ataxia, and spasticity. A high incidence of mid- and late pregnancy
loss is a
common occurrence that often goes unrecognized.
[0108] Mitochondrial myopathies are characterized by excessive proliferation
of normal-
or abnormal-looking mitochondria in the muscle of patients with weakness or
exercise
intolerance. These abnormal fibers are referred to as "ragged red fibers"
because the areas
of mitochondrial accumulation appear purplish when contacted with the modified
Gomori
trichrome stain. Many patients with ragged red fibers often exhibit
encephalomyopathy.
However, the absence of ragged red fibers in a biopsy does not exclude a
mitochondrial
etiology.
[0109] Diagnosis. In some subjects, the clinical picture is characteristic of
a specific
mitochondrial disorder (e.g., LHON, NARP, or maternally inherited Leigh
Syndrome),
and the diagnosis can be confirmed by identification of a mtDNA mutation on
molecular
genetic testing of DNA extracted from a blood sample. In many individuals,
such is not
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CA 02920246 2016-02-09
the case, and a more structured approach is needed, including family history,
blood and/or
CSF lactate concentration, neuroimaging, cardiac evaluation, and molecular
genetic
testing for a mtDNA or nuclear gene mutation. Approaches to molecular genetic
testing of
a proband to consider are serial testing of single genes, multi-gene panel
testing
(simultaneous testing of multiple genes), and/or genomic testing (e.g.,
sequencing of the
entire mitochondrial genome exome or exome sequencing to identify mutation of
a nuclear
gene). In many individuals in whom molecular genetic testing does not yield or
confirm a
diagnosis, further investigation of suspected mitochondrial disease can
involve a range of
different clinical tests, including muscle biopsy for respiratory chain
function.
[0110] A brief nonexhaustive summary of the various mitochondrial diseases or
disorders is provided below.
Alexander Disease
[0111] In decreasing order of frequency, 3 forms of Alexander disease are
recognized,
based on age of onset: infantile, juvenile, and adult. Younger patients
typically present
with seizures, megalencephaly, developmental delay, and spasticity. In older
patients,
bulbar or pseudobulbar symptoms predominate, frequently accompanied by
spasticity.
The disease is progressive, with most patients dying within 10 years of onset.
Imaging
studies of the brain typically show cerebral white matter abnormalities,
preferentially
affecting the frontal region. All 3 forms have been shown to be caused by
autosomal
dominant mutations in the GFAP (Glial fibrillary acidic protein) gene. Some
patients with
Alexander disease also exhibit mutations in NADH-Ubiquinone Oxidoreductase
Flavoprotein 1 (NDUFV1).
[0112] Histologically, Alexander disease is characterized by Rosenthal fibers,

homogeneous eosinophilic masses which form elongated tapered rods up to 30
microns in
length, which are scattered throughout the cortex and white matter and are
most numerous
in the subpial, perivascular and subependymal regions. These fibers are
located in
astrocytes, cells that are closely related to blood vessels. Demyelination is
present, usually
as a prominent feature. A few cases have had hydrocephalus. Rosenthal fibers
are
commonly found in astrocytomas, optic nerve gliomas and states of chronic
reactive
gliosis, but they are especially conspicuous in Alexander disease. Rosenthal
fibers found
in this situation are typically the result of degenerative changes in the
cytoplasm and
cytoplasmic processes of astrocytic glial cell.

CA 02920246 2016-02-09
Alpers-Huttenlocher Disease (Alpers)
[0113] Mitochondrial DNA Depletion Syndrome-4A, also known as Alpers Syndrome,

is an autosomal recessive disorder caused by mutations in POLG. Alpers is
characterized
by a clinical triad of psychomotor retardation, intractable epilepsy, and
liver failure in
infants and young children. Pathologic findings include neuronal loss in the
cerebral gray
matter with reactive astrocytosis and liver cirrhosis. The disorder is
progressive and often
leads to death from hepatic failure or status epilepticus before age 3 years.
Symptoms
include anoxic encephalopathy, fever, developmental delay, epilepsy, impaired
central
visual function, ataxia, sensory loss, neuronal loss, progressive liver
failure, acute liver
dysfunction precipitated by valproic acid, cirrhosis, hypotonia, dementia,
vomiting,
paralysis, stupor, jaundiced liver with fibrosis, inflammation and bile duct
proliferation,
and increased CSF protein and lactate.
[0114] Some affected individuals may show mild intermittent 3-methylglutaconic

aciduria and defects in mitochondrial oxidative phosphorylation. Subjects with
Alpers
typically exhibit perturbations in pyruvate metabolism and NADH oxidation. For

example, a subset of patients with mtDNA depletion and Alpers Syndrome show a
global
reduction in respiratory chain complex I, II/III, and IV activity and
deficiency of
mitochondrial DNA polymerase gamma activity. Neuropathologic changes
characteristic
of Alpers Syndrome, namely laminar cortical necrosis, may also be seen in some
patients
with combined oxidative phosphorylation deficiency-14 (COXPD14) due to a
mutation in
the FARS2 gene.
Alpha-ketoglutarate Dehydrogenase Deficiency
[0115] Alpha-ketoglutarate dehydrogenase (AKDGH) deficiency is a disease of
the
tricarboxylic acid cycle (TCA cycle) that affects mitochondria metabolism.
Alpha-
ketoglutarate dehydrogenase is an enzyme of the TCA cycle that catalyzes the
oxidation of
alpha-ketoglutarate to succinyl CoA. Alpha-ketoglutarate dehydrogenase is one
of 3
alpha-ketoacid dehydrogenases, the others being pyruvate dehydrogenase and
branched--
chain ketoacid dehydrogenase. The alpha-ketoglutarate dehydrogenase complex is
a
multi-enzyme complex consisting of three protein subunits: oxoglutarate
dehydrogenase,
also known as alpha-ketoglutarate dehydrogenase or Elk; dihydrolipoyl
succinyltransferase, also known as DLST or E2k; and dihydrolipoyl
dehydrogenase, also
known as DLD or E3. AKDGH deficiency is associated with DLD deficiency, which
is
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CA 02920246 2016-02-09
caused by a mutation in the DLD gene. AKDGH deficiency is characterized by
encephalopathy and hyperlactatemia resulting in death in early childhood.
Frontotemporal Dementia and/or Amyotrophic Lateral Sclerosis (ALS-FTD)
[0116] ALS-FTD is an autosomal dominant late-onset (between 49 to 65 years)
neurodegenerative disorder comprising frontotemporal dementia, cerebellar
ataxia,
myopathy, and motor neuron disease consistent with amyotrophic lateral
sclerosis, caused
by disruptions in the CHCHD10 gene. Clinical manifestations include
progressive bulbar
dysfunction, dementia, sensorineural deafness, extensor plantar responses,
dysphagia,
dysarthria, myopathy, and a frontal lobe syndrome. Muscle biopsies usually
show ragged
red fibers, cytochrome C oxidase (COX)-negative fibers, and mitochondrial DNA
deletions; many patients also have combined mitochondrial respiratory chain
deficiencies
and fragmented mitochondrial networks in fibroblasts, all suggestive of
mitochondrial
dysfunction. Other features include signs of Parkinsonism, including akinesia
and rigidity,
sensorineural hypoacusis, and fatigue. Overexpression of the mutant CHCHD 10
protein
in HeLa cells results in fragmentation of the mitochondrial network as well as
major
ultrastructural abnormalities, thereby implicating a role for dysfunctional
mitochondria in
the pathogenesis of late-onset frontotemporal dementia with motor neuron
disease.
Anemia
1. Sideroblastic Anemia with Spinocerebellar Ataxia
[0117] Sideroblastic anemia with spinocerebellar ataxia is caused by mutations
in the
ATP-binding cassette 7 (ABCB7) transporter, which mediates ATP-dependent
transfer of
solutes. ABCB7 is an inner mitochondrial membrane protein that contains 2
transmembrane domains that form a membranous pore and 2 cytosolic ATP-binding
domains, which couple ATP binding to solute movement. Affected males exhibit a

moderate hypochromic microcytic anemia with ring sideroblasts on bone marrow
examination and raised free erythrocyte protoporphyrin levels and no excessive

parenchymal iron storage in adulthood. Neurologic features include non-
progressive
ataxia or incoordination (age of onset at 1 year), accompanied by long motor
tract signs
(hyperactive deep tendon reflexes, positive Babinski sign, clonus) in young
affected
males. Heterozygous females may exhibit mild anemia, but not ataxia.
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2. Sideroblastic Anemia, Pyridoxine-refractory
[0118] Pyridoxine-refractory sideroblastic anemia is an autosomal recessive
disorder
caused by a homozygous or compound heterozygous mutation in the SLC25A38 gene.
In
addition, a homozygous mutation in the GLRX5 gene has been identified in some
patients
with late-onset autosomal recessive pyridoxine-refractory sideroblastic
anemia. Clinical
features include severe microcytic hypochromic anemia, hepatosplenomegaly,
jaundice,
iron overload, and cirrhosis. Patients typically exhibit moderate erythroid
expansion in the
bone marrow, and increased iron staining both in erythroblasts and
macrophages, with
28% ringed sideroblasts. In some cases, patients may show low levels of 6-
aminolevulinic
acid synthase in erythroblasts.
3. Growth Retardation, Amino aciduria, Cholestasis, Iron overload, Lactic
acidosis,
Early death (GRACILE) Syndrome
[0119] GRACILE Syndrome, an autosomal recessive disorder usually observed in
Finnish and Turkish populations, is caused by disruptions in the BCSIL gene
which is
required for the expression of functional ubiquinol-cytochrome-c reductase
(be!) complex.
Loss of BCSIL function results in tubulopathy, encephalopathy, and liver
failure due to
complex III deficiency. Clinical features include severe intrauterine growth
retardation,
fulminant lactic acidosis during the first days of life, Fanconi-type amino
aciduria,
spasticity, increased tendon reflexes, and abnormalities in iron metabolism,
including liver
hemosiderosis. Affected infants fail to thrive, and die neonatally or in early
infancy.
Other BCS1L disorders include Bjornstad Syndrome, Leigh Syndrome and
mitochondrial
complex III deficiency, nuclear type 1 (MC3DN1).
4. Anemia and Mitochondriopathy (COXPD18)
[0120] Anemia and mitochondriopathy, or combined oxidative phosphorylation
deficiency 18 (COXPD18) is an autosomal recessive disorder caused by a
homozygous or
compound heterozygous mutation in the SFXN4. COXPD18 is characterized by
intrauterine growth retardation, intellectual disability, dysmetria, tremor,
muscular
atrophy, hypotonia, visual impairment, speech delay, delayed motor skills, and
lactic
acidosis associated with decreased mitochondrial respiratory chain activity.
Affected
patients may also show hematologic abnormalities, mainly macrocytic anemia and

hypersegmented neutrophils, and increased blood lactate and ammonia levels.
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5. Thiamine-responsive Megaloblastic Anemia
[0121] Thiamine-responsive Megaloblastic Anemia Syndrome (TRMA), also known as

Thiamine Metabolism Dysfunction Syndrome-1 (THMD1), can be caused by a
homozygous mutation in the SLC19A2 gene, which encodes a thiamine transporter
protein. Thiamine-responsive Megaloblastic Anemia Syndrome comprises
megaloblastic
anemia, diabetes mellitus, amino aciduria, and sensorineural deafness. Onset
is typically
between infancy and adolescence, but all of the cardinal findings are often
not present
initially. The anemia, and sometimes the diabetes, improves with high doses of
thiamine.
Other more variable features include optic atrophy, congenital heart defects,
short stature,
and stroke.
6. Pearson Syndrome
[0122] Pearson Syndrome is caused by a deletion in mitochondrial DNA and is
characterized by sideroblastic anemia and exocrine pancreas dysfunction. With
Pearson
Syndrome, the bone marrow fails to produce white blood cells called
neutrophils. The
syndrome also leads to anemia, low platelet count, and aplastic anemia.
Pearson
Syndrome causes the exocrine pancreas to not function properly because of
scarring and
atrophy. Individuals with this condition have difficulty absorbing nutrients
from their diet
which leads to malabsorption. Infants with this condition generally do not
grow or gain
weight
[0123] Other clinical features are failure to thrive, pancytopenic crises,
pancreatic
fibrosis with insulin-dependent diabetes and exocrine pancreatic
deficiency, muscle and neurologic impairment, malabsorption, steatorrhea,
metabolic and
lactic acidosis, and early death. The few patients who survive into adulthood
often
develop symptoms of Kearns-Sayre Syndrome.
Ataxia
[0124] Ataxia is defined as the presence of abnormal, uncoordinated movements.

Defects affecting either the mitochondrial or nuclear genomes can cause
mitochondrial
dysfunction, resulting in mitochondrial ataxia. Ataxia associated with mtDNA
defects
typically manifests as part of a multisystem, multisyndrome disorder.
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Maternally Inherited Ataxias
1. HAM Syndrome
[0125] HAM (Hearing loss, Ataxia, Myoclonus) is a maternally-inherited
syndrome
characterized by a combination of sensorineural hearing loss, ataxia, and
myoclonus
observed in a large kindred from Sicily. Hearing loss is the most prevalent
and sometimes
the only symptom found in family members. HAM Syndrome is associated with the
presence of a C7472 insertion mutation in mtDNA regions encompassing the tRNA
genes.
This particular insertion is found in the MT-TS1 gene (nucleotides 7445-7516),
which
encodes the mitochondrial tRNA for serine (UCN). The insertion adds a seventh
cytosine
to a six-cytosine run that is part of the mitochondrial tRNASer(UCN) gene.
Conformational analyses demonstrate that this mutation likely alters the
clover leaf
secondary structure of tRNASer/(UCN).
2. Ataxia, Cataract, and Diabetes Syndrome and MELAS/MERRF Overlap Syndrome
[0126] Mutations in the mitochondrial MT-TS2 gene (nucleotides 12207-12265),
which
encodes the mitochondrial tRNA for serine (AGY) are associated with the
development of
maternally-inherited cerebellar ataxia, cataract, and diabetes mellitus. In
particular, these
phenotypes are associated with a C-to-A transversion at position 12258. It is
thought that
this mutation alters a highly conserved basepair in the acceptor stem of the
tRNA(Ser)
molecule, which would affect aminoacylation of the tRNA thereby altering the
function of
the tRNA for serine and reducing the accuracy of mitochondrial translation.
[0127] Other mutations in the same gene cause MELAS/MERRF Overlap Syndrome.
One such mutation is a heteroplasmic 12207G-A transition in the MT-TS2 gene.
Upon
examination, skeletal muscle biopsies revealed ragged red fibers, significant
pleomorphic
mitochondrial proliferation, and complex I deficiency. The 12207G-A mutation
occurs in
a region involved in the formation of the acceptor stem of the tRNA molecule.
Individuals
with MELAS/MERRF Overlap Syndrome experience a combination of the signs and
symptoms of both disorders as described above.
3. Cytochrome c Oxidase Deficiency
[0128] Cytochrome c oxidase (COX) deficiency is a mitochondrial disorder
caused by a
lack of COX. Cytochrome c oxidase, also known as complex IV, is the terminal
enzyme

CA 02920246 2016-02-09
of the mitochondrial respiratory chain located within the mitochondrial inner
membrane.
Complex IV is composed of 13 polypeptides. Subunits I, II, and III (MTC01,
MTCO2,
and MTC03) are encoded by mtDNA, while subunits IV, Va, Vb, VIa, VIb, VIc,
Vila,
VIIb, VIIc, and VIII are nuclear encoded. Because COX is encoded by both
nuclear and
mitochondrial genes, COX deficiency can be inherited in either an autosomal
recessive or
maternal pattern. A G-to-A transition at nucleotide 6480 of the MTC01 gene,
which
encodes cytochrome c oxidase subunit I, is associated with sensorineural
hearing loss,
ataxia, myoclonic epilepsy, and mental retardation. The signs and symptoms of
COX
deficiency typically manifest before two years of age, but can appear later in
mildly
affected individuals.
[0129] Another form of cytochrome c oxidase deficiency results from mutations
in the
MTCO2 gene, which encodes cytochrome c oxidase subunit II. A T-to-C transition
at
nucleotide 7587 of the MT-0O2 gene is associated with ataxia, distal weakness,

retinopathy, and optic atrophy.
Recessive ataxia syndromes
1. Infantile Cerebellar-retinal Degeneration
[0130] Infantile cerebellar-retinal degeneration (ICRD), also known as
mitochondrial
aconitase deficiency, is associated with a Ser112Arg mutation in the nuclear
ACO2 gene,
which encodes mitochondrial aconitase. Aconitase catalyzes the isomerization
of citrate
to isocitrate via cis-aconitate in the second step of the TCA cycle. ICRD is a
severe
autosomal recessive neurodegenerative disorder characterized by onset between
two and
six months of age of truncal hypotonia, athetosis, seizures, and
ophthalmologic
abnormalities, including optic atrophy and retinal degeneration. Individuals
with ICRD
exhibit profound psychomotor retardation and progressive cerebral and
cerebellar
degeneration.
2. Charlevoix-Saguenay Spastic Ataxia
[0131] Charlevoix-Saguenay spastic ataxia, also known as autosomal recessive
spastic
ataxia of Charlevoix-Saguenay (ARSACS), is caused by a homozygous or compound
heterozygous mutation in the SACS gene encoding the sacsin protein. Research
suggests
that sacsin may interact with the heat shock protein 70 (Hsp70) chaperone
machinery,
which plays an important role in protein folding and the cellular response to
aggregation-
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CA 02920246 2016-02-09
prone mutant proteins associated with neurodegenerative diseases. Mutations in
the SACS
gene lead to the production of unstable sacsin protein that fails to function
normally.
ARSACS is a complex neurodegenerative disorder characterized by the
progressive
degeneration of the cerebellum and spinal cord and early childhood onset of
cerebellar
ataxia, pyramidal tract signs, peripheral neuropathy, retinal changes, and, in
some cases,
cognitive decline.
3. Primary Coenzyme 010 Deficiency-1
[0132] Primary coenzyme Q10 deficiency-1 (C0Q10D1) is an autosomal recessive
disorder caused by a homozygous or compound heterozygous mutation in the COQ2
gene,
which encodes COQ2, or parahydroxybenzoic-polyprenyltransferase. COQ2
catalyzes
one of the final reactions in the biosynthesis of CoQ10, the prenylation of
parahydroxybenzoate with an all-trans polyprenyl group. Coenzyme Q10 (C0Q10),
or
ubiquinone, functions as an electron carrier critical for electron transfer by
the
mitochondrial inner membrane respiratory chain, and is a lipid-soluble
antioxidant.
Primary CoQ10 deficiency-1 disorder is associated with five major phenotypes,
including:
an encephalomyopathic form with seizures and ataxia; a multisystem infantile
form with
encephalopathy, cardiomyopathy and renal failure; a predominantly cerebellar
form with
ataxia and cerebellar atrophy; Leigh Syndrome with grown retardation; and an
isolated
myopathic form.
4. Ataxia with Oculomotor Apraxia Type 1
[0133] Ataxia with oculomotor apraxia (AOA) comprises a group of autosomal
recessive disorders characterized by ataxia, oculomotor apraxia, and
choreoathetosis.
AOA includes ataxia telangiectasia (AT), ataxia telangiectasia like disorder
(ATLD),
ataxia oculomotor apraxia type 1 (A0A1), and ataxia oculomotor apraxia type 2
(A0A2).
AOA 1, also known as ataxia, early-onset, with oculomotor apraxia and
hypoalbumineria,
is characterized by early-onset cerebellar ataxia, oculomotor apraxia,
hypoalbumineria,
hypercholesterolemia, and late axonal sensorimotor neuropathy. A0A1 is caused
by
mutations in the APTX gene, which encodes aprataxin, a member of the histidine
triad
(HIT) superfamily, members of which have nucleotide-binding and diadenosine
polyphosphate hydrolase activities. Aprataxin is a DNA-binding protein
involved in
single-strand DNA break repair, double-strand DNA break repair, and base
excision
repair. Mutations in APTX result in the production of an unstable aprataxin
protein that is
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CA 02920246 2016-02-09
quickly degraded in the cell. Nonfunctional aprataxin leads to an accumulation
of breaks
in DNA, particularly in the neurocytes of the cerebellum where DNA repair is
critical.
5. Autosomal Recessive Spinocerebellar Ataxia-9
[0134] Autosomal recessive spinocerebellar ataxia-9 (SCAR9), also known as
coenzyme
Q10 deficiency-4 (C0Q10D4), is an autosomal recessive disorder caused by
homozygous
or compound heterozygous mutations in the COQ8 gene. SCAR9 is characterized by

childhood-onset of cerebellar ataxia and exercise intolerance. Patients
manifest gait
ataxia, cerebellar atrophy with slow progression. Additional features include
variable
seizures, mild mental impairment, brisk tendon reflexes, and Hoffmann sign.
6. Ataxia, Pyramidal Syndrome, and Cytochrome Oxidase Deficiency
[0135] A homozygous missense mutation in COX20, also known as FAM36A, causes
impaired cytochrome c oxidase assembly and is associated with ataxia and
muscle
hyptonia. Additional clinical symptoms include oligohydramnios and growth
retardation
during pregnancy, low birth weight, delayed speech development, pyramidal
signs, short
stature, mildly elevated serum and cerebrospinal fluid lactate levels, and
myocyte complex
IV deficiency. The mutation has been identified as a homozygous c.154A-C
transversion
in exon 2 of the COX20 gene, resulting in a T52P substitution at a highly
conserved
residue at the interface between the inner-membrane embedded region and the
predicted
mitochondrial matrix-localized loop fragment. The COX2 gene encodes cytochrome
c
oxidase protein 20, which plays a role in the assembly of mitochondrial
complex W and
interacts with cytochrome c oxidase subunit II.
7. Friedreich's Ataxia
[0136] Friedreich's ataxia is an autosomal recessive neurodegenerative
disorder caused
by a mutation in the FXN gene, which encodes frataxin. Frataxin is a nuclear-
encoded
mitochondrial iron chaperone that is localized to the inner mitochondrial
membrane and
involved in iron-sulfur biogenesis and heme biosynthesis. The most common
molecular
abnormality is a GAA trinucleotide repeat expansion in intron 1 of the FXN
gene.
Whereas normal individual have 5 to 30 GAA repeat expansions, individuals
affected with
Friedreich's ataxia have from 70 to more than 1,000 GAA triplets.
[0137] Friedreich's ataxia is characterized by progressive gait and limb
ataxia with
associated limb muscle weakness, absent lower limb reflexes, extensor plantar
responses,
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CA 02920246 2016-02-09
dysarthria, and decreased vibratory sense and proprioception. Other features
include
visual defects, scoliosis, pes cavus, and cardiomyopathy. Onset typically
occurs in the
first or second decade. Affected individuals who develop Friedreich's ataxia
between ages
26 and 39 are considered to have late-onset Friedreich's ataxia (LOFA). When
the signs
and symptoms begin after age 40 the condition is called very late-onset
Friedreich's ataxia
(VLOFA). LOFA and VLOFA usually progress more slowly than typical Friedreich's

ataxia.
8. Infantile Onset Spinocerebellar Ataxia
[0138] Infantile onset spinocerebellar ataxia (IOSCA), also known as
Mitochondrial
DNA Depletion Syndrome-7, is an autosomal recessive severe neurodegenerative
disorder
caused by a homozygous or compound heterozygous mutation in the nuclear-
encoded
C100RF2 gene, which encodes the twinkle and twinky proteins. Twinkle is a
mitochondrial protein involved in mtDNA metabolism. The ClOORF2 gene mutations

that cause IOSCA interfere with the function of twinkle resulting in mtDNA
depletion.
IOSCA is associated with the following C100RF2 mutations: P83S/R463W;
Y508C/A318T; Y508C/R29X; T451I/T4511; c.1460C-T (T487I)/c.1485-1G-A; and
1472C-T.
[0139] IOSCA is characterized by hypotonia, ataxia, ophthalmoplegia, hearing
loss,
seizures, sensory axonal neuropathy, reduced mental capacity, and mtDNA
depletion in
the brain and liver. Individuals affected with IOSCA often develop autonomic
nervous
system disorders and experience excessive sweating, incontinence, and
constipation.
9. Leukoencephalopathy with Brain Stem and Spinal Cord Involvement and Lactate

Elevation
[0140] Leukoencephalopathy with brainstem and spinal cord involvement and
lactate
elevation (LBSL) is an autosomal recessive disorder that can be caused by
homozygous or
compound heterozygous mutations in the gene encoding mitochondrial aspartyl-
tRNA
synthetase (DARS2). The mutation results in reduced aspartyl-tRNA synthetase
activity.
[0141] LBSL is defined by a highly characteristic constellation of
abnormalities
observed by magnetic resonance imaging and spectroscopy. These include a
pattern of
inhomogeneous cerebral white matter abnormalities, selective involvement of
brainstem
and spinal tracts, and increased lactate in the abnormal white matter.
Affected individuals
develop slowly progressive cerebellar ataxia, spasticity, and dorsal column
dysfunction,
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CA 02920246 2016-02-09
sometimes with a mild cognitive deficit or decline. Onset typically occurs
between three
and fifteen years of age.
10. Autosomal Recessive Spastic Ataxia-3
[0142] Autosomal recessive spastic ataxia-3 (SPAX3), also known as autosomal
recessive spastic ataxia with leukoencephalopathy (ARSAL), is caused by
homozygous or
compound heterozygous complex genomic rearrangements involving the MARS2 gene,

which encodes mitochondrial methionyl-tRNA synthetase (mtMetRS), a protein
localized
to the mitochondrial matrix. The protein shares a high degree of identity with
methionyl-
tRNA synthetases from other mammals. Mutations in MARS2 result in reduced
protein
levels. Some affected individuals have a heterozygous 268-bp deletion in the
MARS2
gene, resulting in a frameshift and premature termination
(c.681de1268bpfs236Ter). Other
affected individuals have duplications of the MARS2 gene.
[0143] SPAX3 is a progressive disease characterized by ataxia, dysarthria,
horizontal
nystagmus, spasticity, hyperreflexia, urinary urgency, scoliosis, dystonia,
cognitive
impairment, optic atrophy, cataract, hearing loss, cerebellar atrophy,
cortical atrophy,
leukoencephalopathy, and complex I deficiency. The disease usually manifests
between
birth and fifty-nine years of age.
11. MIRAS and SANDO
[0144] Mitochondrial recessive ataxia syndrome (MIRAS) and sensory ataxia
neuropathy dysarthria and ophthalmoplegia (SANDO) are disorders that fall
under a group
of conditions known as the ataxia neuropathy spectrum. Ataxia neuropathy
spectrum is
caused by mutations in the POLG gene, and, rarely, the ClOORF2 gene. The POLG
gene
encodes DNA polymerase gamma, which functions in the replication of
mitochondrial
DNA. The POLG protein is composed of a C-terminal polymerase domain and an
amino-
terminal exonuclease domain. The exonuclease domain increases the fidelity of
mitochondrial DNA replication by conferring a proofreading activity to the
enzyme.
[0145] MIRAS is associated with W748S and E1143G cis, and homozygous W748S or
A467T POLG1 mutations. Clinical symptoms of MIRAS include ataxia,
polyneuropathy,
reduced muscle strength, cramps, epilepsy, cognitive impairment, athetosis,
tremor,
obesity, eye movement disorders, cerebellar atrophy, white matter changes,
muscle
denervation, and, rarely, mitochondrial alterations. MIRAS onset typically
occurs
between five and thirty-eight years of age.

CA 02920246 2016-02-09
[0146] SANDO is commonly associated with a compound heterozygous or homozygous

A467T mutation. Other mutations associated with SANDO include N468D, G517V,
G737R, R1138C, and E1143G missense mutations. SANDO is a progressive disease
characterized by neuropathy causing sensory loss, variable alterations in
strength, ataxia,
absent or reduced tendon reflexes, ptosis, ophthalmoplegia, dysarthria, facial
weakness,
myoclonic epilepsy, and depression. Additional features include elevated serum
and
cerebrospinal fluid lactate levels, spinocerebellar and dorsal column tract
degeneration,
thalamic lesions, cerebellar atrophy or white matter changes, multiple mtDNA
deletions,
ragged red fibers, loss of myelinated and unmyelinated axons, posterior column
atrophy,
dorsal root ganglia neuron loss, reduced mtDNA number in affected neurons, and
reduced
activity of mitochondrial complexes I and IV.
12. Mitochondrial Spinocerebellar Ataxia and Epilepsy
[0147] Mitochondrial spinocerebellar ataxia and epilepsy (MSCAE) is a disorder

comprising spinocerebellar ataxia, peripheral neuropathy, and epilepsy. Onset
typically
occurs during second and third decades and can be with ataxia or epilepsy, but
all patients
with MSCAE will develop ataxia if they survive, while only approximately 80%
will
develop epilepsy. Other clinical features include migraine, myoclonus or
myoclonic
seizures, high T2 signal in the thalamus, occipital cortex, and cerebellum,
cerebellar
atrophy, enlarged olives, stroke-like lesions, mtDNA depletion in neurons, and

progressively reduced complex I. Several POLG1 mutations are associated with
this
disorder, the most common being the c.1399G-A that gives p.A467T, the c.2243G-
C
giving the p.W748S, and the Gln497His mutation.
13. Spastic Ataxia with Optic Atrophy
[0148] Spastic ataxia with optic atrophy (SPAX4) is a slowly progressive
autosomal
recessive neurodegenerative disease characterized by cerebellar ataxia,
spastic paraparesis,
dysarthria, and optic atrophy. SPAX4 is associated with mutations affecting
the MTPAP
gene, resulting in a defect of mitochondrial mRNA maturation. One particular
mutation is
a homozygous N478D missense mutation. The MTPAP gene encodes a polymerase that
is
a member of the DNA polymerase type-B-like family. The enzyme synthesizes the
3'
poly(A) tail of mitochondrial transcripts and plays a role in replication-
dependent histone
mRNA degradation. Affected individuals exhibit decreased poly(A) tail length
of
mitochondrial transcripts including those for COX1 and RNA14.
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CA 02920246 2016-02-09
14. Mitochondrial Complex I Deficiency
[0149] Mitochondrial complex I deficiency (MT-C1D) is a disorder of the
mitochondrial
respiratory chain associated with mutations in the NUBPL gene. The NUBPL gene
encodes a member of the Mrp/NBP35 ATP-binding proteins family. The encoded
protein
is required for the assembly of complex I (NADH dehydrogenase), located in the

mitochondrial inner membrane. MT-C1D is characterized by a wide variety of
clinical
manifestations ranging from lethal neonatal disease to adult-onset
neurodegenerative
disorders including macrocephaly with progressive leukodystrophy, non-specific

encephalopathy, cardiomyopathy, myopathy, liver disease, Leigh Syndrome, LHON,
and
some forms of Parkinson's disease.
15. Progressive External Ophthalmoplegia with Mitochondrial DNA Deletions
Autosomal Dominant Type 5
[0150] Progressive external ophthalmoplegia with mitochondrial DNA deletions
autosomal dominant type 5 (PEOA5) can be either an autosomal dominant or
recessive
disorder caused by mutations in the nuclear-encoded RRM2B gene. Recessive
inheritance
of PEOA5 is associated with homozygous or compound heterozygous missense
variations
in the RRM2B gene. PEOA5 is characterized by progressive weakness of ocular
muscles
and levator muscle of the upper eyelid. In a minority of cases, it is
associated with skeletal
myopathy, which predominantly involves axial or proximal muscles and which
causes
abnormal fatigability. Ragged red fibers and atrophy are found on muscle
biopsy.
Additional symptoms may include cataracts, hearing loss, sensory axonal
neuropathy,
ataxia, depression, hypogonadism, and Parkinsonism.
16. Mitochondrial Complex III Deficiency Nuclear Type 2
[0151] Mitochondrial complex III deficiency nuclear type 2 (MC3DN2) is an
autosomal
recessive severe neurodegenerative disorder caused by a homozygous or compound

heterozygous mutation in the nuclear-encoded TTC19 gene. The TTC19 gene
encodes
tetratricopeptide repeat protein 19, a subunit of mitochondrial respiratory
chain complex
III, which transfers electrons from coenzyme Q to cytochrome c. This electron
transfer
contributes to the extrusion of protons across the inner mitochondrial
membrane and
contributes to the mitochondrial electrochemical potential. Mutations in the
TTC19 gene
include Leu219X and Gln173X nonsense mutations.
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CA 02920246 2016-02-09
[0152] MC3DN2 presents in childhood, but may show later onset, even in
adulthood.
Affected individuals have motor disability, with ataxia, apraxia, dystonia,
and dysarthria,
associated with necrotic lesions throughout the brain. Most patients also have
cognitive
impairment and axonal neuropathy and become severely disabled later in life.
The
disorder may present clinically as spinocerebellar ataxia or Leigh Syndrome,
or with
psychiatric disturbances. Complex III deficiency is observed on muscle biopsy.
17. Episodic Encephalopathy due to Thiamine Pyrophosphokinase Deficiency
[0153] Episodic encephalopathy due to thiamine pyrophosphokinase deficiency,
also
known as Thiamine Metabolism Dysfunction Syndrome-5 (THMD5), is an autosomal
recessive thiamine metabolism disorder caused by a homozygous or compound
heterozygous mutation in the TPK1 gene. The TPK1 gene encodes thiamine
pyrophosphokinase (TPK), an enzyme involved in the regulation of thiamine
metabolism.
TPK catalyzes the conversion of thiamine, a form of vitamin B 1, to thiamine
pyrophosphate (TPP). Thymine pyrophosphate is an active cofactor for enzymes
involved
in glycolysis and energy production, including transketolase, pyruvate
dehydrogenase, and
alpha-ketoglutarate dehydrogenase.
[0154] Onset of episodic encephalopathy due to thiamine pyrophosphokinase
deficiency
typically occurs between one and four years of age. Affected individuals
present with a
highly variable phenotype characterized by progressive neurologic dysfunction
manifested
as ataxia, dystonia, spasticity, inability to walk, mildly delayed
developments, and
increased serum and cerebrospinal fluid lactate levels. Other clinical
features include
exacerbated encephalopathy during an infection, hypotonia, microcephaly,
epilepsy, and
ophthalmoplegia.
Dominant Ataxia Syndromes
1. Spinocerebellar Ataxia-28
[0155] Spinocerebellar ataxia-28 (SCA28) is an autosomal dominant disorder
caused by
heterozygous mutation in the AFG3L2 gene. The AFG3L2 gene encodes the AFG3-
like
protein 2 (AFG3L2), an ATP-dependent protease localized to the mitochondrial
inner
membrane where it forms the catalytic subunit of the m-AAA protease, which
degrades
misfolded proteins and regulates ribosome assembly. Mutations associated with
SCA28
include the following missense mutations: N432T; S674L; E691K; A694E; R702Q;
and
Y689H. SCA28 is characterized by cerebellar ataxia, dysarthria, nystagmus,
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CA 02920246 2016-02-09
ophthalmoparesis, ptosis, slow saccades, hyperreflexia in legs, extensor
plantar response,
leg and arm spasticity, myoclonic epilepsy, and cerebellar atrophy.
2. Autosomal Dominant Cerebellar Ataxia, Deafness, and Narcolepsy
[0156] Autosomal dominant cerebellar ataxia, deafness, and narcolepsy (ADCA-
DN) is
caused by heterozygous mutation in the DNMT1 gene. The DNMT1 gene encodes DNA
(cytosine-5)-methyltransferases (DNMTs), such as DNMT1, which maintain
patterns of
methylated cytosine residues in the mammalian genome. Methylation patterns are

responsible for the repression of parasitic sequence elements and the
expression status of
genes subject to genomic imprinting and X inactivation. Faithful maintenance
of
methylation patterns is required for normal mammalian development, and
aberrant
methylation patterns are associated with certain human tumors and
developmental
abnormalities. Mutations of DNMT1 associated with the development of ADCA-DN
include the following missense mutations: A1a570Val; Cys596Arg; and Va1606Phe.
[0157] ADCA-DN is characterized by adult onset of progressive cerebellar
ataxia,
narcolepsy/cataplexy, sensorineural deafness, and dementia. More variable
features
include optic atrophy, sensory neuropathy, psychosis, and depression.
Increased lipid
levels are observed on muscle biopsy.
3. Optic Atrophy-1
[0158] Optic atrophy-1 (OPA1) is an autosomal dominant optic atrophy caused by

heterozygous mutation in the OPA1 gene encoding a dynamin-like 120 kDa GTPase
that
localizes to the inner mitochondrial membrane where it regulates cellular
processes
including the stability of the mitochondrial network, mitochondrial
bioenergetics output,
and the sequestration of pro-apoptotic cytochrome c oxidase molecules within
the
mitochondrial cristae spaces. OPA1 directly interacts with subunits of
complexes I, II,
and III, and an apoptosis inducing factor. Over 100 different OPA1 mutations
have been
identified, most of which are localized in the GTPase domain of the OPA1
protein. OPA1
mutations can cause oxidative phosphorylation defects at the level of complex
I,
impairment in mitochondrial ATP synthesis driven by complex I substrates,
fibroblasts
which are more prone to death, and abnormal mitochondrial morphology.
[0159] OPA1 is characterized by an insidious onset of visual impairment in
early
childhood with moderate to severe loss of visual acuity, temporal optic disc
pallor, color
vision deficits, and centrocecal scotoma of variable density. Some patients
with mutations
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CA 02920246 2016-02-09
in the OPA1 gene may also develop extraocular neurologic features, such as
deafness,
progressive external ophthalmoplegia, muscle cramps, hyperreflexia, and
ataxia.
Variable Ataxia Syndromes
1. CAPOS Syndrome
[0160] Cerebellar ataxia, areflexia, pes cavus, optic atrophy, and
sensorineural hearing
loss (CAPOS) syndrome is a neurologic disorder associated with heterozygous
mutation in
the ATP1A3 gene. The ATP1A3 gene encodes a Na+/K+ ATPase subunit a3, which
forms a catalytic component of the active enzyme that catalyzes the hydrolysis
of ATP
coupled with the exchange of sodium and potassium ions across the plasma
membrane.
[0161] CAPOS is characterized by early-childhood onset of recurrent episodes
of acute
ataxic encephalopathy associated with febrile illnesses. These acute episodes
tend to
decrease with time, but the neurologic sequelae are permanent and progressive,
resulting
in gait and limb ataxia and areflexia. Affected individuals also develop
progressive visual
impairment due to optic atrophy and sensorineural hearing loss beginning in
childhood.
More variable features include abnormal eye movements, pes cavus, and
dysphagia.
2. Spinocerebellar Ataxia 7
[0162] Spinocerebellar ataxia 7 (SCA7) is caused by an expanded trinucleotide
repeat in
the gene encoding ataxin-7 (ATXN7). The ATXN7 gene encodes ataxin 7, a
transcription
factor that appears to be critically important for chromatin remodeling at the
level of
histone acetylation and deubiquitination. SCA7 is a neurodegenerative disorder

characterized by adult onset of progressive ataxia associated with pigmental
macular
dystrophy. Associated neurologic signs, such as ophthalmoplegia, pyramidal or
extrapyramidal signs, deep sensory loss, or dementia, are also variable.
Barth Syndrome
[0163] Barth Syndrome is a heritable disorder of phospholipid metabolism
characterized
by dilated cardiomyopathy (DCM), skeletal myopathy, neutropenia, growth delay
and
organic aciduria. The prevalence of Barth Syndrome is estimated at 1/454,000
live births,
with an estimated incidence ranging from 1/400,000 to 1/140,000 depending on
geographic location. Barth Syndrome is an X-linked disorder, and so
disproportionately
affects male patients.

CA 02920246 2016-02-09
[0164] Barth Syndrome is caused by mutations in the TAZ gene (tafazzin).
Defective
TAZ1 function results in abnormal remodeling of cardiolipin and compromises
mitochondrial structure and respiratory chain function. TAZ1 is expressed at
high levels
in cardiac and skeletal muscle and is involved in the maintenance of the inner
membrane
of mitochondria. TAZ1 is involved in maintaining levels of cardiolipin, which
is essential
for energy production in the mitochondria.
[0165] Clinical presentation of Barth Syndrome is highly variable. Most
subjects
develop DCM during the first decade of life, and typically during the first
year of life,
which may be accompanied by endocardial fibroelastosis (EFE) and/or left
ventricular
noncompaction (LVNC). The manifestations of Barth Syndrome may begin in utero,

causing cardiac failure, fetal hydrops and miscarriage or stillbirth during
the 2nd/3rd
trimester of pregnancy. Ventricular arrhythmia, especially during adolescence,
can lead to
sudden cardiac death. There is a significant risk of stroke. Skeletal (mostly
proximal)
myopathy causes delayed motor milestones, hypotonia, severe lethargy or
exercise
intolerance. There is a tendency to hypoglycemia during the neonatal period.
Ninety
percent of patients show mild to severe intermittent or persistent neutropenia
with a risk of
septicemia, severe bacterial sepsis, mouth ulcers and painful gums. Lactic
acidosis and
mild anemia may occur. Affected boys usually show delayed puberty and growth
delay
that is observed until the late teens or early twenties, when a substantial
growth spurt often
occurs. Patients may also present severe difficulties with adequate food
intake. Episodic
diarrhea is common. Many patients have a similar facial appearance with chubby
cheeks,
deep-set eyes and prominent ears. Skewed X chromosome inactivation is common
in
female carriers.
Biotinidase Deficiency
[0166] Biotinidase deficiency is an autosomal recessive metabolic disorder
associated
with mutations in the BTD gene. In biotinidase deficiency, biotin is not
released from
proteins in the diet during digestion or from normal protein turnover in the
cell.
Biotinidase deficiency is associated with mutations in the BTD gene. Biotin,
also called
vitamin B7, is an important water-soluble nutrient that aids in the metabolism
of fats,
carbohydrates, and proteins. Biotin deficiency can result in behavioral
disorders, lack of
coordination, learning disabilities and seizures. Biotin supplementation can
alleviate and
sometimes totally arrest such symptoms
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Blindness
1. Gyrate Atrophy
[0167] Gyrate atrophy of the choroid and retina is caused by a homozygous or
compound heterozygous mutation in the OAT gene and is usually observed in
Finnish
families. Gyrate atrophy of the choroid and retina due to deficiency of
ornithine
aminotransferase typically begins in late childhood and is clinically
characterized by a
triad of progressive chorioretinal degeneration, early cataract formation, and
type II
muscle fiber atrophy. Characteristic chorioretinal atrophy with progressive
constriction of
the visual fields leads to blindness at the latest during the sixth decade of
life. Clinical
symptoms include night-blindness, weakness, glutei atrophy, scapular winging,
type 2
muscular atrophy, tubular aggregation, mental retardation, hyperornithinemia,
and white
matter lesions.
2. Dominant Optic Atrophy
[0168] Dominant optic atrophy (DOA), also known as Kjer's optic neuropathy, is
an
autosomally inherited neuro-ophthalmic disease characterized by a bilateral
degeneration
of the optic nerves, causing insidious visual loss, typically starting during
the first decade
of life. The disease affects primarily the retinal ganglion cells (RGC) and
their axons
forming the optic nerve, which transfer the visual information from the
photoreceptors to
the lateral geniculus in the brain. Vision loss in DOA is due to optic nerve
fiber loss from
mitochondria dysfunction. DOA patients usually suffer of moderate visual loss,
associated
with central or paracentral visual field deficits and color vision defects.
The severity of
the disease is highly variable, the visual acuity ranging from normal to legal
blindness. An
ophthalmic examination of a subject with DOA presents isolated optic disc
pallor or
atrophy, related to the RGC death. About 20% of DOA patients harbor
extraocular multi-
systemic features, including neurosensory hearing loss, or less commonly
chronic
progressive external ophthalmoplegia, myopathy, peripheral neuropathy,
multiple
sclerosis-like illness, spastic paraplegia or cataracts.
[0169] Two genes (OPA I, OPA3), which encode inner mitochondrial membrane
proteins, and three loci (OPA4, OPA5, OPA8) are known to cause DOA. All OPA
genes
identified encode mitochondrial proteins embedded in the inner membrane and
are
ubiquitously expressed. OPA1 mutations affect mitochondrial fusion, energy
metabolism,
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CA 02920246 2016-02-09
control of apoptosis, calcium clearance and maintenance of mitochondrial
genome
integrity. OPA3 mutations only affect the energy metabolism and the control of
apoptosis.
OPA1 is the major gene responsible for DOA.
[0170] In most cases, DOA presents as a non-syndromic, bilateral optic
neuropathy.
Although DOA is usually diagnosed in school-aged children complaining of
reading
problems, the condition can manifest later, during adult life. On fundus
examination, the
optic disk typically presents a bilateral and symmetrical pallor of its
temporal side with the
loss of RGC fibers entering the optic nerve. The optic nerve rim is atrophic
and a
temporal grey crescent is often present. Optic disc excavation may also be
present.
Optical Coherence Tomography (OCT) discloses the reduction of the thickness of
the
peripapillary retinal nerve fiber layer in all four quadrants, but does not
disclose alteration
of other retinal layers. The visual field typically shows a cecocentral
scotoma, and less
frequently a central or paracentral scotoma, while peripheral visual field
remains normal.
Importantly, there is a specific tritanopia, i.e., a blue-yellow axis of color
confusion,
which, when found, is strongly indicative of DOA. The pupillary reflex and
circadian
rhythms are not affected, suggesting that the melanopsin RGC are spared during
the
course of the disease.
[0171] In Syndromic Dominant Optic Atrophy and Deafness (Syndromic DOAD) and
Dominant Optic Atrophy plus (D0Aplus) patients experience full penetrance and
usually
more severe visual deficits. DOAD and DOAplus with extra-ophthalmological
abnormalities represent up to 20% of DOA patients with an OPA1 mutation. The
most
common extra-ocular sign in DOA is sensorineural hearing loss, but other
associated
findings may occur later during life (e.g., myopathy and peripheral
neuropathy),
suggesting that there is a continuum of clinical presentations ranging from a
mild "pure
DOA" affecting only the optic nerve to a severe and multi-systemic
presentations.
Sensorineural hearing loss associated to DOA may range from severe and
congenital to
subclinical with intra- and inter- familial variations, and mostly segregate
with the OPA1
R445H (c.1334G>A) mutation. In general, auditory brain stem responses, which
reflect
the integrity of the auditory pathway from the auditory nerve to the inferior
colliculus, are
absent, but both ears show normal evoked otoacoustic emissions, reflecting the

functionality of presynaptic elements and in particular that of the outer hair
cells.
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CA 02920246 2016-02-09
3. LHON
[0172] Leber's hereditary optic neuropathy (LHON) is a maternally inherited
blinding
disease with variable penetrance. LHON is usually due to one of three
pathogenic
mitochondrial DNA (mtDNA) point mutations. These mutations are at nucleotide
positions 11778 G to A, 3460 G to A and 14484 T to C, respectively in the
MTND4,
MTND1 and MTND6 subunit genes of complex I of the oxidative phosphorylation
chain
in mitochondria. Reduced efficiency of ATP synthesis and increased oxidative
stress are
believed to sensitize the retinal ganglion cells to apoptosis.
[0173] Leber's hereditary optic neuropathy (LHON) is characterized by severe
visual
loss, which usually does not manifest until young adulthood. Maternal
transmission is due
to a mitochondrial DNA (mtDNA) mutation affecting nucleotide positions (nps)
11778/ND4, 14484/ ND6, or 3460/ND1. These three mutations, affecting
respiratory
complex I, account for about 95% of LHON cases. Patients inherit multicopy
mtDNA
entirely from the mother (via the oocyte). The mitochondria may carry only
wild-type or
only LHON mutant mtDNA (homoplasmy), or a mixture of mutant and wild-type
mtDNA
(heteroplasmy). Only high loads of mutant heteroplasmy or, most frequently,
homoplasmic mutant mtDNA in the target tissue put the subject at risk for
blindness from
LHON. Except for patients carrying the 14484/ND6 mutation (who present with a
more
benign disease course), most patients remain legally blind. Typically, a
subject in his
second or third decade of life will present with abrupt and profound loss of
vision in one
eye, followed weeks to months later by similar loss of vision in the other
eye. LHON may
occur later in life and affects both men and women. Environmental factors may
trigger the
visual loss but do not fully explain why only certain individuals within a
family become
symptomatic. Additional symptoms include disc microangiopathy, pseudo disc
edema,
vascular tortuosity, optic atrophy, cardiac conduction defects, spastic
paraparesis, sexual
and urinary disturbances, Sudden Infant Death Syndrome, abnormal visual evoked

potentials, spastic dystonia and encephalopathy.
[0174] Disruptions in ND4 can also lead to spastic paraparesis which is
associated with
leg stiffness, abnormal visual evoked potentials and sexual and urinary
disturbances.
4. Wolfram Syndrome 1
[0175] Wolfram Syndrome-1 (WFS1) is a rare and severe autosomal recessive
neurodegenerative disease caused by homozygous or compound heterozygous
mutations
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CA 02920246 2016-02-09
in the wolframin gene. Wolframin encodes an endoglycosidase H-sensitive
glycoprotein
that is expressed in the heart, brain, pancreas, liver, kidney, skeletal
muscle, hippocampus
CA1, amygdaloid areas, olfactory tubercle and allocortex. WFS1 is
characterized by
diabetes mellitus, optic atrophy, diabetes insipidus, and deafness (DIDMOAD).
Additional clinical features may include renal abnormalities, ataxia,
Nystagmus,
polyneuropathy, central respiratory failure, myoclonus, seizures, organic
brain syndrome,
dementia or mental retardation, urinary tract atony, orthostatic hypotension,
gastroparesis,
and diverse psychiatric illnesses. The minimal diagnostic criteria for Wolfram
Syndrome
are optic atrophy and diabetes mellitus of juvenile onset. Hearing impairment
in Wolfram
Syndrome is typically progressive and mainly affects the higher frequencies,
but a small
fraction of affected individuals have congenital deafness.
[0176] Autosomal dominant mutations in the WFS1 gene have been found to cause
low-
frequency nonsyndromic deafness as well as a Wolfram Syndrome-like phenotype
in
which affected individuals have hearing impairment with diabetes mellitus
and/or optic
atrophy.
[0177] Some cases of Wolfram Syndrome of early-onset diabetes mellitus, optic
atrophy, and deafness may have their basis in a mitochondrial mutation, such
as a 7.6-kb
heteroplasmic deletion of mtDNA extending from nucleotide 6466 to nucleotide
14134,
inclusive. Some patients exhibit mild hyperlactatemia or morphologic and
biochemical
abnormalities of the mitochondria. A high percentage of DIDMOAD patients
harbor so-
called secondary LHON mutations, and both DIDMOAD and LHON patients are
concentrated in 2 different mitochondrial haplotypes defined by sets of
polymorphisms in
ND and tRNA genes. Thus, the different clinical features of the mitochondrial
disease
groups investigated correspond to different clusters of mtDNA variants, which
might act
as predisposing haplotypes, increasing the risk for the given disease.
5. Wolfram Syndrome 2
[0178] Wolfram Syndrome-2 (WFS2) is an autosomal recessive neurodegenerative
disorder caused by homozygous mutations in the CISD2 (ERIS) gene, which
encodes
CDGSH iron sulfur domain protein 2. CISD2 is an endoplasmic reticulum-
localized zinc
finger protein that is expressed in pancreas, brain and other tissues. WFS2 is
characterized
by diabetes mellitus, mild diabetes insipidus, high frequency sensorineural
hearing loss,

CA 02920246 2016-02-09
optic atrophy or neuropathy, urinary tract dilatation, and defective platelet
aggregation
resulting in peptic ulcer bleeding.
6. Age-related Macular Degeneration
[0179] Age-related macular degeneration (ARMD) is a common complex disorder
that
affects the central region of the retina and is the leading cause of blindness
in Caucasian
Americans over 65 years of age. Susceptibility to ARMD is associated with
mutations in
the ARMS2 gene, which encodes a deduced 107-amino acid protein with nine
predicted
phosphorylation sites and a molecular mass of 12 kD. The ARMS2 protein is
localized to
the mitochondrial outer membrane.
Brunner Syndrome
[0180] Brunner Syndrome is a form of X-linked non-dysmorphic mild mental
retardation. Two monoamine oxidase isoenzymes, monoamine oxidase A (MAOA) and
monoamine oxidase B (MAOB), are closely linked in opposite orientation on the
X
chromosome and are expressed in the outer mitochondrial membrane. MAOA and
MAOB
oxidize neurotransmitters and dietary amines, the regulation of which is
important to the
maintenance of normal mental states. MAOA prefers the monoamines serotonin,
norepinephrine, and dopamine as substrates, while MAOB prefers
phenylethylamine.
Brunner Syndrome is caused by an MAOA deficiency, which results in an
accumulation
of serotonin, dopamine, and epinephrine, in the brain. Mutations in the MAOA
gene have
been associated with aggressive, violent, impulsive, autistic, and antisocial
behaviors.
Cardiomyopathy
1. Left Ventricular Noncompaction
[0181] Left ventricular noncompaction-1 (LVNC1) is caused by a heterozygous
mutation in the alpha-dystrobrevin gene and is characterized by numerous
prominent
trabeculations and deep intertrabecular recesses in hypertrophied and
hypokinetic
segments of the left ventricle.
[0182] The developing myocardium gradually condenses, and the large spaces
within the
trabecular meshwork flatten or disappear. Isolated noncompaction of
ventricular
myocardium, sometimes called spongy myocardium or persisting myocardial
sinusoids,
represents an arrest in endomyocardial morphogenesis, and is characterized by
numerous,
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CA 02920246 2016-02-09
excessively prominent trabeculations and deep intertrabecular recesses. LVNC
may occur
in isolation or in association with congenital heart disease. Distinctive
morphologic
features can be recognized on 2-dimensional echocardiography. Clinical
manifestations of
the disorder included depressed left ventricular systolic function,
ventricular arrhythmias,
systemic embolization, and distinctive facial dysmorphism.
[0183] The clinical presentation of left ventricular noncompaction is highly
variable,
ranging from asymptomatic to severe heart failure and sudden death. Higher
occurrence
of familial cases, facial dysmorphism, and congenital arrhythmias such as
Wolff-
Parkinson-White Syndrome are observed in children, whereas secondary
arrhythmias,
such as atrial fibrillation, are more common in adults. The mode of
inheritance is
predominantly autosomal dominant, and sarcomere protein mutations are more
common in
adults.
2. Infantile Histiocytoid Cardiomyopathy
[0184] Histiocytoid cardiomyopathy goes by various names, including infantile
xanthomatous cardiomyopathy, focal lipid cardiomyopathy, oncocytic
cardiomyopathy,
infantile cardiomyopathy with histiocytoid change, and foamy myocardial
transformation
of infancy. The disorder is caused by mutations in the gene encoding
mitochondrial
cytochrome b (MTCYB) and is a rare but distinctive entity of infancy and
childhood
characterized by the presence of characteristic pale granular foamy histiocyte-
like cells
within the myocardium. It usually affects children younger than 2 years of
age, with a
clear predominance of females over males. Infants present with dysrhythmia or
cardiac
arrest, and the clinical course is usually fulminant, sometimes simulating
Sudden Infant
Death Syndrome. Clinical features include high frequency of anomalies
involving the
nervous system and eyes and of oncocytic cells in various glands. Because of
the large
number of mitochondria present in the histiocytoid cells, they resemble
oncocytes. Other
disorders involving MTCYB mutations include exercise intolerance, myopathy,
LHON,
Familial Myalgia Syndrome, colorectal cancer, encephalomyopathy, Parkinsonism,
and
susceptibility to obesity.
3. Cardioencephalomyopathy with Cytochrome c Oxidase Deficiency (CEMCOX1)
[0185] Fatal infantile cardioencephalomyopathy due to cytochrome c oxidase
(COX)
deficiency-1 (CEMCOX1) can be caused by a compound heterozygous mutation in
the
SCO2 gene, a COX assembly gene on chromosome 22q13. Another form of fatal
infantile
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CA 02920246 2016-02-09
cardioencephalomyopathy due to COX deficiency, CEMCOX2 is caused by mutations
in
the COX15 gene on chromosome 10q24. Age of onset for infantile
cardioencephalomyopathy is usually within the first 3 months of infancy and is
equally
prevalent between males and females. Infants usually die at 6 months.
[0186] Infants with COX deficiency caused by a mutation in the SCO2 gene
present
with a fatal infantile cardioencephalomyopathy characterized by hypertrophic
cardiomyopathy, lactic acidosis, and gliosis. Heart and skeletal muscle show
reductions in
COX activity, whereas liver and fibroblasts show mild COX deficiencies.
Patients show a
severe reduction of the mitochondrial-encoded COX I and II subunits, whereas
the
nuclear-encoded COX subunits IV and Va are present but reduced in intensity.
Clinical
features include hypotonia, limb spasticity, muscle atrophy or denervation,
respiratory
difficulties, increased blood and CSF lactate, hypertrophic cardiomyopathy,
seizures,
psychomotor retardation, Leigh-like Syndrome, neutropenia, ptosis, gliosis,
ophthalmoplegia, encephalopathy, and severely reduced COX activity.
4. Sengers Syndrome: Cardiomyopathy, Hypertrophic & Cataracts
[0187] Sengers Syndrome, also known as cardiomyopathic mitochondrial DNA
depletion syndrome-10 (MTDPS10), is caused by a homozygous or compound
heterozygous mutation in the AGK gene. Sengers Syndrome is an autosomal
recessive
mitochondrial disorder characterized by congenital cataracts, hypertrophic
cardiomyopathy, skeletal myopathy, exercise intolerance, and lactic acidosis.
Mental
development is normal, but affected individuals may die early from
cardiomyopathy.
Skeletal muscle biopsies of affected individuals show severe mtDNA depletion.
[0188] While several pieces of evidence pointed indirectly to the involvement
of oxygen
free radicals in the etiology of cardiomyopathy with cataracts, direct
evidence showed that
complex I deficiency is associated with an excessive production of hydroxyl
radicals and
lipid peroxidation. Patients with isolated NADH:ubiquinone oxidoreductase
deficiency
(or complex I deficiency) most commonly present with fatal neonatal lactic
acidosis or
with Leigh disease. Although the clinical features of Sengers Syndrome suggest
a
mitochondrial disorder, no abnormalities are found on routine mitochondrial
biochemical
diagnostics, viz., the determination of pyruvate oxidation rates and enzyme
measurements.
Protein content of mitochondrial ANT 1 is strongly reduced in the muscle
tissues of
affected patients with Sengers Syndrome. Additional clinical phenotypes for
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CA 02920246 2016-02-09
cardiomyopathy with cataracts include hepatopathy, tubulopathy, hypotonia, and
mild
developmental delay.
5. Cardiofaciocutaneous Syndrome 1 (CFC1)
[0189] Cardiofaciocutaneous Syndrome-1 (CFC1), caused by disruptions in the
BRAF
gene, is a multiple congenital anomaly disorder characterized by a distinctive
facial
appearance, heart defects, and mental retardation. The heart defects include
pulmonic
stenosis, atrial septal defect, and hypertrophic cardiomyopathy. Some patients
have
ectodermal abnormalities such as sparse and friable hair, hyperkeratotic skin
lesions, and a
generalized ichthyosis-like condition. Typical facial characteristics include
high forehead
with bitemporal constriction, hypoplastic supraorbital ridges, downslanting
palpebral
fissures, a depressed nasal bridge, and posteriorly angulated ears with
prominent helices.
Most cases occur sporadically, but autosomal dominant transmission has been
rarely
reported.
[0190] Disruptions in BRAF gene function may impact the TCA cycle and
oxidative
metabolism. Clinical features include atopic dermatitis, ichthyosis,
hyperkeratosis
(extensor surfaces), keratosis pilaris, multiple palmar creases, multiple
lentigines, sparse
hair growth, optic nerve dysplasia, increased tendon reflexes, extensor
plantar response,
increased sensitivity to light touch, mental retardation, seizures, cortical
atrophy,
hypoplasia, ptosis, strabismus, oculomotor apraxia, nystagmus, hypertelorism,
exophthalmos, prominent philtrum, micrognathia, macrocephaly, joint
hyperextensibility,
osteopenia, clinodactyly, pectus excavatum or carinatum, short stature, GI
dysmotility,
splenomegaly, enlarged mitochondria, increased frequency of 2C fibers, reduced
C0Q10,
ventriculomegaly, hypsarrhythmia; and focal epileptiform discharges.
6. Trifunctional Protein Deficiency
[0191] Mitochondrial trifunctional protein (MTP) deficiency can be caused by
mutations
in the genes encoding either the alpha (HADHA) or beta (HADHB) subunits of the

mitochondrial trifunctional protein. The mitochondrial trifunctional protein,
composed of
4 alpha and 4 beta subunits, catalyzes 3 steps in mitochondrial beta-oxidation
of fatty
acids: long-chain 3-hydroxyacyl-CoA dehydrogenase (LCHAD), long-chain enoyl-
CoA
hydratase, and long-chain thiolase activities. Trifunctional protein
deficiency is
characterized by decreased activity of all 3 enzymes. Clinically, classic
trifunctional
protein deficiency can be classified into 3 main clinical phenotypes: neonatal
onset of a
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CA 02920246 2016-02-09
severe, lethal condition resulting in sudden unexplained infant death (SIDS),
infantile
onset of a hepatic Reye-like syndrome, and late-adolescent onset of primarily
a skeletal
myopathy.
[0192] Some patients with MTP deficiency show a protracted progressive course
associated with myopathy, recurrent rhabdomyolysis, and sensorimotor axonal
neuropathy. These patients tend to survive into adolescence and adulthood.
Clinical
features include cardiomyopathy, myopathy, liver dysfunction, encephalopathy,
Sudden
Infant Death Syndrome, and axonal neuropathy. Variant syndromes comprising MTP

mutations include hepatic with recurrent Hypoketotic hypoglycemia, later-onset
axonal
sensory neuropathy episodic myoglobinuria, and early-onset axonal sensory
neuropathy.
7. Encephalocardiomyopathv with Cytochrome c Oxidase Deficiency
[0193] Mutations in the nuclear gene C120RF62 have been associated with fatal
infantile encephalocardiomyopathy with cytochrome c oxidase deficiency.
C120RF62 is
a membrane-associated protein that localizes to the mitochondria and promotes
COX I
assembly & coupling with assembly of nascent subunits into COX holoenzyme
complex.
Clinical symptoms include reduced COX activity, neonatal lactic acidosis,
oligoamnios,
septum-lucidum cysts, hypotelorism, microphthalmia, ogival palate, single
palmar crease,
hypertrophic cardiomyopathy, hepatomegaly, renal hypoplasia, adrenal
hyperplasia, brain
hypertrophy, white-matter myelination, and cavities in parieto-occipital
region, brainstem,
and cerebellum.
8. Cardiomyopathy + Encephalopathy
[0194] Mutations in NADH-Ubiquinone oxidoreductase Fe-S Protein 2 (NDUFS2)
have
been associated with cardiomyopathy + encephalomyopathy. NDUFS2 is a component
of
complex I and plays a role in protein transport. The age of onset for the
disorder is from
birth to 7 months. Infants usually die before 2 to 3 years of age. Clinical
symptoms
include axial hypotonia, failure to thrive, hypertrophic cardiomyopathy, limb
hyperreflexia, optic atrophy, nystagmus, progressive encephalopathy, sleep
apnea, high
lactate levels in CSF & blood, hypodensities in basal ganglia; generalized
brain atrophy,
and reduced complex I activity.
9. Mitochondrial Phosphate Carrier Deficiency
[0195] Mitochondrial phosphate carrier deficiency can be caused by disruptions
in
5LC25A3, which encodes a mitochondrial solute carrier. 5LC25A3 aids in the
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CA 02920246 2016-02-09
inorganic phosphate into mitochondrial matrix and functions in ATP synthesis.
Mitochondrial phosphate carrier deficiency is characterized by progressive
hypertrophic
cardiomyopathy, respiratory failure, hypotonia, high serum lactate, lipid
accumulation in
type I muscle fibers, abnormal mitochondrial network, defective ATP synthesis
and
reduced mitochondrial phosphate carrier activity. Some infants die in the 1st
year,
whereas those that survive to adulthood exhibit exercise intolerance and
proximal
weakness.
10. Fatal infantile Cardioencephalomyopathy, due to Cytochrome c Oxidase
Deficiency 2 (CEMCOX2)
[0196] Fatal infantile cardioencephalomyopathy due to cytochrome c oxidase
(COX)
deficiency (CEMCOX2) can be caused by a compound heterozygous mutation in the
COX15 gene. Shortly after birth, patients present with seizures, hypotonia,
and lactic
acidosis. Other clinical symptoms include midface hypoplasia, biventricular
hypertrophic
cardiomyopathy and reduced Complex IV activity. Patients usually die within 1
month of
life.
11. Leigh Syndrome
[0197] Leigh Syndrome mutations have been identified in both nuclear- and
mitochondrial-encoded genes involved in energy metabolism, including
mitochondrial
respiratory chain complexes I, II, III, IV, and V, which are involved in
oxidative
phosphorylation and the generation of ATP, and components of the pyruvate
dehydrogenase complex.
[0198] Mutations in complex I genes include mitochondrial-encoded MTND2,
MTND3,
MTND5, and MTND6, the nuclear-encoded NDUFS1, NDUFS3, NDUFS4, NDUFS7,
NDUFS8, NDUFA2, NDUFA9, NDUFA10, NDUFA12, NDUFAF6, FOXRED1,
COXPD15 and C200RF7, and the complex I assembly factor NDUFAF2. A mutation in
the MTFMT gene, which is involved in mitochondrial translation, has also been
reported
with complex I deficiency.
[0199] Leigh Syndrome is also associated with mutations in complex I
(C80RF38),
complex II (the flavoprotein subunit A (SDHA)); complex III (BCS1L); complex
IV
(MTC03, COX10, COX15, SCO2, SURF1, TAC01, and PET100); complex V
(MTATP6); mitochondrial tRNA proteins (MTTV, MTTS2, MTTK, MTTW, and
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CA 02920246 2016-02-09
MTTL1); components of the pyruvate dehydrogenase complex (e.g., DLD and
PDHA1);
the LRPPRC gene; and coenzyme Q10.
[0200] Leigh Syndrome is an early-onset progressive neurodegenerative disorder
with a
characteristic neuropathology consisting of focal, bilateral lesions in one or
more areas of
the central nervous system, including the brainstem, thalamus, basal ganglia,
cerebellum,
and spinal cord. Age of onset is around 1 year and patients usually die within
2 years of
onset. The lesions are areas of demyelination, gliosis, necrosis, spongiosis,
or capillary
proliferation. Clinical features also include hypotonia, ataxia, vomiting,
choreoathetosis,
hyperventilation, encephalopathy, loss verbal milestones, motor spasticity,
abnormal
breathing rhythm, hearing loss, nystagmus, dystonia, visual loss,
ophthalmoparesis, optic
atrophy, peripheral neuropathy, intercurrent infection, cog-wheel rigidity,
distal renal
tubular acidosis, limb athetosis, seizures, carbohydrate intolerance, COX
deficiency in
muscle, lactic acidosis with hypoglycemia, kyphoscoliosis, short stature,
brisk tendon
reflexes, obesity, and high lactate levels in CSF. Clinical symptoms depend on
which
areas of the central nervous system are involved. The most common underlying
cause is a
defect in oxidative phosphorylation.
[0201] Mutations in NDUFV2, MTND2, MTND5, and MTND6 can result in Leigh
Syndrome due to mitochondrial complex I deficiency. Clinical symptoms include
reduced
Complex I activity, hypertrophic cardiomyopathy, developmental delay, cerebral
atrophy,
hypoplasia of the corpus callosum, acidosis, seizures, coma, cardiovascular
arrest,
demyelinization of corticospinal tracts, subacute necrotizing
encephalomyelopathy,
progressive encephalopathy, respiratory failure, exercise intolerance,
weakness,
mitochondrial proliferation in muscle, motor retardation, hypotonia, deafness,
dystonia,
pyramidal features, brainstem events with oculomotor palsies, strabismus &
recurrent
apnea, lactic acidemia, and basal ganglia lesions.
[0202] Mutations in MTC03 can result in Leigh Syndrome that usually presents
at 4
years of age. Clinical symptoms include spastic paraparesis with
ophthalmoplegia, high
serum lactic acid, Leigh-like lesions in putamen, and reduced COX activity in
muscle.
Mutations also found in MTC03 cause LHON, Myopathy with exercise intolerance,
rhabdomyolysis, episodic encephalopathy, and nonarteritic ischemic optic
neuropathy
(NAION)-Myoclonic epilepsy.
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CA 02920246 2016-02-09
[0203] Mutations in 3-hydroxyisobutyryl-CoA hydrolase (HIBCH) results in 13-
Hydroxyisobutyryl CoA Deacylase (H1BCH) deficiency, a Leigh-like Syndrome that

usually manifests at neonatal to 6 months of age. Symptoms include hypotonia,
regression, poor feeding, dystonia, ataxia, seizures, dysmorphic facies,
vertebral
anomalies, tetralogy of fallot, progressive or acute encephalopathy,
respiratory chain
deficiencies, high CSF lactate, basal ganglia abnormalities, brain agenesis
and
accumulation of metabolites (e.g., methacrylyl-CoA, acryloyl-CoA, hydroxy-C4-
carnitine).
[0204] Mutations in enoyl-CoA hydratase, short-chain, 1 (ECHS1) results in
Short chain
enoyl-CoA hydratase (ECHS1) deficiency, a Leigh-like Syndrome that presents at
the
neonatal stage. ECHS1 catalyzes the second step in mitochondrial fatty acid 13-
oxidation.
Clinical symptoms include hypotonia, respiratory insufficiency or apnea,
bradycardia,
developmental delay, high serum lactate, white matter atrophy, and
accumulation of
metabolites (e.g., methacrylyl-CoA, acryloyl-CoA).
[0205] Mutations in ATP synthase 6 (MTATP6) result in Maternal Inheritance
Leigh
Syndrome (MILS). Clinical symptoms include hypotonia, developmental delay,
peripheral neuropathy, seizures, retinitis pigmentosa or optic atrophy,
ataxia, respiratory
failure, bilateral striatal necrosis, hereditary spastic paraparesis,
myelopathy, limb
spasticity, weakness, and sensory loss or pain.
12. Dilated Cardiomyopathy with Ataxia (DCMA)
[0206] 3-methylglutaconic aciduria type V (MGCA5), also called dilated
cardiomyopathy with ataxia (DCMA), is caused by a homozygous mutation in the
DNAJC19 gene on chromosome 3q26. DNAJC19 encodes a DNAJ domain-containing
protein that is localized to the inner mitochondrial membrane (TIM) and may be
involved
in molecular chaperone systems of Hsp70/Hsp40 type. Mitochondrial import inner

membrane translocase subunit TIM14 may also act as a co-chaperone that
stimulates the
ATP-dependent activity.
[0207] DCMA is an autosomal recessive disorder characterized by the onset of
dilated or
noncompaction cardiomyopathy in infancy or early childhood. Clinical symptoms
include
cardiomyopathy, long Q-T syndrome, cerebellar ataxia, delayed psychomotor
development, optic atrophy, mental retardation, seizures, testicular
dysgenesis,
cryptorchidism to severe perineal hypospadias, growth retardation, microcytic
anemia,
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CA 02920246 2016-02-09
mild muscle weakness, mildly elevated hepatic enzymes and increased urinary
excretion
of 3-methylglutaconic acid.
13. Mitochondrial DNA Depletion Syndrome 12 (Cardiomyopathic type)
[0208] Mitochondrial DNA Depletion Syndrome-12 (MTDPS12) is caused by
homozygous mutations in the Adenine nucleotide translocator 1 (ANTI) gene.
Heterozygous mutations in the ANT 1 gene cause autosomal dominant progressive
external
ophthalmoplegia-2 (PEOA2).
[0209] Mitochondrial DNA Depletion Syndrome-12 is an autosomal recessive
mitochondrial disorder characterized by childhood onset of slowly progressive
hypertrophic cardiomyopathy and generalized skeletal myopathy resulting in
exercise
intolerance and, in some patients, muscle weakness, pain and atrophy. Skeletal
muscle
biopsy shows ragged red fibers, mtDNA depletion, and accumulation of abnormal
mitochondria. Clinical symptoms include headache episodes, nausea, vomiting,
moderately high levels of creatine kinase in serum, ankle contractures, lactic
acidosis,
hyperalaninemia, SDH-positive muscle fibers, multiple mtDNA deletions or
depletions,
abnormal mitochondria containing paracrystalline inclusions, high citrate
synthase levels,
partial reductions in complexes I, III, IV and V, cardiomyocyte degeneration,
subendocardial interstitial fibrosis, and arteriolar smooth muscle
hypertrophy.
14. Cardiomyopathy due to Mitochondrial tRNA Deficiencies
[0210] Mutations in mtRNA lle (MTTI) can result in fatal infantile onset
cardiomyopathy. Clinical features of other mtRNA Ile syndromes include cardiac
dilation
and hypertrophy, short stature, deafness, some MELAS symptoms, death due to
cardiac
failure, low mitochondrial oxidative enzymes, familial progressive necrotizing

encephalopathy, impaired glucose tolerance, hyperlipidemia, hyperuricemia,
progressive
myoclonus epilepsy, ragged red fibers, spastic paraparesis, ataxia; PEO;
mental
retardation, diabetes mellitus, hypomagnesemia, hypokalemia, hypertension,
hypercholesterolemia, increased prevalence of migraine headache, and
rhabdomyolysis.
[0211] Mutations in mtRNA Lys can result in neonatal hypertrophic
cardiomyopathy,
diabetes, MERRF, high lactate and pyruvate levels in serum and infantile
death.
[0212] Mutations in mtRNA Leu (MTTL1) can result in hypertrophic
cardiomyopathy
Barth-like Syndrome, diabetes, dilated cardiomyopathy, MERRF/KSS, MELAS, MERRF-

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CA 02920246 2016-02-09
like with diabetes, optic neuropathy & retinopathy, left ventricular
noncompaction, Wolff-
Parkinson-White conduction defects, Sudden Infant death Syndrome, riboflavin
sensitive
myopathy, rhabdomyolysis, fatigue, PEO, and the like. Age of onset typically
occurs
between 24 to 40 years.
[0213] Mutations in mtRNA Leu (MTTL2) can result in adult onset
cardiomyopathy,
myopathy, sideroblastic anemia, PEO, and encephalomyopathy.
[0214] Mutations in mtRNA His can result in adult onset dilated or
hypertrophic
cardiomyopathy, pigmentary retinopathy and sensorineural deafness.
[0215] Mutations in mtRNA Gly can result in exercise intolerance,
nonobstructive
hypertrophic cardiomyopathy (onset age: neonatal to childhood), Complex IV &
Complexes II + III deficiencies and sudden death.
15. Cardiomyopathy: Mitochondrial ATP synthase (Complex V) Defects
[0216] Mutations in ATP synthase Fl complex assembly factor-2 (ATP 12), which
is
required for Complex V biogenesis, can result in mitochondrial complex V (ATP
synthase) deficiency nuclear type 1 (MC5DN1). The disorder manifests at birth
and
subjects exhibit low APGAR scores and birth weight. Biochemically, the
patients show a
generalized decrease in the content of ATP synthase complex which is less than
30% of
normal as well as high plasma lactate levels. Most cases present with neonatal-
onset
hypotonia, lactic acidosis, hepatomegaly, hyperammonemia, hypertrophic
cardiomyopathy, facial dysmorphism, microcephaly, psychomotor and mental
retardation,
and 3-methylglutaconic aciduria. Many patients die within a few months or
years.
[0217] Mutations in mitochondrial ATP synthase 8 (MT-ATP8), a component of
Complex V, can also result in apical hypertrophic cardiomyopathy and
neuropathy. The
disorder manifests during infancy and is associated with delayed motor
development, gait
and balance disorder, dysarthric speech, extensor plantar response, reduced
tendon
response, mild external ophthalmoplegia, exercise intolerance, shortness of
breath
(dyspnea) during exercise, angina and apical left ventricular hypertrophy,
neuropathy,
reduced Complex V activity & assembly, high lactate levels in CSF and abnormal
nerve
conduction velocity in legs.

CA 02920246 2016-02-09
16. Mitochondrial Complex IV Deficiency
[0218] Complex IV (cytochrome c oxidase) is the terminal enzyme of the
respiratory
chain and consists of 13 polypeptide subunits, 3 of which are encoded by
mitochondrial
DNA. The 3 mitochondrial encoded proteins in the cytochrome oxidase complex
are the
actual catalytic subunits that carry out the electron transport function.
[0219] Cytochrome c oxidase deficiency can be caused by mutations in several
nuclear-
encoded and mitochondrial-encoded genes. Mutations associated with the
disorder have
been identified in several mitochondrial COX genes, MTC01, MTCO2, MTC03, as
well
as in mitochondrial tRNA (ser) (MTTS1) and tRNA (leu) (MTTL1). Mutations in
nuclear
genes include those in COX10, COX6B1, SC01, FASTI(D2, C20RF64 (COA5), COA6,
C120RF62 (COX14), COX20, and APOPT1. COX deficiency caused by mutations in
SCO2 and COX15 have been found to be associated with fatal infantile
cardioencephalomyopathy. Cytochrome c oxidase deficiency associated with Leigh

Syndrome may be caused by mutations in the SURF1 gene, COX15 gene, TAC01 gene,

or PET100 gene. Cytochrome c oxidase deficiency associated with the French
Canadian
type of Leigh Syndrome (LSFC) is caused by mutations in the LRPPRC gene. Most
isolated COX deficiencies are inherited as autosomal recessive disorders
caused by
mutations in nuclear-encoded genes; mutations in the mtDNA-encoded COX subunit

genes are relatively rare.
[0220] Clinical features associated with the disruption of COA5 function
include
hypertrophic restrictive cardiomyopathy, accumulation of lipid droplets in
muscle, reduced
Complex IV activity, and mitochondrial proliferation in muscle. Age of onset
occurs in
less than 1 month or in utero.
[0221] Clinical features associated with the disruption of COA6 function
include
hypertrophic cardiomyopathy, reduced complexes I & IV in cardiac tissue, and
multiple
respiratory chain defects. Age of onset occurs in less than 1 year.
17. Combined Oxidative Phosphorylation Deficiency 8 (COXPD8)
[0222] Combined oxidative phosphorylation deficiency-8 (COXPD8) is caused by a

homozygous or compound heterozygous mutation in the Alanyl-tRNA Synthetase 2
(AARS2) gene, which encodes an amino acid tRNA synthetase.
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CA 02920246 2016-02-09
[0223] COXPD8 is an autosomal recessive disorder due to dysfunction of the
mitochondrial respiratory chain. The main clinical manifestation is a lethal
infantile
hypertrophic cardiomyopathy, but there may also be subtle skeletal muscle and
brain
involvement. Biochemical studies show combined respiratory chain complex
deficiencies
in complexes I, III, and IV in cardiac muscle, skeletal muscle, and brain. The
liver is not
affected. Muscle cells are positive for both COX & SDH.
[0224] A variant AARS2 syndrome is progressive leukoencephalopathy with
ovarian
failure (LKENP), an autosomal recessive neurodegenerative disorder
characterized by loss
of motor and cognitive skills, usually with onset in young adulthood. Some
patients may
have a history of delayed motor development or learning difficulties in early
childhood.
Neurologic decline is severe, usually resulting in gait difficulties, ataxia,
spasticity, and
cognitive decline and dementia. Most patients lose speech and become
wheelchair-bound
or bedridden. Brain MRI shows progressive white matter signal abnormalities in
the deep
white matter. Affected females develop premature ovarian failure. Clinical
features of
LKENP include COX deficiency, ataxia, cerebellar atrophy, spasticity,
cognitive decline,
delayed development, ovarian failure during the 3rd to 5th decade, loss of
motor skills,
speech & cognition by 5th decade, and abnormal cerebral white matter.
18. Combined Oxidative Phosphorylation Deficiency 10 (COXPD10)
[0225] Combined oxidative phosphorylation deficiency-10 (COXPD10) is caused by

homozygous or compound heterozygous mutations in the mitochondrial translation

optimization 1 homolog (MT01) gene. MT01 is a mitochondrial-tRNA modifier that
is
normally expressed in tissues with high metabolic rate, such as skeletal
muscle, liver, and
heart. COXPD10 is an autosomal recessive disorder resulting in variable
defects of
mitochondrial oxidative respiration. Affected individuals present in infancy
with
hypertrophic cardiomyopathy and lactic acidosis. The severity is variable, but
can be fatal
in the most severe cases. Additional clinical symptoms include
oligohydramnios,
hypotonia, psychomotor delay, spasticity, seizures, dystonia, hypoglycemia,
metabolic
acidosis, high serum lactate and reduced Complex I & IV activity.
[0226] Loss of MT01 function can also result in encephalomyopathy, which
usually
manifests at 3 months of age. Symptoms include seizures, infantile spasms,
delayed motor
& cognitive development, axial hypotonia, chorio-athetoid movements, COX
negative
muscle fibers, and Complex IV deficiency.
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CA 02920246 2016-02-09
19. Combined Oxidative Phosphorylation Deficiency 16 (COXPD16)
[0227] Combined oxidative phosphorylation deficiency-16 (COXPD16) is caused by

homozygous mutations in the MRPL44 gene. MRPL44 encodes a structural subunit
of
mitochondrial large (39S) ribosomal subunit and plays role in the assembly and
stability of
the 39S subunit. Age of onset is usually at 3 to 6 months. Clinical features
include
hypertrophic cardiomyopathy, steatosis, high levels of liver transaminases,
high serum
lactate, reduced COX staining in muscle, and reduced Complex I and IV
activity.
[0228] Other mitochondrial ribosomal subunit disorders include disruptions in
MRPS16
and MRPS22, which encode components of the small ribosomal subunit. Symptoms
include early death and severe lactic acidosis. Alternatively, disruptions in
MRPL3, which
encodes a component of the large ribosomal subunit, results in cardiomyopathy
and mental
retardation.
20. Combined Oxidative Phosphorylation Deficiency 17 (COXPD17)
[0229] Combined oxidative phosphorylation deficiency-17 (COXPD17) is caused by

homozygous or compound heterozygous mutations in the ELAC2 gene, which encodes
a
zinc phosphodiesterase protein with tRNA processing endonuclease activity. The
protein
also interacts with PTCD1 and is ubiquitously expressed. Combined oxidative
phosphorylation deficiency-17 is an autosomal recessive disorder of
mitochondrial
dysfunction characterized by onset of severe hypertrophic cardiomyopathy in
the first year
of life. Other features include hypotonia, poor growth, microcephaly, lactic
acidosis,
delayed psychomotor development, impaired central hearing, high alanine and
glutamine
levels, abnormal mitochondrial cristae, reduced Complex I and IV activity and
failure to
thrive. The disorder may be fatal in early childhood.
21. Combined Oxidative Phosphorylation Deficiency 5 (COXPD5)
[0230] Mutations in MRPS22 can result in combined oxidative phosphorylation
deficiency-5 (COXPD5). Patients show reduced activities of mitochondrial
respiratory
chain complexes I, III, and IV, marked and generalized defect in mitochondrial
translation,
microcephaly, dilated cardiomyopathy, dysmorphic features, hypotonia,
metabolic
acidosis, transient seizures, poor growth, lack of development, and spastic
tetraplegia.
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CA 02920246 2016-02-09
[0231] Mutations in NDUFAll can result in mitochondrial complex I deficiency.
Symptoms include fatal infantile metabolic acidosis, encephalocardiomyopathy
with brain
atrophy, no motor development, and hypertrophic cardiomyopathy.
22. Combined Oxidative Phosphorylation Deficiency 9 (COXPD9)
[0232] Combined oxidative phosphorylation deficiency-9 (COXPD9) is caused by
compound heterozygous mutations in the MRPL3 gene. Patients present with
failure to
thrive, poor feeding, hypertrophic cardiomyopathy, hepatomegaly, psychomotor
retardation, mental retardation, increased plasma lactate and alanine,
abnormal liver
enzymes, and decrease in activity of mitochondrial respiratory complexes I,
III, IV, and V,
with a mild decrease in complex II.
Carnitine Disorders
[0233] Carnitine (beta-hydroxy-gamma-trimethylaminobutyric acid) is an
essential
cofactor for transport of long chain fatty acids across mitochondrial
membranes,
permitting beta-oxidation. Carnitine in body fluids is derived from the diet
or biosynthesis
and is actively transported into muscle. Two biochemically and clinically
distinct
disorders cause low concentrations of carnitine in skeletal muscle. Systemic
carnitine
deficiency shows low carnitine in the liver and/or plasma. In muscle carnitine
deficiency,
lipid storage myopathy occurs with low muscle carnitine but normal liver and
serum
carnitine.
[0234] The age of onset for carnitine deficiency, myopathic form occurs during

childhood ¨early adulthood. Symptoms include weakness, cardiomyopathy, and
congestive heart failure.
1. Carnitine Acetyltransferase Deficiency
[0235] Carnitine acetyltransferase (CRAT) deficiency is an autosomal recessive
disorder
characterized by ataxia, oculomotor palsy, hypotonia, poor respiration,
failure to thrive,
and altered consciousness. CRAT functions in the maintenance of normal fatty
acid
metabolism by catalyzing the transfer of acyl groups from acyl-CoA thioester
to carnitine.
CRAT controls the ratio of acyl-CoAJCoA in mitochondria, peroxisomes, and
endoplasmic reticulum. CRAT deficiency has been shown to be associated with
deletions
of mitochondrial DNA, mainly the ND4-ND4L region, in muscle. Other regions of
the
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CA 02920246 2016-02-09
mitochondrial genome also showed deletions of varying size and extent,
suggesting
multiple deletions of the mitochondrial DNA.
2. Carnitine Palmitoyltransferase I Deficiency
[0236] Carnitine palmitoyltransferase I (CPT I) deficiency is an autosomal
recessive
metabolic disorder that affects the mitochondrial oxidation of long-chain
fatty acids in the
liver and kidneys and is characterized by recurrent episodes of fasting-
induced hypoketotic
hypoglycemia and an elevated risk of liver failure. During metabolic crisis,
blood tests
reveal hypoglycemia, elevated levels of plasma carnitine and liver
transaminases, and mild
hyperammonemia. Urine tests may show unusually low levels of ketones, and
medium-
chain dicarboxylic aciduria. CPT I deficiency is associated with mutations in
the CPT1A
gene, which encodes carnitine palmitoyltransferase IA. The carnitine
palmitoyltransferase
enzyme system comprising CPT I and CPT II, in combination with acyl-CoA
synthetase
and carnitine/acylcarnitine translocase, provides the mechanism by which long-
chain fatty
acids are transferred from the cytosol to the mitochondrial matrix. The CPT I
isozymes,
CPT1A and CPT1B are located in the mitochondrial outer membrane, whereas CPT
II is
located in the inner mitochondrial membrane.
3. Myopathic Carnitine Deficiency
[0237] Myopathic carnitine deficiency is a progressive autosomal recessive
disorder
characterized by lipid storage myopathy with low muscle carnitine but normal
liver and
serum carnitine. Clinical features include symmetric, proximal weakness in the
face and
tongue, cardiomyopathy, congestive heart failure, moderately elevated serum
creatine
kinase levels.
4. Primary Systemic Carnitine Deficiency
[0238] Primary systemic carnitine deficiency (CDSP) is an autosomal recessive
disorder
of fatty acid oxidation caused by a homozygous or compound heterozygous
mutation in
the SLC22A5 gene. The SLC22A5 gene encodes solute carrier family 22 member 5
protein, which functions as a sodium-ion dependent, high affinity carnitine
transporter
involved in the active cellular uptake of carnitine. Mutations in the SLC22A5
gene result
in a defective carnitine transporter, which is expressed in muscle, heart,
kidney, and
fibroblasts. This results in impaired fatty acid oxidation in skeletal and
heart muscle. In
addition, renal wasting of carnitine results in low serum levels and
diminished hepatic

CA 02920246 2016-02-09
uptake of carnitine by passive diffusion, which impairs ketogenesis. If
diagnosed early, all
clinical manifestations of the disorder can be completely reversed by
supplementation of
carnitine. However, if left untreated, patients will develop lethal heart
failure.
5. Carnitine Palmitoyltransferase II Deficiency
[0239] Carnitine palmitoyltransferase II (CPT II) deficiency is an autosomal
recessive
disorder and is the most common inherited disorder of mitochondrial long-chain
fatty acid
oxidation and is associated with mutations in the CPT2 gene. The CPT2 gene
encodes
carnitine palmitoyltransferase 2 an enzyme that is essential for fatty acid
oxidation. Over
70 different mutations in the CPT2 gene have been identified. CPT2 mutations
lead to a
reduction in the activity of carnitine palmitoyltransferase 2. There are three
main types of
CPT II deficiency: a lethal neonatal form, a severe infantile
hepatocardiomuscular form,
and a myopathic form.
[0240] The lethal neonatal form becomes apparent soon after birth. Infants
with this
form of CPT II deficiency develop respiratory failure, seizures, liver
failure,
cardiomyopathy, and arrhythmia. Affected infants also exhibit hypoketotic
hypoglycemia
and structurally abnormal brain and kidneys. Infants with the lethal neonatal
form of CPT
II deficiency typically survive for only a few days to a few months.
[0241] The severe infantile hepatocardiomuscular form of CPT II deficiency
affects the
liver, heart, and muscles. Signs and symptoms usually appear within the first
year of life.
This form involves recurring episodes of hypoketotic hypoglycemia, seizures,
hepatomegaly, cardiomyopathy, and arrhythmia. Problems related to this form of
CPT II
deficiency can be triggered by periods of fasting or by illnesses such as
viral infections.
Individuals with the severe infantile hepatocardiomuscular form of CPT II
deficiency are
at risk for liver failure, nervous system damage, coma, and sudden death.
[0242] The myopathic form is the least severe type of CPT II deficiency. This
form is
characterized by recurrent episodes of myalgia and rhabdomyolysis. The
destruction of
muscle tissue results in myoglobinuria. Myoglobin can also damage the kidneys,
in some
cases leading to life-threatening kidney failure. Episodes of myalgia and
rhabdomyolysis
may be triggered by exercise, stress, exposure to extreme temperatures,
infections, or
fasting. The first episode usually occurs during childhood or adolescence.
Most people
with the myopathic form of CPT II deficiency have no signs or symptoms of the
disorder
between episodes.
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6. Carnitine-acylcarnitine Translocase Deficiency
[0243] Carnitine-acylcarnitine translocase deficiency (CACTD) is an autosomal
recessive metabolic disorder of long-chain fatty acid oxidation caused by a
homozygous or
compound heterozygous mutation in the SLC25A20 gene. The SLC25A20 gene encodes

carnitine-acylcarnitine translocase (CACT), one of the components of the
carnitine cycle
that mediates the transport of acylcarnitines of different length across the
mitochondrial
inner membrane from the cytosol to the mitochondrial matrix for their
oxidation by the
mitochondrial fatty acid-oxidation pathway.
[0244] Individuals with CACTD exhibit hypoketotic hypoglycemia under fasting
conditions, hyperammonemia, elevated serum creatine kinase and transaminases,
dicarboxylic aciduria, very low free carnitine, and abnormal acylcarnitine
profile with
marked elevation of the long-chain acylcarnitines. Additional features include
neurologic
abnormalities, cardiomyopathy and arrhythmias, skeletal muscle damage, and
liver
dysfunction. Most patients become symptomatic in the neonatal period with a
rapidly
progressive deterioration and a high mortality rate. However, presentations at
a later age
with a milder phenotype have been reported.
Cartilage-hair Hypoplasia
[0245] Cartilage-hair hypoplasia, a form of short-limbed dwarfism due to
skeletal
dysplasia, is caused by mutations in the RMRP gene. RMRP encodes an RNA with
endoribonuclease activity that cleaves mitochondrial RNA complementary to
light chain
of displacement loop. Clinical symptoms include short stature, joint
hyperextensibility,
metaphyseal dysplasia, hypoplastic sparse hair, neuronal dysplasia, megacolon,

malabsorption, increased risk of lymphoma & skin neoplasm, susceptibility to
chickenpox,
lymphopenia, neutropenia, and hypoplastic macrocytic anemia.
Cerebrotendinous Xanthomatosis
[0246] Cerebrotendinous xanthomatosis (CTX), also known as Van Bogaer-Scherer-
Epstein disease, is an autosomal recessive lipid-storage disorder caused by
the deficient
activity of mitochondrial sterol 27-hydroxylase (CYP27A1). CTX is associated
with
mutations in the CYP27A1 gene, which encodes sterol 27-hydroxylase. CTX is
characterized by the formation of xanthomatous lesions in many tissues,
particularly in the
brain, eye lens, and tendons resulting in progressive neurologic dysfunction,
premature
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CA 02920246 2016-02-09
atherosclerosis, and cataracts. Cholestanol, the 5-alpha-dihydro derivative of
cholesterol,
is enriched relative to cholesterol in all tissues. A diagnosis of CTX is
typically made by
demonstrating that cholestanol is present in abnormal amounts in the serum and
tendon in
suspected affected individuals.
Congenital Adrenal Hvperplasia
[0247] Congenital adrenal hyperplasia (CAH) comprises a group of monogenic
autosomal recessive disorders caused by an enzyme deficiency in steroid
biosynthesis. All
of the adrenal hyperplasia syndromes are examples of mixed hypo- and
hyperadrenocorticism. CAH is associated with 11-beta-hydroxylase deficiency
caused by
a mutation in the CYP11B1 gene. The CYP11B1 gene encodes 11-beta-hydroxylase,
which functions primarily in the mitochondria in the zona fasciculata of the
adrenal cortex
to convert 11-deoxycortisol to cortisol and 11-deoxycorticosterone to
corticosterone.
CAH due to 11-beta-hydroxylase deficiency results in androgen excess,
virilization, and
hypertension. The defect causes decreased cortisol and corticosterone
synthesis in the
zona fasciculata of the adrenal gland, resulting in the accumulation of 11-
deoxycortisol
and 11-deoxycorticosterone.
Congenital Muscular Dystrophy with Mitochondrial Structural Abnormalities
(Megaconial) (MDCMC)
[0248] Megaconial type congenital muscular dystrophy is caused by homozygous
or
compound heterozygous mutations in the choline kinase beta (CHKB) gene. This
form of
autosomal recessive congenital muscular dystrophy is characterized by early-
onset muscle
wasting and mental retardation. Some patients develop fatal cardiomyopathy.
Muscle
biopsy shows peculiar enlarged mitochondria that are prevalent toward the
periphery of
the fibers but are sparse in the center. Additional clinical symptoms include
hypotonia,
progressive weakness, delayed walking, small head circumference, elevated
creatine
kinase, muscle necrosis, and increased endomysial connective tissue.
Cerebral Creatine Deficiency Syndrome-3
[0249] Cerebral creatine deficiency syndromes (CCDS) comprise a group of
inborn
errors of creatine metabolism and include the X-linked creatine transporter
(SLC6A8)
deficiency (CCDS1) and the two autosomal recessive creatine biosynthesis
disorders,
guanidinoacetate methyltransferase (GAMT) deficiency (CCDS2) and L-
arginine:glycine
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amidinotransferase (AGAT or GATM) deficiency (CCDS3). Cerebral creatine
deficiency
syndrome-3 (CCDS3) is associated with the following AGAT mutations:
Ala97ValfsX11;
Trp149X; Arg169X; Tyr203Ser; and Met371AsnfsX6. AGAT is localized to the
mitochondrial intermembrane space.
[0250] These disorders are characterized by developmental delay/regression,
mental
retardation, severe depressive and cognitive speech disturbances, seizures,
and depletion
of creatine/phosphocreatine levels in the brain. Additional manifestations
include
muscular hypotonia and movement disorder (mainly extrapyramidal). The
characteristic
biochemical hallmark of all CCDS is cerebral creatine deficiency as detected
by proton
magnetic resonance spectroscopy (H-MRS). Increased levels of guanidinoacetate
in body
fluids are indicative of GAMT deficiency, whereas reduced guanidinoacetate
levels are
indicative of AGAT deficiency. An elevated urinary creatine/creatinine ratio
is associated
with SLC6A8 deficiency.
Deafness
1. Maternal Nons_yndromic Deafness
[0251] Mutations in mitochondrial DNA (mtDNA) have been found to be associated

with nonsyndromic sensorineural hearing loss. MitochondriaIly inherited
nonsyndromic
sensorineural deafness can be caused by mutations in any 1 of several
mitochondrial
genes, including MTRNR I, MTTS1, MTC01, MTTH, MTND1, and MTTI. Matrilineal
relatives within and among families carrying certain pathogenic mitochondrial
mutations
exhibit a wide range of penetrance, severity, and age of onset of hearing
loss, indicating
that the mitochondrial mutations by themselves are not sufficient to produce a
deafness
phenotype. Modifier factors, such as nuclear and mitochondrial genes, or
environmental
factors, such as exposure to aminoglycosides, appear to modulate the
phenotypic
manifestations.
2. Maternal Syndromic Deafness
[0252] Mitochondrially inherited syndromic sensorineural deafness can be
caused by
mutations in any 1 of several mitochondrial genes (including MTTL1, MTTS1,
MTTS2,
MTTL, MTTK, MTTQ), large (> 1 kb) heteroplasmic deletions, or large (> 1 kb)
heteroplasmic partial duplications.
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3. Sporadic Syndromic Deafness
[0253] Sporadic syndromic deafness can be caused by single large mtDNA
deletion or
mutations in MTC01. Clinical symptoms associated with MTC01-induced syndromic
deafness include cataracts, progressive sensorineural deafness, myopathy,
ataxia,
myoclonic epilepsy, visual loss, optic atrophy, reduced COX activity,
cerebellar atrophy,
and bilateral small symmetrical nodular hyperintensities. Mutations in MTC01
can result
in sideroblastic anemia, exercise intolerance and LHON.
4. Autosomal Dominant Deafness-64 (DFNA64)
[0254] Autosomal dominant deafness-64 (DFNA64) is caused by heterozygous
mutations in the DIABLO gene. The age at onset ranges between 12 and 30 years
(average age of 22). The severity of hearing impairment ranges from severe to
moderate
to mild and correlates with age. High frequency tinnitus was reported in 73%
of affected
individuals at the onset of hearing loss.
5. Deafness-Dystonia-Dementia Syndromes
[0255] Mohr-Tranebjaerg Syndrome and Jensen Syndrome have been found to be
caused by mutations in the T1MM8A (DDP) gene, which aid in the importation of
metabolite transporters from cytoplasm to mitochondrial inner membrane.
Clinical
symptoms of Mohr-Tranebjaerg Syndrome (Deafness-dystonia Syndrome) include
progressive sensory-neural hearing loss, myopia, reduced visual acuity,
constricted visual
fields, retinal change, dystonia, mental deficiency, and cortical blindness.
Clinical
symptoms of Jensen Syndrome include blindness, optic atrophy, sensorineural
hearing
loss, dementia, CNS calcifications, and muscle wasting.
[0256] Mutations in the chaperonin HSP60 also impact mitochondrial protein
importation and may lead to hereditary spastic paraplegia.
6. Dystonia, Deafness with Leigh-like Syndrome (MEGDEL)
[0257] 3-methylglutaconic aciduria with deafness, encephalopathy, and Leigh-
like
Syndrome (MEGDEL) is an autosomal recessive disorder characterized by
childhood
onset of delayed psychomotor development or psychomotor regression,
sensorineural
deafness, spasticity or dystonia, and increased excretion of 3-
methylglutaconic acid.
MEGDEL is caused by homozygous or compound heterozygous mutations in the

CA 02920246 2016-02-09
SERAC1 gene, which plays a role in phospholipid exchange and intracellular
cholesterol
trafficking. Brain imaging of affected subjects shows cerebral and cerebellar
atrophy as
well as lesions in the basal ganglia reminiscent of Leigh Syndrome. Clinical
symptoms
include hypotonia, encephalopathy (Leigh-like Syndrome), mental retardation,
sensorineural deafness, spasticity, dystonia, hepatopathy, increased serum
lactate and
alanine, hyperammonemia, 3-Methylglutaconic aciduria, high transaminases,
coagulopathy, high serum a-fetoprotein, mitochondrial oxidative
phosphorylation defects,
abnormal mitochondria, abnormal phosphatidylglycerol and cardiolipin profiles
in
fibroblasts, and abnormal accumulation of unesterified cholesterol within
cells.
7. Reticular Dysgenesis
[0258] Reticular dysgenesis is one of the rarest and most severe forms of
combined
immunodeficiency and is caused by a homozygous or compound heterozygous
mutation in
the mitochondrial adenylate kinase-2 gene (AK2). Reticular dysgenesis is
characterized
by bilateral sensorineural deafness, congenital agranulocytosis, lymphopenia,
and
lymphoid and thymic hypoplasia with absent cellular and humoral immunity
functions.
8. Steroid-resistant Nephrotic Syndrome & Sensorineural Hearing Loss (C0Q10D6)

[0259] Primary coenzyme Q10 deficiency-6 (C0Q10D6) is an autosomal recessive
disorder characterized by onset in infancy of severe progressive nephrotic
syndrome
resulting in end-stage renal failure and sensorineural deafness. COQ10D6 is
caused by
homozygous or compound heterozygous mutations in the COQ6 gene. Renal biopsy
usually shows focal segmental glomerulosclerosis (FSGS). Clinical features
include
bilateral sensorineural deafness and steroid-resistant nephrotic syndrome.
9. Cataracts, Growth hormone Deficiency, Sensory Neuropathy, Sensorineural
Hearing Loss, Skeletal Dysplasia (CAGSSS)
[0260] Mutations in isoleucyl-tRNA synthetase 2 (IARS2), an aminoacyl-tRNA
synthetase, results in CAGSSS. Clinical symptoms include sensorineural
deafness,
cataracts, skeletal dysplasia, facial dysmorphism, short stature, hip
disorders, scoliosis,
cervical stenosis, C2-odontoid hypoplasia, spondylo-epiphyseal dysplasia,
sensory loss
polyneuropathy, growth hormone deficiency, and pituitary adenohypophysis
atrophy.
Alternate IARS2 syndromes include Leigh Syndrome.
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Diabetes
[0261] Diabetes may arise as a result of mutations in MTTL, MTTK, MTTE, MTTS2,

mitochondrial elongation factor G2 (GFM2), single large mtDNA deletions, and
large
scale mtDNA tandem duplications. Diabetes is usually observed in patients
affected with
Kearns-Sayre Syndrome, Wolfram Syndrome, Friedreich's ataxia and Metabolic
Syndrome in obesity.
Dimethylglycine Dehydrogenase Deficiency
[0262] Dimethylglycine dehydrogenase deficiency (DMGDHD) is an autosomal
recessive glycine metabolism disorder characterized by chronic muscle fatigue,
elevated
serum levels of creatine kinase, and a fishlike body odor. DMGDHD is also
characterized
by an increase of N,N-dimethylglycine (DMG) in serum and urine. DMGDHD is
associated with mutations in the DMGDH gene, which encodes dimethylglycine
dehydrogenase (DMGDH), a mitochondrial matrix flavoprotein that catalyzes the
oxidative demethylation of dimethylglycine to form sarcosine. DMGDH has been
identified as a monomer in the mitochondrial matrix where it uses flavin
adenine
dinucleotide and folate as cofactors.
Encephalopathies
1. Multiple Mitochondrial Encephalopathy
[0263] Multiple mitochondrial encephalopathies can result from Multiple
Mitochondrial
Dysfunctions Syndrome-1 (MMDS1), Multiple Mitochondrial Dysfunctions Syndrome-
2
(MMDS2), and Multiple Mitochondrial Dysfunctions Syndrome-3 (MMDS3). Multiple
mitochondrial dysfunctions syndrome is a severe autosomal recessive disorder
of systemic
energy metabolism, resulting in weakness, respiratory failure, lack of
neurologic
development, lactic acidosis, and early death. MMDS1 be caused by a homozygous
or
compound heterozygous mutation in the NFUl gene. MMDS2 can be caused by
homozygous mutation in the BOLA3 gene. MMDS3 can be caused by homozygous
mutation in the IBA57 gene.
2. Encephalopathies Associated with Mitochondrial Complex I Deficiency
[0264] Encephalopathy can arise as a result of mitochondrial Complex I
deficiencies.
Complex I deficiencies leading to encephalopathy are associated with mutations
in the
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CA 02920246 2016-02-09
following genes: NDUFA1, NDUFAll, C60RF66, VARS2, NDUFA12L, NDUFS1,
NDUFV1, NUBPL, and NDUFV2.
3. Childhood Leukoencephalopathy and Complex II Deficiency
[0265] Childhood leukoencephalopathy associated with mitochondrial Complex II
deficiency can be caused by mutations in the SDHAF1 gene, which encodes
succinate
dehydrogenase complex assembly factor 1.
4. Encephalopathies Associated with Mitochondrial Complex III Deficiency
[0266] Encephalopathy can arise as a result of mitochondrial Complex III
deficiencies.
Complex III deficiencies leading to encephalopathy are associated with
mutations in the
following genes: UQCRQ, UQCC2, LYRM7, and UQCRC2.
5. Encephalopathies Associated with Mitochondrial Complex IV Deficiency
[0267] Encephalopathies associated with mitochondrial Complex IV deficiency
include
encephalocardiomyopathies due to mutations in the MT01 gene and/or C120RF62
genes,
encephalomyopathies due to mutations in the FASTI(D2 and/or AlFM1 genes, and
neonatal hepatoencephalopathy due to mutations in the SCO1 gene.
6. Encephalopathies Associated with Mitochondrial Complex V Deficiency
[0268] Encephalopathies associated with mitochondrial Complex V deficiency
include
neonatal encephalopathy, which is caused by mutation in the ATP5A1 gene, and
neonatal
encephalocardiomyopathy, which is caused by mutation in the TMEM70 gene.
7. Hyperammonemia due to Carbonic Anhydrase VA Deficiency
[0269] Hyperammonemia due to carbonic anhydrase VA deficiency (CA5AD) is
caused
by homozygous mutation in the CASA gene. The disorder is characterized
clinically by
acute onset of encephalopathy in infancy or early childhood. Biochemical
evaluation
shows multiple metabolic abnormalities, including metabolic acidosis and
respiratory
alkalosis. Other abnormalities include hypoglycemia, increased serum lactate
and alanine,
and evidence of impaired provision of bicarbonate to essential mitochondrial
enzymes.
Apart from episodic acute events in early childhood, the disorder showed a
relatively
benign course.
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8. Early Infantile Epileptic Encephalopathy-3
[0270] Early infantile epileptic encephalopathy-3 (EIEE3) is caused by
homozygous
mutation in the SLC25A22 gene. EIEE3 is characterized by onset during the
first months
of life of erratic refractory seizures, usually myoclonic. The prognosis is
poor, and most
children with the condition either die within 1 to 2 years after birth or
survive in a
persistent vegetative state. The EEG pattern often shows a suppression-burst
pattern with
high-voltage bursts of slow waves mixed with multifocal spikes alternating
with
isoelectric suppression phases.
9. 2,4-Dieno_yl-00A Reductase Deficiency
[0271] 2,4-Dienoyl-CoA reductase deficiency (DECRD) is caused by a homozygous
mutation in the NADK2 gene. DECR deficiency is a rare autosomal recessive
inborn error
of metabolism resulting in mitochondrial dysfunction. Affected individuals
have a severe
encephalopathy with neurologic and metabolic dysfunction beginning in early
infancy.
Laboratory studies show decreased activity of the mitochondrial NADP(H)-
dependent
enzymes DECR1 and AASS, resulting in increased C10:2-carnitine levels and
hyperlysinemia.
10. Infection-induced Acute Encephalopathy-3
[0272] Infection-induced acute encephalopathy-3 (IIAE3), also known as acute
necrotizing encephalopathy, is caused by heterozygous mutation in the RANBP2
gene.
Affected individuals typically present with IIAE3 following febrile illness.
11. Ethylmalonic Encephalopathy
[0273] Ethylmalonic encephalopathy (EE) is caused by a homozygous or compound
heterozygous mutation in the ETHE1 gene, which encodes a mitochondrial matrix
protein.
Ethylmalonic encephalopathy is an autosomal recessive severe metabolic
disorder of
infancy affecting the brain, gastrointestinal tract, and peripheral vessels.
The disorder is
characterized by neurodevelopmental delay and regression, prominent pyramidal
and
extrapyramidal signs, recurrent petechiae, orthostatic acrocyanosis, and
chronic diarrhea.
Brain MRI shows necrotic lesions in deep gray matter structures. Death usually
occurs in
the first decade of life.
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12. Hypomyelinating Leukodystrophy
[0274] Hypomyelinating leukodystrophy (HLD4), also known as mitochondrial
Hsp60
chaperonopathy, is caused by mutation in the HSPD1 gene. Affected individuals
experience a form of severe hypomyelinating leukoencephalopathy. Age of onset
typically occurs between birth and three month. The disorder is characterized
by
hypotonia, nystagmus, and psychomotor developmental delay, followed by
appearance of
prominent spasticity, developmental arrest, and regression.
Exocrine Pancreatic Insufficiency, Dyserythropoietic Anemia and Calvarial
Hyperostosis
[0275] Exocrine pancreatic insufficiency, dyserythropoietic anemia and
calvarial
hyperostosis is caused by mutations in cytochrome c oxidase, Subunit IV,
Isoform 2
(C0X4I2). Clinical features include exocrine pancreatic insufficiency,
steatorrhea,
malabsorption of lipid-soluble vitamins, calvarial hyperostosis, delayed bone
age,
osteopenia and dyserythropoietic, megaloblastic anemia.
Glutaric Aciduria Type 1
[0276] Glutaric aciduria type 1 (GA-1), also known as glutaric acidemia, is an
autosomal
recessive disorder characterized by episodes of severe brain dysfunction,
spasticity,
hypotonia, dystonia, seizures, and developmental delays. GA-1 is associated
with
mutations in the GCDH gene causing a deficiency of glutaryl-CoA dehydrogenase
(GCDH) and leading to an accumulation of glutaric and 3-hydroxyglutaric acids
and
secondary carnitine deficiency. Elevated urine C5DC serves as a marker for the
detection
of GA-1.
[0277] GCDH is an acyl dehydrogenase that catalyzes the oxidative
decarboxylation of
glutaryl-CoA to crotonyl-CoA and CO2 in the degradative pathway of L-lysine, L-

hydroxylysine, and L-tryptophan metabolism. The enzyme exists as a
homotetramer of
45-kD subunits in the mitochondrial matrix. Deficiencies in GCDH lead to an
accumulation of L-lysine, L-hydroxylysine, L-tryptophan, and their
metabolites.
Glycine Encephalopathy
[0278] Glycine encephalopathy (GCE), also known as nonketotic hyperglycinemia
(NKH), is an inborn error of glycine metabolism caused by a deficiency of the
glycine
cleavage system. GCE is characterized by abnormally high levels of glycine
leading to a
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CA 02920246 2016-02-09
progressive lethargy, feeding difficulties, hypotonia, dystonia, and
respiratory distress.
The enzyme system for cleavage of glycine, which is confined to the
mitochondria, is
composed of four protein components: P protein (a pyridoxal phosphate-
dependent
glycine decarboxylase), H protein (a lipoic acid-containing protein), T
protein (a
tetrahydrofolate-requiring enzyme), and L protein (a lipoamide dehydrogenase).
GCE
may be caused by a defect in the H, P, or T proteins.
Hepatic Failure
[0279] Acute infantile liver failure is caused by mutations in tRNA 5-
methylaminomethy1-2-thiouridylate methyltransferase (TRMU), which encodes a
mitochondria-specific tRNA-modifying enzyme. Age of onset for this disorder is
usually
between 1 to 4 months and is characterized by hepatic failure, irritability,
poor feeding,
and vomiting. Clinical features include jaundiced sclerae, distended abdomen,
hepatomegaly, lethargy, coagulopathy, low albumin, direct hyperbilirubinemia,
metabolic
acidosis, hyperlactatemia, high ct-fetoprotein, high phenylalanine, tyrosine,
methionine,
glutamine and alanine in plasma, high lactate, phenylalanine and tyrosine
metabolites,
ketotic dicarboxylic and 3-hydroxydicarboxylic aciduria, and reduced Complex
I, III and
IV activity.
[0280] Hepatic failure with hyperlactatemia is caused by mutations in DGUOK,
POLG,
and MPV17.
2-Hydroxyglutaric Aciduria
[0281] 2-Hydroxyglutaric aciduria is an autosomal recessive neurometabolic
disorder
characterized by developmental delay, epilepsy, hypotonia, and dysmorphic
features.
Mutations in the D2HGDH gene, encoding D-2-hydroxyglutarate dehydrogenase
(D2HGDH) are associated with D-2-hydroxyglutaric aciduria (D-2-HGA) type I.
D2HGDH is a mitochondrial enzyme belonging to the FAD-binding
oxidoreductase/transferase type 4 family that is active in liver, kidney,
heart, and brain
where it converts D-2-hydroxyglutarate (D-2-HG) to 2-ketoglutarate. Mutations
in the
IDH2 gene, encoding isocitrate dehydrogenase 2 (IDH2) are associated with D-2-
HGA
type II. IDH2 is a mitochondrial NADP-dependent isocitrate dehydrogenase that
catalyzes
oxidative decarboxylation of isocitrate to alpha-ketoglutarate, producing
NADPH.
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[0282] Another form of 2-hydroxyglutaric aciduria, L-2-hydroxyglutaric
aciduria (L-2-
HGA) is associated with mutations in the L2HGDH gene, encoding L-2-
hydroxyglutarate
dehydrogenase, an FAD-dependent mitochondrial enzyme that oxidizes L-2-
hydroxyglutarate to alpha-ketoglutarate. L-2-HGA particularly affects the
cerebellum,
resulting in balance and muscle coordination abnormalities. Clinical
manifestations of
infantile onset L-2-HGA include ataxia, mental retardation, macrocephaly, a
potential
increased risk of brain neoplasm, leukodystrophy, and the presence of L-2-
hydroxyglutaric
acid in the urine and cerebrospinal fluid. Adult-onset L-2-HGA is associated
with a
c.959delA mutation and causes movement disorder, tremor, and saccades.
[0283] Combined D,L-2-hydroxyglutaric aciduria (D,L-2HGA) is characterized by
neonatal-onset encephalopathy with severe muscular weakness, intractable
seizures,
respiratory distress, and lack of psychomotor development leading to early
death.
3-Hydroxyacyl-CoA Dehydrogenase Deficiency
[0284] 3-Hydroxyacyl-CoA dehydrogenase deficiency, also known as HADH
deficiency, is an autosomal recessive metabolic disorder, resulting from
mutations in the
HADH gene. The 3-Hydroxyacyl-CoA dehydrogenase protein functions in the
mitochondrial matrix to catalyze the oxidation of straight-chain 3-hydroxyacyl-
CoAs as
part of the beta-oxidation pathway. Human HADH encodes a deduced 314-amino
acid
protein comprising a 12-residue mitochondrial import signal peptide and a 302-
residue
HADH protein with a calculated molecular mass of 34.3 kD. 3-Hydroxyacyl-CoA
dehydrogenase has a preference for medium chain substrates, whereas short
chain 3-
hydroxyacyl-CoA dehydrogenase (SCADH) acts on a variety of substrates,
including
steroids, cholic acids, and fatty acids with a preference for short chain
methyl-branched
acyl-CoAs. Mutations in HADH cause one form of familial hyperinsulinemic
hypoglycemia (FHH). FHH is the most common cause of persistent hypoglycemia in

infancy.
Hypercalcemia Infantile
[0285] Hypercalcemia infantile is an autosomal recessive disorder
characterized by
severe hypercalcemia, failure to thrive, vomiting, dehydration, and
nephrocalcinosis.
Hypercalcemia infantile is associated with homozygous or compound heterozygous

mutations in the CYP24A1 gene. 24-Hydroxylase (CYP24A1) is a mitochondrial
enzyme
found mainly in the kidney, bone and intestine, and is likely present in all
cells that
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express the vitamin D receptor. CYP24A1 is a 514-amino acid protein with a
complex
structure of a helices and 13 strands. It interacts with the mitochondrial
membrane,
adrenodoxin, heme, and vitamin D molecules. Disruption of this structure
impairs the
function of the enzyme. Tight control of the vitamin D system requires
inactivation of its
active compound 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) through 24-
hydroxylation by
means of the CYP24A1 enzyme and degradation to calcitroic acid.
Hyperornithinemia-hyperammonemia-homocitrullinuria (HHH) Syndrome
[0286] HHH Syndrome is an autosomal recessive early onset (infancy to 18
years)
disorder caused by mutations in the SLC25A15 gene, which encodes the
mitochondrial
ornithine transporter. Patients with HHH exhibit partial impairment of uptake
of ornithine
by mitochondria. Symptoms include mental retardation and myoclonic seizures
associated
with hyperornithinemia, hyperammonemia, and homocitrullinemia, progressive
spastic
paraparesis, protein intolerance, stuporous episodes, cerebellar ataxia,
muscular weakness
in both legs, myoclonus, lethargy, dysmetria, dysdiadochokinesis, scanning
speech,
learning difficulties, buccofaciolingual dyspraxia, episodic vomiting, retinal

depigmentation, and chorioretinal thinning.
Immunodeficiency with Hyper-IgM Type 5
[0287] Immunodeficiency with hyper-IgM type 5 (HIGM5) is an autosomal
recessive
disorder caused by homozygous or compound heterozygous mutations in the gene
encoding uracil-DNA glycosylase (UNG). HIGM5 is characterized by defective
normal
or elevated serum IgM concentrations in the presence of diminished or absent
IgG, IgA,
and IgE concentrations, indicating a defect in the class-switch recombination
(CSR)
process. UNG removes uracil in DNA resulting from deamination of cytosine or
replicative incorporation of dUMP instead of dTMP, thereby suppressing GC-to-
AT
transition mutations. The UNG gene encodes two isoforms that are individually
targeted
to the mitochondria and nucleus. The mitochondrial isoform is referred to as
UNG1,
UDG1, or UDG1M, and the nuclear isoform is referred to as UNG2, UDG I A, or
UDG1N.
HIGM5 is associated with mutations in the UNG gene. Patients with HIGM5
typically
experience recurrent bacterial infections and often exhibit lymphoid
hyperplasia.
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Inflammatory Myopathies
1. Inclusion Body Mvositis (IBM)
[0288] IBM or Inflammatory Myopathy with Vacuoles, Aggregates and
Mitochondrial
Pathology (IM-VAMP) is a sporadic progressive condition that typically
manifests in 9
out of 106 individuals at > 50 years of age. Clinical features include
proximal and distal
weakness, dysphagia, Inflammatory myopathy with Mitochondrial pathology (PM-
Mito),
respiratory failure, aspiration, cachexia, muscle atrophy, diminished tendon
reflexes,
polyneuropathy, inflammation, muscle fiber hypertrophy, rimmed vacuoles with
granular
material & filaments (f3-Amyloid, Desmin; Ubiquitin; Transglutaminases 1 & 2),

aggregates (stain for SMI-31 antibody, LC-3, P-amyloid, VCP, ubiquitin, aB-
crystallin),
COX deficient and SDH + muscle fibers, multiple mtDNA deletions,
cricopharyngeus
dysfunction, fatty infiltration, elevated transglutaminase activity, MHC I
upregulation in
muscle fibers, and increased frequency of non-organ specific autoantibodies.
[0289] Variant syndromes include autosomal dominant IBM and polymyositis with
mitochondrial pathology.
2. Inflammatory Myopathy + Mitochondrial Pathology in Muscle (IM-Mito)
[0290] The age of onset for IM-Mito ranges from 43 to 71 years. Disease
progression is
slower than IBM. Symptoms include proximal and distal weakness, elevated serum

creatine kinase, COX-negative and SDH-positive muscle fibers, endomysial
inflammation,
focal invasion of muscle fibers by inflammatory cells, multiple mtDNA
deletions, and LC-
3 and/or aB-crystallin aggregates in muscle fibers.
3. Granulomatous Myopathies with Anti-mitochondrial Antibodies
[0291] Granulomatous myopathies with anti-mitochondrial antibodies account for
11%
of inflammatory myopathies in Tokyo and typically manifests between 33 to 72
years of
age. Clinical features include primary biliary cirrhosis, cardiac arrhythmias,
muscle
weakness, atrophy, respiratory defects, skin rash, elevated anti-mitochondrial

autoantibodies, high serum creatine kinase, elevated alkaline phosphatase,
endomysial
fibrosis, necrosis and regeneration, inflammation, granulomas and MHC I
upregulation in
muscle fibers.
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[0292] Other inflammatory myopathies include, but are not limited to,
necrotizing
myopathy with pipestem capillaries, myopathy with deficient chondroitin
sulfate C in
skeletal muscle connective tissue, benign acute childhood myositis, idiopathic
orbital
myositis, masticator myopathy, hemophagocytic lymphohistiocytosis, infection-
associated
myositis, Facioscapulohumeral dystrophy (FSH), Limb-Girdle dystrophy, familial

idiopathic inflammatory myopathy, Schmidt Syndrome (Diabetes mellitus, Addison

disease, Myxedema), TNF receptor-associated Periodic Syndrome (TRAPS), focal
myositis, autoimmune fasciitis, Spanish toxic oil-associated fasciitis,
Eosinophilic
fasciitis, Macrophagic myofasciitis, Graft-vs-host disease fasciitis,
Eosinophilia-myalgia
Syndrome, and perimyositis.
Isovaleric Acidemia
[0293] Isovaleric acidemia (IVA), also known as isovaleric aciduria, is an
autosomal
recessive inborn error of leucine metabolism caused by a deficiency of the
mitochondrial
enzyme isovaleryl-CoA dehydrogenase (IVD) resulting in the accumulation of
derivatives
of isovaleryl-CoA such as isovaleric acid, which is toxic to the central
nervous system.
There are two forms of IVA. The acute neonatal form leads to pernicious
vomiting,
massive metabolic acidosis, and rapid death. The chronic form results in
periodic attacks
of severe ketoacidosis with asymptomatic intervening periods. Symptoms of IVA
include
convulsions, lethargy, dehydration, moderate hepatomegaly, depressed platelets
and
leukocytes, and a distinctive odor resembling that of sweaty feet.
Kearns-Sayre Syndrome
[0294] Kearnes-Sayre Syndrome (KSS), also known as oculocranisomatic disorder
or
oculocraniosomatic neuromuscular disorder with ragged red fibers, is a
mitochondrial
myopathy that is caused by various mitochondrial deletions. Single large mtDNA

deletions (2 to 8 kb) account for 80% of KSS mutations. The mtDNA deletions
that cause
KSS result in the impairment of oxidative phosphorylation and a decrease in
cellular
energy production. In most instances, KSS arises from sporadic somatic
mutations
occurring after conception. Rarely, the mutation is transmitted through
maternal
inheritance.
[0295] Clinical features include progressive external ophthalmoplegia,
pigmentary
degeneration of retina (retinitis pigmentosa), heart block, mitochondrial
myopathy,
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limitation or absence of movement in all fields of gaze, ptosis, dysphagia,
weight loss,
weakness, occasional fatigue or pain on exertion, sensory-motor
polyneuropathy, stroke,
reduced respiratory drive, hearing loss, ataxia, dementia, or impaired
intellect, spasticity,
growth hormone deficiency, increased tendon reflexes, endocrinopathies,
glucose
intolerance, hypothyroidism, hypoparathyroidism, short stature, ragged red
fibers,
variation in muscle fiber size, lactic acidosis, high CSF protein, low 5-
methyltetrahydrofolate (5-MTHF) in CSF, high homovanillic acid (HVA) in CSF,
abnormal choroid plexus function, basal ganglia calcifications, cerebral and
cerebellar
atrophy, and status spongiosis in gray and white matter.
[0296] Another variant syndrome related to KSS, or other disorders having a
single large
mtDNA deletion include 2-oxoadipic aciduria and 2-aminoadipic aciduria.
Affected
patients exhibit episodes of ketosis and acidosis, and may experience coma.
Limb-girdle Muscular Dystrophy (LGMD) Syndromes
[0297] LGMD1 is an autosomal dominant disorder characterized by adult onset of

proximal muscle weakness, beginning in the hip girdle region and later
progressing to the
shoulder girdle region. Distal muscle weakness may occur later. Autosomal
dominant
limb-girdle muscular dystrophy (LGMD) type IA is caused by a heterozygous
mutation in
the gene encoding myotilin (TTID). Other forms of autosomal dominant LGMD
include
LGMD1B, caused by mutations in the LMNA gene; LGMD1C, caused by mutations in
the
CAV3 gene; LGMD1E, caused by mutations in the DNAJB6 gene; LGMD1F, caused by
mutations in the TNP03 gene; LGMD1G, which maps to chromosome 4q21; and
LGMD1H, which maps to chromosome 3p25-p23. The symbol LGMD1D was formerly
used for a disorder later found to be the same as desmin-related myopathy.
[0298] Autosomal recessive forms of LGMD include LGMD2A, caused by mutations
in
Calpain-3; LGMD2B, caused by mutations in Dysferlin; LGMD2C, caused by
mutations
in y-Sarcoglycan; LGMD2D, caused by mutations in a-Sarcoglycan; LGMD2E, caused
by
mutations in f3-Sarcoglycan; LGMD2F, caused by mutations in 6-Sarcoglycan;
LGMD2G,
caused by mutations in Telethonin; LGMD2H, caused by mutations in TRIM32;
LGMD2I (MDDGC5), caused by mutations in FKRP; LGMD2J, caused by mutations in
Titin; LGMD2K (MDDGC1), caused by mutations in POMT1; LGMD2L, caused by
mutations in AN05; LGMD2M (MDDGC4), caused by mutations in Fukutin;
LGMD2N (MDDGC2), caused by mutations in POMT2; LGMD20 (MDDGC3), caused
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by mutations in POMGnTl; LGMD2P (MDDGC9), caused by mutations in DAG1;
LGMD2Q, caused by mutations in Plectin if; LGMD2R, caused by mutations in
Desmin;
and LGMD2S, caused by mutations in TRAPPC11.
Leukodystrophy
[0299] Mutations in COX6B1, which encodes a Complex IV structural subunit, can

result in mitochondrial complex IV deficiency. Symptoms include muscle
weakness, pain,
unsteady gait, visual loss, progressive neurological deterioration, cognitive
decline,
leukodystrophic brain changes, seizures, ataxia, increased serum and CSF
lactate and
decreased COX activity in muscle.
[0300] Mutations in Apoptogenic protein 1 (APOPT1), which mediates
mitochondria-
induced cell death in vascular smooth muscle cells, can result in cavitating
leukodystrophy. This disorder typically manifests between the ages of 2 to 5
years.
Additional clinical features include spastic tetraparesis, ataxia, sensory-
motor
polyneuropathy, reduced cognition, reduced COX staining, large mitochondria
with
osmophilic inclusions, and reduced Complex IV activity.
[0301] Mutations in SDHB can result in leukodystrophy, which usually presents
at 1
year of age. Clinical features include loss of motor skills, leukodystrophy in
deep white
matter and corpus callosum, and reduced Complex II activity.
[0302] Leukodystrophy may arise as a result of large mtDNA deletions. Clinical

features include progressive ataxia, bulbar palsy, white-matter lesions in
occipital to
parietal lobes, and high CSF lactate.
Maple Syrup Urine Disease
[0303] Maple syrup urine disease (MSUD) can be caused by homozygous or
compound
heterozygous mutations in at least 3 genes: BCKDHA, BCKDHB, and DBT. These
genes
encode 2 of the catalytic components of the branched-chain alpha-keto acid
dehydrogenase complex (BCKDC), which catalyzes the catabolism of the branched-
chain
amino acids, leucine, isoleucine, and valine. Maple syrup urine disease caused
by a
mutation in the El-alpha subunit gene is referred to as MSUD type IA; that
caused by a
mutation in the El-beta subunit gene as type IB; and that caused by defect in
the E2
subunit gene as type II. Mutations in the third component, E3 (DLD), on
chromosome
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7q31, cause an overlapping but more severe phenotype known as dihydrolipoamide

dehydrogenase deficiency (DLDD). DLD deficiency is sometimes referred to as
MSUD3.
[0304] Clinical features of maple syrup urine disease include mental and
physical
retardation, neuropathy, ataxia, dystonia, athetosis, dysarthria, weakness,
ophthalmoplegia,
hearing loss, drowsiness, seizures, feeding problems, reduced tendon reflexes,
sensory
loss/pain, endoneurial edema, high lactic acid, and a maple syrup odor to the
urine. The
keto acids of the branched-chain amino acids are present in the urine,
resulting from a
block in oxidative decarboxylation. There are 5 clinical subtypes of MSUD: the
'classic'
neonatal severe form, an 'intermediate' form, an 'intermittent' form, a
'thiamine-responsive'
form, and an 'E3-deficient with lactic acidosis' form. All of these subtypes
can be caused
by mutations in any of the 4 genes mentioned above, except for the E3-
deficient form,
which is caused only by a mutation in the E3 gene.
3-Methylcrotonyl-CoA Carboxylase Deficiency
[0305] 3-Methylcrotonyl-CoA carboxylase (MCC), deficiency also known as 3-
methylcrotonylglycinuria, is an autosomal recessive disorder of leucine
catabolism with a
variable phenotype, ranging from neonatal onset with severe neurological
involvement to
asymptomatic adults. Common symptoms include feeding difficulties, recurrent
episodes
of vomiting and diarrhea, lethargy, and hypotonia. MCC is a heteromeric biotin-

dependent mitochondrial enzyme composed of alpha subunits and smaller beta
subunits,
encoded by MCC1 and MCC2, respectively. MCC is essential for the catabolism of

leucine.
Methylmalonic Aciduria
[0306] Methylmalonic aciduria (MMA), also known as methylmalonyl-CoA epimerase

deficiency, is an autosomal recessive disorder characterized by progressive
encephalopathy, dehydration, developmental delays, failure to thrive,
lethargy, seizures,
and vomiting. MMA is caused by mutations in the MUT, MMAA, MMAB, MMADHC,
and MCEE genes. The long-term effects of MMA depend on which gene is mutated
and
the severity of the mutation.
[0307] Mutations in the MUT gene cause a deficiency of methylmalonyl-CoA
mutase
(MUT), which is a vitamin B12-dependent mitochondrial enzyme that catalyzes
the
isomerization of methylmalonyl-CoA to succinyl-CoA. Mutations in the MUT gene
lead
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CA 02920246 2016-02-09
to a toxic accumulation of methylmalonic acid in the blood. The proteins
encoded by the
MMAA, MMAB, and MMADHC genes are required for the proper function of MUT.
Mutations affecting these genes can impair the activity of MUT, leading to
methylmalonic
aciduria. Mutations in the MCEE gene, which encodes methylmalonyl CoA
epimerase,
lead to a mild form of methylmalonic aciduria.
Miller Syndrome
[0308] Miller Syndrome, also known as postaxial acrofacial dystosis, is an
autosomal
recessive disorder characterized by severe micrognathia, cleft lip and/or
palate, hypoplasia
or aplasia of the postaxial elements of the limbs, coloboma of the eyelids,
and
supernumerary nipples. Miller Syndrome is associated with mutations in the
DHODH
gene encoding dihydroorotate (DHO) dehydrogenase. Dihydroorotate dehydrogenase

catalyzes the fourth enzymatic step in de novo pyrimidine biosynthesis. DHO
dehydrogenase is a monofunctional protein located on the outer surface of the
inner
mitochondrial membrane.
mtDNA Depletion Syndrome-2 (MTDPS2)
[0309] Mitochondrial DNA Depletion Syndrome-2 (MTDPS2) is an autosomal
recessive
disorder characterized primarily by childhood onset of muscle weakness
associated with
depletion of mtDNA in skeletal muscle. MTDPS2 is caused by homozygous or
compound
heterozygous mutations in the nuclear-encoded mitochondrial thymidine kinase
gene
(TK2). There is wide clinical variability; some patients have onset in infancy
and show a
rapidly progressive course with early death due to respiratory failure,
whereas others have
later onset of a slowly progressive myopathy.
[0310] Clinical features include gait impairment, hypotonia, weakness,
respiratory
failure, paralysis, gynecomastia, myopathy, chronic partial denervation, mtDNA
depletion,
reduced Complex I, III, IV and V activity, and elevated plasma lactate.
[0311] Variant TK2 syndromes include spinal muscular atrophy syndrome, rigid
spine
syndrome, and severe myopathy with motor regression.
Mitochondrial DNA Depletion Syndrome-3 (MTSPS3)
[0312] Mitochondrial DNA Depletion Syndrome-3, also known as hepatocerebral
syndrome, is an autosomal recessive disorder caused by homozygous or compound
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heterozygous mutations in the nuclear-encoded DGUOK gene. MTSPS3 is
characterized
by onset in infancy of progressive liver failure and neurologic abnormalities,

hypoglycemia, and increased lactate in body fluids. Affected tissues show both
decreased
activity of the mtDNA-encoded respiratory chain complexes (I, III, IV, and V)
and
mtDNA depletion. Clinical symptoms include weakness, hypotonia, lactic
acidosis,
elevated serum creatine kinase, renal dysfunction, and ragged red fibers.
Mitochondrial Encephalopathy Lactic Acidosis Stroke (MELAS)
[0313] MELAS Syndrome, comprising mitochondrial myopathy, encephalopathy,
lactic
acidosis, and stroke-like episodes, is a genetically heterogeneous
mitochondrial disorder
with a variable clinical phenotype. MELAS Syndrome can be caused by mutations
in
several genes, including POLG, MTTL1, MTTQ, MTTH, MTTK, MTTF, MTTC,
MTTS1, MTTV, MTTQ, MTND1, MTND3, MTND5, MTND6, MTCOI, cytochrome b,
and MTTS2, with mutations in MTTL1 accounting for the majority of MELAS cases.
In
particular, it is estimated that approximately 80% of MELAS patients have an
A3243G
point mutation in the MTTL1 gene. The disorder is accompanied by features of
central
nervous system involvement, including seizures, hemiparesis, hemianopsia,
cortical
blindness, and episodic vomiting. Primary causes of death are cardiopulmonary
failure,
status epilepticus, and pulmonary disease.
[0314] Clinical symptoms include distal arthrogryposis, headache and vomiting,

sensorineural hearing loss, seizures, loss of consciousness, dementia, mental
retardation,
focal events (strokes), cortical visual defects, hemiplegia, neuronal
hyperexcitability, basal
ganglia calcifications, weakness, exercise intolerance, ptosis, external
ophthalmoplegia,
gait disorder, paresthesias and numbness, reduced tendon reflexes, sensory
neuropathy,
chorea, Parkinsonism, ataxia, pigmentary retinopathy, macular dystrophy, optic
atrophy,
visual field defects, hypertelorism, hypertrophic cardiomyopathy, left
ventricular
noncompaction, conduction defects (such as Wolff-Parkinson-White),
hypertension, short
stature, maternally inherited diabetes (MIDD), pancreatitis, constipation,
diarrhea,
intestinal pseudoobstruction (ileus), nausea, dysphagia, abdominal pain,
epigastralgia,
sialoadenitis focal segmental glomerulosclerosis, renal cysts, tubular
dysfunction,
nephrotic syndrome, multihormonal hypopituitarism, Hashimoto thyroiditis,
goiter,
Hypoparathyroidism, Addison's disease, ovarian failure, miscarriage, lipoma,
Atopic
dermatitis, local melanoderma, asymmetric vascular dilatation, lactic
acidosis, white
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CA 02920246 2016-02-09
matter lesions, respiratory chain dysfunction, ragged red fibers, cortical
atrophy, focal
necrosis, Purkinje dendrite cactus formations with increased mitochondria, and

mitochondrial capillary angiopathy.
[0315] Other MTTF disorders include myoglobinuria, MERRF, camptocormia,
seizures,
and ataxia.
Myopathy and External Ophthalmoplegia; Neuropathy; Gastro-Intestinal;
Encephalopathy
(MNGIE)
[0316] Mitochondrial DNA Depletion Syndrome-1 (MTDPS1), which manifests as a
neurogastrointestinal encephalopathy (MNGIE), is caused by homozygous or
compound
heterozygous mutations in the nuclear-encoded thymidine phosphorylase gene
(TYMP).
TYMP catalyzes phosphorolysis of thymidine to thymine and deoxyribose 1-
phosphate,
and plays a role in homeostasis of cellular nucleotide pools. Mitochondrial
DNA
Depletion Syndrome-1 (MTDPS1) is an autosomal recessive progressive
multisystem
disorder clinically characterized by onset between the second and fifth
decades of life of
ptosis, progressive external ophthalmoplegia (PEO), retinal degeneration,
optic atrophy,
gastrointestinal dysmotility (often pseudoobstruction, gastroparesis,
obstipation,
malabsorption, diarrhea, abdominal pain & cramps, nausea & vomiting),
borborygmi,
early satiety, cachexia, thin body habitus, short stature, diffuse
leukoencephalopathy,
myopathy (proximal weakness, exercise intolerance), peripheral neuropathy
(sensory
loss/pain/ataxia, weakness, tendon reflexes absent, axonal loss,
demyelination), hearing
loss, cognitive impairment or dementia, seizures, headaches, and mitochondrial

dysfunction. Mitochondrial DNA abnormalities can include depletion, deletion,
and point
mutations. MNGIE usually presents at < 20 years of age. Additional symptoms
include
incomplete right bundle branch block (cardiac defect), diabetes or glucose
intolerance,
amylase increase, exocrine insufficiency, neoplasms, lactic acidosis, elevated
plasma
thymidine levels, elevated plasma deoxyuridine & deoxythymidine levels,
tetany, cardiac
arrhythmia, high CSF protein, brain atrophy, mitochondrial changes in muscle
fibers and
neurogenic changes.
[0317] Partial loss of thymidine phosphorylase activity can result in a
variant MNGIE
disorder that manifests around the 5th decade of life. Clinical symptoms
include
ophthalmoplegia, ptosis, gastrointestinal features, and axon loss with or
without
demyelination.
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[0318] Mitochondrial DNA Depletion Syndrome-4B (MTDPS4B), which manifests as a

neurogastrointestinal encephalopathy (MNGIE), is caused by compound
heterozygous
mutations in the nuclear-encoded POLG gene. Mitochondrial DNA Depletion
Syndrome-
4B is an autosomal recessive progressive multisystem disorder clinically
characterized by
chronic gastrointestinal dysmotility and pseudoobstruction, cachexia,
progressive external
ophthalmoplegia (PEO), axonal sensory ataxic neuropathy, and muscle weakness.
[0319] Another MNGIE variant is MNGIM Syndrome without encephalopathy, which
is
not associated with mutations in thymidine phosphorylase or dNT-2. Clinical
features
include gastrointestinal malabsorption, diarrhea, borborygmi, abdominal pain,
GI pseudo-
obstruction, weight loss, ophthalmoplegia, ptosis, weakness, cachexia,
polyneuropathy
(pain, gait disorder, sensory ataxia, axonal loss), high CSF protein, ragged
red fibers, and
reduced Complex I¨IV activities.
[0320] Mutations in MTTW can manifest as a neurogastrointestinal
encephalopathy
(MNGIE). Patients present at 1 year of age with recurrent vomiting and failure
to thrive.
Leg discomfort, cognitive regression, seizures, muscle wasting, and
incontinence manifest
later during childhood. Other features include sensorineural deafness, ptosis,

ophthalmoplegia, pigmentary retinopathy, constricted visual fields, short
stature, feeding
difficulties with constipation, colitis and diarrhea, high lactate levels in
blood and CSF,
brain atrophy, and periventricular white matter changes. Muscle biopsies show
COX-
negative fibers and low activity of Complexes I and IV.
[0321] Mutations in MTTV can manifest as a neurogastrointestinal
encephalopathy
(MNGIE). Age of onset is usually during early childhood. Clinical symptoms
include
cachexia, headache, gastrointestinal motility problems (Ileus, Abdominal pain;

Megacolon), hearing loss, developmental delay, high serum lactate, COX-
negative fibers
and low activity of complexes I and IV. Disruption of MTTV function can also
lead to
Ataxia, Seizures & Hearing loss, and Learning difficulties, Hemiplegia &
Movement
disorder.
Menkes Disease, Occipital Horn Syndrome and X-linked Distal Spinal Muscular
Atrophy-
3
[0322] Menkes disease is an X-linked recessive disorder characterized by
generalized
copper deficiency and is caused by mutations in the ATP7A gene. Menkes disease
usually
manifests at birth and its clinical features result from the dysfunction of
several copper-
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CA 02920246 2016-02-09
dependent enzymes. Clinical symptoms include seizures, pili torti, bladder
diverticula,
skin laxity, occipital exostoses, chronic diarrhea, acute onset of severe
intra-abdominal
bleeding, hemorrhagic shock, multiple fractures, hypoglycemia, hypothermia,
feeding
difficulties, hair with an abnormal texture, low serum copper and
ceruloplasmin levels,
subdural hematomas, high arched palate, wormian bones in the lambdoid suture
of the
occipital region, developmental delay, and speech loss.
[0323] Occipital Horn Syndrome (OHS) is caused by mutations in the gene
encoding
Cu(2 )-transporting ATPase, alpha polypeptide (ATP7A). Occipital Horn Syndrome
is a
rare connective tissue disorder characterized by hyperelastic and bruisable
skin, hernias,
bladder diverticula, hyperextensible joints, varicosities, and multiple
skeletal
abnormalities. The disorder is sometimes accompanied by mild neurologic
impairment,
and bony abnormalities of the occiput are a common feature, giving rise to the
name.
Clinical features include severe congenital cutis laxa, extremely loose skin,
with truncal
folds and sagging facial skin, pectus excavatum, craniotabes, stridor, sparse
coarse hair,
fragmented elastin fibers, and low serum copper.
[0324] X-linked distal spinal muscular atrophy-3 (SMAX3) is caused by
mutations in
the copper transport gene ATP7A and is characterized by spinal muscular
atrophy
affecting both the upper and lower limbs. Onset ranges from 1 to 10 years of
age.
Clinical symptoms include foot deformity (pes cavus or pes varus), gait
instability, distal
motor weakness and atrophy.
Methemoglobinemia
[0325] Methemoglobinemia is an autosomal recessive disorder characterized by
decreased oxygen carrying capacity of the blood, resulting in cyanosis and
hypoxia.
Methemoglobinemia is associated with mutations in the CYB5R3 gene, which
encodes
cytochrome b5 reductase-3, an enzyme localized to the mitochondrial outer
membrane
where it catalyzes the transfer of reducing equivalents from NADH to
cytochrome b5.
There are two types of methemoglobin reductase deficiency. In type I, the
defect affects
the soluble isoform of CYB5R3, which is expressed in erythrocytes and
functions to
reduce methemoglobin to hemoglobin. In type II, the defect affects both
soluble and
microsomal isoforms of the enzyme, which play a role in physiologic processes
including
cholesterol biosynthesis and fatty acid elongation and desaturation. Type II
methemoglobinemia is associated with mental deficiency and other neurologic
symptoms.
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Myoclonic Epilepsy Ragged Red Fibers (MERRF)
[0326] MERRF Syndrome represents a maternally-inherited myopathy that can be
produced by mutations in more than 1 mitochondrial gene, e.g., MTTK, MTTL1,
MTTH,
MTTS1, MTTS2, MTTF etc. Features of the MERRF Syndrome have also been
associated with mutations in the MTND5 gene.
[0327] Clinical features include myoclonus, epilepsy, cardiomyopathy, ataxia,
gait
disorder, dementia, optic atrophy, distal sensory loss, hearing loss,
weakness, muscle pain,
cramps, fatigue, short stature, lipomata, ragged red fibers, vacuoles in small
fibers, and
reduced Complex I, III and IV activity.
[0328] Other MTTK syndromes include cardiomyopathy, progressive external
ophthalmoplegia with myoclonus, deafness and diabetes (DD), multiple symmetric

lipomatosis, Leigh Syndrome, MELAS, MNGIE, Myopathy with Episodic high
Creatine
Kinase (MIMECK), Parkinson syndrome neuropathy and myopathy. Clinical features
of
MIMECK include weakness, dysphagia, and episodic myalgias.
[0329] Other MTTS1 disorders include MELAS, Epilepsia Partialis Continua, HAM
Syndrome, myopathy , encephalopathy with cytochrome c oxidase deficiency,
Myoclonus,
epilepsy, cerebellar ataxia & progressive hearing loss, exercise intolerance,
keratoderma,
palmoplantar, with deafness, and sensorineural hearing loss.
[0330] Mutations in MTTP can also result in myoclonic epilepsy, myopathy,
sensorineural deafness, cerebellar ataxia, and pigmentary retinopathy.
Myoglobinuria
[0331] Myoglobinuria can arise as a result of malignant hyperthermia
syndromes,
glycogen metabolic disorders, fatty acid oxidation and lipid metabolism
disorders,
mitochondrial disorders, certain drugs and toxins, hypokalemic myopathy and
rhabdomyolysis, muscle trauma, ischemia, infections, or immune myopathy. Other

disorders associated with occasional myoglobinuria include Brody myopathy,
cylindrical
spiral (myofilamentous) myopathy, familial recurrent rhabdomyolysis,
fingerprint body
disease, G6PDH deficiency, hypokalemic periodic paralysis, Marinesco-Sjogren
Syndrome, myoadenylate deaminase deficiency, myotonias, multicore disease,
Native
American Myopathy, Schwartz-Jampel Syndrome (chondrodystrophic myotonia),
sickle
cell anemia, and several muscular dystrophies including Duchenne and Becker
muscular
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CA 02920246 2016-02-09
dystrophy, Miyoshi myopathy, sacroglycanopathies, limb-girdle muscular
dystrophy-
dystroglycanopathy type C5, and limb-girdle muscular dystrophy-2L.
1. Malignant Hyperthermia Syndromes
[0332] Malignant hyperthermia syndromes leading to myoglobinuria can include
central
core disease, King-Denborough Syndrome, also known as malignant hyperthermia
susceptibility 1 (MHS1), malignant hyperthermia susceptibility 2 (MHS2)
malignant
hyperthermia susceptibility 3 (MHS3), malignant hyperthermia susceptibility 4
(MHS4),
malignant hyperthermia susceptibility 5 (MHS5), malignant hyperthermia
susceptibility 6
(MHS6), and other disorders associated with malignant hyperthermia
susceptibility,
including Duchenne and Becker muscular dystrophies, myotonic dystrophy,
myotonia
congenital, Schwartz-Jampel Syndrome, and Satoyoshi Syndrome.
2. Glycogen Metabolic Disorders
[0333] Glycogen metabolic disorders leading to myoglobinuria can include
McArdle
disease, also known as glycogen storage disease type V (GSD5), Tarui disease,
also
known as glycogen storage disease VII (GSD7), and other glycogenoses,
including
aldolase A deficiency, also known as glycogen storage disease XII (GSD12),
lactate
dehydrogenase A deficiency, also known as glycogen storage disease XI (GSD11),

phosphoglycerate kinase-1 deficiency, phosphoglycerate mutase deficiency, also
known as
glycogen storage disease X (GSD10), phosphorylase kinase deficiency of liver
and
muscle, also known as glycogen storage disease IXb (GSD9B), Forbes disease,
also
known as glycogen storage disease III (GSD3) or glycogen debrancher
deficiency, and [3-
enolase deficiency, also known as glycogen storage disease XIII (GSD13).
3. Fatty Acid Oxidation and Lipid Metabolism Disorders
[0334] Fatty acid oxidation and lipid metabolism disorders leading to
myoglobinuria can
include carnitine palmitoyltransferase II (CPT II) deficiency, acyl-CoA
dehydrogenase
deficiencies, a-methylacyl-CoA racemase (AMACR) deficiency, electron transfer
flavoprotein disorders, ketoacyl CoA thiolase deficiency, recurrent acute
myoglobinuria,
also known as recurrent rhabdomyolysis in childhood, and trifunctional enzyme
deficiency, also known as long chain 3-hydroxyacyl-coenzyme A dehydrogenase
deficiency (LCHAD) deficiency.
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CA 02920246 2016-02-09
[0335] Long-chain 3-hydroxyacyl-CoA dehydrogenase (LCHAD) deficiency is a rare

autosomal recessive condition that prevents the body from converting certain
fats to
energy, particularly during periods without food (fasting). Mutations in the
HADHA gene
cause LCHAD deficiency. Signs and symptoms of LCHAD deficiency typically
appear
during infancy or early childhood and can include feeding difficulties, lack
of energy
(lethargy), low blood sugar (hypoglycemia), weak muscle tone (hypotonia),
liver
problems, and abnormalities in the light-sensitive tissue at the back of the
eye (retina).
Later in childhood, people with this condition may experience muscle pain,
breakdown of
muscle tissue, and a loss of sensation in their arms and legs (peripheral
neuropathy).
Individuals with LCHAD deficiency are also at risk for serious heart problems,
breathing
difficulties, coma, and sudden death. Problems related to LCHAD deficiency can
be
triggered by periods of fasting or by illnesses such as viral infections.
[0336] Medium-chain acyl-CoA dehydrogenase (MCAD) deficiency is an autosomal
recessive condition caused by mutations in the ACADM gene. Signs and symptoms
of
MCAD deficiency typically appear during infancy or early childhood and can
include
vomiting, lack of energy (lethargy), and low blood sugar (hypoglycemia). In
rare cases,
symptoms of this disorder first appear during adulthood. People with MCAD
deficiency
are at risk for serious complications such as seizures, breathing
difficulties, liver problems,
brain damage, coma, and sudden death.
[0337] Long-chain acyl-CoA dehydrogenase (LCAD) deficiency is caused by
mutations
in the ACADL gene. Subjects with LCAD can present with SIDS, hypoglycemia,
hepatomegaly, myopathy, Reye syndrome, and cardiomyopathy. The plasma
acylcarnitine
profile exhibits elevated long chain acyl-carnitine esters. Urine organic
acids typically
show elevations of dicarboxylic acids.
4. Mitochondrial Disorders
[0338] Mitochondrial disorders leading to myoglobinuria can include cytochrome
c
oxidase (COX) deficiencies, cytochrome b deficiency, mitochondrial myopathies,

including coenzyme Q10 deficiency, myopathy with lactic acidosis, also known
as
Swedish type myopathy with exercise intolerance, dihydrolipoamide
dehydrogenase
(DLD) deficiency, mutations in the DGUOK gene, which encodes mitochondrial
deoxyguanosine kinase, and iron-sulfur complex disorders, including those
associated with
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mutations in one or more of the following genes: ISCU, FDX1L, NFU I, BOLA3,
NUBPL, IBA57, LYRM4, and LYRM7.
5. Medication-, Drug- or Toxin-induced Myoglobinuria
[0339] Certain medications such as amiodarone, arsenic trioxide, emetine, c-
amino
caproic acid, lipid lowering agents such as clofibrate and statins, isoniazid,
lamotrigrine,
antipsychotics, nicotinic acid, pentamidine, propofol, proton pump inhibitors,
selective
serotonin reuptake inhibitors, irinotican, temazepam, valproate, vasopressin,
and
zidovudine are associated with the development of myoglobinuria. Drugs and
toxins
associated with the development of myoglobinuria include cocaine, heroin,
snake venom,
insect venom, blowpipe dart poison, and drugs and toxins that produce muscle
overactivity, including amphetamines, hemlock, loxpapine, LSD, mercuric
chloride,
phencyclidine, strychnine, tetanus toxin, and terbutaline. The ingestion of
certain toxins
including ethanol, monensin, chromium picolinate, methylenedioxypyrovalerone,
mephedrone, phencyclidine, and those present in Buffalo fish, burbot,
mushrooms
(Amanita phalloides, Trichloma equestre), kidney beans, and peanut oil may
also cause
myoglobinuria.
[0340] Other drugs and toxins associated with the development of myoglobinuria

include acetaminophen, amoxapine, anticholinergics, azathioprine, baclofen,
barbiturates,
benzodiazepines, butyrophenones, caffeine, chloral hydrate, chlorpromazine,
colchicine,
corticosteroids, daptomycin, diphenhydramine, doxylamine, ephedra,
fenfluramine,
glutethimide, hydroxyzine, ketamine, lysergic acid diethylamide, methanol,
minocycline,
morphine, phencyclidine, phenothiazines, phentermine phenytoin, quinolones,
salicylate,
serotonin antagonists, succinylcholine, sunitinib sympathomimetics,
theophylline,
trimethoprim-sulfamethoxazole, and vincristine.
6. Hypokalemic Myopathy and Rhabdomyolysis
[0341] Hypokalemic myopathy and rhabdomyolysis can be of a pharmacologic or
toxic
origin. Hypokalemic myopathy and rhabdomyolysis having a pharmacologic origin
is
associated with diuretics and laxatives, such as thiazides, amphotericin,
lithium, gossypol,
methylxanthines, and laxative abuse. Toxins associated with the development of

hypokalemic myopathy and rhabdomyolysis include glycyrrhizic acid,
glycyrrhetinic acid,
barium, ethanol, cottonseed oil, and volatile substances, such as toluene.
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7. Muscle trauma
[0342] Muscle trauma leading to myoglobinuria can be acute, such as that
associated
with physical trauma, or chronic, such as that associated with alcohol,
opiates, and
sedatives. Muscle trauma can also be caused by overactivity due to exercise,
drugs and
toxins producing muscle overactivity, hyperthermia, or seizures. Muscle trauma
can also
be caused by compartment syndromes and temperature alterations associated with
heat
stroke, malignant hyperthermia, neuroleptic malignant syndrome, burns, or
hypothermia.
8. Ischemia
[0343] Ischemia leading to myoglobinuria can be caused by vascular occlusion,
hemangioma steal syndrome, sickle cell trait, cocaine, calciphylaxis,
compartment
syndrome, carbon monoxide exposure, or cyanide poisoning.
9. Infections
[0344] Infections associated with myoglobinuria include viral infections such
as
influenza A and B, coxsackie virus, herpes, adenovirus, and HIV-1; bacterial
infections
including Streptococci, Salmonella, Staphylococci, typhoid fever, Legionella,
Clostridia,
and E. coli; Mediterranean tick typhus; tick-borne infections such as
ehrlichiosis,
anaplasmosis, baesiosis, Lyme disease, and Rocky Mountain spotted fever; and
hyperthermia-related infections.
10. Immune myopathy
[0345] Immune myopathies associated with myoglobinuria include polymyositis
and
dermatomyositis.
Myopathy, Lactic Acidosis and Sideroblastic Anemia (MLASA)
[0346] Myopathy, lactic acidosis, and sideroblastic anemia (MLASA) is a rare
autosomal recessive oxidative phosphorylation disorder specific to skeletal
muscle and
bone marrow. Myopathy, lactic acidosis, and sideroblastic anemia-1 (MLASA1)
can be
caused by homozygous mutations in the PUS1, which converts uridine into
pseudouridine
after the nucleotide has been incorporated into RNA. Pseudouridine may have a
functional role in tRNAs and may assist in the peptidyl transfer reaction of
rRNAs.
MLASA1 usually presents in children and teens and is characterized by
progressive
weakness, exercise intolerance, fatigue, nausea and vomiting, ptosis, short
stature,
1 1 8

CA 02920246 2016-02-09
sideroblastic anemia, lactic acidosis and reduced mitochondrial oxidative
enzyme
activities.
[0347] Myopathy, lactic acidosis, and sideroblastic anemia-2 (MLASA2) is an
autosomal recessive disorder of the mitochondrial respiratory chain that is
caused by
homozygous mutations in the aminoacyl-tRNA synthetase gene YARS2. The disorder

shows marked phenotypic variability: some patients have a severe multisystem
disorder
from infancy, including cardiomyopathy and respiratory insufficiency resulting
in early
death, whereas others present in the second or third decade of life with
sideroblastic
anemia and mild muscle weakness. Additional clinical features include
dysphagia,
weakness, exercise intolerance, short stature, high serum lactate, reduced COX
activity,
and reduced Complex I, III and IV activity.
Infantile Mitochondrial Myopathy due to Reversible COX Deficiency (MMIT)
[0348] Infantile mitochondrial myopathy due to reversible COX deficiency is a
rare
mitochondrial disorder characterized by onset in infancy of severe hypotonia
and
generalized muscle weakness associated with lactic acidosis, but is
distinguished from
other mitochondrial disorders in that affected individuals recover
spontaneously after 1
year of age. MMIT is caused by mutations in the MTTE gene, which is encoded by
the
mitochondrial genome.
[0349] Clinical features include muscle weakness, hypotonia, respiratory
failure,
dysphagia, ophthalmoplegia, macroglossia, neuropathy, seizures,
encephalopathy,
hepatomegaly, pneumonia, lactic acidosis, delayed myelination, high serum
creatine
kinase, ragged red fibers, reduced COX activity, reduced Complex I activity,
increased
lipid or glycogen in muscle fibers, muscle degeneration, inflammation, lipid
droplets in
fibers, and mtDNA reduction.
[0350] Variant MTTE syndromes include mitochondrial myopathy with diabetes
mellitus, diabetes-deafness syndrome, LHON, Mitochondrial myopathy with
respiratory
failure, MELAS/LHON/DEAF, progressive encephalopathy, encephalomyopathy with
retinopathy, leukoencephalopathy and exercise intolerance.
[0351] Additionally, certain MTTE mutations can lead to at least one or more
symptoms
such as myopathy, ataxia, lactic acidosis, high serum creatine kinase, SDH+ &
COX
negative muscle fibers, reduced Complexes I, III & IV activity, retinopathy,
severe
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myopathy with respiratory failure, ptosis, PEO, pigmentary retinopathy,
migraines, life-
long exercise intolerance and leukodystrophy.
Specific Sporadic Mitochondrial Myopathy Syndromes
,
1. Myopathy, Exercise Intolerance, Encephalopathy, Lactic acidemia
[0352] Cytochrome c oxidase subunit III (COIII or MTC03) is 1 of 3
mitochondrial
DNA (mtDNA) encoded subunits (MTC01, MTCO2, MTC03) of respiratory Complex
IV. Complex IV is located within the mitochondrial inner membrane and is the
third and
final enzyme of the electron transport chain of mitochondrial oxidative
phosphorylation.
It collects electrons from ferrocytochrome c (reduced cytochrome c) and
transfers then to
oxygen to give water. The energy released is to transport protons across the
mitochondrial
inner membrane. Complex IV is composed of 13 polypeptides. Subunits I, II, and
III
(MTC01, MTCO2, MTC03) are encoded by the mtDNA while subunits VI, Va, Vb, VIa,

VIb, VIc, VIIa, Vllb, Vile, and VIII are nuclear encoded. Subunits VIa, VIIa,
and VIII
have systemic as well as heart muscle isoforms.
[0353] Mutations in MTC03 can result in Myopathy, Exercise intolerance,
Encephalopathy, Lactic acidemia Syndrome, which usually manifests between 4 to
20
years of age. Clinical symptoms include weakness, myalgia, fatigue,
myoglobinuria,
encephalopathy, migraine, spastic paraparesis, mental retardation,
ophthalmoplegia, high
serum lactate, COX deficiency, SDH positive muscle fibers, and lipid
accumulation in
type I fibers.
[0354] Mutations in MTC03 can also result in isolated myopathy (characterized
by
weakness, COX deficiency, persistent ragged red fibers), myoglobinuria,
maternally
inherited myopathies, MELAS-like disorder, Leigh-like disorder, and
nonarteritic
ischemic optic neuropathy (NAION)-Myoclonic epilepsy.
2. Myoglobinuria & Exercise Intolerance
[0355] Mutations in MTC01 can result in Myoglobinuria and exercise
intolerance,
which usually manifests at childhood. Clinical symptoms include exercise
intolerance,
myoglobinuria, COX deficiency, and defects in Complex I & III. Other MTC01
syndromes include acquired sideroblastic anemia; Deafness, Ataxia, Blindness,
Myopathy;
epilepsy partialis continua; motor neuron disease; LHON; Myopathy,
Cardiomyopathy,
Stroke; MELAS-like Syndrome.
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3. Exercise Intolerance, Proximal Weakness Myoglobinuria
[0356] Cytochrome b (MTCYB) is the only mitochondrial DNA (mtDNA) encoded
subunit of respiratory Complex III (ubiquinol:ferrocytochrome c
oxidoreductase, or
cytochrome bcl, complex). Complex III is located within the mitochondrial
inner
membrane and is the second enzyme in the electron transport chain of
mitochondrial
oxidative phosphorylation. It catalyzes the transfer of electrons from
ubiquinol (reduced
Coenzyme Q10) to cytochrome c and utilizes the energy to translocate protons
from inside
the mitochondrial inner membrane to outside.
[0357] Disruption of MTCYB function can result in exercise intolerance,
proximal
weakness myoglobinuria syndrome, which manifests during childhood. Symptoms
include sensation of cramps, myalgias or fatigue, weakness, myoglobinuria,
septo-optic
dysplasia, retardation, encephalopathy, seizures, high serum lactate,
myopathy, deficient
Complex III activity, and ragged red fibers.
[0358] Mutations in MTCYB can lead to Encephalopathy & Seizures Syndrome,
which
usually presents at 9 to 13 years of age. Clinical features include exercise
intolerance,
lactic acidosis, encephalopathy, poor balance, seizures, visual
hallucinations, depression,
emotional lability, and ragged red fibers.
[0359] Other variant disorders caused by mutations in MTCYB include septo-
optic
dysplasia (characterized by mental retardation, delayed walking, exercise
intolerance,
retinitis pigmentosa, optic atrophy, hypertrophic cardiomyopathy, Wolff-
Parkinson-White,
lactic acidosis, and cerebellar hypoplasia), Familial Myalgia Syndrome,
Exercise
intolerance, LHON, colon cancer, LVNC, MELAS, Parkinsonism, obesity, and
Migraine,
Epilepsy, Polyneuropathy, Stroke-like episodes.
4. Exercise Intolerance Mild Weakness
[0360] Mutations in several mitochondrial genes such as MTTW, Cytochrome
b (Complex III), MTND1 (Complex I), MTND2 (Complex I), and MTND4 (Complex I)
can cause exercise intolerance with or without mild weakness, which manifests
at
childhood. Additional clinical features include dyspnea, tachycardia, high
serum lactate,
and ragged red fibers.
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5. Myopathy Exercise Intolerance, Growth or CNS disorder
[0361] Mutations in MTTM can result in Myopathy with or without Exercise
intolerance, Growth or CNS disorders, which usually manifests at 10 to 56
years of age.
Clinical symptoms include myopathy, proximal and distal weakness, exercise
intolerance,
muscle atrophy, ptosis, reduced tendon reflexes, growth retardation, mental
retardation,
lactic acidosis, high serum Creatine Kinase, ragged red fibers, COX
deficiency, muscular
dystrophy, cortical atrophy, and myelomalacia. Other variant MTTM syndromes
include
Exercise intolerance, Autoimmune polyendocrinopathy and Lactic acidosis.
6. Myopathy with Episodic High Creatine Kinase (MIMECK)
[0362] Mutations in MTTK can result in Myopathy with Episodic high Creatine
Kinase
(MIMECK), which usually manifests between the ages of 15 to 69 years. Clinical
features
include weakness, dysphagia, myalgias, and episodic high serum Creatine
Kinase.
Maternally-Inherited Mitochondrial Myopathies
[0363] Maternally-inherited mitochondrial myopathies can be caused by
mutations in
Cytochrome c Oxidase, Subunit II (COX II or MTCO2). Myopathy usually manifests
in
children and teens. Clinical features include weakness, fatigue and exercise
intolerance,
rhabdomyolysis, ataxia, retinopathy, optic atrophy, reduction in COX activity,
lipid in type
I fibers, cataracts, hearing loss, cardiac arrhythmia, depression, short
stature, lactic
acidosis, elevated serum or CSF lactate and mitochondrial proliferation.
[0364] Mutations in MTTS1 can cause Myopathy, Deafness & CNS disorders that
usually manifest at 8 years of age. Clinical features include weakness or
contractures,
fatigue, sensorineural deafness, ataxia, cognitive impairment, optic atrophy,
axonal
sensory neuropathy, high serum and CSF lactate, mitochondrial proliferation,
COX-
fibers, and reduced Complex I & IV activity.
[0365] Mutations in MTTW can cause Myopathy, Ptosis & Dysphonia, which usually

manifests at 50 years of age. Clinical features include ptosis, weakness,
fatigue, SDH+
and COX negative muscle fibers, and cytochrome c oxidase reduction.
[0366] Mutations in MTTE can cause Myopathy, Diabetes & CNS disorders, which
usually manifest in teens or adults. Clinical features include fatigue,
weakness, orbicularis
oculi, respiratory failure, FSH dystrophy, fatigue, diabetes, polyneuropathy,
cerebellar
ataxia, nystagmus, congenital encephalopathy, endomysial fibrosis,
mitochondrial
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CA 02920246 2016-02-09
proliferation, COX negative muscle fibers, reduced Complex I & IV activity,
and focal
COX reductions in cardiac muscle.
Autosomal Recessive Mitochondrial Myopathies
1. Myopathy with Lactic Acidosis
[0367] Myopathy with lactic acidosis, also known as Swedish type myopathy with

exercise intolerance, is caused by homozygous or compound heterozygous
mutations in
the ISCU gene, encoding the iron-sulfur cluster scaffold protein, on
chromosome 12q24.
Hereditary myopathy with lactic acidosis is an autosomal recessive muscular
disorder
characterized by childhood onset of exercise intolerance with muscle
tenderness,
cramping, dyspnea, and palpitations. Clinical features include fatigue,
shortness of breath,
tachycardia, weakness, lactic acidosis, rhabdomyolysis, muscle swelling,
myalgias,
cardiac hypertrophy, SDH deficiency, abnormality of muscle mitochondrial iron-
sulfur
cluster-containing proteins, high serum lactate, reduced COX expression, and
mitochondrial inclusions. Disruption of ISCU function can also result in
Myopathy with
Myoglobinuria.
[0368] Iron-sulfur cluster disorders can also arise as a result of mutations
in FDX1L,
Glutaredoxin 5, NFUl, BOLA3, NUBPL, 11BA57, LYRM4 and LYRM7.
2. Myopathy + Rhabdomyolysis
[0369] Myopathy with rhabdomyolysis is caused by mutations in Ferredoxin 1-
like
protein (FDX1L), which plays a role in Fe-S cluster biogenesis. Clinical
symptoms
include weakness, dyspnea, myoglobinuria, fatigue, reduced Complex I, II & III
activities,
reduced aconitase activity, high citrate synthase, high lactate, 3-methyl
glutaconic acid,
ketones & Krebs cycle metabolites.
3. Myopathy + Cataracts & Combined Respiratory Chain Defects
[0370] Myopathy with cataract and combined respiratory chain deficiency can be
caused
by mutations in the GFER gene, which plays a role in the mitochondrial
disulfide relay
system. Clinical features include reduced Complex I, II, and IV activity,
accumulation
of multiple mtDNA deletions, cataracts, hypotonia, developmental delay, muscle

smallness, reduced tendon reflexes, sensorineural hearing loss, SDH+ and COX
negative
muscle fibers, high serum lactate, low serum ferritin, and high serum amylase.
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4. Myopathy with Abnormal Mitochondrial Translation
[0371] Myopathy with abnormal mitochondrial translation is an autosomal
disorder that
manifests during childhood. Clinical symptoms include weakness, fatiguability,

hypotonia, ptosis, ophthalmoplegia, short stature, sideroblastic anemia,
mitochondrial
proliferation in muscle fibers, reduced COX activity, reduced Complex I, II,
III and IV
activity, and mitochondrial translation defects.
5. Fatigue & Exercise Intolerance
[0372] Fatigue Syndrome is caused by homozygous or compound heterozygous
mutations in the ACAD9 gene, which encodes a protein that catalyzes the
initial rate-
limiting step in 13-oxidation of fatty acyl-CoA. ACAD9 deficiency is an
autosomal
recessive multisystemic disorder characterized by infantile onset of acute
metabolic
acidosis, hypertrophic cardiomyopathy, and muscle weakness associated with a
deficiency
of mitochondrial complex I activity in muscle, liver, and fibroblasts.
Clinical features
include exercise intolerance, urge to vomit, sense of mental slowness, reduced
Complex I
activity, high serum lactate. Episodic hepatic dysfunction is also present in
some variants
of the syndrome.
6. Myopathy with Extrapyramidal Movement Disorders (MPXPS)
[0373] Myopathy with extrapyramidal signs is an autosomal recessive disorder
characterized by early childhood onset of proximal muscle weakness and
learning
disabilities. While the muscle weakness is static, most patients develop
progressive
extrapyramidal signs that may become disabling. Myopathy with extrapyramidal
signs
(MPXPS) is caused by homozygous mutations in the MICUl gene, which plays a
role in
mitochondrial Ca2+ uptake. Clinical features include chorea, tremor, dystonia,
orofacial
dyskinesia, ataxia, microcephaly, ophthalmoplegia, ptosis, optic atrophy, and
peripheral
neuropathy.
7. Glutaric aciduria II (MADD)
[0374] MADD, also known as glutaric acidemia II or glutaric aciduria II, can
be caused
by mutations in at least 3 different genes: ETFA, ETFB, and ETFDH. These genes
are all
involved in electron transfer in the mitochondrial respiratory chain. The
disorders
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CA 02920246 2016-02-09
resulting from defects in these 3 genes are referred to as glutaric acidemia
IIA, JIB, and
IIC, respectively, although there appears to be no difference in the clinical
phenotypes.
[0375] Glutaric aciduria II (GA II) is an autosomal recessively inherited
disorder of fatty
acid, amino acid, and choline metabolism. It differs from GA Tin that multiple
acyl-CoA
dehydrogenase deficiencies result in large excretion not only of glutaric
acid, but also of
lactic, ethylmalonic, butyric, isobutyric, 2-methyl-butyric, and isovaleric
acids. GA II
results from deficiency of any 1 of 3 molecules: the alpha (ETFA) and beta
(ETFB)
subunits of electron transfer flavoprotein, and electron transfer flavoprotein
dehydrogenase (ETFDH).
[0376] The heterogeneous clinical features of patients with MADD fall into 3
classes: a
neonatal-onset form with congenital anomalies (type I), a neonatal-onset form
without
congenital anomalies (type II), and a late-onset form (type III). The neonatal-
onset forms
are usually fatal and are characterized by severe nonketotic hypoglycemia,
metabolic
acidosis, multisystem involvement, and excretion of large amounts of fatty
acid- and
amino acid-derived metabolites. Symptoms and age at presentation of late-onset
MADD
are highly variable and characterized by recurrent episodes of lethargy,
vomiting,
hypoglycemia, metabolic acidosis, and hepatomegaly often preceded by metabolic
stress.
Muscle involvement in the form of pain, weakness, and lipid storage myopathy
also
occurs. The organic aciduria in patients with the late-onset form of MADD is
often
intermittent and only evident during periods of illness or catabolic stress.
8. Coenzyme Q10 Deficiency
[0377] Primary CoQ10 deficiency is a rare, clinically heterogeneous autosomal
recessive
disorder caused by mutation in any of the genes encoding proteins directly
involved in the
synthesis of coenzyme Q. Coenzyme Q10 (CoQ10), or ubiquinone, is a mobile
lipophilic
electron carrier critical for electron transfer by the mitochondrial inner
membrane
respiratory chain.
[0378] The disorder has been associated with 5 major phenotypes, but the
molecular
basis has not been determined in most patients with the disorder and there are
no clear
genotype/phenotype correlations. The phenotypes include an encephalomyopathic
form
with seizures and ataxia; a multisystem infantile form with encephalopathy,
cardiomyopathy and renal failure; a predominantly cerebellar form with ataxia
and
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cerebellar atrophy; Leigh Syndrome with growth retardation; and an isolated
myopathic
form.
[0379] Autosomal recessive forms of the disorder include COQ10D1, caused by
mutations in COQ2; COQ10D2, caused by mutations in the PDSS1 gene; COQ10D3,
caused by mutations in the PDSS2 gene; COQ10D4, caused by mutations in the
COQ8
gene (ADCK3); COQ10D5, caused by mutations in the COQ9 gene; and COQ10D6,
caused by mutations in the COQ6 gene.
[0380] Secondary C0Q10 deficiency has been reported in association with
glutaric
aciduria type IIC (MADD), caused by mutation in the ETFDH gene, and with
ataxia-
oculomotor apraxia syndrome-1 (A0A1), caused by mutation in the APTX gene.
Autosomal Dominant Mitochondrial Myopathy
[0381] Dominant mutations in coiled-coil-helix-coiled-coil-helix domain-
containing
protein 10 (CHCHD10) can lead to mitochondrial myopathy with exercise
intolerance,
which usually manifests within the first decade of life. Clinical features
include exercise
intolerance, weakness in legs, arms, and face, restrictive deficits in
pulmonary function,
short stature, high serum lactate, high serum pyruvate, ragged red fibers,
reduced
cytochrome c oxidase (Complex IV) activity, and reduced succinate cytochrome c

reductase (Complex II & III) activity.
[0382] Other examples of autosomal dominant mitochondrial myopathies include
myopathy with focal depletion of mitochondria, mitochondrial DNA breakage
syndrome
(PEO + Myopathy), LGMD1H, and lipid type mitochondrial myopathy.
Multiple Symmetric Lipomatosis (Madelung Syndrome)
[0383] Multiple symmetric lipomatosis (MSL) is a rare disorder characterized
by the
growth of uncapsulated masses of adipose tissue. It is associated with high
ethanol intake
and may be complicated by somatic and autonomic neuropathy and by the
infiltration of
the adipose tissue at the mediastinal level. MSL can arise as a result of an
autosomal
dominant, mitochondrial, or sporadic mutation. Clinical features include
multiple lipomas
in the nape of the neck, supraclavicular and deltoid regions, full body
lipomas,
polyneuropathy, hyperuricemia, high triglycerides (VLDL, chylomicrons), high
HDL, and
ragged red fibers.
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N-acetylglutamate Synthase Deficiency
[0384] N-acetylglutamate synthase (NAGS) deficiency is an inborn error of
metabolism
affecting ammonia detoxification in the urea cycle. N-acetylglutamate synthase
is a
mitochondrial enzyme that catalyzes the formation of N-acetylglutamate (NAG).
NAG is
an essential allosteric activator of carbamoylphosphate synthase 1 (CPS1), the
first and
rate-limiting enzyme in the urea cycle. Most NAGS genes contain a C-terminus
transferase domain in which the catalytic activity resides and an N-terminus
kinase
domain where arginine binds. Because CPS1 is inactive without NAG, the urea
cycle
function can be severely affected resulting in fatal hyperammonemia in
neonatal patients
or at any later stage in life. Clinical manifestations of NAGS deficiency
include poor
feeding, vomiting, altered levels of consciousness, seizures, and coma.
Neoplasms
[0385] Mutations in certain nuclear encoded mitochondrial genes can give rise
to
neoplasms, such as paraganglionoma, leiomyomatosis, renal cell cancer, and B-
cell
lymphoma. Paragangliomas, also referred to as 'glomus body tumors,' are tumors
derived
from paraganglia located throughout the body. Nonchromaffin types primarily
serve as
chemoreceptors (hence, the tumor name 'chemodectomas') and are located in the
head and
neck region (i.e., carotid body, jugular, vagal, and tympanic regions),
whereas chromaffin
types have endocrine activity, conventionally referred to as
'pheochromocytomas,' and are
usually located below the head and neck (i.e., adrenal medulla and pre- and
paravertebral
thoracoabdominal regions). PGL can manifest as nonchromaffin head and neck
tumors
only, adrenal and/or extraadrenal pheochromocytomas only, or a combination of
the 2
types of tumors.
[0386] Familial paragangliomas-1 (PGL I) is caused by mutations in the SDHD
gene,
which encodes the small subunit of cytochrome B in succinate-ubiquinone
oxidoreductase.
PGL1 manifests as benign vascularized tumors in the head and neck.
[0387] Hereditary paragangliomas-2 (PGL2) is caused by mutations in the SDHAF2

gene, which encodes a protein necessary for flavination of SDHA. PGL1
manifests as
tumors in the head and neck, and especially the carotid body.
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[0388] Hereditary paragangliomas-3 (PGL3) is caused by heterozygous mutations
in the
SDHC gene, which encodes subunit C of the succinate dehydrogenase complex.
PGL3
manifests as benign vascularized tumors in the head and neck.
[0389] Familial paragangliomas-4 (PGL4) is caused by heterozygous mutations in
the
SDHB gene, which encodes the iron sulfur subunit of succinate dehydrogenase.
Clinical
features include susceptibility to pheochromocytoma and paraganglioma, and
Cowden-like
Syndrome (CWD2).
[0390] Paragangliomas-5 (PGL5) can be caused by heterozygous mutations in the
SDHA gene. Clinical features include hypertension and hyperadrenergic
symptoms, such
as dizziness, tachycardia, and sweating. Patients exhibit high concentrations
of urinary
normetanephrine, norepinephrine, and chromogranin A. Perturbations in SDHA can
also
lead to cardiomyopathy and mitochondrial respiratory chain complex 2
deficiency.
[0391] BCL2 is an integral inner mitochondrial membrane protein of relative
molecular
mass 25,000. Overexpression of BCL2 blocks the apoptotic death of a pro-B-
lymphocyte
cell line, and can result in B-cell lymphoma. Thus, BCL2 is unique among prom-
oncogenes, being localized in mitochondria and interfering with programmed
cell death
independent of promoting cell division.
[0392] Heterozygous mutations in the fumarate hydratase gene can cause
hereditary
leiomyomatosis and renal cell cancer.
[0393] Susceptibility to the development of neuroblastoma-1 (NBLST1) and
isolated
pheochromocytoma is associated with mutations in the KIF1B gene, which encodes

kinesin family member 1B. This protein is a member of the kinesin family of
proteins that
are essential for intracellular transport, including the transport of
mitochondria. NBLST1
is common neoplasm of early childhood arising from embryonic cells that form
the
primitive neural crest and give rise to the adrenal medulla and the
sympathetic nervous
system. Pheochromocytoma is caused by a catecholamine-producing tumor of
chromaffin
tissue of the adrenal medulla or sympathetic paraganglia. The cardinal
symptom,
reflecting the increased secretion of epinephrine and norepinephrine, is
hypertension,
which may be persistent or intermittent.
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Nephronophthisis
[0394] Nephronophthisis (NPHP), also known as nephronophthisis-like
nephropathy 1,
is an autosomal recessive cystic kidney disease characterized by the onset of
end-stage
renal failure in the first three decades of life. Features of NPHP include
irregular tubular
basement membrane, tubular cyst formation, and interstitial cell infiltration
with fibrosis.
The disorder is also frequently associated with extrarenal manifestations
including liver
fibrosis, retinal degeneration, and central nervous system abnormalities.
Mutations in ten
causative genes (NPHP1-NPHP9 and NPHP11), whose products localize to the
primary
cilia-centrosome complex, have been identified and are linked to the
development of
NPHP. In addition, homozygous frameshift and splice-site mutations in the X-
prolyl
aminopeptidase 3 (XPNPEP3) gene have been identified and are associated with
the
development of a nephronophthisis-like nephropathy. In contrast to all known
NPHP
proteins, XPNPEP3 localizes to mitochondria of renal cells. XPNPEP3 belongs to
a
family of X-pro-aminopeptidases that utilize a metal cofactor and remove the N-
terminal
amino acid from peptides with a proline residue in the penultimate position.
Neuropathy; Ataxia; Retinitis Pigmentosa (NARP)
[0395] NARP Syndrome is caused by mutations in the gene encoding subunit 6 of
mitochondrial H(+)-ATPase (MTATP6) and usually presents at childhood (2nd
decade) or
adult stage. The MT-ATP6 protein forms one subunit of complex V (ATP
synthase),
which is responsible for the last step in ATP production. Mutations in MT-ATP6
alter the
structure or function of ATP synthase, reducing the ability of mitochondria to
produce
ATP. Most individuals with NARP have a specific point mutation at nucleotide
8993,
with a T8993G mutation causing more severe symptoms than a T8993C mutation.
Some
cases involve a G8989C point mutation.
[0396] Clinical features include sensory neuropathy, proximal and distal
weakness,
reduced tendon reflexes, retinitis pigmentosa, reduced night vision, Bull's
eye
maculopathy, pigment in posterior pole & mid-periphery, small retinal scars,
vascular
narrowing, central and paracentral scotomas, gait disorder, dysarthria,
dementia, seizures,
Tonic-clonic seizures, developmental delay, pyramidal signs, dystonia, hearing
loss,
cardiac hypertrophy, denervation, cerebral atrophy, cortical cerebellar
atrophy, focal cystic
necrosis, and rod or cone dysfunction.
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[0397] Disruption of MTATP6 function can result in Distal Hereditary Motor
Neuropathy (dHMN), which usually presents during the 1st or 2nd decade of
life. Clinical
features include gait disorder, weakness, sensory loss, brisk tendon reflexes,
extensor
plantar reflex, pes cayus, Kyphoscoliosis, motor axon loss, sensory axon loss,
and reduced
Complex V activity.
Ornithine Transcarbamylase Deficiency
[0398] Ornithine transcarbamylase (OTC) deficiency is an X-linked inborn error
of
metabolism of the urea cycle that causes hyperammonemia. Ornithine
carbamoyltransferase is a nuclear-encoded mitochondrial matrix enzyme that
catalyzes the
second step of the urea cycle in mammals. OTC deficiency is associated with
mutations in
the OTC gene. OTC is the most common urea cycle defect and is characterized by
the
triad of hyperammonemia, encephalopathy, and respiratory alkalosis.
Paroxysmal Nonkinesigenic Dyskinesia
[0399] Paroxysmal nonkinesigenic dyskinesia (PNI(D) is an autosomal dominant
movement disorder characterized by sudden attacks of dystonia, chorea, and
athetosis.
PNKD is associated with mutations in the myofibrillogenesis regulator-1 gene
(MR1).
MR1 is transcribed into three alternatively spliced isoforms: long (MR-1L);
medium (MR-
1M); and small (MR-1S). The MR-1L and MR-1M isoforms are mitochondrial
proteins
imported into the organelle by a 39-amino acid, N-terminal mitochondrial
targeting
sequence (MTS).
Progressive External Ophthalmoplegia (PEO)
[0400] PEO is a slowly progressive disorder associated with slow eye movement
speed,
limited gaze in all directions, ptosis, and extraocular muscle pathology. PEO
may arise
sporadically or as a consequence of autosomal dominant, autosomal recessive,
or maternal
inheritance.
1. Sporadic PEO
[0401] Syndromes with severe ophthalmoplegia include Kearns-Sayre, PEO +
Proximal myopathy, and PEO.
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[0402] Chronic PEO is caused by a single large mtDNA deletion and usually
manifests
at > 20 years of age. Symptoms include ophthalmoplegia, and heart block in
some
patients.
[0403] PEO with sensory ataxic neuropathy usually manifests between 10 to 31
years of
age. Clinical features include sensory loss, gait disorder, distal motor
weakness, absent
tendon reflexes, external ophthalmoplegia, ptosis, dysarthria, facial
weakness, myopathy,
and ragged red muscle fibers.
[0404] Mutations in MTTQ can result in PEO that presents at 5 years of age.
Clinical
symptoms include weakness, ptosis, dysphonia, dysphagia, ophthalmoplegia,
reduced
tendon reflexes, ragged red fibers, COX negative muscle fibers and impairment
in
mitochondrial protein synthesis.
[0405] Mutations in MTTA can result in PEO that presents in the 6th decade of
life.
Clinical symptoms include ptosis, weakness, decreased eye movements,
dysphagia, COX
negative muscle fibers, mitochondrial proliferation, and partial defect of
Complex I.
[0406] Mutations in MTTL can result in PEO that presents in the 5th decade of
life.
Clinical symptoms include ptosis, migraines, decreased eye movements, exercise

intolerance, short stature, COX negative, ragged red muscle fibers, and
partial defects of
Complex I & IV.
[0407] Mutations in MTTY can result in PEO that presents in the 4th decade of
life.
Clinical symptoms include ptosis, exercise intolerance, ophthalmoplegia,
myopathy, COX
negative muscle fibers with increased SDH staining, and partial defect of
Complex I & IV.
Other MTTY syndromes include exercise intolerance with Complex III deficiency,
and
focal segmental glomerulosclerosis and dilated cardiomyopathy.
2. Maternally-inherited PEO
[0408] Maternal PEO is caused by mtDNA point mutations in MTTL, MTTN, MTTQ,
MTTA, and MTTK.
3. Autosomal Dominant PEO
[0409] Autosomal dominant progressive external ophthalmoplegia (adPEO) with
mitochondrial DNA (mtDNA) deletions-3 (PEOA3) is caused by heterozygous
mutations
in the nuclear-encoded twinkle gene (C 1 OORF2), which binds to the 13-subunit
of
polymerase-y (POLO). Progressive external ophthalmoplegia is characterized by
multiple
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mitochondrial DNA deletions in skeletal muscle. The most common clinical
features
include adult onset of weakness of the external eye muscles and exercise
intolerance.
Patients with ClOORF2-linked adPEO may have other clinical features including
proximal
muscle weakness, muscle pain, cramps, respiratory failure, ataxia, peripheral
neuropathy,
cardiomyopathy, cataracts, depression, ptosis, dysarthria, dysphagia,
dysphonia, hearing
loss, memory loss, Parkinsonism, avoidant personality traits, SDH+ COX
negative muscle
fibers, ragged red fibers, ketoacidosis, cortical atrophy or white matter
lesions, and
endocrine abnormalities. Variant syndromes involving Twinkle mutations include

Infantile Onset Spinocerebellar Ataxia (IOSCA), SANDO, MTDPS7, PEO + Dementia,

PEO + Parkinson, and Perrault.
[0410] Autosomal dominant progressive external ophthalmoplegia (adPEO) with
mitochondrial DNA (mtDNA) deletions-2 (PEOA2) is caused by heterozygous
mutations
in the nuclear-encoded ANT 1 gene (SLC25A4), which usually manifests at 20 to
35 years
of age. Clinical symptoms include ophthalmoplegia, ptosis, dysphagia,
dysphonia, face,
proximal, and respiratory weakness, cataracts, sensorineural hypoacusia,
goiter, dementia,
Bipolar affective disorder, high serum lactic acid, and multiple mtDNA
deletions. Over-
expression of ANTI is also observed in FSH dystrophy muscle.
[0411] PEOA2 can also be caused by heterozygous mutations in the nuclear-
encoded
twinkle gene (C100RF2). The most common mutation is an Ala359Thr missense
mutation, the homozygous version producing more severe effects than the
heterozygous
version. In addition, adPEO is characterized by multiple mitochondrial DNA
deletions in
skeletal muscle. A severe CNS phenotype with polyneuropathy is associated with
a 39-bp
deletion. In general, the mutations tend to cluster in regions of the protein
involved in
subunit interactions (amino acids 303-508). The twinkle protein is involved in
mtDNA
metabolism and could function as an adenine nucleotide-dependent DNA helicase.
The
function of the twinkle protein is believed to be critical for lifetime
maintenance of
mtDNA integrity. The most common clinical features of adPEO include adult
onset of
weakness of the external eye muscles and exercise intolerance. Patients with
C100RF2-
linked adPEO may have other clinical features including proximal muscle
weakness,
ataxia, peripheral neuropathy, cardiomyopathy, cataracts, depression, and
endocrine
abnormalities.
[0412] Autosomal dominant progressive external ophthalmoplegia (adPEO) with
mitochondrial DNA (mtDNA) deletions-1 (PEOA1) is caused by mutations in the
nuclear-
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encoded DNA polymerase-gamma gene (POLG). Autosomal recessive PEO (PEOB) is
also caused by mutations in the POLG gene. PEO1 manifests at 16 to 39 years of
age.
Clinical features include PEO, muscle weakness, exercise intolerance, sensory
loss, absent
tendon reflexes, poorly formed 2 sexual characteristics, early menopause,
testicular
atrophy, Parkinsonism, proximal weakness & wasting, dysphagia, dysphonia,
facial
diplegia, abnormal gait, depression, extrapyramidal syndrome, ragged red
fibers, COX
negative and SDH + fibers, and proximal myopathy. Other clinical syndromes
associated
with dominant POLG mutations include PEO+ Demyelinating neuropathy, PEO +
Distal
myopathy, Sensory neuropathy, PEO & Tremor, and PEO + Hypogonadism. Clinical
syndromes associated with recessive POLG mutations include Alpers-Huttenlocher

Syndrome (AHS), Childhood myocerebrohepatopathy spectrum (MCHS), Myoclonic
epilepsy, Myopathy, Sensory ataxia (MEMSA), SANDO, MIRAS, MNGIE and
Parkinsons.
[0413] PEO+ Demyelinating neuropathy manifests at the second decade of life
and is
characterized by weakness, sensory loss, absent tendon reflexes, PEO with
ptosis,
dysphonia, dysphagia, nerve pathology, ragged red fibers, COX negative fibers,
and
reduced Complex I, III & IV activity.
[0414] Mitochondrial Recessive Ataxia Syndrome (MIRAS) usually manifests
between
the ages of 5 to 38 years. Clinical symptoms include balance disorder,
epilepsy,
dysarthria, nystagmus, reduced tendon reflexes, pain, sensory neuropathy,
cramps,
cognitive impairment, athetosis, tremor, obesity, and eye movement disorders.
[0415] PEO + Hypogonadism is characterized by delayed sexual maturation,
primary
amenorrhea, early menopause, testicular atrophy, cataracts, cerebellar ataxia,
tremor,
Parkinsonism, depression, mental retardation, polyneuropathy, PEO, dysarthria,

dysphonia, proximal weakness, rhabdomyolysis, hypoacusis, Pes cavus, ragged
red fibers,
and cytochrome c oxidase negative muscle fibers.
[0416] Distal myopathy, Cachexia & PEO is caused by dominant or sporadic
mutations
in POLG1 and usually manifests between the third and fourth decade of life.
Clinical
features include weakness, dysarthria, dysphagia, cachexia, ptosis,
ophthalmoplegia,
cataracts, and ragged red & COX negative muscle fibers.
[0417] Autosomal dominant progressive external ophthalmoplegia (adPEO) with
mitochondrial DNA (mtDNA) deletions-4 (PEOA4) is caused by heterozygous
mutations
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in the nuclear-encoded DNA polymerase gamma-2 gene (POLG2). Progressive
external
ophthalmoplegia-4 is an autosomal dominant form of mitochondrial disease that
variably
affects skeletal muscle, the nervous system, the liver, and the
gastrointestinal tract. Age of
onset ranges from infancy to adulthood. The phenotype ranges from relatively
mild, with
adult-onset skeletal muscle weakness and weakness of the external eye muscles,
to severe,
with a multisystem disorder characterized by delayed psychomotor development,
lactic
acidosis, constipation, and liver involvement. Clinical features include
ptosis, external
ophthalmoplegia, exercise intolerance, pain, weakness, seizures, hypotonia,
impaired
glucose tolerance, high lactate, cerebellar atrophy, cardiac conduction
defect, and
abnormal mitochondrial morphology.
[0418] Autosomal dominant progressive external ophthalmoplegia-6 (PEOA6) is
caused
by heterozygous mutations in the DNA2 gene. PEOA6 is characterized by muscle
weakness, mainly affecting the lower limbs, external ophthalmoplegia, exercise

intolerance, and mitochondrial DNA (mtDNA) deletions on muscle biopsy.
Clinical
features include hypotonia, myalgia, exertional dyspnea, ptosis or
ophthalmoplegia,
lordosis, and muscular atrophy. Symptoms may appear in childhood or adulthood
and
show slow progression.
[0419] In some embodiments, dominant POLG mutations may lead to sensory
neuropathy, tremor and PEO.
4. Autosomal Recessive PEO
[0420] PEO + Myopathy & Parkinsonism is an adult onset autosomal recessive
disorder.
Clinical features include extrapyramidal signs (e.g., akinesia, rigidity, rest
tremor), ptosis,
ophthalmoplegia, proximal & facial weakness, occasional distal leg weakness,
hearing
loss, SDH + and COX negative muscle fibers, reduced complex III activity, and
multiple
mtDNA deletions.
[0421] Autosomal recessive progressive external ophthalmoplegia (PEOB) is
caused by
homozygous or compound heterozygous mutations in the nuclear-encoded DNA
polymerase-gamma gene (POLG). Recessive mutations in the POLG gene can also
cause
sensory ataxic neuropathy, dysarthria, and ophthalmoparesis (SANDO), which
shows
overlapping features. Autosomal recessive PEO is usually more severe than
autosomal
dominant PEO.
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[0422] SANDO usually manifests between the ages of 16 to 38 years and is
characterized by exercise intolerance, ptosis, and paresthesias. Clinical
symptoms include
sensory loss, ataxic gait, pseudoathetosis, small fiber modality loss,
weakness, reduced
tendon reflexes, ptosis, ophthalmoplegia, dysarthria, myoclonic epilepsy,
depression, high
CSF and serum lactate, degeneration of spinocerebellar and dorsal column
tracts, thalamic
lesions, cerebellar atrophy or White matter lesions, ragged red fibers, loss
of myelinated &
unmyelinated axons, and reduced activity of Complex I & IV.
[0423] Mitochondrial DNA Depletion Syndrome-11 (MTDPS11) can be caused by
homozygous mutations in the MGME1 gene. Mitochondrial DNA Depletion Syndrome-
11 is an autosomal recessive mitochondrial disorder characterized by onset in
childhood or
adulthood of progressive external ophthalmoplegia (PEO), ptosis, muscle
weakness and
atrophy, exercise intolerance, dysphonia, dysphagia, and respiratory
insufficiency due to
muscle weakness. More variable features include spinal deformity, emaciation,
and
cardiac abnormalities. Skeletal muscle biopsies show deletion and depletion of

mitochondrial DNA (mtDNA) with variable defects in respiratory chain enzyme
activities.
Additional features include scapular winging, mental retardation, memory
deficits, nausea,
flatulence, abdominal fullness, diarrhea, loss of appetite, SDH+ & COX
negative fibers,
Complex I or I + IV deficiencies, and cerebellar atrophy.
[0424] PEO with cardiomyopathy is caused by recessive mutations in POLG and
usually
manifests at childhood. Clinical features include PEO, cardiomyopathy,
proximal
weakness, multiple mtDNA deletions, and ragged red fibers.
[0425] An additional POLG syndrome is Parkinsonism without external
ophthalmoplegia. Clinical feature include Parkinsonism or Dystonia, weakness,
high
serum lactate, COX negative muscle fibers, polyneuropathy, and cerebral and
cerebellar
atrophy.
[0426] Ataxia with sensory neuropathy is a variant POLG syndrome that is not
associated with ophthalmoplegia.
PEPCK Deficiency
[0427] PEPCK deficiency is an autosomal recessive disorder of carbohydrate
metabolism. A deficiency of the enzyme phosphoenolpyruvate carboxykinase
(PEPCK),
which is a key enzyme in gluconeogenesis, causes acidemia. PEPCK converts
oxaloacetate into phosphoenolpyruvate and carbon dioxide. PEPCK deficiency is
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CA 02920246 2016-02-09
characterized by hypoglycemia, hypotonia, hepatomegaly, liver impairment, and
failure to
thrive. In humans, there are two forms of PEPCK deficiency: cytosolic and
mitochondrial.
Both forms result from an inherited deficiency in the enzyme PEPCK. Cytosolic
PEPCK
is encoded by PCK1 and the mitochondrial enzyme is encoded by PCK2. PCK2
encodes a
deduced 640-amino acid polypeptide that shares 70% homology with cytosolic
PCK.
Perrault Syndromes
[0428] Perrault Syndrome (PRLTS) is a sex-influenced, autosomal recessive
disorder
characterized by sensorineural deafness in both males and females and
premature ovarian
failure (POF) secondary to ovarian dysgenesis in females. Some patients also
have
neurologic manifestations, including mild mental retardation and cerebellar
and peripheral
nervous system involvement. Perrault Syndrome is classified into type I, which
is static
and without neurologic disease, and type II, which is with progressive
neurologic disease.
[0429] Perrault Syndrome-1 (PRLTS1) is caused by compound heterozygous
mutations
in the HSD17B4 gene, which encodes a D-bifunctional protein (DBP).
[0430] Perrault Syndrome-2 (PRLTS2) is caused by compound heterozygous
mutations
in the mitochondrial histidyl-tRNA synthetase, HARS2. Affected females have
primary
amenorrhea, streak gonads, and infertility, whereas affected males show normal
pubertal
development and are fertile
[0431] Perrault Syndrome-3 (PRLTS3) is caused by homozygous or compound
heterozygous mutations in the CLPP gene, an endopeptidase component of a
mitochondrial ATP-dependent proteolytic complex required for protein
degradation in the
mitochondria.
[0432] Perrault Syndrome-4 (PRLTS4) is caused by homozygous or compound
heterozygous mutations in the LARS2 gene.
[0433] Mutations in the Twinkle gene can also lead to Perrault Syndrome. In
addition to
sensorineural deafness and female hypogonadism, patients exhibit symptoms such
as
nystagmus, gait disorder, epilepsy, polyneuropathy, ophthalmoplegia, increased
serum
lactate, and muscle atrophy.
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Propionic Acidemia
[0434] Propionic acidemia (PA) is caused by a deficiency of propionyl-CoA
carboxylase
(PCC), a biotin-dependent carboxylase located in the mitochondrial inner
membrane
space. PCC catalyzes the conversion of propionyl-CoA to methylmalonyl-CoA,
which
eventually enters the TCA cycle as succinyl-CoA. Propionyl-CoA is common to
the
pathway for degradation of some amino acids (isoleucine, valine, threonine,
and
methionine), odd-chain fatty acids, and cholesterol. Gut bacteria (i.e.,
Propionibacterium
sp.) are also an important source of propionate metabolized through PCC. PCC
is a
heterododecamer (a606) composed of six a-subunits encoded by PCCA and six 0-
subunits
encoded by PCCB. Biallelic mutation of either PCCA or PCCB results in PA.
[0435] Patients with PA exhibit episodic vomiting, lethargy, ketosis,
neutropenia,
periodic thrombocytopenia, hypogammaglobulinemia, developmental retardation,
and
intolerance to protein. Chemical features include hyperglycinemia and
hyperglycinuria.
Pyruvate Disorders
[0436] Pyruvate dehydrogenase complex (PDHC) is a nuclear-encoded
mitochondrial
matrix multienzyme complex composed of multiple copies of 3 enzymes: El,
Dihydrolipoyl transacetylase (DLAT), and Dihydrolipoyl dehydrogenase (DLD).
PDHC
catalyzes the irreversible conversion of pyruvate into acetyl-CoA. Pyruvate
disorders may
arise as a consequence of perturbations in PDHA 1, PDHB, PDHX, PDK3, PDP1,
DLAT,
DLD, NFU1, BOLA3, Lipoic acid synthase (LIAS), TPK1, Pyruvate carboxylase and
Pyruvate transporter.
1. Pyruvate Carboxylase Deficiency
[0437] Pyruvate carboxylase converts pyruvate & CO2 to oxaloacetate and plays
a role
in gluconeogenesis. Pyruvate carboxylase deficiency is caused by mutations in
the
pyruvate carboxylase gene and is categorized into 3 phenotypic subgroups: Type
A, Type
B and Type C. Type A patients have lactic acidemia and psychomotor
retardation,
whereas Type B patients have a more complex biochemical phenotype with
increased
serum lactate, ammonia, citrulline, and lysine, as well as an intracellular
redox disturbance
in which the cytosolic compartment is more reduced and the mitochondrial
compartment
is more oxidized. Type B patients have decreased survival compared to group A,
and
usually do not survive beyond 3 months of age. Type C is relatively benign.
Clinical
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features include hypotonia, delayed neurologic development, ataxia, chronic
lactic
acidemia, developmental delay, seizures, lactic acidosis, increased
lactate:pyruvate &
acetoacetate:3-hydroxybutyrate ratios, and episodic metabolic acidosis.
2. Pyruvate Dehydrogenase El-a Deficiency (PDHAD)
[0438] Pyruvate dehydrogenase El-alpha deficiency (PDHAD) is caused by
mutations
in the gene encoding the El-alpha polypeptide (PDHA1) of the pyruvate
dehydrogenase
(PDH) complex. Genetic defects in the pyruvate dehydrogenase complex are one
of the
most common causes of primary lactic acidosis in children. Most cases are
caused by
mutation in the El-alpha subunit gene on the X chromosome. X-linked PDH
deficiency is
one of the few X-linked diseases in which a high proportion of heterozygous
females
manifest severe symptoms. Clinical features of PDHAD include seizures,
hyperventilation, episodic cerebellar ataxia, chorioathetosis, lactic
acidosis, carbohydrate
intolerance, high serum pyruvic acid, and high serum alanine.
[0439] Variant syndromes associated with Pyruvate dehydrogenase El-alpha
deficiency
are also common and are characterized by hypotonia, lethargy, seizures,
dystonia,
psychomotor retardation, Leigh-like lesions and hyperlactataemia.
3. Pyruvate Dehydrogenase E1-13 Deficiency (PDHBD)
[0440] Pyruvate dehydrogenase El-beta deficiency (PDHBD) is caused by
homozygous
mutations in the PDHB gene, and typically presents at the infant stage.
Clinical symptoms
include hypotonia, respiratory insufficiency, lactic acidosis, corpus callosum
agenesis, and
reduced PDH activity.
4. Dihydrolipoamide Dehydrogenase (DLD) Deficiency
[0441] The DLD gene encodes dihydrolipoamide dehydrogenase (EC 1.8.1.4), a
flavoprotein component known as E3 that is common to the 3 alpha-ketoacid
dehydrogenase multienzyme complexes, namely, pyruvate dehydrogenase complex,
the
alpha-ketoglutarate dehydrogenase complex (KGDC), and the branched-chain alpha-
keto
acid dehydrogenase complex (BCKDC). The enzyme is a functional homodimer of
the
DLD protein and catalyzes the oxidative regeneration of a lipoic acid cofactor
covalently
bound to E2 (DBT) yielding NADH. The DLD enzyme is also a component, referred
to as
the L protein, of the mitochondrial glycine cleavage system (GCS). Clinical
symptoms
include vomiting and abdominal pain, stroke-like episodes, hypothermia, motor
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CA 02920246 2016-02-09
retardation, myoglobinuria, exertional fatigue, lactic acidosis, hypoglycemia,
and high
pyruvate, lactate, a-ketoglutarate, and branched-chain amino acids.
5. Pyruvate Dehydrogenase Phosphatase Deficiency (PDHPD)
[0442] Pyruvate dehydrogenase phosphatase deficiency can be caused by
mutations in
the PDP1 gene. Clinical features include hypotonia, developmental delay,
seizures, lactic
acidosis, and posterior white matter pathology.
6. Pyruvate Dehydrogenase E3-binding Protein Deficiency (PDHXD)
[0443] Pyruvate dehydrogenase E3-binding protein deficiency is caused by
homozygous
or compound heterozygous mutations in the PDHX gene. Clinical features include

hypotonia, psychomotor retardation, Leigh Syndrome, optic atrophy, diplegia,
dysarthria,
lactic acidosis, putaminal lesions, and hemolytic anemia.
7. Mitochondrial Pyruvate Carrier Deficiency (MPYCD)
[0444] Mitochondrial pyruvate carrier deficiency (MPYCD) is an autosomal
recessive
metabolic disorder characterized by delayed psychomotor development and lactic
acidosis
with a normal lactate/pyruvate ratio resulting from impaired mitochondrial
pyruvate
oxidation. MPYCD is caused by homozygous mutations in the BRP44L gene and
usually
manifests at birth or childhood. Clinical features include hypotonia,
psychomotor
retardation, peripheral neuropathy, dysmorphic features (face, single palmar
fold, wide
spaced nipples), hepatomegaly, metabolic acidosis, hyperlactacidemia, and
periventricular
cysts.
Schwartz-Jampel Syndrome Type 1 (SJS1)
[0445] Schwartz-Jampel Syndrome type 1 (SJS1) is caused by mutations in the
gene
encoding perlecan (HSPG2), a heparan sulfate proteoglycan. Perlecan is a major

component of basement membranes & interstitial matrix in cartilage and
functions as a
coreceptor for FGF2.
[0446] Schwartz-Jampel Syndrome type lA occurs during childhood (usually < 3
years).
Clinical features include respiratory difficulties, impaired swallowing,
polyhydramnios,
absent stomach bubble, short femurs, skeletal contractures, muscle stiffness,
reduced
tendon reflexes, muscle hypertrophy, malignant hyperthermia, mental
retardation, bone
dysplasia, micrognathia, platyspondyly, cleft vertebrae, reduced height,
kyphoscoliosis,
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myopia, cataracts, blepharophimosis, medial displacement of outer canthi,
hirsutism, small
testes, microstomia, jaw muscle rigidity. SJS Type 1B occurs at birth and is
associated
with more severe bone dysplasia. Silverman-Handmaker type of dyssegmental
dysplasia
(DDSH) refers to an allelic disorder with a more severe phenotype.
Selenium Deficiency
[0447] Selenium deficiency results in reduced glutathione peroxidase activity,
oxidative
damage, reduced levels of selenoproteins and increased toxicity of drugs &
toxins (e.g.,
nitrofurantoin, paraquat). Clinical features include myopathy, cardiomyopathy,

selenoprotein disorders (congenital muscular dystrophy with rigid spine,
hyperthyroxinemia), nail and hair loss, gastroenteritis, dermatitis,
malabsorption, muscle
pain, high serum creatine kinase, low vitamin E levels, and enlarged
mitochondria.
Short-chain Acyl-CoA Dehydrogenase deficiency
[0448] Short-chain acyl-CoA dehydrogenase (SCAD) deficiency is an autosomal
recessive metabolic disorder of mitochondrial fatty acid beta-oxidation. The
disorder is
associated with mutations in the ACADS gene encoding short-chain acyl-CoA
dehydrogenase. Two clinical phenotypes of SCAD deficiency have been
identified. One
form of the disorder is an infantile onset characterized by acute acidosis,
myopathy, failure
to thrive, developmental delay, and seizures. The other form is observed in
middle-aged
patients who exhibit chronic myopathy, ophthalmoplegia, ptosis, and scoliosis.
Succinyl CoA:3-oxacid CoA Transferase Deficiency
[0449] Succinyl CoA:3-oxacid CoA transferase (SCOT) deficiency is an inborn
error of
ketone body metabolism associated with mutations in the OXCT1 gene. SCOT is a
key
mitochondrial enzyme in the metabolism of ketone bodies in various organs.
Deficiency
of SCOT activity inhibits peripheral ketone body utilization and causes
episodes of severe
ketoacidosis. Ketones are molecules produced in the liver during the breakdown
of fats
and are the major vectors of energy transfer from the liver to extrahepatic
tissues. As the
first step of ketone body utilization, SCOT catalyzes the reversible transfer
of CoA from
succinyl-CoA to acetoacetate.
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Stuve-Wiedemann Syndrome (STWS)
[0450] Stuve-Wiedemann Syndrome (STWS), also known as neonatal Schwartz-Jampel

Syndrome type 2 (SJS2), is caused by a mutation in the leukemia inhibitory
factor receptor
gene (LIFR).
[0451] Stuve-Wiedemann Syndrome (STWS) is an autosomal recessive disorder
characterized by bowing of the long bones and other skeletal anomalies,
episodic
hyperthermia, and respiratory and feeding distress usually resulting in early
death. Age of
onset is typically at birth. Clinical features include hypotonia, respiratory
& feeding
difficulties, hyperthermic episodes, high mortality in infancy, joint
contractures, bent bone
dysplasia, bowing of lower limbs, internal cortical thickening, wide
metaphyses,
camptodactyly, spontaneous fractures, short stature, malignant hyperthermia,
temperature
instability, loss of corneal reflex, smooth tongue, reduced tendon reflexes,
and reduced
Complex I and IV activity.
Thrombocytopenia
[0452] Thrombocytopenia (THC) is characterized by a decrease in platelet
count,
resulting in the potential for increased bleeding and a decreased clotting
ability. Although
inherited forms of this syndrome are relatively rare, a number of genes
underlying
thrombocytopenia have been identified. One form of autosomal dominant
nonsyndromic
thrombocytopenia is caused by a mutation in the CYCS gene encoding cytochrome
c.
Cytochrome c is located in the mitochondria of all aerobic cells and is
involved in the
electron transport chain that functions in oxidative phosphorylation.
Mutations in the
CYCS gene have been shown to increase the apoptotic activity of cytochrome c
in
individuals with autosomal dominant nonsyndromic thrombocytopenia.
Very Long-chain Acyl-CoA Dehydrogenase Deficiency
[0453] Very long-chain acyl-CoA dehydrogenase deficiency (VLCADD) is a
disorder of
fatty acid oxidation associated with the accumulation of fatty acids and
decreases in cell
energy metabolism due to enzyme defects in the fatty acid metabolic pathway.
VLCADD
is caused by homozygous or compound heterozygous mutations in the ACADVL gene
that
encodes very long-chain acyl-CoA dehydrogenase. Very long-chain acyl-CoA
dehydrogenase (VLCAD) is unique among the acyl-CoA dehydrogenases in its size,

structure, and intramitochondrial distribution. Whereas other acyl-CoA
dehydrogenases
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CA 02920246 2016-02-09
are homotetramers of a 43- to 45-kD subunit, VLCAD has been shown to be a 154-
kD
homodimer of a 70-kD subunit. VLCAD has been found to be loosely bound to the
mitochondrial inner membrane and required detergent for stabilization. By
contrast, the
other three acyl-CoA dehydrogenases are readily extractable without detergent,
indicating
that they are located in the mitochondrial matrix.
[0454] VLCAD deficiency is classified into three forms: a severe early-onset
with a high
incidence of cardiomyopathy and high mortality; an intermediate form with
childhood
onset, usually with hypoketotic hypoglycemia and a more favorable outcome; and
an
adult-onset, myopathic form with isolated skeletal muscle involvement,
rhabdomyolysis,
and myoglobinuria after exercise or fasting.
Vitamin D-dependent Rickets Type 1A
[0455] Vitamin D-dependent rickets type 1A (VDDR1A) is an autosomal recessive
disorder characterized by hypocalcemia, secondary hyperparathyroidism, and
early onset
severe rickets. The disorder is caused by a mutation in the CYP27B1 gene
encoding the
enzyme 25-hydroxyvitamin D3-1-alpha-hydroxylase, which is localized to the
mitochondrial inner membrane. 25-hydroxyvitamin D3-1-alpha-hydroxylase is
expressed
in the renal proximal tubule where it catalyzes the hydroxylation of 25-
hydroxyvitamin D3
into 1-alpha,25-dihydroxyvitamin D3 (1,25(OH)2D3, or calcitrol). The active
metabolite
1,25(OH)2D3 binds and activates the nuclear vitamin D receptor (VDR) and
regulates
physiologic events such as calcium homeostasis and cellular differentiation
and
proliferation.
Wilson's Disease
[0456] Wilson's disease is caused by homozygous or compound heterozygous
mutations
in the ATP7B gene. Wilson's disease is an autosomal recessive disorder
characterized by
dramatic build-up of intracellular hepatic copper with subsequent hepatic and
neurologic
abnormalities. In Wilson disease, the basal ganglia and liver undergo changes
that express
themselves in neurologic manifestations and signs of cirrhosis, respectively.
Markedly
reduced levels of cytochrome oxidase activity and low ceruloplasmin serum
levels are
observed in affected individuals. Ceruloplasmin functions in enzymatic
transfer of copper
to copper-containing enzymes such as cytochrome oxidase.
[0457] There are at least 3 forms of Wilson disease. In a rare 'atypical
form,' the
heterozygotes show about 50% of the normal level of ceruloplasmin. In the 2
typical
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CA 02920246 2016-02-09
forms, the Slavic and the juvenile type, heterozygotes have normal
ceruloplasmin levels,
although they can be identified by decreased reappearance of radioactive
copper into
serum and ceruloplasmin. The Slavic type has a late age of onset and is
predominantly a
neurologic disease. The juvenile type, which occurs in Western Europeans and
several
other ethnic groups, has onset before age 16 years and is frequently a hepatic
disease.
[0458] The Kayser-Fleischer ring is a deep copper-colored ring at the
periphery of the
cornea which is frequently found in Wilson disease and is thought to represent
copper
deposits. Additional clinical symptoms include azure lunulae of the
fingernails,
hypercalciuria, nephrocalcinosis, renal stones, nephrolithiasis,
chondrocalcinosis,
osteoarthritis, hemolytic anemia, leukoencephalopathy, neuropathy, respiratory
chain
defects, myocardial abnormalities, intermittent paresthesia and weakness in
both hands
and feet.
Peroxisome Biogenesis Disorder 3A (PBD3A): Zellweger Syndrome
[0459] Zellweger Syndrome (PBD3A) is caused by homozygous or compound
heterozygous mutations in the PEX12 gene on chromosome 17. The peroxisomal
biogenesis disorder (PBD) Zellweger Syndrome (ZS) is an autosomal recessive
multiple
congenital anomaly syndrome resulting from disordered peroxisome biogenesis.
Affected
children present in the newborn period with profound hypotonia, seizures, and
inability to
feed. Characteristic craniofacial anomalies, eye abnormalities, neuronal
migration defects,
hepatomegaly, and chondrodysplasia punctata are present. Children with this
condition do
not show any significant development and usually die in the first year of
life. Brain MRIs
of affected subjects show reduced white matter and hypoplasia in corpus
callosum.
[0460] Another form of peroxisome biogenesis disorder (PBD8B) is caused by
homozygous mutations in the PEX16 gene. Mutations in PEX16 also cause
Zellweger
Syndrome. The age of onset usually occurs between 1 to 2 years. Clinical
symptoms are
progressive and include spasticity, dysarthria, dysphagia, ataxia, abnormal
gait, delayed
walking, optic atrophy, cataracts, constipation, and neuropathy.
[0461] The overlapping phenotypes of neonatal adrenoleukodystrophy (NALD) and
infantile Refsum disease (IRD) represent the milder manifestations of the
Zellweger
Syndrome spectrum (ZSS) of peroxisome biogenesis disorders. The clinical
course of
patients with the NALD and IRD presentation is variable and may include
developmental
delay, hypotonia, liver dysfunction, sensorineural hearing loss, retinal
dystrophy, and
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visual impairment. Children with the NALD presentation may reach their teens,
and those
with the IRD presentation may reach adulthood.
Mitochondrial Disorders Associated with Drugs and Toxins
1. Arsenic Trioxide Myopathy
[0462] Arsenic trioxide (ATO) has a proven therapeutic efficacy in acute
promyelocytic
leukemia (APL). However, APL patient who have undergone ATO treatment may
develop a delayed, severe, and partially reversible mitochondrial myopathy.
Affected
individuals may present with the inability to walk, myopathy with cytoplasmic
lipid
droplets, decreased mitochondrial respiratory chain complex activity, multiple
mtDNA
deletions, and elevated muscle arsenic content.
2. Myopathy and Neuropathy Resulting from Nucleoside Analogues
[0463] Nucleoside analogues are molecules that function as nucleosides in DNA
or RNA
replication. These analogs include a range of antiviral products used in the
prevention of
viral replication. Various nucleoside analogues including azidothymidine
(AZT),
clevudine, telbivudine, and fialuridine are associated with the development
myopathies
and neuropathies.
3. Germanium Myopathy
[0464] Germanium can have a toxic effect on skeletal muscle leading to
myopathy and
polyneuropathy. Pathological examinations of skeletal muscle from individuals
affected
by germanium intoxication exhibit vacuolar myopathy with lipid excess,
increased acid
phosphatase activity, decreased cytochrome oxidase activity, and mitochondrial

abnormalities.
4. Parkinsonism and Mitochondrial Complex I Neurotoxicity due to
Trichloroethylene
[0465] Long-term exposure to trichloroethylene is associated with Parkinsonism
and
mitochondrial Complex I neurotoxicity. Neurotoxic actions of trichloroethylene
include
selective Complex 1 impairment in the midbrain with concomitant striatonigral
fiber
degeneration and loss of dopamine neurons.
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5. Valproate-induced Hepatic Failure
[0466] Valproate is an anticonvulsant that is administered to control certain
types of
seizures in the treatment of epilepsy. There is an increased risk of Valproate-
induced liver
failure in patients with hereditary neurometabolic syndromes caused by
mutations of the
mitochondrial DNA polymerase y (POLG) gene.
Other Mitochondrial Syndromes Characterized by Infantile and Childhood Onset
1. Neurodegeneration with Brain Iron Accumulation
[0467] Neurodegeneration with brain iron accumulation-4 (NBIA4) is an
autosomal
recessive neurodegenerative disorder caused by a homozygous or compound
heterozygous
mutation in the C190RF12 gene. Neurodegeneration with brain iron accumulation-
1
(NBIA1), also known as Hallervorden-Spatz disease, is caused by a homozygous
or
compound heterozygous mutation in the pantothenate kinase-2 gene, PANK2.
2. Primary Coenzyme 010 Deficiency-3
[0468] Primary coenzyme Q10 deficiency-3 (C0Q10D3) is a fatal
encephalomyopathic
form of coenzyme Q10 deficiency with nephrotic syndrome that can be caused by
compound heterozygous mutation in the PDSS2 gene, which encodes a subunit of
decaprenyl diphosphate synthase, the first enzyme of the C0Q10 biosynthetic
pathway.
3. Combined Mitochondrial Complex Deficiencies
[0469] Combined complex deficiencies include combined complex I, II, IV, V
deficiency, combined complex I, II, and III deficiency, combined oxidative
phosphorylation deficiency-1 (COXPD1), combined oxidative phosphorylation
deficiency-2 (COXPD2), combined oxidative phosphorylation deficiency-3
(COXPD3),
combined oxidative phosphorylation deficiency-4 (COXPD4), combined oxidative
phosphorylation deficiency-5 (COXPD5), combined oxidative phosphorylation
deficiency-6 (COXPD6), combined oxidative phosphorylation deficiency-7
(COXPD7),
combined oxidative phosphorylation deficiency-8 (COXPD8), combined oxidative
phosphorylation deficiency-9 (COXPD9), combined oxidative phosphorylation
deficiency-10 (COXPD10), combined oxidative phosphorylation deficiency-11
(COXPD11), combined oxidative phosphorylation deficiency-12 (COXPD12),
combined
oxidative phosphorylation deficiency-13 (COXPD13), combined oxidative
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phosphorylation deficiency-14 (COXPD14), combined oxidative phosphorylation
deficiency-15 (COXPD15), combined oxidative phosphorylation deficiency-16
(COXPD16), combined oxidative phosphorylation deficiency-17 (COXPD17),
combined
oxidative phosphorylation deficiency-18 (COXPD18), combined oxidative
phosphorylation deficiency-19 (COXPD19), combined oxidative phosphorylation
deficiency-20 (COXPD20), combined oxidative phosphorylation deficiency-21
(COXPD21), mitochondrial DNA depletion myopathy (MTDPS2), and Multiple
Mitochondrial Dysfunctions Syndrome (MMDS).
4. Complex I Deficiency
[0470] Mitochondrial Complex I (NADH-ubiquinone reductase) deficiency is
associated
with several disorders including cardiomyopathy due to mutations in the NDUFS2
gene,
fatal multisystemic complex I deficiency due to mutations in the NDUFS4 gene,
and lethal
infantile mitochondrial disease due to mutations in the NDUFS6, C200RF7,
NDUFAF3,
and/or NDUFB2 genes.
5. Complex II Deficiency
[0471] Mitochondrial Complex II (succinate dehydrogenase-CoQ oxoreductase)
deficiency is associated with disorders including Leigh Syndrome due to
mutations in the
SDHA gene, infantile leukoencephalopathy due to SDHAF1 mutations, iron-sulfur
disorders, paragangliomas and pheochromocytomas due to mutations in the
SDHAF2,
SDHB, SDHC, and SDHD genes.
6. Complex III Deficiency
[0472] Mitochondrial Complex III (cytochrome reductase) deficiency is
associated with
disorders including insulin-responsive hyperglycemia and encephalopathy due to

mutations in the CYC1 gene and hypoglycemia due to mutations in the UQCRB
gene.
7. Complex IV Deficiency
[0473] Complex IV (cytochrome oxidase) deficiency is associated with disorders

including developmental delay and multisystem disorders due to mutations in
CEP89,
hepatic failure due to mutations in SC01, leukodystrophies due to mutations in
COX6B1
and/or APOPT1, and spastic ataxia due to mutations in COX10.
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CA 02920246 2016-02-09
8. Complex V Deficiency
[0474] Complex V (ATP synthase) deficiency is associated with disorders
including
apical hypertrophic cardiomyopathy due to mutations in MT-ATP8, dysmorphic
cerebrooculofacioskeletal features due to mutations in ATPAF2, and mental
retardation,
polyneuropathy, and episodic lactic acidosis due to mutations in TTP5E.
9. Fumarase Deficiency
[0475] Fumarase deficiency, also known as fumaric aciduria, is caused by a
homozygous
or compound heterozygous mutation in the fumarate hydratase gene (FH).
Fumarase
deficiency is a severe autosomal recessive metabolic disorder characterized by
early-onset
hypotonia, profound psychomotor retardation, and brain abnormalities, such as
agenesis of
the corpus callosum, gyral defects, and ventriculomegaly. Many patients show
neonatal
distress, metabolic acidosis, and/or encephalopathy.
10. 3-Hydroxy-3-methvlglutaryl-CoA Synthase-2 Deficiency
[0476] Mitochondrial HMG-CoA synthase-2 deficiency is caused by mutation in
the
gene encoding mitochondrial HMG-CoA synthase-2 (HMGCS2). Mitochondrial HMG-
CoA synthase deficiency is an inherited metabolic disorder caused by a defect
in the
enzyme that regulates the formation of ketone bodies. Patients present with
hypoketotic
hypoglycemia, encephalopathy, and hepatomegaly, usually precipitated by an
intercurrent
infection or prolonged fasting.
11. Hyperuricemia, Pulmonary Hypertension, Renal Failure, and Alkalosis
Syndrome
[0477] Hyperuricemia, pulmonary hypertension, renal failure, and alkalosis
(HUPRA)
Syndrome is caused by homozygous mutation in the SARS2 gene, which encodes
mitochondrial seryl-tRNA synthetase. HUPRA Syndrome is a severe autosomal
recessive
multisystem disorder characterized by onset in infancy of progressive renal
failure leading
to electrolyte imbalances, metabolic alkalosis, pulmonary hypertension,
hypotonia, and
delayed development. Affected individuals are born prematurely.
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CA 02920246 2016-02-09
12. Linear Skin Lesions
[0478] Linear skin lesions are associated with syndromic microphthalmia-7
(MCOPS7)
and reticulolinear aplasia cutis congenita with microcephaly, facial
dysmorphism, and
other congenital anomalies (APLCC).
[0479] Syndromic microphthalmia-7 is caused by mutation in the HCCS gene. The
microphthalmia with linear skin defects syndrome (MLS) is an X-linked dominant

disorder characterized by unilateral or bilateral microphthalmia and linear
skin defects¨
which are limited to the face and neck, consisting of areas of aplastic skin
that heal with
age to form hyperpigmented areas¨in affected females and in utero lethality
for males. A
similar form of congenital linear skin defects, also limited to the face and
neck and
associated with microcephaly, is APLCC, which can be caused by mutation in the
COX7B
gene.
13. Pontocerebellar Hypoplasia Type 6
[0480] Pontocerebellar hypoplasia (PCH) is a heterogeneous group of disorders
characterized by an abnormally small cerebellum and brainstem and associated
with
severe developmental delay. Pontocerebellar hypoplasia type 6 (PCH6) is caused
by a
homozygous or compound heterozygous mutation in the gene encoding
mitochondrial
arginyl-tRNA synthetase (RARS2).
14. Pyruvate Dehydrogenase Complex Disorders
[0481] Pyruvate dehydrogenase complex (PDHC) disorders are a common cause of
lactic acidosis and encephalopathy in children. PDHC disorders are associated
with
mutations in the following genes: PDHA 1, PDHB, PDHX, PDP1, DLD, DLAT, LIAS,
and TPK1.
15. Mitochondrial DNA Depletion Syndrome-9
[0482] Mitochondrial DNA Depletion Syndrome-9 (MTDPS9P), also known as severe
neonatal lactic acidosis with mtDNA depletion, is caused by a homozygous or
compound
heterozygous mutation in the alpha subunit of the succinate-CoA ligase gene
(SUCLG1).
MTDPS9P is a severe autosomal recessive disorder characterized by infantile
onset of
hypotonia, lactic acidosis, severe psychomotor retardation, progressive
neurologic
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deterioration, and excretion of methylmalonic acid. Some patients with MTDPS9
die in
early infancy.
16. Sudden Infant Death Syndrome
[0483] Sudden infant death Syndrome (SIDS) is associated with mutations
identified in
MTTL1, which encodes mitochondrial leucine transfer RNA 1, MTND2, which
encodes
NADH dehydrogenase subunit 1, and HADHB, which encodes the beta subunit of the

mitochondrial trifunctional protein.
[0484] In one aspect, the present disclosure provides a method of treating,
ameliorating
or preventing a mitochondrial disease or disorder or signs and symptoms
thereof,
comprising administering a therapeutically effective amount of a composition
comprising
chroman derivatives, analogues, or pharmaceutically acceptable salts thereof.
In some
embodiments of the method, the mitochondrial disease or disorder is selected
from the
group consisting of Alexander disease, Alpers Syndrome, Alpha-ketoglutarate
dehydrogenase (AKDGH) deficiency, ALS-FTD, Sideroblastic anemia with
spinocerebellar ataxia, Pyridoxine-refractory sideroblastic anemia, GRACILE
Syndrome,
Bjornstad Syndrome, Leigh Syndrome, mitochondrial complex III deficiency
nuclear type
1 (MC3DN1), combined oxidative phosphorylation deficiency 18 (COXPD18),
Thiamine-
responsive megaloblastic anemia syndrome (TRMA), Pearson Syndrome, HAM
Syndrome, Ataxia, Cataract, and Diabetes Syndrome, MELAS/MERRF Overlap
Syndrome, combined oxidative phosphorylation deficiency-14 (COXPD14),
Infantile
cerebellar-retinal degeneration (ICRD), Charlevoix-Saguenay spastic ataxia,
Primary
coenzyme Q10 deficiency-1 (C0Q10D1), ataxia oculomotor apraxia type 1 (A0A1),
Autosomal recessive spinocerebellar ataxia-9/ coenzyme Q10 deficiency-4
(C0Q10D4),
Ataxia, Pyramidal Syndrome, and Cytochrome Oxidase Deficiency, Friedreich's
ataxia,
Infantile onset spinocerebellar ataxia (IOSCA)/ Mitochondrial DNA Depletion
Syndrome-
7, Leukoencephalopathy with brainstem and spinal cord involvement and lactate
elevation
(LBSL), Autosomal recessive spastic ataxia-3 (SPAX3), MIRAS, SANDO,
mitochondrial
spinocerebellar ataxia and epilepsy (MSCAE), spastic ataxia with optic atrophy
(SPAX4),
progressive external ophthalmoplegia with mitochondrial DNA deletions
autosomal
dominant type 5 (PEOA5), mitochondrial complex III deficiency nuclear type 2
(MC3DN2), episodic encephalopathy due to thiamine pyrophosphokinase
deficiency/Thiamine Metabolism Dysfunction Syndrome-5 (THMD5), Spinocerebellar
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CA 02920246 2016-02-09
ataxia-28 (SCA28), autosomal dominant cerebellar ataxia, deafness, and
narcolepsy
(ADCA-DN), Dominant Optic Atrophy (DOA), cerebellar ataxia, areflexia, pes
cavus,
optic atrophy, and sensorineural hearing loss (CAPOS) Syndrome,
spinocerebellar ataxia 7
(SCA7), Barth Syndrome, Biotinidase deficiency, gyrate atrophy, Syndromic
Dominant
Optic Atrophy and Deafness (Syndromic DOAD), Dominant Optic Atrophy plus
(D0Aplus), Leber's hereditary optic neuropathy (LHON), Wolfram Syndrome-1
(WFS1),
Wolfram Syndrome-2 (WFS2), Age-related macular degeneration (ARMD), Brunner
Syndrome, Left ventricular noncompaction-1 (LVNC1), histiocytoid
cardiomyopathy,
Familial Myalgia Syndrome, Parkinsonism, Fatal infantile
cardioencephalomyopathy due
to cytochrome c oxidase (COX) deficiency-1 (CEMCOX1), Sengers Syndrome,
Cardiofaciocutaneous Syndrome-1 (CFC1), Mitochondrial trifunctional protein
(MTP)
deficiency, infantile encephalocardiomyopathy with cytochrome c oxidase
deficiency,
cardiomyopathy + encephalomyopathy, mitochondrial phosphate carrier
deficiency,
infantile cardioencephalomyopathy due to cytochrome c oxidase (COX) deficiency

(CEMCOX2), P-Hydroxyisobutyryl CoA Deacylase (HIBCH) deficiency, ECHS1)
deficiency, Maternal Inheritance Leigh Syndrome (MILS), dilated cardiomyopathy
with
ataxia (DCMA), Mitochondrial DNA Depletion Syndrome-12 (MTDPS12),
cardiomyopathy due to mitochondrial tRNA deficiencies, mitochondrial complex V
(ATP
synthase) deficiency nuclear type 1 (MC5DN1), combined oxidative
phosphorylation
deficiency-8 (COXPD8), progressive leukoencephalopathy with ovarian failure
(LKENP),
combined oxidative phosphorylation deficiency-10 (COXPD10), combined oxidative

phosphorylation deficiency-16 (COXPD16), combined oxidative phosphorylation
deficiency-17 (COXPD17), combined oxidative phosphorylation deficiency-5
(COXPD5),
combined oxidative phosphorylation deficiency-9 (COXPD9), carnitine
acetyltransferase
(CRAT) deficiency, carnitine palmitoyltransferase I (CPT I) deficiency,
myopathic
carnitine deficiency, primary systemic carnitine deficiency (CDSP), carnitine
palmitoyltransferase II (CPT II) deficiency, carnitine-acylcarnitine
translocase deficiency
(CACTD), cartilage-hair hypoplasia, cerebrotendinous xanthomatosis (CTX),
congenital
adrenal hyperplasia (CAH), megaconial type congenital muscular dystrophy,
cerebral
creatine deficiency syndrome-3 (CCDS3), maternal nonsyndromic deafness,
maternal
nonsyndromic deafness, autosomal dominant deafness-64 (DFNA64), Mohr-
Tranebjaerg
Syndrome, Jensen Syndrome, MEGDEL, reticular dysgenesis, primary coenzyme Q10
deficiency-6 (C0Q10D6), CAGSSS, diabetes, Dimethylglycine dehydrogenase
deficiency
(DMGDHD), Multiple Mitochondrial Dysfunctions Syndrome-1 (MMDS1), Multiple
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Mitochondrial Dysfunctions Syndrome-2 (MMDS2), Multiple Mitochondrial
Dysfunctions Syndrome-3 (MMDS3), childhood leukoencephalopathy associated with

mitochondrial Complex II deficiency, encephalopathies associated with
mitochondrial
Complex I deficiency, encephalopathies associated with mitochondrial Complex
III
deficiency, encephalopathies associated with mitochondrial Complex IV
deficiency,
encephalopathies associated with mitochondrial Complex V deficiency,
hyperammonemia
due to carbonic anhydrase VA deficiency (CA5AD), early infantile epileptic
encephalopathy-3 (EIEE3), 2,4-Dienoyl-CoA reductase deficiency (DECRD),
infection-
induced acute encephalopathy-3 (IIAE3), ethylmalonic encephalopathy (EE),
hypomyelinating leukodystrophy (HLD4), exocrine pancreatic insufficiency,
dyserythropoietic anemia and calvarial hyperostosis, Glutaric aciduria type 1
(GA-1),
glycine encephalopathy (GCE), hepatic failure, 2-hydroxyglutaric aciduria, 3-
hydroxyacyl-CoA dehydrogenase deficiency, familial hyperinsulinemic
hypoglycemia
(FHH), hypercalcemia infantile, hyperornithinemia-hyperammonemia-
homocitrullinuria
(HHH) Syndrome, Immunodeficiency with hyper-IgM type 5 (HIGM5), Inclusion Body

Myositis (IBM), polymyositis with mitochondrial pathology, IM-Mito,
granulomatous
myopathies with anti-mitochondrial antibodies, necrotizing myopathy with
pipestem
capillaries, myopathy with deficient chondroitin sulfate C in skeletal muscle
connective
tissue, benign acute childhood myositis, idiopathic orbital myositis,
masticator myopathy,
hemophagocytic lymphohistiocytosis, infection-associated myositis,
Facioscapulohumeral
dystrophy (FSH), familial idiopathic inflammatory myopathy, Schmidt Syndrome
(Diabetes mellitus, Addison disease, Myxedema), TNF receptor-associated
Periodic
Syndrome (TRAPS), focal myositis, autoimmune fasciitis, Spanish toxic oil-
associated
fasciitis, Eosinophilic fasciitis, Macrophagic myofasciitis, Graft-vs-host
disease fasciitis,
Eosinophilia-myalgia Syndrome, perimyositis, isovaleric acidemia (IVA),
Kearnes-Sayre
Syndrome (KS 5), 2-oxoadipic aciduria, 2-aminoadipic aciduria, Limb-girdle
Muscular
Dystrophy Syndromes, leukodystrophy, Maple syrup urine disease (MSUD), 3-
Methylcrotonyl-CoA carboxylase (MCC), Methylmalonic aciduria (MMA), Miller
Syndrome, Mitochondrial DNA Depletion Syndrome-2 (MTDPS2), spinal muscular
atrophy syndrome, rigid spine syndrome, severe myopathy with motor regression,

Mitochondrial DNA Depletion Syndrome-3, MELAS Syndrome, camptocormia, MNGIE,
MNGIM Syndrome, Menkes Disease, Occipital Horn Syndrome, X-linked distal
spinal
muscular atrophy-3 (SMAX3), methemoglobinemia, MERRF, progressive external
ophthalmoplegia with myoclonus, deafness and diabetes (DD), multiple symmetric
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lipomatosis, Myopathy with Episodic high Creatine Kinase (MIMECK), Epilepsia
Partialis Continua, malignant hyperthermia syndromes, glycogen metabolic
disorders,
fatty acid oxidation and lipid metabolism disorders, medication-, drug- or
toxin-induced
myoglobinuria, mitochondrial disorder-associated myoglobinuria, hypokalemic
myopathy
and rhabdomyolysis, muscle trauma-associated myoglobinuria, ischemia-induced
myoglobinuria, infection-induced myoglobinuria, immune myopathies associated
with
myoglobinuria, Myopathy, lactic acidosis, and sideroblastic anemia (MLASA),
infantile
mitochondrial myopathy due to reversible COX deficiency (MMIT), Myopathy,
Exercise
intolerance, Encephalopathy and Lactic acidemia Syndrome, myoglobinuria and
exercise
intolerance syndrome, exercise intolerance, proximal weakness myoglobinuria
syndrome, encephalopathy and seizures syndrome, septo-optic dysplasia,
exercise
intolerance mild weakness, myopathy exercise intolerance, growth or CNS
disorder,
maternally-inherited mitochondrial myopathies, myopathy with lactic acidosis,
myopathy
with rhabdomyolysis, Myopathy with cataract and combined respiratory chain
deficiency,
myopathy with abnormal mitochondrial translation, Fatigue Syndrome, myopathy
with
extrapyramidal movement disorders (MPXPS), glutaric aciduria II (MADD),
primary
C0Q10 deficiency-1 (C0Q10D1), primary C0Q10 deficiency-2 (C0Q10D2), primary
CoQ10 deficiency-3 (C0Q10D3), primary CoQ10 deficiency-5 (C0Q10D5), secondary
CoQ10 deficiency, autosomal dominant mitochondrial myopathy, myopathy with
focal
depletion of mitochondria, mitochondrial DNA breakage syndrome (PEO +
Myopathy),
lipid type mitochondrial myopathy, multiple symmetric lipomatosis (MSL), N-
acetylglutamate synthase (NAGS) deficiency, Nephronophthisis (NPHP), ornithine

transcarbamylase (OTC) deficiency, neoplasms, NARP Syndrome, paroxysmal
nonkinesigenic dyskinesia (PNKD), sporadic PEO, maternally-inherited PEO,
autosomal
dominant progressive external ophthalmoplegia with mitochondrial DNA deletions-
3
(PEOA3), autosomal dominant progressive external ophthalmoplegia with
mitochondrial
DNA deletions-2 (PEOA2), autosomal dominant progressive external
ophthalmoplegia
with mitochondrial DNA deletions-1 (PEOA1), PEO+ demyelinating neuropathy, PEO
+
hypogonadism, autosomal dominant progressive external ophthalmoplegia with
mitochondrial DNA deletions-4 (PEOA4), distal myopathy, cachexia & PEO,
autosomal
dominant progressive external ophthalmoplegia-6 (PEOA6), PEO + Myopathy and
Parkinsonism, autosomal recessive progressive external ophthalmoplegia (PEOB),

Mitochondrial DNA Depletion Syndrome-11 (MTDPS11), PEO with cardiomyopathy,
PEPCK deficiency, Perrault Syndromes (PRLTS), propionic acidemia (PA),
pyruvate
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carboxylase deficiency, pyruvate dehydrogenase El-alpha deficiency (PDHAD),
pyruvate
dehydrogenase El-beta deficiency (PDHBD), dihydrolipoamide dehydrogenase (DLD)

deficiency, pyruvate dehydrogenase phosphatase deficiency, pyruvate
dehydrogenase E3-
binding protein deficiency (PDHXD), mitochondrial pyruvate carrier deficiency
(MPYCD), Schwartz-Jampel Syndrome type 1 (SJS1), selenium deficiency, short-
chain
acyl-CoA dehydrogenase (SCAD) deficiency, succinyl CoA:3-oxacid CoA
transferase
(SCOT) deficiency, Stuve-Wiedemann Syndrome (STWS), thrombocytopenia (THC),
Very long-chain acyl-CoA dehydrogenase deficiency (VLCADD), Vitamin D-
dependent
rickets type lA (VDDR1A), Wilson's disease, Zellweger Syndrome (PBD3A),
arsenic
trioxide myopathy, myopathy and neuropathy resulting from nucleoside
analogues,
germanium myopathy, Parkinsonism and mitochondrial Complex I neurotoxicity due
to
trichloroethylene, valproate-induced hepatic failure, neurodegeneration with
brain iron
accumulation-4 (NBIA4), Complex I deficiency, Complex II deficiency, Complex
III
deficiency, Complex IV deficiency, Complex V deficiency, Cytochrome c oxidase
(COX)
deficiency, combined complex I, II, IV, V deficiency, combined complex I,
II, and III
deficiency, combined oxidative phosphorylation deficiency-1 (COXPD1), combined

oxidative phosphorylation deficiency-2 (COXPD2), combined oxidative
phosphorylation
deficiency-3 (COXPD3), combined oxidative phosphorylation deficiency-4
(COXPD4),
combined oxidative phosphorylation deficiency-6 (COXPD6), combined oxidative
phosphorylation deficiency-7 (COXPD7), combined oxidative phosphorylation
deficiency-9 (COXPD9), combined oxidative phosphorylation deficiency-11
(COXPD11),
combined oxidative phosphorylation deficiency-12 (COXPD12), combined oxidative

phosphorylation deficiency-13 (COXPD13), combined oxidative phosphorylation
deficiency-15 (COXPD15), combined oxidative phosphorylation deficiency-16
(COXPD16), combined oxidative phosphorylation deficiency-19 (COXPD19),
combined
oxidative phosphorylation deficiency-20 (COXPD20), combined oxidative
phosphorylation deficiency-21 (COXPD21), fumarase deficiency, HMG-CoA synthase-
2
deficiency, hyperuricemia, pulmonary hypertension, renal failure, and
alkalosis (HUPRA)
Syndrome, syndromic microphthalmia-7, pontocerebellar hypoplasia type 6
(PCH6),
Mitochondrial DNA Depletion Syndrome-9 (MTDPS9P), and Sudden infant death
Syndrome (SIDS).
[0485] In one aspect, the present disclosure provides a method of treating a
disease or
condition characterized by excessive mitochondrial fission, comprising
administering a
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CA 02920246 2016-02-09
therapeutically effective amount of a composition comprising chroman
derivatives,
analogues, or pharmaceutically acceptable salts thereof.
[0486] In some embodiments, chroman derivatives (or analogues, or
pharmaceutically
acceptable salts thereof) are useful to regulate mitochondrial fission.
[0487] In some embodiments, chroman derivatives (or analogues, or
pharmaceutically
acceptable salts thereof) of the present technology are useful to prevent or
treat Leber's
Hereditary Optic Neuropathy.
[0488] In some embodiments, chroman derivatives (or analogues, or
pharmaceutically
acceptable salts thereof) of the present technology are useful to prevent or
treat
Friedreich's Ataxia.
[0489] In some embodiments, chroman derivatives (or analogues, or
pharmaceutically
acceptable salts thereof) of the present technology are useful to treat one or
more signs,
symptoms or complications of Friedreich's Ataxia including mitochondrial iron
loading,
Complex I and ATP content deficiency, and defects in iron-sulfur cluster
biosynthesis.
[0490] In some embodiments, chroman derivatives (or analogues, or
pharmaceutically
acceptable salts thereof) of the present technology are useful to reduce tumor
growth in a
subject in need thereof.
Treatment of a Mitochondrial Disease or Disorder
[0491] In some embodiments, the disclosure provides for both prophylactic and
therapeutic methods of treating a subject having or suspected of having a
mitochondrial
disease, condition or disorder. For example, in some embodiments, the
disclosure
provides for both prophylactic and therapeutic methods of treating a subject
having a
disruption in oxidative phosphorylation caused by a gene mutation e.g., SURF1,
POLG
etc.
[0492] In some embodiments, the present technology provides methods for the
treatment, amelioration or prevention of a mitochondrial disease, condition or
disorder in
subjects through administration of therapeutically effective amounts of
chroman
derivatives (or analogues, or pharmaceutically acceptable salts thereof) of
the present
technology as disclosed herein to subjects in need thereof. In some
embodiments of the
method, the mitochondrial disease, condition or disorder is selected from the
group
consisting of Alexander disease, Alpers Syndrome, Alpha-ketoglutarate
dehydrogenase
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CA 02920246 2016-02-09
(AKDGH) deficiency, ALS-FTD, Sideroblastic anemia with spinocerebellar ataxia,

Pyridoxine-refractory sideroblastic anemia, GRACILE Syndrome, Bjornstad
Syndrome,
Leigh Syndrome, mitochondrial complex III deficiency nuclear type 1 (MC3DN1),
combined oxidative phosphorylation deficiency 18 (COXPD18), Thiamine-
responsive
megaloblastic anemia syndrome (TRMA), Pearson Syndrome, HAM Syndrome, Ataxia,
Cataract, and Diabetes Syndrome, MELAS/MERRF Overlap Syndrome, combined
oxidative phosphorylation deficiency-14 (COXPD14), Infantile cerebellar-
retinal
degeneration (ICRD), Charlevoix-Saguenay spastic ataxia, Primary coenzyme Q10
deficiency-1 (C0Q10D1), ataxia oculomotor apraxia type 1 (A0A1), Autosomal
recessive
spinocerebellar ataxia-9/ coenzyme Q10 deficiency-4 (C0Q10D4), Ataxia,
Pyramidal
Syndrome, and Cytochrome Oxidase Deficiency, Friedreich's ataxia, Infantile
onset
spinocerebellar ataxia (IOSCA)/ Mitochondrial DNA Depletion Syndrome-7,
Leukoencephalopathy with brainstem and spinal cord involvement and lactate
elevation
(LBSL), Autosomal recessive spastic ataxia-3 (SPAX3), MIRAS, SANDO,
mitochondrial
spinocerebellar ataxia and epilepsy (MSCAE), spastic ataxia with optic atrophy
(SPAX4),
progressive external ophthalmoplegia with mitochondrial DNA deletions
autosomal
dominant type 5 (PEOA5), mitochondrial complex III deficiency nuclear type 2
(MC3DN2), episodic encephalopathy due to thiamine pyrophosphokinase
deficiency/Thiamine Metabolism Dysfunction Syndrome-5 (THMD5), Spinocerebellar

ataxia-28 (SCA28), autosomal dominant cerebellar ataxia, deafness, and
narcolepsy
(ADCA-DN), Dominant Optic Atrophy (DOA), cerebellar ataxia, areflexia, pes
cavus,
optic atrophy, and sensorineural hearing loss (CAPOS) Syndrome,
spinocerebellar ataxia 7
(SCA7), Barth Syndrome, Biotinidase deficiency, gyrate atrophy, Syndromic
Dominant
Optic Atrophy and Deafness (Syndromic DOAD), Dominant Optic Atrophy plus
(D0Aplus), Leber's hereditary optic neuropathy (LHON), Wolfram Syndrome-1
(WFS1),
Wolfram Syndrome-2 (WFS2), Age-related macular degeneration (ARMD), Brunner
Syndrome, Left ventricular noncompaction-1 (LVNC1), histiocytoid
cardiomyopathy,
Familial Myalgia Syndrome, Parkinsonism, Fatal infantile
cardioencephalomyopathy due
to cytochrome c oxidase (COX) deficiency-1 (CEMCOX1), Sengers Syndrome,
Cardiofaciocutaneous Syndrome-1 (CFC1), Mitochondrial trifunctional protein
(MTP)
deficiency, infantile encephalocardiomyopathy with cytochrome c oxidase
deficiency,
cardiomyopathy + encephalomyopathy, mitochondrial phosphate carrier
deficiency,
infantile cardioencephalomyopathy due to cytochrome c oxidase (COX) deficiency

(CEMCOX2), P-Hydroxyisobutyryl CoA Deacylase (HIBCH) deficiency, ECHS1)
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CA 02920246 2016-02-09
deficiency, Maternal Inheritance Leigh Syndrome (MILS), dilated cardiomyopathy
with
ataxia (DCMA), Mitochondrial DNA Depletion Syndrome-12 (MTDPS12),
cardiomyopathy due to mitochondrial tRNA deficiencies, mitochondrial complex V
(ATP
synthase) deficiency nuclear type 1 (MC5DN1), combined oxidative
phosphorylation
deficiency-8 (COXPD8), progressive leukoencephalopathy with ovarian failure
(LKENP),
combined oxidative phosphorylation deficiency-10 (COXPD10), combined oxidative

phosphorylation deficiency-16 (COXPD16), combined oxidative phosphorylation
deficiency-17 (COXPD17), combined oxidative phosphorylation deficiency-5
(COXPD5),
combined oxidative phosphorylation deficiency-9 (COXPD9), carnitine
acetyltransferase
(CRAT) deficiency, carnitine palmitoyltransferase I (CPT I) deficiency,
myopathic
carnitine deficiency, primary systemic carnitine deficiency (CDSP), carnitine
palmitoyltransferase II (CPT II) deficiency, carnitine-acylcarnitine
translocase deficiency
(CACTD), cartilage-hair hypoplasia, cerebrotendinous xanthomatosis (CTX),
congenital
adrenal hyperplasia (CAH), megaconial type congenital muscular dystrophy,
cerebral
creatine deficiency syndrome-3 (CCDS3), maternal nonsyndromic deafness,
maternal
nonsyndromic deafness, autosomal dominant deafness-64 (DFNA64), Mohr-
Tranebjaerg
Syndrome, Jensen Syndrome, MEGDEL, reticular dysgenesis, primary coenzyme Q10
deficiency-6 (C0Q10D6), CAGSSS, diabetes, Dimethylglycine dehydrogenase
deficiency
(DMGDHD), Multiple Mitochondrial Dysfunctions Syndrome-1 (MMDS1), Multiple
Mitochondrial Dysfunctions Syndrome-2 (MMDS2), Multiple Mitochondrial
Dysfunctions Syndrome-3 (MMDS3), childhood leukoencephalopathy associated with

mitochondrial Complex II deficiency, encephalopathies associated with
mitochondrial
Complex I deficiency, encephalopathies associated with mitochondrial Complex
III
deficiency, encephalopathies associated with mitochondrial Complex IV
deficiency,
encephalopathies associated with mitochondrial Complex V deficiency,
hyperammonemia
due to carbonic anhydrase VA deficiency (CA5AD), early infantile epileptic
encephalopathy-3 (EIEE3), 2,4-Dienoyl-CoA reductase deficiency (DECRD),
infection-
induced acute encephalopathy-3 (IIAE3), ethylmalonic encephalopathy (EE),
hypomyelinating leukodystrophy (HLD4), exocrine pancreatic insufficiency,
dyserythropoietic anemia and calvarial hyperostosis, Glutaric aciduria type 1
(GA-1),
glycine encephalopathy (GCE), hepatic failure, 2-hydroxyglutaric aciduria, 3-
hydroxyacyl-CoA dehydrogenase deficiency, familial hyperinsulinemic
hypoglycemia
(FHH), hypercalcemia infantile, hyperornithinemia-hyperammonemia-
homocitrullinuria
(HHH) Syndrome, Immunodeficiency with hyper-IgM type 5 (HIGM5), Inclusion Body
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Myositis (IBM), polymyositis with mitochondrial pathology, IM-Mito,
granulomatous
myopathies with anti-mitochondrial antibodies, necrotizing myopathy with
pipestem
capillaries, myopathy with deficient chondroitin sulfate C in skeletal muscle
connective
tissue, benign acute childhood myositis, idiopathic orbital myositis,
masticator myopathy,
hemophagocytic lymphohistiocytosis, infection-associated myositis,
Facioscapulohumeral
dystrophy (FSH), familial idiopathic inflammatory myopathy, Schmidt Syndrome
(Diabetes mellitus, Addison disease, Myxedema), TNF receptor-associated
Periodic
Syndrome (TRAPS), focal myositis, autoimmune fasciitis, Spanish toxic oil-
associated
fasciitis, Eosinophilic fasciitis, Macrophagic myofasciitis, Graft-vs-host
disease fasciitis,
Eosinophilia-myalgia Syndrome, perimyositis, isovaleric acidemia (IVA),
Kearnes-Sayre
Syndrome (KSS), 2-oxoadipic aciduria, 2-aminoadipic aciduria, Limb-girdle
Muscular
Dystrophy Syndromes, leukodystrophy, Maple syrup urine disease (MSUD), 3-
Methylcrotonyl-CoA carboxylase (MCC), Methylmalonic aciduria (MMA), Miller
Syndrome, Mitochondrial DNA Depletion Syndrome-2 (MTDPS2), spinal muscular
atrophy syndrome, rigid spine syndrome, severe myopathy with motor regression,

Mitochondrial DNA Depletion Syndrome-3, MELAS Syndrome, camptocormia, MNGIE,
MNGIM Syndrome, Menkes Disease, Occipital Horn Syndrome, X-linked distal
spinal
muscular atrophy-3 (SMAX3), methemoglobinemia, MERRF, progressive external
ophthalmoplegia with myoclonus, deafness and diabetes (DD), multiple symmetric

lipomatosis, Myopathy with Episodic high Creatine Kinase (MIMECK), Epilepsia
Partialis Continua, malignant hyperthermia syndromes, glycogen metabolic
disorders,
fatty acid oxidation and lipid metabolism disorders, medication-, drug- or
toxin-induced
myoglobinuria, mitochondrial disorder-associated myoglobinuria, hypokalemic
myopathy
and rhabdomyolysis, muscle trauma-associated myoglobinuria, ischemia-induced
myoglobinuria, infection-induced myoglobinuria, immune myopathies associated
with
myoglobinuria, Myopathy, lactic acidosis, and sideroblastic anemia (MLASA),
infantile
mitochondrial myopathy due to reversible COX deficiency (MMIT), Myopathy,
Exercise
intolerance, Encephalopathy and Lactic acidemia Syndrome, myoglobinuria and
exercise
intolerance syndrome, exercise intolerance, proximal weakness myoglobinuria
syndrome, encephalopathy and seizures syndrome, septo-optic dysplasia,
exercise
intolerance mild weakness, myopathy exercise intolerance, growth or CNS
disorder,
maternally-inherited mitochondrial myopathies, myopathy with lactic acidosis,
myopathy
with rhabdomyolysis, Myopathy with cataract and combined respiratory chain
deficiency,
myopathy with abnormal mitochondrial translation, Fatigue Syndrome, myopathy
with
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CA 02920246 2016-02-09
extrapyramidal movement disorders (MPXPS), glutaric aciduria II (MADD),
primary
CoQ10 deficiency-1 (C0Q10D1), primary C0Q10 deficiency-2 (C0Q10D2), primary
C0Q10 deficiency-3 (C0Q10D3), primary CoQ10 deficiency-5 (C0Q10D5), secondary
CoQ10 deficiency, autosomal dominant mitochondrial myopathy, myopathy with
focal
depletion of mitochondria, mitochondrial DNA breakage syndrome (PEO +
Myopathy),
lipid type mitochondrial myopathy, multiple symmetric lipomatosis (MSL), N-
acetylglutamate synthase (NAGS) deficiency, Nephronophthisis (NPHP), ornithine

transcarbamylase (OTC) deficiency, neoplasms, NARP Syndrome, paroxysmal
nonkinesigenic dyskinesia (PNKD), sporadic PEO, maternally-inherited PEO,
autosomal
dominant progressive external ophthalmoplegia with mitochondrial DNA deletions-
3
(PEOA3), autosomal dominant progressive external ophthalmoplegia with
mitochondrial
DNA deletions-2 (PEOA2), autosomal dominant progressive external
ophthalmoplegia
with mitochondrial DNA deletions-1 (PEOA1), PEO+ demyelinating neuropathy, PEO
+
hypogonadism, autosomal dominant progressive external ophthalmoplegia with
mitochondrial DNA deletions-4 (PEOA4), distal myopathy, cachexia & PEO,
autosomal
dominant progressive external ophthalmoplegia-6 (PEOA6), PEO + Myopathy and
Parkinsonism, autosomal recessive progressive external ophthalmoplegia (PEOB),

Mitochondrial DNA Depletion Syndrome-11 (MTDPS11), PEO with cardiomyopathy,
PEPCK deficiency, Perrault Syndromes (PRLTS), propionic acidemia (PA),
pyruvate
carboxylase deficiency, pyruvate dehydrogenase El-alpha deficiency (PDHAD),
pyruvate
dehydrogenase El-beta deficiency (PDHBD), dihydrolipoamide dehydrogenase (DLD)

deficiency, pyruvate dehydrogenase phosphatase deficiency, pyruvate
dehydrogenase E3-
binding protein deficiency (PDHXD), mitochondrial pyruvate carrier deficiency
(MPYCD), Schwartz-Jampel Syndrome type 1 (SJS1), selenium deficiency, short-
chain
acyl-CoA dehydrogenase (SCAD) deficiency, succinyl CoA:3-oxacid CoA
transferase
(SCOT) deficiency, Stuve-Wiedemann Syndrome (STWS), thrombocytopenia (THC),
Very long-chain acyl-CoA dehydrogenase deficiency (VLCADD), Vitamin D-
dependent
rickets type 1A (VDDR1A), Wilson's disease, Zellweger Syndrome (PBD3A),
arsenic
trioxide myopathy, myopathy and neuropathy resulting from nucleoside
analogues,
germanium myopathy, Parkinsonism and mitochondrial Complex I neurotoxicity due
to
trichloroethylene, valproate-induced hepatic failure, neurodegeneration with
brain iron
accumulation-4 (NBIA4), Complex I deficiency, Complex IT deficiency, Complex
III
deficiency, Complex IV deficiency, Complex V deficiency, Cytochrome c oxidase
(COX)
deficiency, combined complex I, II, IV, V deficiency, combined complex I,
II, and III
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CA 02920246 2016-02-09
deficiency, combined oxidative phosphorylation deficiency-1 (COXPD1), combined

oxidative phosphorylation deficiency-2 (COXPD2), combined oxidative
phosphorylation
deficiency-3 (COXPD3), combined oxidative phosphorylation deficiency-4
(COXPD4),
combined oxidative phosphorylation deficiency-6 (COXPD6), combined oxidative
phosphorylation deficiency-7 (COXPD7), combined oxidative phosphorylation
deficiency-9 (COXPD9), combined oxidative phosphorylation deficiency-11
(COXPD11),
combined oxidative phosphorylation deficiency-12 (COXPD12), combined oxidative

phosphorylation deficiency-13 (COXPD13), combined oxidative phosphorylation
deficiency-15 (COXPD15), combined oxidative phosphorylation deficiency-16
(COXPD16), combined oxidative phosphorylation deficiency-19 (COXPD19),
combined
oxidative phosphorylation deficiency-20 (COXPD20), combined oxidative
phosphorylation deficiency-21 (COXPD21), fumarase deficiency, HMG-CoA synthase-
2
deficiency, hyperuricemia, pulmonary hypertension, renal failure, and
alkalosis (HUPRA)
Syndrome, syndromic microphthalmia-7, pontocerebellar hypoplasia type 6
(PCH6),
Mitochondrial DNA Depletion Syndrome-9 (MTDPS9P), and Sudden infant death
Syndrome (SIDS).
[0493] In some embodiments, the present technology provides methods for the
prevention and/or treatment of mitochondrial disease or disorder in a subject
by
administering an effective amount of chroman derivatives (or analogues, or
pharmaceutically acceptable salts thereof) of the present technology to a
subject in need
thereof to reduce disruption in oxidative phosphorylation of the subject.
[0494] In some embodiments, chroman derivatives (or analogues, or
pharmaceutically
acceptable salts thereof) of the present technology are useful in decreasing
intracellular
ROS (reactive oxygen species) and increasing survival in cells of a subject in
need thereof,
e.g., a subject suffering from a disease or condition characterized by
mitochondrial
dysfunction.
[0495] In some embodiments, chroman derivatives (or analogues, or
pharmaceutically
acceptable salts thereof) of the present technology are useful in preventing
loss of cell
viability in subjects suffering from a disease or condition characterized by
mitochondrial
dysfunction.
[0496] In some embodiments, chroman derivatives (or analogues, or
pharmaceutically
acceptable salts thereof) of the present technology are useful in decreasing
the percent of
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CA 02920246 2016-02-09
cells showing increased caspase activity in a subject in need thereof, e.g., a
subject
suffering from a disease or condition characterized by mitochondrial
dysfunction.
[0497] In some embodiments, chroman derivatives (or analogues, or
pharmaceutically
acceptable salts thereof) of the present technology are useful in reducing the
rate of ROS
accumulation in a subject in need thereof, e.g., a subject suffering from a
disease or
condition characterized by mitochondrial dysfunction.
[0498] In some embodiments, chroman derivatives (or analogues, or
pharmaceutically
acceptable salts thereof) of the present technology are useful in inhibiting
lipid
peroxidation in a subject in need thereof, e.g., a subject suffering from a
disease or
condition characterized by mitochondrial dysfunction.
[0499] In some embodiments, chroman derivatives (or analogues, or
pharmaceutically
acceptable salts thereof) of the present technology are useful in preventing
mitochondrial
depolarization and ROS accumulation in a subject in need thereof, e.g., a
subject suffering
from a disease or condition characterized by mitochondrial dysfunction.
[0500] In some embodiments, chroman derivatives (or analogues, or
pharmaceutically
acceptable salts thereof) of the present technology are useful in preventing
apoptosis in a
subject in need thereof, e.g., a subject suffering from a disease or condition
characterized
by mitochondrial dysfunction.
[0501] In one aspect, the present technology provides a method of preventing,
treating or
ameliorating a medical disease or condition by administering a therapeutically
effective
amount of chroman derivatives (or analogues, or pharmaceutically acceptable
salts
thereof) to a subject in need thereof. In some embodiments the medical disease
or
condition is a mitochondrial disorder. In another aspect, the present
technology provides a
method of modulating one or more energy biomarkers, normalizing one or more
energy
biomarkers, or enhancing one or more energy biomarkers by administering a
therapeutically effective amount of chroman derivatives (or analogues, or
pharmaceutically acceptable salts thereof) to a subject in need thereof.
Use of Chroman Derivatives to Treat IPF, Alport Syndrome, Vitiligo, and
Porphyria
[0502] In some embodiments, chroman derivatives (or analogues, or
pharmaceutically
acceptable salts thereof) of the present technology are useful in methods for
treating,
ameliorating, or reversing idiopathic pulmonary fibrosis (IPF). In certain
embodiments of
the method, IPF is induced by TGF-I3 signaling. In other embodiments of the
method, IPF
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CA 02920246 2016-02-09
is induced by exposure to bleomycin. In some embodiments of the methods, IPF
symptoms or signs include an increase in TGF-131-induced epithelial to
mesenchymal
transition (EMT), myofibroblast activation, collagen production, and severe
progressive
fibrosis including fibrotic foci and honeycombing. In some embodiments, EMT is

characterized by loss of epithelial markers such as E-cadherin, cytoskeletal
reorganization,
and transition to a spindle-shaped morphology with the acquisition of
mesenchymal
markers (a-SMA and collagen I). EMT of alveolar epithelial cells (AECs) has
been
widely observed in patients with lPF.
[0503] In some embodiments, chroman derivatives (or analogues, or
pharmaceutically
acceptable salts thereof) of the present technology are useful in reducing the
formation of
fibroblast foci and lung scarring in the subject, as evidenced by a decrease
in collagen
content using sircol assay and fibrosis scoring.
[0504] In some embodiments, chroman derivatives (or analogues, or
pharmaceutically
acceptable salts thereof) of the present technology are useful in reducing
myofibroblast
activation and collagen production in the subject, as evidenced by a decrease
in a-SMA
and collagen I expression.
[0505] In some embodiments, chroman derivatives (or analogues, or
pharmaceutically
acceptable salts thereof) of the present technology are useful in reducing TGF-
f31-induced
EMT in the subject, as evidenced by the persistence of E-cadherin expression
and/or
decrease in spindle-shaped morphology. In some embodiments, administration of
a
therapeutically effective dose of chroman derivatives (or analogues, or
pharmaceutically
acceptable salts thereof) to a subject in need thereof, results in a reduction
of TGF-(31-
induced EMT in the subject, as evidenced by a decrease in a-SMA or vimentin
expression.
In some embodiments, administration of a therapeutically effective dose of
chroman
derivatives (or analogues, or pharmaceutically acceptable salts thereof) to a
subject in need
thereof, results in a reduction of TGF-131-induced EMT in the subject, as
evidenced by a
decrease in cytoskeletal reorganization.
[0506] In some embodiments, chroman derivatives (or analogues, or
pharmaceutically
acceptable salts thereof) of the present technology are useful in treating or
ameliorating
melanocyte degeneration in a subject in need thereof. In one particular
embodiment,
chroman derivatives (or analogues, or pharmaceutically acceptable salts
thereof) of the
present technology are useful in the treatment, amelioration or prevention of
vitiligo in
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subjects through administration of therapeutically effective amounts of
chroman
derivatives as disclosed herein, or pharmaceutically acceptable salts thereof,
to subjects in
need thereof.
[0507] Vitiligo is a pigmentation disorder in which melanocytes, the cells
responsible
for skin pigmentation, are destroyed. As a result, white patches appear on the
skin in
different parts of the body. Vitiligo lesions can appear anywhere, but are
most commonly
found on the acral areas, mucous membranes (tissues that line the inside of
the mouth and
nose), retina and genitals. Other symptoms include increased photosensitivity,
decreased
contact sensitivity response to dinitrochlorobenzene, and premature whitening
or graying
of hair that grows on areas affected by vitiligo. Non-segmental vitiligo (NSV)
is
associated with some form of symmetry in the location of the patches of
depigmentation.
Classes of NSV include generalized vitiligo, universal vitiligo, and focal
vitiligo.
Generalized vitiligo (GV), the most common category, affects approximately
0.5% of the
world's population, with an average age of onset at about 24 years and
occurring with
approximately equal frequencies in males and females. Vitiligo lesions have an
infiltrate
of inflammatory cells, particularly cytotoxic and helper T cells and
macrophages. Patients
with vitiligo are also more likely to have at least one other autoimmune
disease including
Hashimoto's thyroiditis, Graves' disease, pernicious anemia, rheumatoid
arthritis,
psoriasis, type I diabetes, Addison's disease, celiac disease, inflammatory
bowel disorder,
and systemic lupus erythematosus.
[0508] In some embodiments, chroman derivatives (or analogues, or
pharmaceutically
acceptable salts thereof) of the present technology are useful in the
treatment, amelioration
or prevention of porphyria in a subject in need thereof. The porphyrias, are
metabolic
disorders, each resulting from the deficiency of a specific enzyme in the heme
biosynthetic
pathway. These enzyme deficiencies are inherited as autosomal dominant,
autosomal
recessive, or X-linked traits, with the exception of the most common
porphyria, porphyria
cutanea tarda, which usually is sporadic. Porphyrias have been classified as
either hepatic
or erythropoietic depending on the primary site of overproduction and
accumulation of
porphyrin precursors or porphyrins, although some porphyrias have overlapping
features.
The hepatic porphyrias are characterized by overproduction and initial
accumulation of the
porphyrin precursors, ALA and PBG, and/or porphyrins primarily in the liver,
whereas in
the erythropoietic porphyrias, overproduction and initial accumulation of the
pathway
intermediates occur primarily in bone marrow erythroid cells. The eight major
porphyrias
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CA 02920246 2016-02-09
can be classified into three groups: (1) the four acute hepatic porphyrias,
(2) the single
hepatic cutaneous porphyria (i.e., porphyria cutanea tarda), and (3) the three
erythropoietic
cutaneous porphyrias. In certain embodiments, the acute hepatic porphyria is
acute
intermittent porphyria (AIP), hereditary coproporphyria (HCP), variegate
porphyria (VP)
or autosomal recessive ALA-dehydratase-deficient porphyria. In some
embodiments, the
erythropoietic cutaneous porphyria is congenital erythropoietic porphyria
(CEP),
erythropoietic protoporphyria (EPP) and X-linked porphyria (XLP). Symptoms
associated
with porphyria include, but are not limited to, cutaneous lesions, blistering
skin lesions,
hypertrichosis, hyperpigmentation, thickening and/or scarring of the skin,
friability of the
skin, photosensitivity of the skin, lichenification, leathery pseudovesicles,
labial grooving,
nail changes, life threatening acute neurological attacks, abdominal pain and
cramping,
constipation, diarrhea, increased bowel sounds, decreased bowel sounds,
nausea, vomiting,
tachycardia, hypertension, headache, mental symptoms, extremity pain, neck
pain, chest
pain, muscle weakness, sensory loss, tremors, sweating, dysuria, and bladder
distension.
[0509] Variegate porphyria (VP) is an autosomal dominant disorder of porphyrin-
heme
metabolism characterized by accumulations of the photosensitizing porphyrins,
protoporphyrin and coproporphyrin, arising from mutations of the gene encoding
the
enzyme protoporphyrinogen oxidase (PPDX). PPDX is an enzyme in the heme
biosynthetic pathway that catalyzes the oxidation of protoporphyrinogen IX to
form
protoporphyrin IX. PPDX is localized to the mitochondrial intermembrane space
and is
found in various tissues, including liver, lymphocytes, and cultured
fibroblasts.
[0510] Manifestations of VP may include cutaneous manifestations, including
photosensitivity, blistering, skin fragility, and postinflammatory
hyperpigmentation.
Acute exacerbations of VP are characterized by the occurrence of neuro-
visceral attacks
that include abdominal pain, the passage of dark urine, and neuropsychiatric
symptoms
such as bulbar paralysis, quadriplegia, motor neuropathy, and weakness of the
limbs. VP
is associated with a heterozygous mutation in the gene for protoporphyrinogen
oxidase
(PPDX). The homozygous variant of VP is characterized by severe PPDX
deficiency,
onset of photosensitization by porphyrins in early childhood, skeletal
abnormalities of the
hand, short stature, mental retardation, and convulsions.
[0511] In some embodiments, chroman derivatives (or analogues, or
pharmaceutically
acceptable salts thereof) of the present technology are useful in the
treatment, amelioration
or prevention of Alport Syndrome in a subject in need thereof. Alport Syndrome
is a
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genetic condition characterized by kidney disease, hearing loss, and eye
abnormalities and
occurs in approximately 1 in 50,000 newborns. Mutations in the COL4A3, COL4A4,

and COL4A5 genes cause Alport Syndrome. These genes each provide instructions
for
making one component of a protein called type IV collagen. This protein plays
an
important role in the kidneys, specifically in structures called glomeruli.
Glomeruli are
clusters of specialized blood vessels that remove water and waste products
from blood and
create urine. Mutations in these genes result in abnormalities of the type IV
collagen in
glomeruli, which prevents the kidneys from properly filtering the blood and
allows blood
and protein to pass into the urine. Gradual scarring of the kidneys occurs,
eventually
leading to progressive loss of kidney function and end-stage renal disease in
many people
with Alport Syndrome.
[0512] Type IV collagen is also an important component of inner ear
structures,
particularly the organ of Corti, that transform sound waves into nerve
impulses for the
brain. Alterations in type IV collagen often result in abnormal inner ear
function during
late childhood or early adolescence, which can lead to sensorineural deafness.
In the eye,
type IV collagen is important for maintaining the shape of the lens and the
normal color of
the retina. Mutations that disrupt type IV collagen can result in misshapen
lenses (anterior
lenticonus) and an abnormally colored retina. Significant hearing loss, eye
abnormalities,
and progressive kidney disease are more common in males with Alport Syndrome
than in
affected females. Symptoms associated with Alport Syndrome, including, but not
limited
to, e.g., hematuria, proteinuria, cylindruria, leukocyturia, hypertension,
edema,
microalbuminuria, declining glomerular filtration rate, fibrosis, Glomerular
Basement
Membrane (GBM) ultrastructural abnormalities, nephrotic Syndrome,
glomerulonephritis,
end-stage kidney disease, chronic anemia, macrothrombocytopenia,
osteodystrophy,
sensorineural deafness, anterior lenticonus, dot-and-fleck retinopathy,
posterior
polymorphous corneal dystrophy, recurrent corneal erosion, temporal macular
thinning,
cataracts, lacrimation, photophobia, vision loss, keratoconus, and
leiomyomatosis.
Therapeutic Methods
[0513] The following discussion is presented by way of example only, and is
not
intended to be limiting.
[0514] One aspect of the present technology includes methods of treating a
mitochondrial disease or disorder in a subject diagnosed as having, suspected
as having, or
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at risk of having a mitochondrial disease or disorder. In therapeutic
applications,
compositions or medicaments comprising a chroman derivative or a
pharmaceutically
acceptable salt thereof, are administered to a subject suspected of, or
already suffering
from such a disease (such as, e.g., subjects exhibiting pathological levels of
one or more
energy biomarkers such as, lactic acid (lactate) levels; pyruvic acid
(pyruvate) levels; total,
reduced or oxidized glutathione levels; total, reduced or oxidized cysteine
levels;
phosphocreatine levels; NADH (NADH+H30) or NADPH (NADPH+H30 ) levels; NAD
or NADP levels; ATP levels; reduced coenzyme Q (CoQred) levels; oxidized
coenzyme Q
(CoQox) levels; total coenzyme Q (CoQtot) levels; oxidized cytochrome C
levels; reduced
cytochrome C levels; acetoacetate levels; beta-hydroxy butyrate levels; 8-
hydroxy-2'-
deoxyguanosine (8-0HdG) levels; and reactive oxygen species levels compared to
a
normal control subject, or alternatively a subject diagnosed with a
mitochondrial disease
or disorder), in an amount sufficient to cure, or at least partially arrest,
the symptoms of
the disease, including its complications and intermediate pathological
phenotypes in
development of the disease. In some embodiments of the method, the lactate
levels of one
or more of whole blood, plasma, cerebrospinal fluid, or cerebral ventricular
fluid are
abnormal compared to a normal control subject. In some embodiments of the
method, the
pyruvate levels of one or more of whole blood, plasma, cerebrospinal fluid, or
cerebral
ventricular fluid are abnormal compared to a normal control subject. In some
embodiments of the method, the total, reduced or oxidized glutathione levels
of one or
more of whole blood, plasma, lymphocytes, cerebrospinal fluid, or cerebral
ventricular
fluid are abnormal compared to a normal control subject. In some embodiments
of the
method, the total, reduced or oxidized cysteine levels of one or more of whole
blood,
plasma, lymphocytes, cerebrospinal fluid, or cerebral ventricular fluid are
abnormal
compared to a normal control subject.
[0515] Subjects suffering from a mitochondrial disease or disorder can be
identified by
any or a combination of diagnostic or prognostic assays known in the art. For
example,
typical symptoms of a mitochondrial disease or disorder include, but are not
limited to,
poor growth, loss of muscle coordination, muscle weakness, neurological
deficit, seizures,
autism, autistic spectrum, autistic-like features, learning disabilities,
heart disease, liver
disease, kidney disease, gastrointestinal disorders, severe constipation,
diabetes, increased
risk of infection, thyroid dysfunction, adrenal dysfunction, autonomic
dysfunction,
confusion, disorientation, memory loss, failure to thrive, poor coordination,
sensory
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(vision, hearing) problems, reduced mental functions, hypotonia, disease of
the organ,
dementia, respiratory problems, hypoglycemia, apnea, lactic acidosis,
seizures,
swallowing difficulties, developmental delays, movement disorders (dystonia,
muscle
spasms, tremors, chorea), stroke, brain atrophy, or any other sign or symptom
of a
mitochondrial disease state disclosed herein.
[0516] In some embodiments, the subject may exhibit pathological levels of one
or more
energy biomarkers such as, lactic acid (lactate) levels; pyruvic acid
(pyruvate) levels; total,
reduced or oxidized glutathione levels; total, reduced or oxidized cysteine
levels;
phosphocreatine levels; NADH (NADH+H30) or NADPH (NADPH+H30 ) levels; NAD
or NADP levels; ATP levels; reduced coenzyme Q (CoQred) levels; oxidized
coenzyme Q
(CoQox) levels; total coenzyme Q (CoQtot) levels; oxidized cytochrome C
levels; reduced
cytochrome C levels; acetoacetate levels; beta-hydroxy butyrate levels; 8-
hydroxy-2'-
deoxyguanosine (8-0HdG) levels; and reactive oxygen species levels compared to
a
normal control subject, which is measureable using techniques known in the
art. In some
embodiments of the method, the lactate levels of one or more of whole blood,
plasma,
cerebrospinal fluid, or cerebral ventricular fluid are abnormal compared to a
normal
control subject. In some embodiments of the method, the pyruvate levels of one
or more
of whole blood, plasma, cerebrospinal fluid, or cerebral ventricular fluid are
abnormal
compared to a normal control subject. In some embodiments of the method, the
total,
reduced or oxidized glutathione levels of one or more of whole blood, plasma,
lymphocytes, cerebrospinal fluid, or cerebral ventricular fluid are abnormal
compared to a
normal control subject. In some embodiments of the method, the total, reduced
or
oxidized cysteine levels of one or more of whole blood, plasma, lymphocytes,
cerebrospinal fluid, or cerebral ventricular fluid are abnormal compared to a
normal
control subject.
[0517] In some embodiments, the subject may exhibit one or more mtDNA or
nuclear
DNA mutations in one or more genes described herein that play a
biological/physiological
role in the mitochondria (e.g., mitochondrial protein synthesis, respiratory
chain function,
intergenomic signaling, mitochondrial importation of nDNA-encoded proteins,
synthesis
of inner mitochondrial membrane phospholipids, mitochondrial motility and
fission,
mitophagy etc.). Such mutations are detectable using techniques known in the
art.
[0518] In some embodiments, administration of a chroman derivative to subjects

suffering from a mitochondrial disease or disorder will result in the
amelioration or
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elimination of one or more of the following symptoms: poor growth, loss of
muscle
coordination, muscle weakness, neurological deficit, seizures, autism,
autistic spectrum,
autistic-like features, learning disabilities, heart disease, liver disease,
kidney disease,
gastrointestinal disorders, severe constipation, diabetes, increased risk of
infection, thyroid
dysfunction, adrenal dysfunction, autonomic dysfunction, confusion,
disorientation,
memory loss, failure to thrive, poor coordination, sensory (vision, hearing)
problems,
reduced mental functions, hypotonia, disease of the organ, dementia,
respiratory problems,
hypoglycemia, apnea, lactic acidosis, seizures, swallowing difficulties,
developmental
delays, movement disorders (dystonia, muscle spasms, tremors, chorea), stroke,
brain
atrophy, or any other sign or symptom of a mitochondrial disease state
disclosed herein.
[0519] In some embodiments, administration of a chroman derivative to subjects

suffering from a mitochondrial disease or disorder will result in the
normalization of one
or more energy biomarkers such as, lactic acid (lactate) levels; pyruvic acid
(pyruvate)
levels; total, reduced or oxidized glutathione levels; total, reduced or
oxidized cysteine
levels; phosphocreatine levels; NADH (NADH+H30) or NADPH (NADPH+H30 ) levels;
NAD or NADP levels; ATP levels; reduced coenzyme Q (CoQred) levels; oxidized
coenzyme Q (CoQox) levels; total coenzyme Q (CoQtot) levels; oxidized
cytochrome C
levels; reduced cytochrome C levels; acetoacetate levels; beta-hydroxy
butyrate levels; 8-
hydroxy-2'-deoxyguanosine (8-0HdG) levels; and reactive oxygen species levels
compared to untreated subjects with a mitochondrial disease or disorder. In
some
embodiments of the method, the lactate levels of one or more of whole blood,
plasma,
cerebrospinal fluid, or cerebral ventricular fluid in a treated subject are
normalized
compared to untreated subjects with a mitochondrial disease or disorder. In
some
embodiments of the method, the pyruvate levels of one or more of whole blood,
plasma,
cerebrospinal fluid, or cerebral ventricular fluid in a treated subject are
normalized
compared to untreated subjects with a mitochondrial disease or disorder. In
some
embodiments of the method, the total, reduced or oxidized glutathione levels
of one or
more of whole blood, plasma, lymphocytes, cerebrospinal fluid, or cerebral
ventricular
fluid in a treated subject are normalized compared to untreated subjects with
a
mitochondrial disease or disorder. In some embodiments of the method, the
total, reduced
or oxidized cysteine levels of one or more of whole blood, plasma,
lymphocytes,
cerebrospinal fluid, or cerebral ventricular fluid in a treated subject are
normalized
compared to untreated subjects with a mitochondrial disease or disorder.
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[0520] One aspect of the present technology includes methods of treating
Alport
Syndrome in a subject diagnosed as having, suspected as having, or at risk of
having
Alport Syndrome. In therapeutic applications, compositions or medicaments
comprising a
chroman derivative or a pharmaceutically acceptable salt thereof, are
administered to a
subject suspected of, or already suffering from such a disease (such as, e.g.,
subjects
exhibiting aberrant levels and/or function of one or more of ADAM8,
fibronectin, myosin
10, MMP-2, MMP-9, and podocin compared to a normal control subject, or a
subject
diagnosed with Alport Syndrome), in an amount sufficient to cure, or at least
partially
arrest, the symptoms of the disease, including its complications and
intermediate
pathological phenotypes in development of the disease.
[0521] Subjects suffering from Alport Syndrome can be identified by any or a
combination of diagnostic or prognostic assays known in the art. For example,
typical
symptoms of Alport Syndrome include, but are not limited to, hematuria,
proteinuria,
cylindruria, leukocyturia, hypertension, edema, microalbuminuria, declining
glomerular
filtration rate, fibrosis, GBM ultrastructural abnormalities, nephrotic
syndrome,
glomerulonephritis, end-stage kidney disease, chronic anemia,
macrothrombocytopenia,
osteodystrophy, sensorineural deafness, anterior lenticonus, dot-and-fleck
retinopathy,
posterior polymorphous corneal dystrophy, recurrent corneal erosion, temporal
macular
thinning, cataracts, lacrimation, photophobia, vision loss, keratoconus, and
leiomyomatosis.
[0522] In some embodiments, the subject may exhibit aberrant levels or
function of one
or more of ADAM8, fibronectin, myosin 10, MMP-2, MMP-9, and podocin compared
to a
normal control subject, which is measureable using techniques known in the
art. In some
embodiments, the subject may exhibit one or more mutations in COL4A3, COL4A4,
and
COL4A5, which are involved in the production or assembly of type IV collagen
fibers and
are detectable using techniques known in the art.
[0523] In some embodiments, Alport Syndrome subjects treated with the chroman
derivative will show amelioration or elimination of one or more of the
following
symptoms: hematuria, proteinuria, cylindruria, leukocyturia, hypertension,
edema,
microalbuminuria, declining glomerular filtration rate, fibrosis, GBM
ultrastructural
abnormalities, nephrotic syndrome, glomerulonephritis, end-stage kidney
disease, chronic
anemia, macrothrombocytopenia, osteodystrophy, sensorineural deafness,
anterior
lenticonus, dot-and-fleck retinopathy, posterior polymorphous corneal
dystrophy,
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recurrent corneal erosion, temporal macular thinning, cataracts, lacrimation,
photophobia,
vision loss, keratoconus, and leiomyomatosis. In certain embodiments, Alport
Syndrome
subjects treated with the chroman derivative will show normalization of one or
more of
ADAM8, fibronectin, myosin 10, MMP-2, MMP-9, and podocin urine levels by at
least
10% compared to untreated Alport Syndrome subjects. In certain embodiments,
Alport
Syndrome subjects treated with the chroman derivative will show MMP-9
expression
levels in mesangial cells that are similar to that observed in a normal
control subject.
[0524] In another aspect, the present technology includes methods of treating
porphyria
in a subject diagnosed as having, suspected as having, or at risk of having
porphyria. In
therapeutic applications, compositions or medicaments comprising a chroman
derivative,
or a pharmaceutically acceptable salt thereof, are administered to a subject
suspected of, or
already suffering from such a disease, such as, e.g., aberrant levels and/or
function of
enzymes involved in heme biosynthesis compared to a normal control subject or
porphyria, in an amount sufficient to cure, or at least partially arrest, the
symptoms of the
disease, including its complications and intermediate pathological phenotypes
in
development of the disease.
[0525] Subjects suffering from porphyria can be identified by any or a
combination of
diagnostic or prognostic assays known in the art. For example, typical
symptoms of
porphyria include, but are not limited to, cutaneous lesions, blistering skin
lesions,
hypertrichosis, hyperpigmentation, thickening and/or scarring of the skin,
friability of the
skin, photosensitivity of the skin, lichenification, leathery pseudovesicles,
labial grooving,
nail changes, life threatening acute neurological attacks, abdominal pain and
cramping,
constipation, diarrhea, increased bowel sounds, decreased bowel sounds,
nausea, vomiting,
tachycardia, hypertension, headache, mental symptoms, extremity pain, neck
pain, chest
pain, muscle weakness, sensory loss, tremors, sweating, dysuria, and bladder
distension.
[0526] In some embodiments, the subject may exhibit aberrant levels or
function of
enzymes required for heme biosynthesis compared to a normal control subject,
which is
measureable using techniques known in the art. In some embodiments, the
subject may
exhibit one or more mutations in genes encoding enzymes required for heme
biosynthesis,
which are detectable using techniques known in the art.
[0527] In some embodiments, administration of a chroman derivative to a
subject that is
diagnosed as having, is suspected of having, or is at risk of having porphyria
will result in
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amelioration or elimination of one or more of the following symptoms:
cutaneous lesions,
blistering skin lesions, hypertrichosis, hyperpigmentation, thickening and/or
scarring of
the skin, friability of the skin, photosensitivity of the skin,
lichenification, leathery
pseudovesicles, labial grooving, nail changes, life threatening acute
neurological attacks,
abdominal pain and cramping, constipation, diarrhea, increased bowel sounds,
decreased
bowel sounds, nausea, vomiting, tachycardia, hypertension, headache, mental
symptoms,
extremity pain, neck pain, chest pain, muscle weakness, sensory loss, tremors,
sweating,
dysuria, and bladder distension. In certain embodiments of the method,
porphyria subjects
treated with the chroman derivative will show normalization of the levels
and/or function
of one or more enzymes required for heme biosynthesis compared to untreated
porphyria
subjects.
[0528] One aspect of the present technology includes methods of treating
vitiligo in a
subject diagnosed as having, suspected as having, or at risk of having
vitiligo. In
therapeutic applications, compositions or medicaments comprising a chroman
derivative,
or a pharmaceutically acceptable salt thereof, are administered to a subject
suspected of, or
already suffering from such a disease, in an amount sufficient to cure, or at
least partially
arrest, the symptoms of the disease, including its complications and
intermediate
pathological phenotypes in development of the disease.
[0529] Subjects suffering from vitiligo can be identified by any or a
combination of
diagnostic or prognostic assays known in the art. For example, typical
symptoms of
vitiligo include, but are not limited to, increased photosensitivity,
decreased contact
sensitivity response to dinitrochlorobenzene, depigmentation of the skin,
mucous
membranes (tissues that line the inside of the mouth and nose), retina, or
genitals, and
premature whitening or graying of hair on the scalp, eyelashes, eyebrows or
beard.
[0530] In some embodiments, vitiligo subjects treated with the chroman
derivative will
show amelioration or elimination of one or more of the following symptoms:
increased
photosensitivity, decreased contact sensitivity response to
dinitrochlorobenzene,
depigmentation of the skin, mucous membranes (tissues that line the inside of
the mouth
and nose), retina, or genitals, and premature whitening or graying of hair on
the scalp,
eyelashes, eyebrows or beard.
[0531] In some embodiments, administration of a chroman derivative to a
subject that is
diagnosed as having, is suspected of having, or is at risk of having IPF will
result in
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amelioration or elimination of one or more of the following symptoms: increase
in TGF-
01-induced epithelial to mesenchymal transition (EMT), myofibroblast
activation,
collagen production, lung scarring, and severe progressive fibrosis including
fibrotic foci
and honeycombing.
Prophylactic Methods
[0532] In one aspect, the present technology provides a method for preventing
or
delaying the onset of a mitochondrial disease or disorder in a subject at risk
of having a
mitochondrial disease or disorder. In some embodiments, the subject may
exhibit one or
more mtDNA or nuclear DNA mutations in one or more genes described herein that
play a
biological/physiological role in the mitochondria (e.g., mitochondrial protein
synthesis,
respiratory chain function, intergenomic signaling, mitochondrial importation
of nDNA-
encoded proteins, synthesis of inner mitochondrial membrane phospholipids,
mitochondrial motility and fission, mitophagy etc.).
[0533] Subjects at risk for pathological levels of one or more energy
biomarkers such as,
lactic acid (lactate) levels (in one or more of whole blood, plasma,
cerebrospinal fluid, or
cerebral ventricular fluid); pyruvic acid (pyruvate) levels (in one or more of
whole blood,
plasma, cerebrospinal fluid, or cerebral ventricular fluid); total, reduced or
oxidized
glutathione levels (in one or more of whole blood, plasma, lymphocytes,
cerebrospinal
fluid, or cerebral ventricular fluid); total, reduced or oxidized cysteine
levels (in one or
more of whole blood, plasma, lymphocytes, cerebrospinal fluid, or cerebral
ventricular
fluid); phosphocreatine levels; NADH (NADH+H30) or NADPH (NADPH+H30 ) levels;
NAD or NADP levels; ATP levels; reduced coenzyme Q (CoQred) levels; oxidized
coenzyme Q (CoQox) levels; total coenzyme Q (CoQtot) levels; oxidized
cytochrome C
levels; reduced cytochrome C levels; acetoacetate levels; beta-hydroxy
butyrate levels; 8-
hydroxy-2'-deoxyguanosine (8-0HdG) levels; and reactive oxygen species levels
compared to a normal control subject, or alternatively a mitochondrial disease
or disorder,
can be identified by, e.g., any or a combination of diagnostic or prognostic
assays known
in the art.
[0534] In prophylactic applications, pharmaceutical compositions or
medicaments
comprising a chroman derivative or a pharmaceutically acceptable salt thereof,
are
administered to a subject susceptible to, or otherwise at risk of a
mitochondrial disease or
disorder in an amount sufficient to eliminate or reduce the risk, or delay the
onset of the
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disease, including biochemical, histologic and/or behavioral symptoms of the
disease, its
complications and intermediate pathological phenotypes presenting during
development of
the disease. Administration of a prophylactic chroman derivative can occur
prior to the
manifestation of symptoms characteristic of the disease or disorder, such that
the disease
or disorder is prevented or, alternatively, delayed in its progression.
[0535] Subjects at risk for pathological levels of one or more energy
biomarkers
compared to a normal control subject, or alternatively a mitochondrial disease
or disorder
include, but are not limited to, subjects harboring mutations in one or more
genes
described herein that play a biological/physiological role in the mitochondria
(e.g.,
mitochondrial protein synthesis, respiratory chain function, intergenomic
signaling,
mitochondrial importation of nDNA-encoded proteins, synthesis of inner
mitochondrial
membrane phospholipids, mitochondrial motility and fission, mitophagy etc.).
[0536] In some embodiments, treatment with the chroman derivative will prevent
or
delay the onset of one or more of the following symptoms: poor growth, loss of
muscle
coordination, muscle weakness, neurological deficit, seizures, autism,
autistic spectrum,
autistic-like features, learning disabilities, heart disease, liver disease,
kidney disease,
gastrointestinal disorders, severe constipation, diabetes, increased risk of
infection, thyroid
dysfunction, adrenal dysfunction, autonomic dysfunction, confusion,
disorientation,
memory loss, failure to thrive, poor coordination, sensory (vision, hearing)
problems,
reduced mental functions, hypotonia, disease of the organ, dementia,
respiratory problems,
hypoglycemia, apnea, lactic acidosis, seizures, swallowing difficulties,
developmental
delays, movement disorders (dystonia, muscle spasms, tremors, chorea), stroke,
brain
atrophy, or any other sign or symptom of a mitochondrial disease state
disclosed herein.
[0537] In some embodiments, administration of a chroman derivative in subjects
with a
mitochondrial disease or disorder will cause the levels of one or more energy
biomarkers
to be similar to that observed in a normal control subject. In certain
embodiments, the
energy biomarker is selected from the group consisting of lactic acid
(lactate) levels;
pyruvic acid (pyruvate) levels; total, reduced or oxidized glutathione levels;
total, reduced
or oxidized cysteine levels; phosphocreatine levels; NADH (NADH+H30) or NADPH
(NADPH+H30 ) levels; NAD or NADP levels; ATP levels; reduced coenzyme Q
(CoQred) levels; oxidized coenzyme Q (CoQox) levels; total coenzyme Q (CoQtot)
levels;
oxidized cytochrome C levels; reduced cytochrome C levels; acetoacetate
levels; beta-
hydroxy butyrate levels; 8-hydroxy-2'-deoxyguanosine (8-0HdG) levels; and
reactive
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oxygen species levels. In some embodiments of the method, the lactate levels
of one or
more of whole blood, plasma, cerebrospinal fluid, or cerebral ventricular
fluid in a treated
subject are similar to that observed in a normal control subject. In some
embodiments of
the method, the pyruvate levels of one or more of whole blood, plasma,
cerebrospinal
fluid, or cerebral ventricular fluid in a treated subject are similar to that
observed in a
normal control subject. In some embodiments of the method, the total, reduced
or
oxidized glutathione levels of one or more of whole blood, plasma,
lymphocytes,
cerebrospinal fluid, or cerebral ventricular fluid in a treated subject are
similar to that
observed in a normal control subject. In some embodiments of the method, the
total,
reduced or oxidized cysteine levels of one or more of whole blood, plasma,
lymphocytes,
cerebrospinal fluid, or cerebral ventricular fluid in a treated subject are
similar to that
observed in a normal control subject.
[0538] In one aspect, the present technology provides a method for preventing
or
delaying the onset of Alport Syndrome or symptoms of Alport Syndrome in a
subject at
risk of having Alport Syndrome. In some embodiments, the subject may exhibit
one or
more mutations in COL4A3, COL4A4, and COL4A5, which are involved in the
production or assembly of type IV collagen fibers.
[0539] Subjects at risk for aberrant levels and/or function of one or more of
ADAM8,
fibronectin, myosin 10, MMP-2, MMP-9, and podocin compared to a normal control

subject or Alport Syndrome can be identified by, e.g., any or a combination of
diagnostic
or prognostic assays known in the art. In prophylactic applications,
pharmaceutical
compositions or medicaments of a chroman derivative, or a pharmaceutically
acceptable
salt thereof, are administered to a subject susceptible to, or otherwise at
risk of a disease or
condition such as e.g., Alport Syndrome, in an amount sufficient to eliminate
or reduce the
risk, or delay the onset of the disease, including biochemical, histologic
and/or behavioral
symptoms of the disease, its complications and intermediate pathological
phenotypes
presenting during development of the disease. Administration of a prophylactic
chroman
derivative can occur prior to the manifestation of symptoms characteristic of
the disease or
disorder, such that the disease or disorder is prevented or, alternatively,
delayed in its
progression.
[0540] Subjects at risk for aberrant levels and/or function of one or more of
ADAM8,
fibronectin, myosin 10, MMP-2, MMP-9, and podocin compared to a normal control

subject or Alport Syndrome include, but are not limited to, subjects harboring
mutations in
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CA 02920246 2016-02-09
COL4A3, COL4A4, and COL4A5, which are involved in the synthesis of type IV
collagen fibers.
[0541] In some embodiments, treatment with the chroman derivative will prevent
or
delay the onset of one or more of the following symptoms: hematuria,
proteinuria,
cylindruria, leukocyturia, hypertension, edema, microalbuminuria, declining
glomerular
filtration rate, fibrosis, GBM ultrastructural abnormalities, nephrotic
syndrome,
glomerulonephritis, end-stage kidney disease, chronic anemia,
macrothrombocytopenia,
osteodystrophy, sensorineural deafness, anterior lenticonus, dot-and-fleck
retinopathy,
posterior polymorphous corneal dystrophy, recurrent corneal erosion, temporal
macular
thinning, cataracts, lacrimation, photophobia, vision loss, keratoconus, and
leiomyomatosis. In certain embodiments, the urine levels of one or more of
ADAM8,
fibronectin, myosin 10, MMP-2, MMP-9, and podocin in Alport Syndrome subjects
treated with the chroman derivative will resemble those observed in healthy
controls. In
certain embodiments, Alport Syndrome subjects treated with the chroman
derivative will
show MMP-9 expression in mesangial cells that is similar to that observed in a
normal
control subject.
[0542] In one aspect, the present technology provides a method for preventing
or
delaying the onset of porphyria or symptoms of porphyria in a subject at risk
of having
porphyria. In some embodiments, the subject may exhibit one or more mutations
in genes
encoding enzymes required for heme biosynthesis.
[0543] Subjects at risk for aberrant levels and/or function of enzymes
involved in heme
biosynthesis compared to a normal control subject or porphyria can be
identified by, e.g.,
any or a combination of diagnostic or prognostic assays known in the art. In
prophylactic
applications, pharmaceutical compositions or medicaments of a chroman
derivative, or a
pharmaceutically acceptable salt thereof, are administered to a subject
susceptible to, or
otherwise at risk of a disease or condition such as e.g., porphyria, in an
amount sufficient
to eliminate or reduce the risk, or delay the outset of the disease, including
biochemical,
histologic and/or behavioral symptoms of the disease, its complications and
intermediate
pathological phenotypes presenting during development of the disease.
Administration of
a prophylactic chroman derivative can occur prior to the manifestation of
symptoms
characteristic of the disease or disorder, such that the disease or disorder
is prevented or,
alternatively, delayed in its progression.
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CA 02920246 2016-02-09
[0544] Subjects at risk for aberrant levels and/or function of enzymes
involved in heme
biosynthesis compared to a normal control subject, or porphyria include, but
are not
limited to, subjects harboring mutations in one or more genes encoding enzymes
involved
in heme biosynthesis.
[0545] In some embodiments, treatment with the chroman derivative will prevent
or
delay the onset of one or more of the following symptoms: cutaneous lesions,
blistering
skin lesions, hypertrichosis, hyperpigmentation, thickening and/or scarring of
the skin,
friability of the skin, photosensitivity of the skin, lichenification,
leathery pseudovesicles,
labial grooving, nail changes, life threatening acute neurological attacks,
abdominal pain
and cramping, constipation, diarrhea, increased bowel sounds, decreased bowel
sounds,
nausea, vomiting, tachycardia, hypertension, headache, mental symptoms,
extremity pain,
neck pain, chest pain, muscle weakness, sensory loss, tremors, sweating,
dysuria, and
bladder distension. In certain embodiments of the method, porphyria subjects
treated with
the chroman derivative will show normalization of the levels and/or function
of one or
more enzymes required for heme biosynthesis compared to untreated porphyria
subjects.
In certain embodiments, the levels and/or function of one or more enzymes
involved in
heme biosynthesis in porphyria subjects treated with the chroman derivative
will resemble
those observed in healthy controls.
[0546] In one aspect, the present technology provides a method for preventing
or
delaying the onset of vitiligo or symptoms of vitiligo in a subject at risk of
having vitiligo.
In some embodiments, the subject may exhibit one or more mutations in NLRP1,
TYR,
HLA class I, HLA class II, HLA class III, PTPN22, XBP1, IL2RA, LPP, RERE,
FOXP1,
TSLP, CCR6, GZMB, UBASH3A, C1QTNF6, and FOXP3.
[0547] In prophylactic applications, pharmaceutical compositions or
medicaments of a
chroman derivative or a pharmaceutically acceptable salt thereof, are
administered to a
subject susceptible to, or otherwise at risk of a disease or condition such as
vitiligo, in an
amount sufficient to eliminate or reduce the risk, or delay the onset of the
disease,
including biochemical, histologic and/or behavioral symptoms of the disease,
its
complications and intermediate pathological phenotypes presenting during
development of
the disease. Administration of a prophylactic chroman derivative can occur
prior to the
manifestation of symptoms characteristic of the disease or disorder, such that
the disease
or disorder is prevented or, alternatively, delayed in its progression.
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CA 02920246 2016-02-09
[0548] Subjects at risk for vitiligo include, but are not limited to, subjects
harboring
mutations in NLRP1, TYR, HLA class I, HLA class II, HLA class III, PTPN22,
XBP1,
IL2RA, LPP, RERE, FOXP1, TSLP, CCR6, GZMB, UBASH3A, C1QTNF6, and FOXP3.
[0549] In some embodiments, treatment with the chroman derivative will prevent
or
delay the onset of one or more of the following symptoms: increased
photosensitivity,
decreased contact sensitivity response to dinitrochlorobenzene, depigmentation
of the skin,
mucous membranes, retina, or genitals, and premature whitening or graying of
hair on the
scalp, eyelashes, eyebrows or beard.
[0550] In some embodiments, treatment with the chroman derivative will prevent
or
delay the onset of one or more of the symptoms of IPF, including but not
limited to, an
increase in TGF-01-induced epithelial to mesenchymal transition (EMT),
myofibroblast
activation, collagen production, lung scarring, and severe progressive
fibrosis including
fibrotic foci and honeycombing.
[0551] For therapeutic and/or prophylactic applications, a composition
comprising a
chroman derivative, or a pharmaceutically acceptable salt thereof, is
administered to the
subject. In some embodiments, the chroman derivative composition is
administered one,
two, three, four, or five times per day. In some embodiments, the chroman
derivative
composition is administered more than five times per day. Additionally or
alternatively, in
some embodiments, the chroman derivative composition is administered every
day, every
other day, every third day, every fourth day, every fifth day, or every sixth
day. In some
embodiments, the chroman derivative composition is administered weekly, bi-
weekly, tri-
weekly, or monthly. In some embodiments, the chroman derivative composition is

administered for a period of one, two, three, four, or five weeks. In some
embodiments,
the chroman derivative is administered for six weeks or more. In some
embodiments, the
chroman derivative is administered for twelve weeks or more. In some
embodiments, the
chroman derivative is administered for a period of less than one year. In some

embodiments, the chroman derivative is administered for a period of more than
one year.
[0552] Additionally or alternatively, in some embodiments of the method, the
chroman
derivative is administered daily for one, two, three, four or five weeks. In
some
embodiments of the method, the chroman derivative is administered daily for
less than 6
weeks. In some embodiments of the method, the chroman derivative is
administered daily
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CA 02920246 2016-02-09
for 6 weeks or more. In other embodiments of the method, the chroman
derivative is
administered daily for 12 weeks or more.
Determination of the Biological Effect of the Chroman Derivatives of the
Present
Technology
[0553] In various embodiments, suitable in vitro or in vivo assays are
performed to
determine the effect of a specific chroman derivative of the present
technology and
whether its administration is indicated for treatment. In various embodiments,
in vitro
assays can be performed with representative animal models, to determine if a
given
chroman derivative-based therapeutic exerts the desired effect in reducing
disruption of
mitochondrial function, such as disruption of OXPHOS, or alternatively
treating a medical
disease or condition, such as vitiligo, Alport Syndrome, porphyria or IPF.
Compounds for
use in therapy can be tested in suitable animal model systems including, but
not limited to
rats, mice, chicken, cows, monkeys, rabbits, and the like, prior to testing in
human
subjects. Similarly, for in vivo testing, any of the animal model system known
in the art
can be used prior to administration to human subjects. In some embodiments, in
vitro or
in vivo testing is directed to the biological function of a chroman
derivative, or a
pharmaceutically acceptable salt thereof.
[0554] The chroman derivatives of the present technology can be tested in
vitro for
efficacy. One such assay is ability of a compound to rescue FRDA fibroblasts
stressed by
addition of L-buthionine-(S,R)-sulfoximine (BSO), as described in Jauslin et
al., Hum.
Mol. Genet. 11(24):3055 (2002), Jauslin et al., FASEB J. 17:1972-4 (2003), and

International Patent Application WO 2004/003565. Human dermal fibroblasts from

Friedreich's Ataxia patients have been shown to be hypersensitive to
inhibition of the de
novo synthesis of glutathione (GSH) with L-buthionine-(S,R)-sulfoximine (BSO),
a
specific inhibitor of GSH synthetase (Jauslin et al., Hum. Mol. Genet.
11(24):3055
(2002)). This specific BSO-mediated cell death can be prevented by
administration of
antioxidants or molecules involved in the antioxidant pathway, such as a-
tocopherol, short
chain quinones, selenium, or small molecule glutathione peroxidase mimetics.
However,
antioxidants differ in their potency, i.e., the concentration at which they
are able to rescue
BSO-stressed FRDA fibroblasts. With this assay, EC50 concentrations of the
compounds
of the present technology can be determined and compared to known reference
antioxidants. Similar screens can be applied to fibroblasts derived from
patients diagnosed
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CA 02920246 2016-02-09
as having, suspected as having, or at risk of having LHON, Huntington's
Disease,
Parkinson's Disease, CoQ10 deficiencies, etc.
[0555] In some embodiments, disruption in oxidative phosphorylation is
determined by
assays well known in the art. By way of example, but not by way of limitation,
a
disruption in oxidative phosphorylation is determined by assays that measures
levels of
coenzyme Qi 0 (C0Q10). In some embodiments, disruption in oxidative
phosphorylation
is determined by assays that measure OXPHOS capacity by the uncoupling ratio.
In some
embodiments, disruption in oxidative phosphorylation is determined by assays
that
measure the net routine flux control ratio. In some embodiments, disruption in
oxidative
phosphorylation is determined by assays that measure leak flux control ratio.
In some
embodiments, disruption in oxidative phosphorylation is determined by assays
that
measure the phosphorylation respiratory control ratio.
[0556] Uncoupling ratio (UCR) is an expression of the respiratory reserve
capacity and
indicates the OXPHOS capacity of the cells. In some embodiments, UCR is
defined as
Cru / Cr. Cru is the maximum rate of oxygen utilization (Oxygen flux) produced
when
mitochondria are chemically uncoupled using FCCP (Carbonyl cyanide 4-
(trifluoromethoxy) phenylhydrazone). FCCP titration must be performed since
the
concentration of FCCP required to produce maximum oxygen utilization varies
among
different cell lines. Once the maximum oxygen utilization is reached, further
increases in
FCCP inhibit oxygen utilization by oxidative phosphorylation. In some
embodiments, Cr
represents oxygen utilization by the cells during a normal cellular
respiration with excess
substrates.
[0557] In some embodiments, the Net Routine Flux Control Ratio (Cr! Cru) is
the
inverse of the UCR. In some embodiments, this value assesses how close routine

respiration operates to the respiratory capacity of oxidative phosphorylation.
[0558] In some embodiments, the Respiratory Control Ratio (RCR) is defined as
Cru /
Cro. Cr u is defined above. Cro = Respiration after inhibition of Complex V
(ATP synthase)
by oligomycin. In some embodiments, this ratio allows assessment of uncoupling
and
OXPHOS dysfunction.
[0559] In some embodiments, the Leak Flux Control Ratio is determined by Cro /
Cru.
In some embodiments, this parameter is the inverse of RCR and represent proton
leak with
inhibition of ADP phosphorylation by oligomycin.
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CA 02920246 2016-02-09
[0560] In some embodiments, the Phosphorylation Respiratory Control Ratio
(RCRp) is
defined as (Cr ¨ Cro)/ Cr u (or 1/UCR ¨ 1/RCR). In some embodiments, the RCRp
is an
index which expresses phosphorylation-related respiration (Cr- Cro) as a
function of
respiratory capacity (Cru). In some embodiments, the RCRp remains constant, if
partial
uncoupling is fully compensated by an increased routine respiration rate and a
constant
rate of oxidative phosphorylation is maintained. In some embodiments, if the
respiratory
capacity declines without effect on the rate of oxidative phosphorylation; in
some
embodiments, the RCRp increases, which indicates that, a higher proportion of
the
maximum capacity is activated to drive ATP synthesis. In some embodiments, the
RCRp
declines to zero in either fully uncoupled cells or in cells under complete
metabolic arrest.
[0561] Accordingly, in some embodiments, therapeutic and/or prophylactic
treatment of
subjects having mitochondrial disorder or disease, with a chroman derivative
as disclosed
herein, or a pharmaceutically acceptable salt thereof, will reduce the
disruption in
oxidative phosphorylation, thereby ameliorating symptoms of mitochondrial
diseases and
disorders. Symptoms of mitochondrial diseases or disorders include, but are
not limited
to, poor growth, loss of muscle coordination, muscle weakness, neurological
deficit,
seizures, autism, autistic spectrum, autistic-like features, learning
disabilities, heart
disease, liver disease, kidney disease, gastrointestinal disorders, severe
constipation,
diabetes, increased risk of infection, thyroid dysfunction, adrenal
dysfunction, autonomic
dysfunction, confusion, disorientation, memory loss, poor growth, failure to
thrive, poor
coordination, sensory (vision, hearing) problems, reduced mental functions,
disease of the
organ, dementia, respiratory problems, hypoglycemia, apnea, lactic acidosis,
seizures,
swallowing difficulties, developmental delays, movement disorders (dystonia,
muscle
spasms, tremors, chorea), stroke, brain atrophy, or any other sign or symptom
of a
mitochondrial disease state disclosed herein.
[0562] Animal models of various diseases or conditions described herein (e.g.,
vitiligo,
Alport Syndrome, IPF, porphyria) may be generated using techniques known in
the art.
Such models may be used to demonstrate the biological effect of chroman
derivatives of
the present technology, in the prevention and treatment of conditions arising
from
disruption of a particular gene, and for determining what comprises a
therapeutically
effective amount of a chroman derivative in a given context.
[0563] In some embodiments, melanocyte degeneration is determined by assays
well
known in the art. In some embodiments, melanocyte degeneration is determined
by assays
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CA 02920246 2016-02-09
that measure cytotoxicity after epidermal cells are exposed to 100 or 250[1,M
of 4-tertiary
butyl phenol (4-TBP), a common inducer of vitiligo. In some embodiments,
melanocyte
degeneration is determined by assays that measure the survival rate of
epidermal cells that
have been exposed to 100 or 2501AM of 4-TBP.
[0564] In some embodiments, melanocyte degeneration is determined by assays
that
measure melanocyte antigen-specific T cell accumulation and cytotoxic activity
in
autologous skin explants. For a detailed description of the autologous skin
explant model,
see Van Den Boom et at., Journal of Investigative Dermatology, 129: 2220-2232
(2009).
[0565] In some embodiments, melanocyte degeneration is determined by assays
that
measure the progressive depigmentation in the pelage of the vitiligo mouse
model before
and two weeks after plucking dorsal hairs. In some embodiments, melanocyte
degeneration is determined by assays that measure the presence of ocular
pigmentation in
vitiligo mice. In some embodiments, melanocyte degeneration is determined by
assays
that measure the contact sensitivity of vitiligo mice to dinitrochlorobenzene.
For a
detailed description of the vitiligo mouse model, see Lerner et al., Journal
of Investigative
Dermatology, 87(3): 299-304 (1986).
[0566] In some embodiments, melanocyte degeneration is determined by assays
that
measure epidermal depigmentation in an adoptive transfer mouse model of
vitiligo. In
some embodiments, melanocyte degeneration is determined by assays that measure

tyrosinase RNA expression in an adoptive transfer mouse model of vitiligo. For
a detailed
description of the adoptive transfer mouse model of vitiligo, see Harris et
at., Journal of
Investigative Dermatology, 132: 1869-1876 (2012).
[0567] Accordingly, in some embodiments, therapeutic and/or prophylactic
treatment of
subjects having vitiligo, with a chroman derivative as disclosed herein, or a
pharmaceutically acceptable salt thereof, will reduce melanocyte degeneration,
thereby
ameliorating symptoms of vitiligo. Symptoms of vitiligo include, but are not
limited to,
increased photosensitivity, decreased contact sensitivity response to
dinitrochlorobenzene,
depigmentation of the skin, mucous membranes, retina, or genitals, and
premature
whitening or graying of hair on the scalp, eyelashes, eyebrows or beard.
[0568] Animal models of Alport Syndrome may be generated using techniques
known in
the art, including, for example by generating random or targeted mutations in
one or more
of COL4A3, COL4A4, and COL4A5. For example, murine models of X-linked Alport
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CA 02920246 2016-02-09
Syndrome and autosomal recessive Alport Syndrome have been generated by
targeted
disruption of the mouse Col4a5 gene and mouse Co14a3 gene respectively. See
Rheault et
al., J Am Soc Nephrol. 15(6):1466-74 (2004); Cosgrove et al., Genes Dev.
10(23):2981-92
(1996).
[0569] Accordingly, in some embodiments, therapeutic and/or prophylactic
treatment of
subjects having Alport Syndrome, with a chroman derivative as disclosed
herein, or a
pharmaceutically acceptable salt thereof, will ameliorate symptoms of Alport
Syndrome.
Symptoms of Alport Syndrome include, but are not limited to, hematuria,
proteinuria,
cylindruria, leukocyturia, hypertension, edema, microalbuminuria, declining
glomerular
filtration rate, fibrosis, GBM ultrastructural abnormalities, nephrotic
syndrome,
glomerulonephritis, end-stage kidney disease, chronic anemia,
macrothrombocytopenia,
osteodystrophy, sensorineural deafness, anterior lenticonus, dot-and-fleck
retinopathy,
posterior polymorphous corneal dystrophy, recurrent corneal erosion, temporal
macular
thinning, cataracts, lacrimation, photophobia, vision loss, keratoconus, and
leiomyomatosis.
[0570] Animals subjected to TGF-I31-adenovirus-induced lung fibrosis or
bleomycin-
induced lung fibrosis may be used as an in vivo model for IPF. MacKinnon et
al., Am. J.
Respir. Crit. Care Med. 185(5):537-46 (2012).
[0571] Accordingly, in some embodiments, therapeutic and/or prophylactic
treatment of
subjects having 1PF, with a chroman derivative as disclosed herein, or a
pharmaceutically
acceptable salt thereof, will ameliorate symptoms of IPF.
[0572] Animal models of porphyria may be generated using techniques known in
the art,
including, for example by generating random or targeted mutations in one or
more genes
encoding enzymes involved in heme biosynthesis. For example, a murine model of

familial porphyria cutanea tarda has been generated by targeted disruption of
the URO-D
gene by homologous recombination.
[0573] Accordingly, in some embodiments, therapeutic and/or prophylactic
treatment of
subjects having porphyria, with a chroman derivative as disclosed herein, or a

pharmaceutically acceptable salt thereof, will ameliorate symptoms of
porphyria.
Symptoms of porphyria include, but are not limited to, cutaneous lesions,
blistering skin
lesions, hypertrichosis, hyperpigmentation, thickening and/or scarring of the
skin,
friability of the skin, photosensitivity of the skin, lichenification,
leathery pseudovesicles,
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CA 02920246 2016-02-09
labial grooving, nail changes, acute neurological attacks, abdominal pain and
cramping,
constipation, diarrhea, increased bowel sounds, decreased bowel sounds,
nausea, vomiting,
tachycardia, hypertension, headache, mental symptoms, extremity pain, neck
pain, chest
pain, muscle weakness, sensory loss, tremors, sweating, dysuria, and bladder
distension.
Use of Chroman Derivatives of the Present Technology for Modulation of Energy
Biomarkers
[0574] In addition to monitoring energy biomarkers to assess the status of
treatment or
suppression of mitochondrial diseases, the chroman derivatives of the present
technology
can be used in subjects or patients to modulate one or more energy biomarkers.

Modulation of energy biomarkers can be done to normalize energy biomarkers in
a
subject, or to enhance energy biomarkers in a subject.
[0575] Normalization of one or more energy biomarkers is defined as either
restoring the
level of one or more such energy biomarkers to normal or near-normal levels in
a subject
whose levels of one or more energy biomarkers show pathological differences
from
normal levels (i.e., levels in a healthy subject), or to change the levels of
one or more
energy biomarkers to alleviate pathological symptoms in a subject. Depending
on the
nature of the energy biomarker, such levels may show measured values either
above or
below a normal value. For example, a pathological lactate level is typically
higher than
the lactate level in a normal (i.e., healthy) person, and a decrease in the
level may be
desirable. A pathological ATP level is typically lower than the ATP level in a
normal
(i.e., healthy) person, and an increase in the level of ATP may be desirable.
Accordingly,
normalization of energy biomarkers can involve restoring the level of energy
biomarkers
to within about at least two standard deviations of normal in a subject, or to
within about
at least one standard deviation of normal in a subject, to within about at
least one-half
standard deviation of normal, or to within about at least one-quarter standard
deviation of
normal.
[0576] When an increase in an energy biomarker level is desired to normalize
the one or
more such energy biomarker, the level of the energy biomarker can be increased
to within
about at least two standard deviations of normal in a subject, increased to
within about at
least one standard deviation of normal in a subject, increased to within about
at least one-
half standard deviation of normal, or increased to within about at least one-
quarter
standard deviation of normal, by administration of one or more compounds
according to
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CA 02920246 2016-02-09
the present technology. Alternatively, the level of one or more of the energy
biomarkers
can be increased by about at least 10% above the subject's level of the
respective one or
more energy biomarkers before administration; by about at least 20% above the
subject's
level of the respective one or more energy biomarkers before administration,
by about at
least 30% above the subject's level of the respective one or more energy
biomarkers before
administration, by about at least 40% above the subject's level of the
respective one or
more energy biomarkers before administration, by about at least 50% above the
subject's
level of the respective one or more energy biomarkers before administration,
by about at
least 75% above the subject's level of the respective one or more energy
biomarkers before
administration, or by about at least 100% above the subject's level of the
respective one or
more energy biomarkers before administration.
[0577] When a decrease in a level of one or more energy biomarkers is desired
to
normalize the one or more energy biomarkers, the level of the one or more
energy
biomarkers can be decreased to a level within about at least two standard
deviations of
normal in a subject, decreased to within about at least one standard deviation
of normal in
a subject, decreased to within about at least one-half standard deviation of
normal, or
decreased to within about at least one-quarter standard deviation of normal,
by
administration of one or more compounds according to the present technology.
Alternatively, the level of the one or more energy biomarkers can be decreased
by about at
least 10% below the subject's level of the respective one or more energy
biomarkers before
administration, by about at least 20% below the subject's level of the
respective one or
more energy biomarkers before administration, by about at least 30% below the
subject's
level of the respective one or more energy biomarkers before administration,
by about at
least 40% below the subject's level of the respective one or more energy
biomarkers before
administration, by about at least 50% below the subject's level of the
respective one or
more energy biomarkers before administration, by about at least 75% below the
subject's
level of the respective one or more energy biomarkers before administration,
or by about
at least 90% below the subject's level of the respective one or more energy
biomarkers
before administration.
[0578] Enhancement of the level of one or more energy biomarkers is defined as

changing the extant levels of one or more energy biomarkers in a subject to a
level which
provides beneficial or desired effects for the subject. For example, a person
undergoing
strenuous effort or prolonged vigorous physical activity, such as mountain
climbing, could
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CA 02920246 2016-02-09
benefit from increased ATP levels or decreased lactate levels. As described
above,
normalization of energy biomarkers may not achieve the optimum state for a
subject with
a mitochondrial disease, and such subjects can also benefit from enhancement
of energy
biomarkers. Examples of subjects who could benefit from enhanced levels of one
or more
energy biomarkers include, but are not limited to, subjects undergoing
strenuous or
prolonged physical activity, subjects with chronic energy problems, or
subjects with
chronic respiratory problems. Such subjects include, but are not limited to,
pregnant
females, particularly pregnant females in labor; neonates, particularly
premature neonates;
subjects exposed to extreme environments, such as hot environments
(temperatures
routinely exceeding about 85-86 degrees Fahrenheit or about 30 degrees Celsius
for about
4 hours daily or more), cold environments (temperatures routinely below about
32 degrees
Fahrenheit or about 0 degrees Celsius for about 4 hours daily or more), or
environments
with lower-than-average oxygen content, higher-than-average carbon dioxide
content, or
higher-than-average levels of air pollution (airline travelers, flight
attendants, subjects at
elevated altitudes, subjects living in cities with lower-than average air
quality, subjects
working in enclosed environments where air quality is degraded); subjects with
lung
diseases or lower-than-average lung capacity, such as tubercular patients,
lung cancer
patients, emphysema patients, and cystic fibrosis patients; subjects
recovering from
surgery or illness; elderly subjects, including elderly subjects experiencing
decreased
energy; subjects suffering from chronic fatigue, including chronic fatigue
syndrome;
subjects undergoing acute trauma; subjects in shock; subjects requiring acute
oxygen
administration; subjects requiring chronic oxygen administration; or other
subjects with
acute, chronic, or ongoing energy demands who can benefit from enhancement of
energy
biomarkers.
[0579] In another embodiment of the present technology, including any of the
foregoing
embodiments, the chroman derivatives described herein are administered to
subjects
suffering from a mitochondrial disorder to modulate one or more of various
energy
biomarkers, including, but not limited to, lactic acid (lactate) levels (in
one or more of
whole blood, plasma, cerebrospinal fluid, or cerebral ventricular fluid);
pyruvic acid
(pyruvate) levels (in one or more of whole blood, plasma, cerebrospinal fluid,
or cerebral
ventricular fluid); lactate/pyruvate ratios (in one or more of whole blood,
plasma,
cerebrospinal fluid, or cerebral ventricular fluid); total, reduced or
oxidized glutathione
levels, or reduced/oxidized glutathione ratios (in one or more of whole blood,
plasma,
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CA 02920246 2016-02-09
lymphocytes, cerebrospinal fluid, or cerebral ventricular fluid); total,
reduced or oxidized
cysteine levels, or reduced/oxidized cysteine ratios (in one or more of whole
blood,
plasma, lymphocytes, cerebrospinal fluid, or cerebral ventricular fluid);
phosphocreatine
levels; NADH (NADH+H") or NADPH (NADPH+H30 ) levels; NAD or NADP levels;
ATP levels; reduced coenzyme Q (CoQred) levels; oxidized coenzyme Q (CoQox)
levels;
total coenzyme Q (CoQtot) levels; oxidized cytochrome C levels; reduced
cytochrome C
levels; oxidized cytochrome C/reduced cytochrome C ratio; acetoacetate levels;
beta-
hydroxy butyrate levels; acetoacetate/ beta-hydroxy butyrate ratio; 8-hydroxy-
2'-
deoxyguanosine (8-0HdG) levels; levels of reactive oxygen species; oxygen
consumption
(V02), carbon dioxide output (VCO2), respiratory quotient (VCO2NO2), and to
modulate exercise intolerance (or conversely, modulate exercise tolerance) and
to
modulate anaerobic threshold. Energy biomarkers can be measured in whole
blood,
plasma, cerebrospinal fluid, cerebroventricular fluid, arterial blood, venous
blood, or any
other body fluid, body gas, or other biological sample useful for such
measurement. In
one embodiment, the levels are modulated to a value within about 2 standard
deviations of
the value in a healthy subject. In another embodiment, the levels are
modulated to a value
within about 1 standard deviation of the value in a healthy subject. In
another
embodiment, the levels in a subject are changed by at least about 10% above or
below the
level in the subject prior to modulation. In another embodiment, the levels
are changed by
at least about 20% above or below the level in the subject prior to
modulation. In another
embodiment, the levels are changed by at least about 30% above or below the
level in the
subject prior to modulation. In another embodiment, the levels are changed by
at least
about 40% above or below the level in the subject prior to modulation. In
another
embodiment, the levels are changed by at least about 50% above or below the
level in the
subject prior to modulation. In another embodiment, the levels are changed by
at least
about 75% above or below the level in the subject prior to modulation. In
another
embodiment, the levels are changed by at least about 100% above or at least
about 90%
below the level in the subject prior to modulation.
[0580] Several metabolic biomarkers have already been used to evaluate
efficacy of
CoQ10, and these metabolic biomarkers can be monitored as energy biomarkers
for use in
the methods of the present technology. Pyruvate, a product of the anaerobic
metabolism
of glucose, is removed by reduction to lactic acid in an anaerobic setting or
by oxidative
metabolism, which is dependent on a functional mitochondrial respiratory
chain.
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Dysfunction of the respiratory chain may lead to inadequate removal of lactate
and
pyruvate from the circulation and elevated lactate/pyruvate ratios are
observed in
mitochondrial cytopathies (see Scriver C R, The Metabolic and Molecular Bases
of
Inherited Disease, 7th ed., New York: McGraw-Hill, Health Professions
Division, 1995;
and Munnich etal., J. Inherit. Metab. Dis. 15(4):448-55 (1992)). Blood
lactate/pyruvate
ratio (Chariot et at., Arch. Pathol. Lab. Med. 118(7):695-7 (1994)) is,
therefore, widely
used as a noninvasive test for detection of mitochondrial cytopathies (see
again Scriver C
R, The Metabolic and Molecular Bases of Inherited Disease, 7th ed., New York:
McGraw-
Hill, Health Professions Division, 1995; and Munnich et al., J. Inherit.
Metab. Dis.
15(4):448-55 (1992)) and toxic mitochondrial myopathies (Chariot et al.,
Arthritis Rheum.
37(4):583-6 (1994)). Changes in the redox state of liver mitochondria can be
investigated
by measuring the arterial ketone body ratio (acetoacetate/3-hydroxybutyrate:
AKBR)
(Ueda et at., J. Cardiol. 29(2):95-102 (1997)). Urinary excretion of 8-hydroxy-
2'-
deoxyguanosine (8-0HdG) often has been used as a biomarker to assess the
extent of
repair of ROS-induced DNA damage in both clinical and occupational settings
(Erhola et
at., FEBS Lett. 409(2):287-91 (1997); Honda et at., Leuk. Res. 24(6):461-8
(2000); Pilger
et at., Free Radic. Res. 35(3):273-80 (2001); Kim et at. Environ Health
Perspect
112(6):666-71 (2004)).
[0581] Magnetic resonance spectroscopy (MRS) has been useful in the diagnoses
of
mitochondrial cytopathy by demonstrating elevations in cerebrospinal fluid
(CSF) and
cortical white matter lactate using proton MRS (1H-MRS) (Kaufmann et at.,
Neurology
62(8):1297-302 (2004)). Phosphorous MRS (31P-MRS) has been used to demonstrate

low levels of cortical phosphocreatine (PCr) (Matthews et at., Ann. Neurol.
29(4):435-8
(1991)), and a delay in PCr recovery kinetics following exercise in skeletal
muscle
(Matthews etal., Ann. Neurol. 29(4):435-8 (1991); Barbiroli etal., J. Neurol.
242(7):472-
7 (1995); Fabrizi etal., J. Neurol. Sci. 137(1):20-7 (1996)). A low skeletal
muscle PCr
has also been confirmed in patients with mitochondrial cytopathy by direct
biochemical
measurements.
[0582] Exercise testing is particularly helpful as an evaluation and screening
tool in
mitochondrial myopathies. One of the hallmark characteristics of mitochondrial

myopathies is a reduction in maximal whole body oxygen consumption (V02max)
(Taivassalo etal., Brain 126(Pt 2):413-23 (2003)). Given that VO2max is
determined by
cardiac output (Qc) and peripheral oxygen extraction (arterial-venous total
oxygen
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CA 02920246 2016-02-09
content) difference, some mitochondrial cytopathies affect cardiac function
where delivery
can be altered; however, most mitochondrial myopathies show a characteristic
deficit in
peripheral oxygen extraction (A-V02 difference) and an enhanced oxygen
delivery
(hyperkinetic circulation) (Taivassalo et al., Brain 126(Pt 2):413-23 (2003)).
This can be
demonstrated by a lack of exercise induced deoxygenation of venous blood with
direct AV
balance measurements (Taivassalo et al., Ann. Neurol. 51(1):38-44 (2002)) and
non-
invasively by near infrared spectroscopy (Lynch et al., Muscle Nerve 25(5):664-
73 (2002);
van Beekvelt et al., Ann. Neurol. 46(4):667-70 (1999)).
[0583] Several of these energy biomarkers are discussed in more detail as
follows. It
should be emphasized that, while certain energy biomarkers are discussed and
enumerated
herein, the present technology is not limited to modulation, normalization or
enhancement
of only these enumerated energy biomarkers.
[0584] Lactic acid (lactate) levels: Mitochondrial dysfunction typically
results in
abnormal levels of lactic acid, as pyruvate levels increase and pyruvate is
converted to
lactate to maintain capacity for glycolysis. Mitochondrial dysfunction can
also result in
abnormal levels of NADH+H30, NADPH+H30, NAD, or NADP, as the reduced
nicotinamide adenine dinucleotides are not efficiently processed by the
respiratory chain.
Lactate levels can be measured by taking samples of appropriate bodily fluids
such as
whole blood, plasma, or cerebrospinal fluid. Using magnetic resonance, lactate
levels can
be measured in virtually any volume of the body desired, such as the brain.
[0585] Measurement of cerebral lactic acidosis using magnetic resonance in
patients is
described in Kaufmann et al., Neurology 62(8): 1297 (2004). Whole blood,
plasma, and
cerebrospinal fluid lactate levels can be measured by commercially available
equipment
such as the YSI 2300 STAT Plus Glucose & Lactate Analyzer (YSI Life Sciences,
Ohio).
[0586] NAD, NADP, NADH and NADPH levels: Measurement of NAD, NADP,
NADH (NADH+H3 ) or NADPH (NADPH+H3 ) can be measured by a variety of
fluorescent, enzymatic, or electrochemical techniques, e.g., the
electrochemical assay
described in US 2005/0067303.
[0587] Oxygen consumption (v02 or V02), carbon dioxide output (vCO2 or VCO2),
and
respiratory quotient (VCO2/V02): v02 is usually measured either while resting
(resting
v02) or at maximal exercise intensity (v02 max). Optimally, both values will
be
measured. However, for severely disabled patients, measurement of v02 max may
be
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CA 02920246 2016-02-09
impractical. Measurement of both forms of v02 is readily accomplished using
standard
equipment from a variety of vendors, e.g., Korr Medical Technologies, Inc.
(Salt Lake
City, Utah). VCO2 can also be readily measured, and the ratio of VCO2 to V02
under the
same conditions (VCO2/V02, either resting or at maximal exercise intensity)
provides the
respiratory quotient (RQ).
[0588] Oxidized Cytochrome C, reduced Cytochrome C, and ratio of oxidized
Cytochrome C to reduced Cytochrome C: Cytochrome C parameters, such as
oxidized
cytochrome C levels (Cyt Cm), reduced cytochrome C levels (Cyt Cred), and the
ratio of
oxidized cytochrome C/reduced cytochrome C ratio (Cyt C.,)/(Cyt Cred), can be
measured
by in vivo near infrared spectroscopy. See, e.g., Rolfe, P., "In vivo near-
infrared
spectroscopy," Annu. Rev. Biomed. Eng. 2:715-54 (2000) and Strangman et al.,
"Non-
invasive neuroimaging using near-infrared light" Biol. Psychiatry 52:679-93
(2002).
[0589] Exercise tolerance/Exercise intolerance: Exercise intolerance is
defined as "the
reduced ability to perform activities that involve dynamic movement of large
skeletal
muscles because of symptoms of dyspnea or fatigue" (Pina et al., Circulation
107:1210
(2003)). Exercise intolerance is often accompanied by myoglobinuria, due to
breakdown
of muscle tissue and subsequent excretion of muscle myoglobin in the urine.
Various
measures of exercise intolerance can be used, such as time spent walking or
running on a
treadmill before exhaustion, time spent on an exercise bicycle (stationary
bicycle) before
exhaustion, and the like. Treatment with the compositions or methods of the
present
technology can result in about a 10% or greater improvement in exercise
tolerance (for
example, about a 10% or greater increase in time to exhaustion, e.g., from 10
minutes to
11 minutes), about a 20% or greater improvement in exercise tolerance, about a
30% or
greater improvement in exercise tolerance, about a 40% or greater improvement
in
exercise tolerance, about a 50% or greater improvement in exercise tolerance,
about a 75%
or greater improvement in exercise tolerance, or about a 100% or greater
improvement in
exercise tolerance. While exercise tolerance is not, strictly speaking, an
energy biomarker,
for the purposes of the present technology, modulation, normalization, or
enhancement of
energy biomarkers includes modulation, normalization, or enhancement of
exercise
tolerance.
[0590] Similarly, tests for normal and abnormal values of pyruvic acid
(pyruvate) levels,
lactate/pyruvate ratio, ATP levels, anaerobic threshold, reduced coenzyme Q
(CoQred)
levels, oxidized coenzyme Q (CoQ") levels, total coenzyme Q (CoQto t) levels,
oxidized
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CA 02920246 2016-02-09
cytochrome C levels, reduced cytochrome C levels, oxidized cytochrome
C/reduced
cytochrome C ratio, acetoacetate levels, P-hydroxy butyrate levels,
acetoacetate/13-hydroxy
butyrate ratio, 8-hydroxy-2'-deoxyguanosine (8-0HdG) levels, and levels of
reactive
oxygen species are known in the art and can be used to evaluate efficacy of
the
compositions and methods of the present technology. (For the purposes of the
present
technology, modulation, normalization, or enhancement of energy biomarkers
includes
modulation, normalization, or enhancement of anaerobic threshold.)
[0591] Neuroimaging is indicated in individuals with suspected CNS disease. CT
may
show basal ganglia calcification and/or diffuse atrophy. MRI may show focal
atrophy of
the cortex or cerebellum, or high signal change on T2-weighted images,
particularly in the
occipital cortex. There may also be evidence of a generalized
leukoencephalopathy.
Cerebellar atrophy is a prominent feature in children.
[0592] Electroencephalography (EEG) is indicated in individuals with suspected

encephalopathy or seizures. Encephalopathy may be associated with generalized
slow
wave activity on the EEG. Generalized or focal spike and wave discharges may
be seen in
individuals with seizures.
[0593] Peripheral neurophysiologic studies are indicated in individuals with
limb
weakness, sensory symptoms, or areflexia. Electromyography (EMG) is often
normal but
may show myopathic features. Nerve conduction velocity (NCV) may be normal or
may
show a predominantly axonal sensorimotor polyneuropathy.
[0594] Magnetic resonance spectroscopy (MRS) and exercise testing (with
measurement
of blood concentration of lactate) may be used to detect evidence of abnormal
mitochondrial function non-invasively.
[0595] Glucose. An elevated concentration of fasting blood glucose may
indicate
diabetes mellitus.
[0596] Cardiac. Both electrocardiography and echocardiography may indicate
cardiac
involvement (cardiomyopathy or atrioventricular conduction defects).
[0597] Treatment of a subject afflicted by a mitochondrial disease in
accordance with
the methods of the present technology may result in the inducement of a
reduction or
alleviation of symptoms in the subject, e.g., to halt the further progression
of the disorder.
Partial or complete suppression of the mitochondrial disease can result in a
lessening of
the severity of one or more of the symptoms that the subject would otherwise
experience.
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CA 02920246 2016-02-09
[0598] Any one, or any combination of, the energy biomarkers described herein
(e.g.,
Figure 1) provide conveniently measurable benchmarks by which to gauge the
effectiveness of treatment or suppressive therapy. Additionally, other energy
biomarkers
are known to those skilled in the art and can be monitored to evaluate the
efficacy of
treatment or suppressive therapy.
Modes of Administration and Effective Dosag_es
[0599] Any method known to those in the art for contacting a cell, organ or
tissue with a
chroman derivative of the present technology, or a pharmaceutically acceptable
salt
thereof, may be employed. Suitable methods include in vitro, ex vivo, or in
vivo methods.
In vivo methods typically include the administration of a chroman derivative,
such as those
described above, to a mammal, suitably a human. When used in vivo for therapy,
the
chroman derivatives, or pharmaceutically acceptable salts thereof, are
administered to the
subject in effective amounts (i.e., amounts that have desired therapeutic
effect). The dose
and dosage regimen will depend upon the degree of the infection in the
subject, the
characteristics of the particular chroman derivative used, e.g., its
therapeutic index, the
subject, and the subject's history.
[0600] The effective amount may be determined during pre-clinical trials and
clinical
trials by methods familiar to physicians and clinicians. An effective amount
of a chroman
derivative useful in the methods may be administered to a mammal in need
thereof by any
of a number of well-known methods for administering pharmaceutical compounds.
The
chroman derivative may be administered systemically or locally.
[0601] The chroman derivative may be formulated as a pharmaceutically
acceptable salt.
The term "pharmaceutically acceptable salt" means a salt prepared from a base
or an acid
which is acceptable for administration to a patient, such as a mammal (e.g.,
salts having
acceptable mammalian safety for a given dosage regime). However, it is
understood that
the salts are not required to be pharmaceutically acceptable salts, such as
salts of
intermediate compounds that are not intended for administration to a patient.
Pharmaceutically acceptable salts can be derived from pharmaceutically
acceptable
inorganic or organic bases and from pharmaceutically acceptable inorganic or
organic
acids. In addition, when a chroman derivative contains both a basic moiety,
such as an
amine, pyridine or imidazole, and an acidic moiety such as a carboxylic acid
or tetrazole,
zwitterions may be formed and are included within the term "salt" as used
herein. Salts
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CA 02920246 2016-02-09
derived from pharmaceutically acceptable inorganic bases include ammonium,
calcium,
copper, ferric, ferrous, lithium, magnesium, manganic, manganous, potassium,
sodium,
and zinc salts, and the like. Salts derived from pharmaceutically acceptable
organic bases
include salts of primary, secondary and tertiary amines, including substituted
amines,
cyclic amines, naturally-occurring amines and the like, such as arginine,
betaine, caffeine,
choline, N,N'-dibenzylethylenediamine, diethylamine, 2-diethylaminoethanol, 2-
dimethylaminoethanol, ethanolamine, ethylenediamine, N-ethylmorpholine, N-
ethylpiperidine, glucamine, glucosamine, histidine, hydrabamine,
isopropylamine, lysine,
methylglucamine, morpholine, piperazine, piperadine, polyamine resins,
procaine, purines,
theobromine, triethylamine, trimethylamine, tripropylamine, tromethamine and
the like.
Salts derived from pharmaceutically acceptable inorganic acids include salts
of boric,
carbonic, hydrohalic (hydrobromic, hydrochloric, hydrofluoric or hydroiodic),
nitric,
phosphoric, sulfamic and sulfuric acids. Salts derived from pharmaceutically
acceptable
organic acids include salts of aliphatic hydroxyl acids (e.g., citric,
gluconic, glycolic,
lactic, lactobionic, malic, and tartaric acids), aliphatic monocarboxylic
acids (e.g., acetic,
butyric, formic, propionic and trifluoroacetic acids), amino acids (e.g.,
aspartic and
glutamic acids), aromatic carboxylic acids (e.g., benzoic, p-chlorobenzoic,
diphenylacetic,
gentisic, hippuric, and triphenylacetic acids), aromatic hydroxyl acids (e.g.,
o-
hydroxybenzoic, p-hydroxybenzoic, 1-hydroxynaphthalene-2-carboxylic and 3-
hydroxynaphthalene-2-carboxylic acids), ascorbic, dicarboxylic acids (e.g.,
fumaric,
maleic, oxalic and succinic acids), glucuronic, mandelic, mucic, nicotinic,
orotic, pamoic,
pantothenic, sulfonic acids (e.g., benzenesulfonic, camphosulfonic, edisylic,
ethanesulfonic, isethionic, methanesulfonic, naphthalenesulfonic, naphthalene-
1,5-
disulfonic, naphthalene-2,6-disulfonic and p-toluenesulfonic acids), xinafoic
acid, and the
like.
[0602] The chroman derivatives described herein, or pharmaceutically
acceptable salts
thereof, can be incorporated into pharmaceutical compositions for
administration, singly
or in combination, to a subject for the treatment or prevention of a disorder
described
herein. Such compositions typically include the active agent and a
pharmaceutically
acceptable carrier. As used herein the term "pharmaceutically acceptable
carrier" includes
saline, solvents, dispersion media, coatings, antibacterial and antifungal
agents, isotonic
and absorption delaying agents, and the like, compatible with pharmaceutical
191

CA 02920246 2016-02-09
administration. Supplementary active compounds can also be incorporated into
the
compositions.
[0603] Pharmaceutical compositions are typically formulated to be compatible
with its
intended route of administration. Examples of routes of administration include
parenteral
(e.g., intravenous, intradermal, intraperitoneal or subcutaneous), oral,
inhalation,
intrathecal, transdermal (topical), intraocular, iontophoretic, and
transmucosal
administration. Solutions or suspensions used for parenteral, intradermal, or
subcutaneous
application can include the following components: a sterile diluent such as
water for
injection, saline solution, fixed oils, polyethylene glycols, glycerine,
propylene glycol or
other synthetic solvents; antibacterial agents such as benzyl alcohol or
methyl parabens;
antioxidants such as ascorbic acid or sodium bisulfite; chelating agents such
as
ethylenediaminetetraacetic acid; buffers such as acetates, citrates or
phosphates and agents
for the adjustment of tonicity such as sodium chloride or dextrose. pH can be
adjusted
with acids or bases, such as hydrochloric acid or sodium hydroxide. The
parenteral
preparation can be enclosed in ampoules, disposable syringes or multiple dose
vials made
of glass or plastic. For convenience of the patient or treating physician, the
dosing
formulation can be provided in a kit containing all necessary equipment (e.g.,
vials of
drug, vials of diluent, syringes and needles) for a treatment course (e.g., 7
days of
treatment).
[0604] Pharmaceutical compositions suitable for injectable use can include
sterile
aqueous solutions (where water soluble) or dispersions and sterile powders for
the
extemporaneous preparation of sterile injectable solutions or dispersion. For
intravenous
administration, suitable carriers include physiological saline, bacteriostatic
water,
Cremophor ELTM (BASF, Parsippany, N.J.) or phosphate buffered saline (PBS). In
all
cases, a composition for parenteral administration must be sterile and should
be fluid to
the extent that easy syringability exists. It should be stable under the
conditions of
manufacture and storage and must be preserved against the contaminating action
of
microorganisms such as bacteria and fungi.
[0605] The chroman derivative compositions can include a carrier, which can be
a
solvent or dispersion medium containing, for example, water, ethanol, polyol
(for
example, glycerol, propylene glycol, and liquid polyethylene glycol, and the
like), and
suitable mixtures thereof. The proper fluidity can be maintained, for example,
by the use
of a coating such as lecithin, by the maintenance of the required particle
size in the case of
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CA 02920246 2016-02-09
dispersion and by the use of surfactants. Prevention of the action of
microorganisms can
be achieved by various antibacterial and antifungal agents, for example,
parabens,
chlorobutanol, phenol, ascorbic acid, thiomerasol, and the like. Glutathione
and other
antioxidants can be included to prevent oxidation. In some embodiments, the
chroman
derivative compositions include isotonic agents, for example, sugars,
polyalcohols such as
mannitol, sorbitol, or sodium chloride in the composition. Prolonged
absorption of the
injectable compositions can be brought about by including in the composition
an agent
that delays absorption, for example, aluminum monostearate or gelatin.
[0606] Sterile injectable solutions can be prepared by incorporating the
active compound
in the required amount in an appropriate solvent with one or a combination of
ingredients
enumerated above, as required, followed by filtered sterilization. Generally,
dispersions
are prepared by incorporating the active compound into a sterile vehicle,
which contains a
basic dispersion medium and the required other ingredients from those
enumerated above.
In the case of sterile powders for the preparation of sterile injectable
solutions, typical
methods of preparation include vacuum drying and freeze drying, which can
yield a
powder of the active ingredient plus any additional desired ingredient from a
previously
sterile-filtered solution thereof.
[0607] Oral compositions generally include an inert diluent or an edible
carrier. For the
purpose of oral therapeutic administration, the active compound can be
incorporated with
excipients and used in the form of tablets, troches, or capsules, e.g.,
gelatin capsules. Oral
compositions can also be prepared using a fluid carrier for use as a
mouthwash.
Pharmaceutically compatible binding agents, and/or adjuvant materials can be
included as
part of the composition. The tablets, pills, capsules, troches and the like
can contain any
of the following ingredients, or compounds of a similar nature: a binder such
as
microcrystalline cellulose, gum tragacanth or gelatin; an excipient such as
starch or
lactose, a disintegrating agent such as alginic acid, Primogel, or corn
starch; a lubricant
such as magnesium stearate or Sterotes; a glidant such as colloidal silicon
dioxide; a
sweetening agent such as sucrose or saccharin; or a flavoring agent such as
peppermint,
methyl salicylate, or orange flavoring.
[0608] For administration by inhalation, the compounds can be delivered in the
form of
an aerosol spray from a pressurized container or dispenser, which contains a
suitable
propellant, e.g., a gas such as carbon dioxide, or a nebulizer. Such methods
include those
described in U.S. Pat. No. 6,468,798.
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CA 02920246 2016-02-09
[0609] Systemic administration of a therapeutic compound as described herein
can also
be by transmucosal or transdermal means. For transmucosal or transdermal
administration, penetrants appropriate to the barrier to be permeated are used
in the
formulation. Such penetrants are generally known in the art, and include, for
example, for
transmucosal administration, detergents, bile salts, and fusidic acid
derivatives.
Transmucosal administration can be accomplished through the use of nasal
sprays. For
transdermal administration, the active compounds are formulated into
ointments, salves,
gels, or creams as generally known in the art. In one embodiment, transdermal
administration may be performed by iontophoresis.
[0610] A therapeutic chroman derivative can be formulated in a carrier system.
The
carrier can be a colloidal system. The colloidal system can be a liposome, a
phospholipid
bilayer vehicle. In one embodiment, the therapeutic chroman derivative is
encapsulated in
a liposome while maintaining its structural integrity. As one skilled in the
art would
appreciate, there are a variety of methods to prepare liposomes. (See
Lichtenberg, et al.,
Methods Biochem. Anal., 33:337-462 (1988); Anselem, et al., Liposome
Technology, CRC
Press (1993)). Liposomal formulations can delay clearance and increase
cellular uptake
(See Reddy, Ann. Pharmacother., 34(7-8):915-923 (2000)). An active agent can
also be
loaded into a particle prepared from pharmaceutically acceptable ingredients
including,
but not limited to, soluble, insoluble, permeable, impermeable, biodegradable
or
gastroretentive polymers or liposomes. Such particles include, but are not
limited to,
nanoparticles, biodegradable nanoparticles, microparticles, biodegradable
microparticles,
nanospheres, biodegradable nanospheres, microspheres, biodegradable
microspheres,
capsules, emulsions, liposomes, micelles and viral vector systems.
[0611] The carrier can also be a polymer, e.g., a biodegradable, biocompatible
polymer
matrix. In one embodiment, the therapeutic chroman derivative can be embedded
in the
polymer matrix, while maintaining protein integrity. The polymer may be
natural, such as
polysaccharides, or synthetic, such as poly a-hydroxy acids. Examples include
carriers
made of, e.g., collagen, fibronectin, elastin, cellulose acetate, cellulose
nitrate,
polysaccharide, fibrin, gelatin, and combinations thereof. In one embodiment,
the
polymer is poly-lactic acid (PLA) or copoly lactic/glycolic acid (PGLA). The
polymeric
matrices can be prepared and isolated in a variety of forms and sizes,
including
microspheres and nanospheres. Polymer formulations can lead to prolonged
duration of
therapeutic effect. (See Reddy, Ann. Pharmacother., 34(7-8):915-923 (2000)). A
polymer
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CA 02920246 2016-02-09
formulation for human growth hormone (hGH) has been used in clinical trials.
(See
Kozarich and Rich, Chemical Biology, 2:548-552 (1998)).
[0612] Examples of polymer microsphere sustained release formulations are
described in
PCT publication WO 99/15154 (Tracy, et al.), U.S. Pat. Nos. 5,674,534 and
5,716,644
(both to Zale, et al.), PCT publication WO 96/40073 (Zale, et al.), and PCT
publication
WO 00/38651 (Shah, et al.). U.S. Pat. Nos. 5,674,534 and 5,716,644 and PCT
publication
WO 96/40073 describe a polymeric matrix containing particles of erythropoietin
that are
stabilized against aggregation with a salt.
[0613] In some embodiments, the therapeutic compounds are prepared with
carriers that
will protect the therapeutic compounds against rapid elimination from the
body, such as a
controlled release formulation, including implants and microencapsulated
delivery
systems. Biodegradable, biocompatible polymers can be used, such as ethylene
vinyl
acetate, polyanhydrides, polyglycolic acid, collagen, polyorthoesters, and
polylactic acid.
Such formulations can be prepared using known techniques. The materials can
also be
obtained commercially, e.g., from Alza Corporation and Nova Pharmaceuticals,
Inc.
Liposomal suspensions (including liposomes targeted to specific cells with
monoclonal
antibodies to cell-specific antigens) can also be used as pharmaceutically
acceptable
carriers. These can be prepared according to methods known to those skilled in
the art, for
example, as described in U.S. Pat. No. 4,522,811.
[0614] The therapeutic compounds can also be formulated to enhance
intracellular
delivery. For example, liposomal delivery systems are known in the art, see,
e.g., Chonn
and Cullis, "Recent Advances in Liposome Drug Delivery Systems," Current
Opinion in
Biotechnology 6:698-708 (1995); Weiner, "Liposomes for Protein Delivery:
Selecting
Manufacture and Development Processes," Immunomethods, 4(3):201-9 (1994); and
Gregoriadis, "Engineering Liposomes for Drug Delivery: Progress and Problems,"
Trends
Biotechnol., 13(12):527-37 (1995). Mizguchi, et al., Cancer Lett., 100:63-69
(1996),
describes the use of fusogenic liposomes to deliver a protein to cells both in
vivo and in
vitro.
[0615] Dosage, toxicity and therapeutic efficacy of the therapeutic agents can
be
determined by standard pharmaceutical procedures in cell cultures or
experimental
animals, e.g., for determining the LD50 (the dose lethal to 50% of the
population) and the
ED50 (the dose therapeutically effective in 50% of the population). The dose
ratio
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CA 02920246 2016-02-09
between toxic and therapeutic effects is the therapeutic index and it can be
expressed as
the ratio LD50/ED50. Compounds that exhibit high therapeutic indices are
preferred.
While compounds that exhibit toxic side effects may be used, care should be
taken to
design a delivery system that targets such compounds to the site of affected
tissue in order
to minimize potential damage to uninfected cells and, thereby, reduce side
effects.
[0616] The data obtained from the cell culture assays and animal studies can
be used in
formulating a range of dosage for use in humans. In some embodiments, the
dosage of
such compounds lies within a range of circulating concentrations that include
the ED50
with little or no toxicity. The dosage may vary within this range depending
upon the
dosage form employed and the route of administration utilized. For any
compound used in
the methods, the therapeutically effective dose can be estimated initially
from cell culture
assays. A dose can be formulated in animal models to achieve a circulating
plasma
concentration range that includes the IC50 (i.e., the concentration of the
test compound
which achieves a half-maximal inhibition of symptoms) as determined in cell
culture.
Such information can be used to determine useful doses in humans accurately.
Levels in
plasma may be measured, for example, by high performance liquid
chromatography.
[0617] Typically, an effective amount of the chroman derivatives, sufficient
for
achieving a therapeutic or prophylactic effect, ranges from about 0.000001 mg
per
kilogram body weight per day to about 10,000 mg per kilogram body weight per
day.
Suitably, the dosage ranges are from about 0.0001 mg per kilogram body weight
per day
to about 100 mg per kilogram body weight per day. For example dosages can be 1
mg/kg
body weight or 10 mg/kg body weight every day, every two days or every three
days or
within the range of 1-10 mg/kg every week, every two weeks or every three
weeks. In one
embodiment, a single dosage of chroman derivatives ranges from 0.001-10,000
micrograms per kg body weight. In one embodiment, chroman derivative
concentrations
in a carrier range from 0.2 to 2000 micrograms per delivered milliliter. An
exemplary
treatment regime entails administration once per day or once a week. In
therapeutic
applications, a relatively high dosage at relatively short intervals is
sometimes required
until progression of the disease is reduced or terminated, and in certain
embodiments, until
the subject shows partial or complete amelioration of symptoms of disease.
Thereafter,
the patient can be administered a prophylactic regime.
[0618] In some embodiments, a therapeutically effective amount of a chroman
derivative
may be defined as a concentration of a chroman derivative at the target tissue
of 10-12 to
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CA 02920246 2016-02-09
10-6 molar, e.g., approximately 10-7 molar. This concentration may be
delivered by
systemic doses of 0.001 to 100 mg/kg or equivalent dose by body surface area.
In some
embodiments, the schedule of doses would be optimized to maintain the
therapeutic
concentration at the target tissue, by single daily or weekly administration,
but also
including continuous administration (e.g., parenteral infusion or transdermal
application).
[0619] The skilled artisan will appreciate that certain factors may influence
the dosage
and timing required to effectively treat a subject, including but not limited
to, the severity
of the disease or disorder, previous treatments, the general health and/or age
of the subject,
and other diseases present. Moreover, treatment of a subject with a
therapeutically
effective amount of the therapeutic compositions described herein can include
a single
treatment or a series of treatments.
[0620] The mammal treated in accordance present methods can be any mammal,
including, for example, farm animals, such as sheep, pigs, cows, and horses;
pet animals,
such as dogs and cats; laboratory animals, such as rats, mice and rabbits. In
one
embodiment, the mammal is a human.
Combination Therapy with Chroman Derivatives and Other Therapeutic Agents
[0621] In one embodiment, an additional therapeutic agent is administered to a
subject in
combination with a chroman derivative of the present technology, such that a
synergistic
therapeutic effect is produced. In one embodiment, the administration of the
chroman
derivative in combination with an additional therapeutic agent "primes" the
tissue, so that
it is more responsive to the therapeutic effects of one or more therapeutic
agents.
[0622] In any case, the multiple therapeutic agents may be administered in any
order. In
some embodiments, the subject is administered multiple therapeutic agents
simultaneously, separately, or sequentially. If simultaneously, the multiple
therapeutic
agents may be provided in a single, unified form, or in multiple forms (by way
of example
only, either as a single pill or as two separate pills). One of the
therapeutic agents may be
given in multiple doses, or both may be given as multiple doses. If not
simultaneous, the
timing between the multiple doses may vary from more than zero weeks to less
than four
weeks. In some embodiments, the chroman derivative, or a pharmaceutically
acceptable
salt thereof, is administered prior to or subsequent to additional therapeutic
agent. In some
embodiments, the subject is administered the multiple therapeutic agents
before the signs,
symptoms or complications of a disease or condition are evident. In addition,
the
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CA 02920246 2016-02-09
combination methods, compositions and formulations are not to be limited to
the use of
only two agents.
[0623] By way of example, but not by way of limitation, the treatment for
mitochondrial
diseases or disorders typically involves taking vitamins and cofactors. In
addition,
antibiotics, hormones, antineoplastic agents, steroids, immunomodulators,
dermatologic
drugs, antithrombotic, antianemic, and cardiovascular agents, by way of non-
limiting
example, may also be administered.
[0624] In one embodiment, chroman derivatives of the present technology are
combined
with one or more cofactors, vitamins, iron chelators, antioxidants, frataxin
level modifiers,
ACE inhibitors and 13-blockers. By way of example, but not by way of
limitation, such
compounds may include one or more of CoQ10, Levocarnitine, riboflavin, acetyl-
L-
carnitine, thiamine, nicotinamide, vitamin E, vitamin C, lipoic acid,
selenium, 13-carotene,
biotin, folic acid, calcium, magnesium, phosphorous, succinate, selenium,
creatine,
uridine, citratesm prednisone, vitamin K, deferoxamine, deferiprone,
idebenone,
erythropoietin, 1713-estradiol, methylene blue, and histone deacetylase
inhibitors such as
BML-210 and compound 106.
[0625] In some embodiments, chroman derivatives of the present technology can
be
used in combination with a therapeutically effective amount of various anti-
oxidant
compounds including, but not limited to, e.g., parenteral or oral
administration of
compositions comprising glycyrrhizin, schisandra, ascorbic acid, L-
glutathione, silymarin,
lipoic acid, and D-alpha-tocopherol (see U.S. Pat. No. 7,078,064, incorporated
expressly
by reference for all purposes).
[0626] In some embodiments, chroman derivatives of the present technology can
be
used in combination with a therapeutically effective amount of various anti-
oxidant
compounds including, but not limited to, e.g., parenteral or oral
administration of
compositions comprising a water soluble Vitamin E preparation, mixed
carotenoids, or
selenium (see U.S. Pat. No. 6,596,762, incorporated expressly by reference for
all
purposes).
[0627] In some embodiments, chroman derivatives of the present technology can
be
used in combination with a therapeutically effective amount of parenteral or
oral
administration of lecithin or vitamin B complex (see U.S. Pat. Nos. 7,018,652;
6.180,139,
incorporated expressly by reference for all purposes).
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[0628] In some embodiments, chroman derivatives of the present technology can
be
used in combination with a therapeutically effective amount of bile salt
preparations
including, but not limited to, e.g., ursodeoxycholic acid, chenodeoxycholic
acid of other
naturally occurring or synthetic bile acids or bile acid salts (see U.S. Pat.
No. 6.297,229,
incorporated expressly by reference for all purposes).
[0629] In some embodiments, chroman derivatives of the present technology can
be
used in combination with a therapeutically effective amount of a PPAR
(peroxisome
proliferator-activated receptor) activity regulators (see U.S. Pat. No.
7,994,353,
incorporated expressly by reference for all purposes).
[0630] In some embodiments, chroman derivatives of the present technology can
be
used in combination with a therapeutically effective amount of a
benzothiazepine or
benzothiepine compound represented by the following formula having a thioamide
bond
and a quaternary ammonium substituent (see U.S. Pat. No. 7,973.030,
incorporated
expressly by reference for all purposes).
[0631] In some embodiments, chroman derivatives of the present technology can
be
used in combination with a therapeutically effective amount of a
mineralocorticoid
receptor antagonist, for example, but not limited to, spironolactone and
eplerenone.
[0632] In some embodiments, chroman derivatives of the present technology can
be
used in combination with a therapeutically effective amount of a beta-
adrenergic
antagonist (beta-blocker), for example, but not limited to, metoprolol,
bisoprolol,
carvedilol, atenolol, and nebivolol.
[0633] In some embodiments, chroman derivatives of the present technology can
be
used in combination with a therapeutically effective amount of a
axacyclopentane
derivative that inhibits stearoyl-coenzyme alpha delta-9 desaturase (see U.S.
Pat. No.
7,754,745, incorporated expressly by reference for all purposes).
[0634] In some embodiments, chroman derivatives of the present technology can
be
used in combination with a therapeutically effective amount of a acylamide
compound
having secretagogue or inducer activity of adiponectin (see U.S. Pat. No.
7,732,637,
incorporated expressly herein by reference for all purposes).
[0635] In some embodiments, chroman derivatives of the present technology can
be
used in combination with a therapeutically effective amount of quaternary
ammonium
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CA 02920246 2016-02-09
compounds (see U.S. Pat. No. 7,312,208, incorporated expressly by reference
for all
purposes).
[0636] In some embodiments, chroman derivatives of the present technology can
be
used in combination with a therapeutically effective amount of an isof1avone
compound
(see U.S. Pat. No. 6,592,910, incorporated expressly by reference for all
purposes).
[0637] In some embodiments, chroman derivatives of the present technology can
be
used in combination with a therapeutically effective amount of a macrolide
antibiotic (see
U.S. Pat. No. 5,760,010, incorporated expressly by reference for all
purposes).
[0638] In some embodiments, chroman derivatives of the present technology can
be
used in combination with a therapeutically effective amount of carnitine.
[0639] In some embodiments, chroman derivatives of the present technology can
be
used in combination with a therapeutically effective amount of a statin, for
example, but
not limited to, HMG-CoA reductase inhibitors such as atorvastatin and
simvastatin.
[0640] In some embodiments, chroman derivatives of the present technology can
be
used in combination with a therapeutically effective amount of an N-acetyl
cysteine.
[0641] In some embodiments, chroman derivatives of the present technology can
be
used in combination with a therapeutically effective amount of another
galectin inhibitor
that may inhibit a single galectin protein or multiple galectin proteins,
including, but not
limited to, e.g., small organic inhibitors of galectin, monoclonal antibodies,
RNA
inhibitors, or protein inhibitors.
[0642] In some embodiments, chroman derivatives of the present technology can
be
used in combination with a therapeutically effective amount of a monoclonal
antibody to
inhibit lysyl oxidase or monoclonal antibody that binds to connective tissue
growth factor.
[0643] In another embodiment, chroman derivatives of the present technology
can be
used in combination with a therapeutically effective amount of pentraxin
proteins,
including, but not limited to, e.g., recombinant pentraxin-2.
[0644] In another embodiment, chroman derivatives of the present technology
can be
used in combination with a therapeutically effective amount of an angiotensin
receptor
blocker (ARB) or an angiotensin-converting enzyme (ACE) inhibitor.
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CA 02920246 2016-02-09
[0645] In another embodiment, chroman derivatives of the present technology
can be
used in combination with a therapeutically effective amount of a cGMP
activating
compound.
[0646] In another embodiment, chroman derivatives of the present technology
can be
used in combination with a therapeutically effective amount of a calcium
channel blocker,
for example, but not limited to, verapamil.
[0647] In another embodiment, chroman derivatives of the present technology
can be
used in combination with a therapeutically effective amount of a
phosphodiesterase 5
inhibitor, for example, but not limited to, sildenafil, tadalafil, or
vardenafil.
[0648] In some embodiments chroman derivatives of the present technology can
be used
in combination with a therapeutically effective amount of a diuretic.
[0649] In some embodiments, chroman derivatives of the present technology can
be
used in combination with one or more additional agents selected from the group
consisting
of diuretics, ACE inhibitors, digoxin (also called digitalis), calcium channel
blockers, and
beta-blockers. In some embodiments, thiazide diuretics, such as
hydrochlorothiazide at
25-50 mg/day or chlorothiazide at 250-500 mg/day, can be used. However,
supplemental
potassium chloride may be needed, since chronic diuresis causes hypokalemis
alkalosis.
Typical doses of ACE inhibitors include captopril at 25-50 mg/day and
quinapril at 10
mg/day.
[0650] In one embodiment, chroman derivatives of the present technology can be
used in
combination with an adrenergic beta-2 agonist. An "adrenergic beta-2 agonist"
refers to
adrenergic beta-2 agonists and analogues and derivatives thereof, including,
for example,
natural or synthetic functional variants which have adrenergic beta-2 agonist
biological
activity, as well as fragments of an adrenergic beta-2 agonist having
adrenergic beta-2
agonist biological activity. The term "adrenergic beta-2 agonist biological
activity" refers
to activity that mimics the effects of adrenaline and noradrenaline in a
subject and which
improves myocardial contractility in a patient having heart failure. Commonly
known
adrenergic beta-2 agonists include, but are not limited to, e.g., clenbuterol,
albuterol,
formeoterol, levalbuterol, metaproterenol, pirbuterol, salmeterol, and
terbutaline.
[0651] In one embodiment, chroman derivatives of the present technology can be
used in
combination with an adrenergic beta-1 antagonist. Adrenergic beta-1
antagonists and
adrenergic beta-1 blockers refer to adrenergic beta-1 antagonists and
analogues and
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CA 02920246 2016-02-09
derivatives thereof, including, for example, natural or synthetic functional
variants which
have adrenergic beta-1 antagonist biological activity, as well as fragments of
an adrenergic
beta-1 antagonist having adrenergic beta-1 antagonist biological activity.
Adrenergic beta-
1 antagonist biological activity refers to activity that blocks the effects of
adrenaline on
beta receptors. Commonly known adrenergic beta-1 antagonists include, but are
not
limited to, acebutolol, atenolol, betaxolol, bisoprolol, esmolol, and
metoprolol.
[0652] Clenbuterol, for example, is available under numerous brand names
including
Spiropent (Boehinger Ingelheim), Broncodil0 (Von Boch I), Broncoterol
(Quimedical
PT), Cesbron (Fidelis PT), and Clenbuter (Biomedica Foscama). Similarly,
methods
of preparing adrenergic beta-1 antagonists such as metoprolol and their
analogues and
derivatives are well-known in the art. Metoprolol, in particular, is
commercially available
under the brand names Lopressor (metoprolol tartate) manufactured by Novartis

Pharmaceuticals Corporation, One Health Plaza, East Hanover, N.J. 07936-1080.
Generic
versions of Lopressor are also available from Mylan Laboratories Inc., 1500
Corporate
Drive, Suite 400, Canonsburg, Pa. 15317; and Watson Pharmaceuticals, Inc., 360
Mt.
Kemble Ave. Morristown, N.J. 07962. Metoprolol is also commercially available
under
the brand name Toprol XL , manufactured by Astra Zeneca, LP.
[0653] In one embodiment, chroman derivatives of the present technology may be

combined with one or more additional therapies for the prevention or treatment
of
porphyria. Treatment for acute attacks of hepatic porphyria typically
comprise, but are not
limited to, the use of narcotic analgesics (e.g., for abdominal pain),
phenothiazines (e.g.,
for nausea, vomiting, anxiety, and restlessness), chloral hydrate (e.g., for
insomnia), short-
acting benzodiazepines (e.g., for insomnia), carbohydrate loading, intravenous
hemin (e.g.,
lyophilized hematin, heme albumin, and heme arginate), allogenic liver
transplantation,
and liver-directed gene therapy. Treatment for porphyria cutanea tarda
typically
comprises, but is not limited to, discontinuing risk factors (e.g., alcohol,
estrogens, iron
supplements), phlebotomy, and low-dose regimens of chloroquine or
hydroxychloroquine.
Treatment for erythropoietic cutaneous porphyrias typically comprise, but is
not limited to,
chronic transfusions (e.g., for anemia), protection from sunlight, treatment
of complicating
bacterial infections, and bone marrow and cord blood transplantation.
Treatment for EPP
and XLP typically comprise, but is not limited to, sunlight avoidance, oral I3-
carotene,
administration of an a-melanocyte stimulating hormone analog, administration
of
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CA 02920246 2016-02-09
cholestyramine and other porphyrin absorbents (e.g., activated charcoal),
plasmapheresis,
intravenous hemin, and liver transplantation.
[0654] In some embodiments, the chroman derivative is administered in
combination
with one or more narcotic analgesics, phenothiazines, chloral hydrate,
benzodiazepines,
hemin, chloroquine, hydroxychloroquine, 13-carotene, a-melanocyte stimulating
hormone,
cholestyramine, or activated charcoal, such that a synergistic effect in the
prevention or
treatment of porphyria results.
[0655] In one embodiment, chroman derivatives of the present technology may be

combined with one or more additional therapies for the prevention or treatment
of Alport
Syndrome. Treatment for Alport Syndrome typically comprises, but are not
limited to, the
use of ACE inhibitors, ARBs, HMG-CoA reductase inhibitors, aldosterone
inhibitors,
aliskiren, calcineurin inhibitors (e.g., cyclosporine A, tacrolimus),
endothelin receptor
antagonists (e.g., sitaxentan, ambrisentan (LETAIRIS), atrasentan, BQ-123,
zibotentan,
bosentan (TRACLEER), macitentan, tezosentan, BQ-788 and A192621), sulodexide,
vasopeptidase inhibitors (e.g., AVE7688), anti-transforming growth factor-131
antibody,
chemokine receptor 1 blockers, bone morphogenetic protein-7, PPARy agonists
(e.g., rosiglitazone, pioglitazone, MRL24, Fmoc-L -Leu, 5R1664, SR1824,
GW0072,
MCC555, CLX-0921, PAT5A, L-764406, nTZDpa, CDDO (2-cyano-3,12-dioxooleana-
1,9-dien-28-oic acid), ragaglitazar, 0-arylmandelic acids, and NSAIDs) and BAY-
12-
9566.
[0656] In some embodiments, the ACE inhibitors are selected from the group
consisting
of captopril, alacepril, lisinopril, imidapril, quinapril, temocapril,
delapril, benazepril,
cilazapril, trandolapril, enalapril, ceronapril, fosinopril, imadapril,
mobertpril, perindopril,
ramipril, spirapril, randolapril and pharmaceutically acceptable salts of such
compounds.
[0657] In some embodiments, the ARBs are selected from the group consisting of

losartan, candesartan, valsartan, eprosartan, telmisartan, and irbesartan.
[0658] In some embodiments, the HMG-CoA reductase inhibitors (or statins) are
selected from the group consisting of lovastatin (e.g., ADVICOR (niacin
extended-
release/lovastatin) (AbbVie Pharmaceuticals, Chicago, Illinois), ALTOPREVTm
(lovastatin extended-release) (Shiongi, Inc., Atlanta, GA), MEVACOR (Merck,
Whitehouse Station, NJ), atorvastatin (e.g., CADUET (amlodipine and
atorvastatin)
(Pfizer, Morrisville, PA), LIPITOR (Pfizer, Morrisville, PA)), rosuvastatin
and/or
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rosuvastatin calcium (e.g., CRESTOR (AstraZeneca, London, England)),
simvastatin
(e.g., JUVISYNC (sitagliptin/simvastatin) (Merck, Whitehouse Station, NJ)),
SIMCOR
(niacin extended-release/simvastatin) (AbbVie Pharmaceuticals, Chicago,
Illinois),
VYTORIN (ezetimibe/simvastatin) (Merck, Whitehouse Station, NJ), and ZOCOR
(Merck, Whitehouse Station, NJ)), fluvastatin and/or fluvastatin sodium (e.g.,
LESCOL ,
LESCOL XL (fluvastatin extended-release) (Mylan Pharmaceuticals, Morgantown,
WV)),
pitavastatin (e.g., LIVALO (Kowa Pharmaceuticals, Montgomery, AL)),
pravastatin and
pravastatin sodium (e.g., PRAVACHOL (Bristol-Myers Squibb, New York, NY)).
[0659] In some embodiments, the aldosterone inhibitors are selected from the
group
consisting of spironolactone (Aldactone ), eplerenone (Inspra ), canrenone
(canrenoate
potassium), prorenone (prorenoate potassium), and mexrenone (mexrenoate
potassium).
[0660] In some embodiments, the chroman derivative is administered in
combination
with one or more ACE inhibitors, ARBs, HMG-CoA reductase inhibitors,
aldosterone
inhibitors, aliskiren, calcineurin inhibitors (e.g., cyclosporine A,
tacrolimus), endothelin
receptor antagonists (e.g., sitaxentan, ambrisentan (LETAIRIS), atrasentan, BQ-
123,
zibotentan, bosentan (TRACLEER), macitentan, tezosentan, BQ-788 and A192621),
sulodexide, vasopeptidase inhibitors (e.g., AVE7688), anti-transforming growth
factor-r31
antibody, chemokine receptor 1 blockers, bone morphogenetic protein-7, PPARy
agonists
(e.g., rosiglitazone, pioglitazone, MRL24, Fmoc-L -Leu, SR1664, 5R1824,
GW0072,
MCC555, CLX-0921, PAT5A, L-764406, nTZDpa, CDDO (2-cyano-3,12-dioxooleana-
1,9-dien-28-oic acid), ragaglitazar, 0-arylmandelic acids, and NSAIDs) and/or
BAY-12-
9566, such that a synergistic effect in the prevention or treatment of Alport
Syndrome
results.
[0661] In one embodiment, chroman derivatives of the present technology may be

combined with one or more additional therapies for the prevention or treatment
of vitiligo.
Treatment for vitiligo typically comprises, but is not limited to, the use of
topical steroid
creams, monobenzone, antibiotics, vitamins, hormones, immunomodulators,
dermatologic
drugs, or administering psoralen photochemotherapy. In some embodiments, the
chroman
derivative is administered in combination with one or more topical steroid
creams,
monobenzone, antibiotics, vitamins, hormones, immunomodulators, dermatologic
drugs,
psoralen photochemotherapy, such that a synergistic effect in the prevention
or treatment
of vitiligo results.
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[0662] In one embodiment, chroman derivatives of the present technology may be

combined with one or more additional therapies for the prevention or treatment
of 1PF.
Additional therapies include, but are not limited to, oral corticosteroids,
azathioprine, N-
acetylcysteine, soluble human TNF receptor, interferon-y lb therapy,
endothelin receptor
antagonists, phosphodiesterase inhibitors, tyrosine kinase inhibitors,
antifibrotic agents,
colchicine, and anticoagulants.
EXAMPLES
[0663] The present technology is further illustrated by the following
examples, which
should not be construed as limiting in any way.
Example 1 ¨ Use of Chroman Derivatives in the Treatment of Porphyria
[0664] This Example demonstrates the use of chroman derivatives, or
pharmaceutically
acceptable salts thereof, in the treatment of porphyria.
[0665] Subjects suspected of having or diagnosed as having porphyria receive
daily
administrations of a therapeutically effective amount of a chroman derivative,
or a
pharmaceutically acceptable salt thereof, alone or in combination with one or
more
additional agents for the treatment or prevention of porphyria. Chroman
derivatives
and/or additional agents are administered orally, intranasally, intrathecally,
intraocularly,
intradermally, transmucosally, iontophoretically, topically, systemically,
intravenously,
subcutaneously, intraperitoneally, or intramuscularly according to methods
known in the
art. Subjects will be evaluated weekly for the presence and/or severity of
signs and
symptoms associated with porphyria, including, but not limited to, e.g.,
cutaneous lesions,
blistering skin lesions, hypertrichosis, hyperpigmentation, thickening and/or
scarring of
the skin, friability of the skin, photosensitivity of the skin,
lichenification, leathery
pseudovesicles, labial grooving, nail changes, life threatening acute
neurological attacks,
abdominal pain and cramping, constipation, diarrhea, increased bowel sounds,
decreased
bowel sounds, nausea, vomiting, tachycardia, hypertension, headache, mental
symptoms,
extremity pain, neck pain, chest pain, muscle weakness, sensory loss, tremors,
sweating,
dysuria, and bladder distension. Treatments are maintained until such a time
as one or
more signs or symptoms of porphyria are ameliorated or eliminated.
[0666] It is predicted that subjects suspected of having or diagnosed as
having porphyria
and receiving therapeutically effective amounts of a chroman derivative, or a
pharmaceutically acceptable salt thereof, will display reduced severity or
elimination of
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CA 02920246 2016-02-09
one or more symptoms associated with porphyria. It is further expected that
administration of chroman derivatives in combination with one or more
additional agents
will have synergistic effects in this regard.
[0667] These results will show that chroman derivatives, or pharmaceutically
acceptable
salts thereof, are useful in the treatment of porphyria. Accordingly, the
chroman
derivatives are useful in methods comprising administering chroman derivatives
to a
subject in need thereof for the treatment of porphyria.
Example 2 ¨ Use of Chroman Derivatives in the Prevention of Porphyria
[0668] This Example demonstrates the use of chroman derivatives or
pharmaceutically
acceptable salts thereof, in the prevention of porphyria.
[0669] Subjects at risk of having porphyria receive daily administrations of a

therapeutically effective amount of chroman derivatives, or pharmaceutically
acceptable
salts thereof, alone or in combination with one or more additional agents for
the treatment
or prevention of porphyria. Chroman derivatives and/or additional agents are
administered orally, intranasally, intrathecally, intraocularly,
intradermally,
transmucosally, iontophoretically, topically, systemically, intravenously,
subcutaneously,
intraperitoneally, or intramuscularly according to methods known in the art.
Subjects will
be evaluated weekly for the presence and/or severity of signs and symptoms
associated
with porphyria, including, but not limited to, e.g., cutaneous lesions,
blistering skin
lesions, hypertrichosis, hyperpigmentation, thickening and/or scarring of the
skin,
friability of the skin, photosensitivity of the skin, lichenification,
leathery pseudovesicles,
labial grooving, nail changes, life threatening acute neurological attacks,
abdominal pain
and cramping, constipation, diarrhea, increased bowel sounds, decreased bowel
sounds,
nausea, vomiting, tachycardia, hypertension, headache, mental symptoms,
extremity pain,
neck pain, chest pain, muscle weakness, sensory loss, tremors, sweating,
dysuria, and
bladder distension.
[0670] It is predicted that subjects at risk of having or diagnosed as having
porphyria
and receiving therapeutically effective amounts of a chroman derivative, or a
pharmaceutically acceptable salt thereof, will display delayed onset of
porphyria, or
prevention of onset of porphyria. It is further expected that administration
of chroman
derivatives in combination with one or more additional agents will have
synergistic effects
in this regard.
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CA 02920246 2016-02-09
[0671] These results will show that chroman derivatives or pharmaceutically
acceptable
salts thereof, are useful in the prevention of porphyria. Accordingly, the
chroman
derivatives are useful in methods comprising administering chroman derivatives
to a
subject in need thereof for the prevention of porphyria.
Example 3 ¨ Use of Chroman Derivatives in Treating IPF
[0672] TGF-,81-adenovirus induced lung fibrosis: TGF-131 adenovirus (Ad-TGF-
131) or
control virus (Ad-DL) is prepared and treated as previously described in Sime
et al., J ClM
Invest 100:768-776 (1997). Ad-TGF-131 refers to porcine TGF-131 adenovirus (Ad-

TGF13 1223/225), an adenovirus construct containing a mutation of cysteine to
serine at
positions 223 and 225, rendering the expressed TGF-131 biologically active.
This virus
expresses active TGF-131 in the lung over a period of 7 to 14 days and
produces extensive
and progressive fibrosis in rats and mice. C57/B6 mice will receive 2 x 108
PFU virus in
50 [IL sterile saline intratracheally and will be treated with saline; or a
chroman derivative.
Mice are culled 5 or 14 days post instillation.
[0673] Determination of lung fibrosis and inflammation: Collagen content in
the left
lung is determined by sircol assay as per manufacturer's instructions.
Histological lung
inflammation and fibrosis score is carried out in Masson's trichrome stained
sections.
[0674] Isolation of murine primary lung fibroblasts and primary type II
alveolar
epithelial cells: Primary cultures of lung fibroblasts are isolated by
collagenase digestion
(0.5 mg/ml for 1 hour at 37 C) of minced lungs and digests passed through a
100- m cell
strainer. Cells are cultured in DMEM containing 10% FCS for 4 days until
confluent.
Lung fibroblasts are used at passage 2. Lung alveolar epithelial cells (AECs)
are extracted
following the method originally described by Corti et al., Am J Respir Cell
Mol Biol
14:309-315 (1996). Immunofluorescence is carried out using the following
primary
antibodies: mouse monoclonal anti-a-SMA clone 1A4 (Sigma, Poole, UK), rabbit
anti-
mouse collagen 1 and mouse anti-active (ABC) 13-catenin (Millipore).
[0675] Results: It is expected that intratracheal administration of adenoviral
TGF-131
(Ad-TGF-131) in saline-treated mice will stimulate the formation of fibroblast
foci,
whereas mice treated with the Ad-DL control virus will not exhibit pulmonary
fibrosis.
Additionally, AECs from saline-treated Ad-TGF-131 mice will show an increase
in a-SMA
and collagen-1 expression levels compared to that observed in AECs isolated
from Ad-DL
infected mice. It is also anticipated that Ad-TGF- 131 mice treated with the
chroman
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derivatives will show a decrease in lung fibrosis and/or reduced collagen-1
and a-SMA
levels compared to Ad-TGF-I31 mice treated with saline only.
[0676] These results will show that chroman derivatives of the present
technology are
useful in treating IPF in mammalian subjects.
Example 4 ¨ Use of Chroman Derivatives to Reduce Tumor Growth
[0677] This Example will demonstrate use of the chroman derivatives of the
present
technology to reduce the growth rate of implanted tumors.
[0678] A standard panel of 12 tumor cell lines will be used for the hollow
fiber
screening of the chroman derivatives. These include NCI-H23, NCI-H522, MDA-MB-
231, MDA-MB-435, SW-620, COLO 205, LOX, UACC-62, OVCAR-3, OVCAR-5, U251
and SF-295. The cell lines are cultivated in RPMI-1640 containing 10% FBS and
2 mM
glutamine. On the day preceding hollow fiber preparation, the cells are given
a
supplementation of fresh medium to maintain log phase growth. For fiber
preparation, the
cells are harvested by standard trypsinization technique and resuspended at
the desired cell
density (2-10 x 106 cells/mL). The cell suspension is then flushed into 1 mm
(internal
diameter) polyvinylidene fluoride hollow fibers with a molecular weight
exclusion of
500,000 Da. The hollow fibers are heat-sealed at 2 cm intervals and the
samples generated
from these seals are placed into tissue culture medium and incubated at 37 in
5% CO2 for
24-48 hours prior to implantation. A total of 3 different tumor lines are
prepared for each
experiment so that each mouse receives 3 intraperitoneal implants (1 of each
tumor line)
and 3 subcutaneous implants (1 of each tumor line). On the day of
implantation, samples
of each tumor cell line preparation are quantitated for viable cell mass by a
stable endpoint
MTT assay so that the time zero cell mass is known. Mice are treated with
vehicle or
chroman derivatives starting on day 3 or 4 following fiber implantation and
continuing
daily for 4 days. Control animals receive the tumor implants and are treated
with only the
empty vehicle. The therapeutic compositions are administered by
intraperitoneal injection
at 2 dose levels. The doses are based on the maximum tolerated dose (MTD)
determined
during prior toxicity testing. The fibers are collected from the mice on the
day following
the fourth compound treatment and subjected to the stable endpoint MTT assay.
The
optical density of each implanted tumor sample is determined
spectrophotometrically at
540 nm and the mean of each treatment group is calculated. The percent net
growth for
each cell line in each treatment group is calculated and compared to the
percent net growth
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in the vehicle treated controls. A 50% or greater reduction in percent net
growth in the
treated samples compared to the vehicle control samples is considered a
positive result.
Each positive result is given a score of 2 and all of the scores are totaled
for a given
chroman derivative. The maximum possible score for an agent is 96 (12 cell
lines X 2
sites X 2 dose levels X 2 [score]). A compound is considered for xenograft
testing if it has
a combined ip + sc score of 20 or greater, a sc score of 8 or greater, or
produces cell kill of
any cell line at either dose level evaluated.
[0679] Results: It is expected that vehicle treated controls will show an
increase in tumor
net growth after 4 days. It is also anticipated that treatment with the
chroman derivatives
will result in significantly reduced tumor net growth compared to vehicle
treated controls.
[0680] These results will show that the chroman derivatives of the present
technology
are useful in methods for reducing tumor growth in mammalian subjects. The
results will
show that the chroman derivatives of the present technology are generally
useful in
treating a neoplastic disease.
Example 5 ¨ Chroman Derivatives Inhibit HUVEC Cell Migration
[0681] Chemotaxis is an integral part of angiogenesis, and this Example
demonstrates
the effect of chroman derivatives of the present technology in inhibiting
angiogenesis.
[0682] In the first portion of the experimental series, the effect of the
chemoattractant
vascular endothelial growth factor (VEGF) on human umbilical vein endothelial
cells
(HUVEC) is quantified. The experiment is carried out in a transwell plate, and
in
preparation therefor, HUVEC cells are grown to approximately 80% confluency.
The
cells are suspended in basal media and placed in a transwell plate on
fibronectin coated
membrane inserts at 50,000 cells per insert. Varying concentrations of VEGF
are added to
the bottom chamber of the transwell plate, and the plates are incubated for 4
hours at 37 C
with a 5% CO2 atmosphere. Following incubation, the membranes are fixed and
stained.
Nonmigrated cells are removed by mechanical abrasion and cells that migrate
through the
membrane are counted.
[0683] It is anticipated that VEGF will act as a chemotactic agent that
induces cell
migration, a process that is crucial to angiogenesis. Specifically, it is
expected that certain
VEGF concentrations will produce a strong chemotactic effect.
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[0684] In the second portion of the experiment, the effect of chroman
derivatives in
moderating chemotaxis, and hence angiogenesis, will be evaluated.
[0685] In this experimental series, HUVEC cells are incubated in a transwell
plate with
30 ng/ml VEGF, and varying concentrations of the chroman derivatives, under
experimental conditions as described above. Group A cells will be incubated
with VEGF
only (positive control); Group B cells will be incubated with VEGF and a
chroman
derivative; Group C will be incubated with VEGF-deficient growth medium only
(negative control).
[0686] It is anticipated that cells incubated with VEGF alone will show an
increase in
cell migration compared to cells incubated with VEGF-deficient growth medium.
It is
also anticipated that the cells treated with chroman derivatives will show a
decrease in
VEGF-mediated cell migration compared to the Group A positive control cells.
[0687] These results will show that chroman derivatives of the present
technology are
useful as potent inhibitors of the angiogenic process, and as such will have
utility in the
treatment of diseases in which angiogenesis is a factor.
Example 6 ¨ Therapeutic Effects of Chroman Derivatives on 4-tertiary Butyl
Phenol (4-
TBP)-induced Cytotoxicity and Apoptosis in Melanocytes
[0688] This Example will demonstrate the therapeutic effect of chroman
derivatives on
4-TBP-induced vitiligo.
[0689] Melanocytes are cultured and treated with 4-TBP to induce vitiligo
according to
the procedures described in Yang & Boissy, Pigment Cell Research, 12:237-245
(1999).
The experimental group of melanocytes is treated with 1-10 Fig of chroman
derivatives
after exposure to 4-TBP. The control melanocyte group is exposed to 4-TBP
only.
[0690] It is anticipated that untreated melanocytes will exhibit high levels
of cytotoxicity
and apoptosis following exposure to 4-TBP (Vitiligo control) compared to
melanocytes
that are not exposed to 4-TBP (Normal). However, it is anticipated that
melanocytes
treated with chroman derivatives will show cell survival rates that are
similar to normal
melanocytes that are not exposed to 4-TBP and greater than untreated
melanocytes
following 4-TBP exposure.
[0691] These results will show that chroman derivatives of the present
technology, or
pharmaceutically acceptable salts thereof, are useful in treating apoptosis
and cytotoxicity
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associated with chemically-induced vitiligo. Accordingly, the chroman
derivatives of the
present technology, are useful in treating, or ameliorating melanocyte
degeneration and
depigmentation observed in a subject suffering from or predisposed to
vitiligo.
Example 7 ¨ Use of Chroman Derivatives in the Treatment of Alport Syndrome in

Humans
[0692] This Example demonstrates the use of chroman derivatives, or
pharmaceutically
acceptable salts thereof, in the treatment of Alport Syndrome.
[0693] Subjects suspected of having or diagnosed as having Alport Syndrome
receive
daily administrations of 1%, 5% or 10% solution of chroman derivatives, or
pharmaceutically acceptable salts thereof, alone or in combination with one or
more
additional agents for the treatment or prevention of Alport Syndrome. Chroman
derivatives and/or additional agents are administered orally, intranasally,
intrathecally,
intraocularly, intradermally, transmucosally, iontophoretically, topically,
systemically,
intravenously, subcutaneously, intraperitoneally, or intramuscularly according
to methods
known in the art. Subjects will be evaluated weekly for the presence and/or
severity of
signs and symptoms associated with Alport Syndrome, including, but not limited
to, e.g.,
hematuria, proteinuria, cylindruria, leukocyturia, hypertension, edema,
microalbuminuria,
declining glomerular filtration rate, fibrosis, Glomerular Basement Membrane
(GBM)
ultrastructural abnormalities, nephrotic syndrome, glomerulonephritis, end-
stage kidney
disease, chronic anemia, macrothrombocytopenia, osteodystrophy, sensorineural
deafness,
anterior lenticonus, dot-and-fleck retinopathy, posterior polymorphous corneal
dystrophy,
recurrent corneal erosion, temporal macular thinning, cataracts, lacrimation,
photophobia,
vision loss, keratoconus, and leiomyomatosis. Treatments are maintained until
such a time
as one or more signs or symptoms of Alport Syndrome are ameliorated or
eliminated.
[0694] It is predicted that subjects suspected of having or diagnosed as
having Alport
Syndrome and receiving therapeutically effective amounts of chroman
derivatives, or
pharmaceutically acceptable salts thereof, will display reduced severity or
elimination of
one or more symptoms associated with Alport Syndrome. It is also expected that
Alport
Syndrome subjects treated with the chroman derivatives will show normalization
of one or
more of ADAM8, fibronectin, myosin 10, MMP-2, MMP-9, and podocin urine levels
by at
least 10% compared to the untreated Alport Syndrome controls. It is further
expected that
administration of chroman derivatives in combination with one or more
additional agents
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will have synergistic effects in this regard compared to that observed in
subjects treated
with the chroman derivatives or the additional agents alone.
[0695] These results will show that chroman derivatives, or pharmaceutically
acceptable
salts thereof, are useful in the treatment of Alport Syndrome. These results
will show that
chroman derivatives, or pharmaceutically acceptable salts thereof, are useful
in
ameliorating one or more of the following symptoms: hematuria, proteinuria,
cylindruria,
leukocyturia, hypertension, edema, microalbuminuria, declining glomerular
filtration rate,
fibrosis, GBM ultrastructural abnormalities, nephrotic syndrome,
glomerulonephritis, end-
stage kidney disease, chronic anemia, macrothrombocytopenia, osteodystrophy,
sensorineural deafness, anterior lenticonus, dot-and-fleck retinopathy,
posterior
polymorphous corneal dystrophy, recurrent corneal erosion, temporal macular
thinning,
cataracts, lacrimation, photophobia, vision loss, keratoconus, and
leiomyomatosis.
Accordingly, the chroman derivatives are useful in methods comprising
administering
chroman derivatives to a subject in need thereof for the treatment of Alport
Syndrome.
Example 8 ¨ Use of Chroman Derivatives in the Prevention of Leber's Hereditary
Optic
Neuropathy (LHON) in a Mouse Model
[0696] This Example will demonstrate the use of chroman derivatives in the
prevention
of Leber's Hereditary Optic Neuropathy in a mouse model.
[0697] Marine Model. This Example uses the murine model of LHON previously
described by Lin et al., Proc. Natl. Acad. Sci. 109(49):20065-20070 (2012).
The animals
harbor an ND6 P25L mutation. The LT13 cell line corresponds to the ND6 P25L
mutant
fibroblast line used for mouse embryonic stem cell fusions.
[0698] Mice harboring the ND6 P25L mutation are administered 1-10 [tg of
chroman
derivatives, or saline vehicle (control) subcutaneously once daily from 0-14
months of
age. Various aspects of LHON are assessed in treatment and control animals at
14 and 24
months of age, with the ND6 P25L compared to wild-type mice for each parameter

measured.
[0699] It is expected that administration of chroman derivatives once daily
from 0-14
months of age will prevent the onset of, delay the onset of, and/or reduce the
severity of
the effects of the ND6 P25L mutation, thereby preventing LHON in ND6 P25L
mutant
mice.
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[0700] Reduced Retinal Response. The ND6 P25L mice are examined for ocular
function by electroretinogram beginning at 14 months of age. It is expected
that the
animals will show a significant deficit in nearly all parameters examined. The
scotopic B
wave of dark-adapted ND6 P25L eyes is expected to be reduced in amplitude by
approximately 25.5% and approximately 33.1% with 0.01 and 1 cd=s/m2 (maximum)
stimulations. The scotopic A-wave of ND6 P25L mutant eyes is expected to show
approximately a 23% reduction. The scotopic oscillatory potentials (OPs), a
high-
frequency response derived from multiple retinal cell types, are expected to
show
approximately a 20.7% and approximately a 21.7% reduction with 0.01 and 1
cd=s/m2
stimulations. Photopic B-wave ERG amplitude, measuring cone functions, is
expected to
be decreased approximately 17.7%. There is further expected a trend toward
increased
latencies to the A and B waves. Despite the functional deficit observed in the
ERGs, it is
expected that the ND6 P25L mutants will not exhibit reduced visual responses,
as assessed
by optokinetic analysis.
[0701] It is expected that administration of chroman derivatives once daily
from 0-14
months of age will prevent the onset of, delay the onset of, and/or reduce the
severity of
these effects of the ND6 P25L mutation, thereby preventing these aspects of
LHON in
ND6 P25L mutant mice.
[0702] RGC Axonal Swelling and Preferential Loss of Smallest Fibers. Electron
microscopic analysis of RGC axons is expected to reveal that ND6 P25L mutants
exhibit
axonal swelling in the optic nerve. The average axonal diameter is expected to
be
approximately 0.67 tm in wild-type and approximately 0.80 lam in ND6 P25L
mutant 14-
month-old mice, and approximately 0.73 vin in wild-type and approximately 0.85
!Ern in
ND6 P25L mutant mice at 24 months of age. Fourteen-month-old ND6 P25L mutant
mice
are expected to have an increased number of large fibers but fewer small
axonal fibers
(Ø5 [1m). The change in axonal diameters is expected to be more pronounced
in 24-
month-old ND6 P25L mice. Hence, ND6 P25L mice are expected to have fewer small
and
medium axons (Ø8 [tm) and more swollen axonal fibers with diameters larger
than 1 !am.
This effect is expected to be the most severe in the area of the smallest
fibers in the central
and temporal regions of the mouse optic nerve, which corresponds to the human
temporal
region most affected in LHON.
[0703] Quantification of the number of axons in the optic nerves is expected
to reveal no
significant difference in the total counts at 14 months of age, and
approximately a 30%
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CA 02920246 2016-02-09
reduction at 24 months of age. Thus, the observed shift toward larger axons is
predicted to
be attributable initially (14 months) to swelling of medium axons, and later
(24 months),
to the loss of small axons.
[0704] It is expected that administration of chroman derivatives once daily
from 0-14
months of age will prevent the onset of, delay the onset of, or reduce the
severity of these
effects in ND6 P25L mutant animals, thereby preventing these aspects of LHON.
[0705] Abnormal Mitochondrial Morphology and Proliferation in RGC Axons.
Mitochondria in the optic tracts of the ND6 P25L mutants are expected to be
abnormal and
increased in number, consistent with the compensatory mitochondrial
proliferation
observed in LHON patients. The optic tract axons of 14-month-old ND6 P25L mice
are
expected to have approximately a 58% increase in mitochondria, with 24-month-
old
animals having approximately a 94% increase. The ND6 P25L mitochondria are
expected
to appear hollowed with irregular cristae, with approximately 31.5% more of
the ND6
P25L mitochondria being abnormal at 14 months and approximately 56% more at 24

months of age. Axons filled with abnormal mitochondria are expected to
demonstrate
marked thinning of the myelin sheath.
[0706] It is expected that administration of chroman derivatives once daily
from 0-14
months of age will prevent the onset of, delay the onset of, or reduce the
severity of these
effects in ND6 P25L mutant animals, thereby preventing these aspects of LHON.
[0707] Altered Liver Mitochondria Complex I Activity. The complex I activity
of the
ND6 P25L mice is assayed in liver mitochondria. Results are expected to
demonstrate that
rotenone-sensitive NADH:ubiquinone oxidoreductase activity is decreased by
approximately 29%, which is equivalent to the reduction seen in the LT13 cell
line. It is
expected that the decrease in activity will not be attributable to a lower
abundance of
complex I, as it is expected that the NADH:ferricyanide oxidoreductase will be
unaltered
in the ND6 mutant mice. It is further expected that the ND6 mutation will
cause
approximately a 25% decrease in mitochondrial oxygen consumption, also seen in
the
LT13 cell line.
[0708] It is expected that administration of chroman derivatives once daily
from 0-14
months of age will prevent the onset of, delay the onset of, or reduce the
severity of these
effects in ND6 P25L mutant animals, thereby preventing these aspects of LHON.
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[0709] These results will show that chroman derivatives of the present
technology, are
useful for preventing the onset of, delaying the onset of, and/or reducing the
severity of the
symptoms of LHON in a mammalian subject. As such, chroman derivatives of the
present
technology are useful in methods for preventing LHON in a mammalian subject.
Example 9 ¨ Use of Chroman Derivatives in Treating Friedreich's Ataxia in in
vitro Cell
Culture
[0710] This Example will demonstrate the use of chroman derivatives of the
present
technology in the treatment of Friedreich's Ataxia in a cell culture model of
the disease.
[0711] Cell line model. This Example uses human dermal fibroblasts derived
from
Friedreich's Ataxia patients previously described by Jauslin et al., Hum. Mol.
Genet.
11(24):3055 (2002).
[0712] Fibroblasts from Friedreich's Ataxia (FRDA) patients have been shown to
be
hypersensitive to L-buthionine-(S,R)-sulfoximine (BSO), a specific inhibitor
of GSH
synthetase. Jauslin et al., Hum. Mol. Genet. 11(24):3055 (2002), Jauslin et
al., FASEB J.
17:1972-4 (2003), and International Patent Application WO 2004/003565. The
therapeutic efficacy of a compound can be assessed by assaying its ability to
suppress
BSO-mediated cell death in FRDA fibroblasts.
[0713] FRDA fibroblasts and fibroblasts from normal subjects are seeded in
microtiter
plates at a density of 4000 cells per 100 iL in growth medium consisting of
25% (v/v)
M199 EBS and 64% (v/v) MEM EBS without phenol red (Bioconcept, Allschwil,
Switzerland) supplemented with 10% (v/v) fetal calf serum (PAA Laboratories,
Linz,
Austria), 100 U/mL penicillin, 100 [ig/mL streptomycin (PAA Laboratories,
Linz,
Austria), 10 [ig/mL insulin (Sigma, Buchs, Switzerland), 10 ng/mL EGF (Sigma,
Buchs,
Switzerland), 10 ng/mL bFGF (PreproTech, Rocky Hill, NJ, USA) and 2 mM
glutamine
(Sigma, Buchs, Switzerland).
[0714] The test samples are supplied in 1.5 ml glass vials. The chroman
derivatives are
diluted with DMSO, ethanol or PBS to result in a 5 mM stock solution. Once
dissolved,
they are stored at ¨20 C. Reference antioxidants (Idebenone, decylubiquinone,
a-
tocopherol acetate and trolox) are dissolved in DMSO.
[0715] Test samples are screened according to the following protocol:
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[0716] A culture with FRDA fibroblasts is started from a 1 ml vial with
approximately
500,000 cells stored in liquid nitrogen. Cells are propagated in 10 cm cell
culture dishes
by splitting every third day in a ratio of 1:3 until nine plates are
available. Once confluent,
fibroblasts are harvested. For 54 micro titer plates (96 well-MTP) a total of
14.3 million
cells (passage eight) are re-suspended in 480 ml medium, corresponding to 100
I medium
with 3,000 cells/well. The remaining cells are distributed in 10 cm cell
culture plates
(500,000 cells/plate) for propagation. The plates are incubated overnight at
37 C. in an
atmosphere with 95% humidity and 5% CO2 to allow attachment of the cells to
the culture
plate.
[0717] MTP medium (243 IA) is added to a well of the microtiter plate. The
chroman
derivatives are thawed, and 7.5 ill of a 5 mM stock solution is dissolved in
the well
containing 243 pi medium, resulting in a 150 M master solution. Serial
dilutions from
the master solution are made. The period between the single dilution steps is
kept as short
as possible (generally less than 1 second).
[0718] Plates are kept overnight in the cell culture incubator. The next day,
10 1 of a 10
mM BSO solution is added to the wells, resulting in a 1 mM final BSO
concentration.
Forty-eight hours later, three plates are examined under a phase-contrast
microscope to
verify that the cells in the 0% control (wells El-Hi) are clearly dead. The
medium from
all plates is discarded, and the remaining liquid is removed by gently tapping
the plate
inversed onto a paper towel.
[0719] 100 1 of PBS containing 1.2 M Calcein AM is then added to each well.
The
plates are incubated for 50-70 minutes at room temperature. Then, the PBS is
discarded,
and the plate is gently tapped on a paper towel. Fluorescence intensity is
measured with a
Gemini Spectramax XS spectrofluorimeter (Molecular Devices, Sunnyvale, CA,
USA)
using excitation and emission wavelengths of 485 and 525 nm, respectively.
[0720] It is anticipated that untreated FRDA cells will exhibit high levels of
cell death
following exposure to BSO (FRDA Control) as compared to fibroblasts derived
from
normal subjects (Normal). However, it is anticipated that FRDA fibroblasts
treated with
chroman derivatives will show cell survival rates that are similar to normal
subjects and
greater than untreated FRDA fibroblasts, following BSO exposure.
[0721] These results will show that chroman derivatives of the present
technology are
useful in the treatment of Friedreich's Ataxia.
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Example 10 ¨ Use of Chroman Derivatives in Treating Mitochondrial Iron Loading
in
Friedreich's Ataxia Mouse Model
[0722] This Example will demonstrate the use of chroman derivatives of the
present
technology in treating mitochondrial iron loading in a mouse model of
Friedreich's Ataxia.
[0723] Mouse model. This Example uses the muscle creatine kinase (MCK)
conditional
frataxin knockout mice described by Puccio etal., Nat. Genet. 27:181-186
(2001). In this
model, the tissue-specific Cre transgene under the control of MCK promoter
results in the
conditional deletion of frataxin in only the heart and skeletal muscle.
[0724] 8-week-old mutant mice are administered a daily dose of 0.25 mg/kg/day
of the
chroman derivatives, or saline vehicle only (control) subcutaneously for two
weeks. Total
RNA is isolated from hearts of two 10-week-old wild-type mice, two 10-week-old

untreated mutant mice and two 10-week-old treated mutant mice. Total RNA is
isolated
using TRIzol (Invitrogen). First-strand cDNA synthesis and biotin-labeled cRNA
are
performed and hybridized to the mouse Affymetrix GeneChip 430 2Ø A 2-phase
strategy
is used to identify differentially expressed genes. First, genome-wide
screening is
performed using Affymetrix GeneChips. Then, low-level analysis is performed
with
Affymetrix GeneChip Operating Software 1.3.0, followed by the GC robust
multiarray
average (GCRMA) method for background correction and quantile¨quantile
normalization
of expression. Tukey's method for multiple pairwise comparisons is applied to
acquire
fold-change estimations. Tests for significance are calculated and adjusted
for multiple
comparisons by controlling the false discovery rate at 5%.
[0725] Definitive evidence of differential expression is obtained from RT-PCR
assessment of samples used for the microarray analysis and at least 3 other
independent
samples. Principal component analysis is performed by standard methods.
Western blot
analysis is performed using antibodies against frataxin (US Biological); Tfrl
(Invitrogen);
Fpnl (D. Haile, University of Texas Health Science Center); Hmoxl
(AssayDesigns);
Sdha, Gapdh, and Iscul/2 (Santa Cruz Biotechnology); Fech (H. Dailey,
University of
Georgia, Biomedical and Health Sciences Institute); Hfe2 (S. Parkkila,
University of
Tampere, Institute of Medical Technology); Nfsl, Uros, and Alad (Abnova);
Sec1511
(N.C. Andrews, Duke University); Ftl 1, Fthl, Ftmt (S. Levi, San Raffaele
Institute); and
Hifl a (BD Biosciences).
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[0726] For heme assays, hearts are exhaustively perfused and washed with PBS
(0.2%
heparin at 37 C) to remove blood. After homogenization, heme is quantified
using the
QuantiChrom Heme Assay (BioAssay Systems). Tissue iron is measured via
inductively
coupled plasma atomic emission spectrometry.
[0727] It is anticipated that untreated mutant mice will exhibit decreased
expression of
genes involved in heme synthesis, iron¨sulfur cluster assembly, and iron
storage (FRDA
Control) as compared to wild-type mice (Normal). However, it is anticipated
that mutant
mice treated with the chroman derivatives will show expression levels that are
similar to
normal subjects with respect to genes involved in these three mitochondrial
iron utilization
pathways.
[0728] These results will show that chroman derivatives of the present
technology are
useful in treating mitochondrial iron loading in a mammalian model of
Friedreich's
Ataxia.
Example 11 ¨ Use of Chroman Derivatives in Treating Complex I and ATP Content

Deficiency in Patients Suffering from a Mitochondrial Disease or Disorder
[0729] This Example will demonstrate the use of chroman derivatives of the
present
technology in treating complex I and ATP content deficiency in patients
suffering from a
mitochondrial disease or disorder.
[0730] Patients diagnosed with any mitochondrial disease or disorder described
herein
are administered a daily dose of 0.5 mg/kg/day of the chroman derivative; or
saline vehicle
(control) for six weeks.
[0731] Isolation of Lymphocytes from Peripheral Blood. Blood is diluted with
Hank's
solution at a ratio of 1:2 within one hour of extraction and slowly layered
onto a 15-mL
screw-cap tube containing 5 mL Ficolymph (Bharafshan Co. Tehran, Iran.). The
tubes are
centrifuged for 20 minutes at 1000 x g, after which the lymphocyte-containing
layer is
collected into a new centrifuge tube using a sterile pipette. The lymphocyte
mix is then
diluted in 10 mL Hank's solution and centrifuged for 10 minutes at 440xg. The
supernatant is discarded, 5 mL of Hank's solution is added, the pellet is
mixed gently in
this buffer, and the mixture is allowed to sit for about 45 seconds (s). The
mixture is
gently pipetted and then centrifuged at 230xg for 15 minutes. The supernatant
is
discarded, and the pellet is suspended in RPMI 1640 medium (Bharashan Co.
Tehran,
Iran) supplemented with L-glutamine.
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[0732] Complex I activity assay. Fresh lymphocyte pellets are homogenized by
sonication in 20 mmol/L potassium phosphate buffer (pH 7.5) for 15s (three
bursts of 5s
each) at 30W on ice. The final protein concentration is quantified according
to Bradford's
method. The homogenate, containing 2-4 g/L protein, is kept on ice and used
for assay the
same day. Biochemical studies are carried out on lymphocyte homogenate of 12
patients
and 25 controls. NADH-ferricyanide reductase activity is also assayed
spectrophotometrically by following the disappearance of oxidized ferricyanide
at 410 nm
and 30 C. The assay mixture contained in 1 mL: NADH, ferricyanide,
triethanolamin and
phosphate buffer (pH 7.8). The reaction is started by the addition of the
lymphocyte
homogenate.
[0733] Extraction and quantification of intracellular ATP. The lymphocyte
cells are
pelleted in a microcentrifuge tube by centrifugation at 12,000 g for 10 min.
The cellular
ATP is then extracted by adding 0.5 mL water and boiling the cell pellet for 5
min. After
vortexing and centrifugation (12,000 g for 5 min at 4 C), 50 [A,L of the
supernatant is used
for bioluminescence measurement. The standard curve of ATP is obtained by
serial
dilutions of 4 mM ATP solution (0.25, 0.5, 1.0, 2.0, and 4.0). Light emission
is measured
with a Sirius tube luminometer, Berthold defection system (Germany). After
calibration
against the ATP standard, the ATP content of the cell extract is determined.
[0734] It is anticipated that lymphocytes derived from untreated subjects will
exhibit
decreased complex I activity and reduced intracellular ATP levels
(mitochondrial disease
Control) as compared to controls (Normal). However, it is anticipated that
subjects treated
with the chroman derivatives will show complex I activity and ATP levels that
are similar
to normal subjects and greater than untreated subjects suffering from a
mitochondrial
disease or disorder.
[0735] These results will show that chroman derivatives of the present
technology are
useful in treating complex I and ATP content deficiency in patients suffering
from a
mitochondrial disease or disorder.
Example 12 ¨ Use of Chroman Derivatives in Restoring Aconitase Activity in
Cultured
Cells Following Deferiprone Exposure
[0736] This Example will demonstrate the use of chroman derivatives of the
present
technology in restoring aconitase activity in cultured cells that have been
exposed to
deferiprone.
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CA 02920246 2016-02-09
[0737] Deferiprone has been shown to potently impair aconitase activity,
presumably
through reduced iron-sulfur cluster biosynthesis. Goncalves et al., BMC
Neurology 8:20
(2008).
[0738] Fibroblasts derived from forearm biopsies taken from healthy controls
are grown
under standard conditions in Dulbecco's modified Eagle's medium (DMEM; Gibco
Invitrogen, Cergy Pontoise, France) supplemented with 10% fetal calf serum, 10
mg/mL
penicillin/streptomycin and 2 mM L-Glutamine (as GlutamaxTM; Gibco
Invitrogen). Final
iron content in culture medium will amount to 2-3 ALM. The medium (4 mL/25 cm2
flask;
3 mL/10 cm2 well) is changed every three days.
[0739] Fibroblasts are administered 1-10 Atg of chroman derivatives, or empty
vehicle
(control) for 24 hours before addition of deferiprone. Fibroblasts are seeded
at 18 x 103
cells/cm2. Fibroblasts are then treated with 75 AtM deferiprone for 7 days.
Aconitase
measurement is spectrophotometrically carried out by following aconitate
production from
citrate at 240 nm on the supernatant (800 g x 5 min) of detergent-treated
cells (0.2% lauryl
maltoside). Protein concentration is measured according to Bradford method.
[0740] It is anticipated that untreated fibroblasts will exhibit reduced
aconitase activity
following exposure to deferiprone (Control) as compared to fibroblasts that
are not
exposed to deferiprone (Normal). However, it is anticipated that concurrent
treatment
with chroman derivatives will show aconitase activity that is similar to
normal subjects
and greater than untreated fibroblasts following deferiprone exposure.
[0741] These results will show that chroman derivatives of the present
technology are
useful in restoring aconitase activity in cultured cells that have been
exposed to
deferiprone.
Example 13 ¨ Use of Chroman Derivatives in Reducing Mitochondrial Fission
[0742] This Example will demonstrate use of the chroman derivatives of the
present
technology in the reduction of mitochondrial fission.
[0743] Cultured human SH-SY5Y neuronal cells are treated with buffer; 5 [AM
CCCP
(carbonyl cyanide m-chloro phenyl hydrazone, a mitochondrial uncoupler); or 5
AtM
CCCP and chroman derivatives; for 30 minutes. The cells are then stained with
anti-
Tom20 antibody, a mitochondrial marker, and Hoechst stain. Mitochondrial
morphology
is analyzed using 63X oil immersion lens.
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CA 02920246 2016-02-09
[0744] Results ¨ It is expected that control cells treated with CCCP will show
extensive
mitochondrial fragmentation as manifested by small, round or dot-like staining
patterns. It
is also anticipated that treatment with the chroman derivatives will result in
significantly
reduced mitochondrial fission compared to control cells that are only exposed
to CCCP.
[0745] These results will show that the chroman derivatives of the present
technology
are useful in methods for reducing mitochondrial fission in mammalian
subjects.
Example 14 ¨ Use of Chroman Derivatives to Increase Protein Expression Levels
of Fully
Assembled Complex I and Complex II in Cells Bearing Complex I Mutations
[0746] This Example will demonstrate use of the chroman derivatives of the
present
technology to restore electron transport chain function in complex I mutant
cells.
[0747] Experimental fibroblast cells are derived from patients with a mutation
in
different Complex I subunits. Control cells are human skin fibroblasts derived
from
healthy controls. Cultured Complex I mutant fibroblasts are incubated with
buffer or a
chroman derivative for up to 72 hours. The cells are then harvested by
trypsinization and
washed twice with ice-cold PBS. The cell suspensions are centrifuged for 5
minutes at 4
C and the cell pellets are snap-frozen in liquid nitrogen. The cell pellets
are subsequently
thawed on ice and resuspended in 100 p.1 of ice-cold PBS.
[0748] Isolation of OXPHOS complexes: The cell suspension is incubated with
100 1_,
(4 mg/mL) digitonin (Sigma, Zwijndrecht, Netherlands) on ice for 10 min.
Digitonin
dissociates membranes that contain cholesterol, thereby dissociating the cell
membrane
and the outer mitochondrial membrane, but not the inner mitochondrial
membrane. Next,
1 mL ice-cold PBS is added to dilute the digitonin, followed by centrifugation
(10 min;
15,600xg; 4 C). The resulting pellets contain a cell fraction which is
enriched for
mitoplasts. The supernatant is removed and the pellets are resuspended in 100
pt ice-cold
PBS. 1 mL ice-cold PBS is then added and the suspension is centrifuged again
(5 min;
15,600 xg; 4 C), followed by removal of the supernatant and resuspension of
the pellet in
100 lit ice-cold PBS. The supernatant is removed with a syringe and needle and
the
pellets containing the mitoplast fraction are stored overnight (-20 C).
[0749] The complexes of the OXPHOS system are extracted from the inner
membrane
with P-lauryl maltoside and aminocaproic acid. The pellets are thawed on ice
and
solubilized in 100 pt ACBT buffer containing 1.5 M E-aminocaproic acid (Serva,

Amsterdam, Netherlands) and 75 mM Bis-Tris/HC1 (pH 7.0) (Sigma). Subsequently
10
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CA 02920246 2016-02-09
AL 20% (w/v) [3-lauryl maltoside (Sigma) is added and the suspension is left
on ice for 10
min. Next, the suspensions are centrifuged (30 min; 15,600 xg; 4 C) and the
supernatants
which contain the isolated complexes are transferred to a clean tube (L.G.
Nijtmans et al.,
Methods 26 (4): 327-334 (2002)). The protein concentration of the isolated
OXPHOS
complexes is determined using a Biorad Protein Assay (Biorad, Veenendaal,
Netherlands).
Blue-native PAGE analysis of mitoplasts is performed as described in L.G.
Nijtmans et
al., Methods 26 (4): 327-334 (2002).
[0750] Complex I or complex II protein detection: To visualize the amount of
complex I
or complex II present in the BN-PAGE gels, the proteins are transferred to a
PVDF
membrane (Millipore, Amsterdam, Netherlands) using standard Western blotting
techniques and detected by immunostaining. After the blotting and prior to
blocking the
PVDF membrane with 1:1 PBS-diluted Odyssey blocking buffer (Li-cor
Biosciences,
Cambridge, UK), the PVDF blot is stripped with stripping buffer for 15 min at
60 C. The
stripping buffer consists of PBS, 0.1% Tween-20 (Sigma) and 2% SDS (Serva). A
monoclonal primary antibody against NDUFA9 (39 kDa) (Molecular probes, Leiden,
The
Netherlands) is used for detection of Complex I. To detect Complex II, a
monoclonal
antibody against the 70 kDa subunit of complex II is used (Molecular probes).
Both
primary antibodies are diluted in PBS, 0.1% Tween-20 and 2.5% Protifar Plus
(Nutricia,
Cuijk, The Netherlands) and allowed to bind to the complex for 4 hours at room

temperature or overnight at 4 C. The bound primary antibodies are subsequently
detected
by IRDye 800 CW conjugated anti-Mouse antibody (Li-cor Biosciences) at a final

concentration of 0.1 i_tg/mL.
[0751] Results: It is expected that untreated Complex I mutant cells will show
reduced
protein expression levels of Complex I and Complex II compared to untreated
healthy
control cells. It is also anticipated that treatment with the chroman
derivatives will result
in an increase in fully assembled complex I and complex II protein levels in
Complex I
mutant cells.
[0752] These results will show that the chroman derivatives of the present
technology
are useful in methods for elevating Complex I and Complex II protein levels in
mammalian subjects. The results will show that the chroman derivatives of the
present
technology are useful in promoting electron transport chain function
generally.
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Example 15 ¨ In vivo Effect of Chroman Derivatives on Grip Strength in Ndufs4

Knockout Mice
[0753] This Example will demonstrate use of the chroman derivatives of the
present
technology to improve grip strength in Ndufs4 knockout (Complex I deficient)
mice.
[0754] Animals and Treatments: Ndufs4 knockout (KO) and wild-type (WT) mice
are
generated by crossing Ndufs4 heterozygote males and females (Kruse SE, et al.,
2008,
Cell Metab 7:312-320). Animals are divided into the following groups: Vehicle-
WT;
Vehicle-KO; or Chroman Derivative-KO. Animals are tested at 3, 5 and 6 weeks
of age.
Animals will receive either vehicle (control) injections, consisting of
sterile water, or
injections consisting of a chroman derivative. Animals are injected twice a
day.
Injections begin during week 3 of life, and are continued daily until the
conclusion of the
experiment in week 6.
[0755] Data Analysis: All data are expressed as mean + SEM. Data are analyzed
using a
one way ANOVA in SPSS version 20Ø Significant overall effects (i.e.,
genotype,
treatment and/or genotype treatment interaction) are further analyzed using
Fisher's PLSD
post-hoc analyses.
[0756] Grip Strength Paradigm: The grip strength test is designed to measure
muscular
strength in rodents. The apparatus consists of a single bar, which the animal
will grasp by
instinct. Once the bar has been grasped, the experimenter gently retracts the
animal until
the animal is forced to release the bar. The amount of force exerted by the
animal on the
bar is measured in Pond (p) (1 p = 1 gram). The grip strength test is repeated
5 times and
the average force exerted is used as the quantitative readout. All
measurements will be
corrected for body weight, using the following equation:
[0757] Grip Strength Score = ((week X trials 1 + 2 + 3 + 4 +5)/5)/ Average
Body
Weight week X (g) (Week X = week 3, 5 or 6)
[0758] Testing Procedure: On testing days, animals will receive their morning
injection
30 minutes prior to their testing time. After injections, the animals will be
placed in the
testing room for a 30 minute acclimation period.
[0759] Results: It is expected that vehicle KO animals will show remarkably
decreased
grip strength compared to wild-type control animals. It is also anticipated
that chronic
treatment with the chroman derivatives will result in significantly improved
grip strength
in the knockout animals compared to vehicle knockouts.
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[0760] These results will show that the chroman derivatives of the present
technology
are useful in methods for improving grip strength in mammalian subjects. The
results will
show that the chroman derivatives of the present technology are generally
useful in
treating neuromuscular defects in Complex I deficient subjects.
Example 16 ¨ Chroman Derivatives Restore Motor and Cognitive Function in an in
vivo
Huntington Disease (HD) Animal Model
[0761] This Example will demonstrate use of the chroman derivatives of the
present
technology to reduce the neurological defects associated with HD.
[0762] R6/2 mice, expressing exon 1 of the human HD gene carrying more than
120
CAG repeats, exhibit progressive neurological phenotypes that mimic the
features of HD
in humans. The mice develop progressive neurological phenotypes gradually with
mild
phenotype (e.g., resting tremor) as early as 5 weeks of age and severe
symptoms
(including reduced mobility and seizures) at 9-11 weeks, with many of the mice
dying by
14 weeks.
[0763] R6/2 HD transgenic mice are treated with an empty vehicle or a chroman
derivative using Alzet osmotic mini-pumps from age 5 weeks to 13 weeks. These
animals
will be subjected to a number of behavioral assessments to study motor and
cognitive
function. Rotor-rod and mobility in an activity chamber are used for
assessment of motor
function, and the Y-maze is used for assessment of working memory.
[0764] Results ¨ It is anticipated that vehicle-treated R6/2 mice will display
major motor
deficits such as a reduced ability to stand on their rear limbs and increased
periods of
immobility compared to wild-type controls. It is further anticipated that
treatment with the
chroman derivatives will restore motor activity and improve cognitive function
(as
demonstrated by the animals' performance in the Y-maze test).
[0765] These results will show that the chroman derivatives of the present
technology
are useful in methods for restoring cognitive and motor function in mammals
suffering
from HD. The results will show that the chroman derivatives of the present
technology
are generally useful in treating symptoms associated with neurodegenerative
diseases.
Example 17 ¨ Use of Chroman Derivatives to Suppress A13-mediated Toxicity in
the Brain
[0766] This Example will demonstrate use of the chroman derivatives of the
present
technology to treat or ameliorate the toxic effects of AP accumulation in
brain tissue.
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CA 02920246 2016-02-09
[0767] Rats are treated with saline or a chroman derivative (0.5-2 iumol/kg
body weight,
n=12). The compositions are injected intraperitoneally into the animal 24
hours before
hippocampal slices are obtained to measure long-term potentiation (LTP). Brain
slices
from each group are incubated with An fragments for 15 min before evaluating
LTP.
[0768] Results ¨ It is expected that brain slices recovered from saline-
treated controls
will show impaired LTP post An treatment. It is also anticipated that
treatment with the
chroman derivatives will suppress An-mediated impairment of LTP.
[0769] These results will show that the chroman derivatives of the present
technology
are useful in methods for treating or ameliorating An-mediated toxicity in
brain tissue.
The results will show that the chroman derivatives of the present technology
are generally
useful in reducing the synaptic dysfunction and memory loss caused by An
accumulation
generally.
Example 18 ¨ Use of Chroman Derivatives to Delay Ageing
[0770] This Example will demonstrate use of the methods and compositions of
the
present technology to reduce the frequency and/or severity of age-related
symptoms. The
Example will demonstrate the use of chroman derivatives of the present
technology in
delaying ageing.
[0771] Ercc 1-/A progeroid mice are treated with chroman derivatives (i.p.
about 0.5-2
mg/kg) in sunflower oil carrier three times per week over an 18-21 week
period. Control
animals are Ercc 1-/A progeroid mice that receive sunflower seed oil according
to the same
schedule. The treated and control mice are monitored twice a week for weight
and
symptom/sign development. Symptoms include dystonia, trembling, kyphosis,
ataxia,
wasting, priapism, decreased activity, incontinence, and vision loss. The rate
of
deterioration of intervertebral discs (an index of degenerative disease of the
vertebra) is
assessed by measuring the level of glycosaminoglycan in the discs in treated
and control
mice.
[0772] Results ¨ It is expected that treatment with the chroman derivatives
will result in
a significant delay in onset of age-related degeneration compared to controls
treated with
vehicle only. It is also anticipated that the intervertebral discs of mice
treated with the
chroman derivatives will contain more glycosaminoglycan relative to control
mice,
indicating inhibition of disc degeneration.
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CA 02920246 2016-02-09
[0773] These results will show that the chroman derivatives of the present
technology
are useful in methods for reducing the frequency and/or severity of age-
related symptoms.
The results will show that the methods and compositions described herein are
useful in
delaying ageing generally.
Example 19 ¨ Use of Chroman Derivatives to Treat Mitochondrial Dysfunction
[0774] This Example demonstrates the use of chroman derivatives, or
pharmaceutically
acceptable salts thereof, to treat different aspects of mitochondrial
dysfunction.
[0775] Lymphocytes, fibroblasts or neurons are derived from subjects suspected
of
having or diagnosed as having a mitochondrial disease or disorder. The
isolated cells are
cultured using conventional methods that promote optimal growth of a given
cell type.
The resulting cell cultures are subjected to the following assays:
[0776] Mitochondrial Membrane Potential (don) Assay: For the determination of
Awm,
cells are pre-treated with or without chroman derivatives. The cells are
treated with 5 mM
Dulbecco's modified Eagle's minimal essential medium (DEM) for 120 minutes,
collected
by centrifugation at 300xg for 3 minutes and then washed twice with phosphate
buffered
saline. The cells are re-suspended in PBS buffer and incubated at 37 C. in
the dark for 15
minutes with 250 nM TMRM (a cationic dye which accumulates within mitochondria
in
accordance with the AymNernst potential). Cells are collected by
centrifugation at 300xg
for 3 minutes and then washed twice with phosphate buffered saline. The
samples are
analyzed immediately by flow cytometry using 488 nm excitation laser and the
FL2-H
channel. The protonophore FCCP (30 ilM) will be used to dissipate the
chemiosmotic
proton gradient (Aptfr) and serves as a control for loss of Am. The results
obtained will
be verified in three independent experiments.
[0777] Trypan Blue Cell Viability Assay: This technique is used to assess the
cytoprotective effects of chroman derivatives in cultured cells
pharmacologically treated
to induce cell death by GSH depletion. DEM is used to deplete cellular GSH and
induce
oxidative stress. The viability of DEM-treated cells is determined by their
ability to
exclude the dye trypan blue. Viable cells exclude trypan blue; whereas, non-
viable cells
take up the dye and stain blue. Briefly, cells are seeded at a density of
lx106 cells/mL and
treated with different concentrations of chroman derivatives. Cells are
incubated at 37 C
in a humidified atmosphere of 5% CO2 in air for three hours with 5 mM DEM.
Cell
226

CA 02920246 2016-02-09
viability is determined by staining cells with 0.4% trypan blue using a
hemocytometer. At
least 500 cells are counted for each experimental group.
[0778] Cytochrome c Reduction Assay: The rate of cytochrome c (10 RIVI)
reduction is
measured by monitoring the change in absorbance at 550 nm. Briefly the
reaction is
initiated by addition of 100 [iM of chroman derivatives to a mixture
containing 50 mM
phosphate buffer, 0.1 mM EDTA, pH 7.8, and 101.1M cytochrome c (Sigma, St.
Louis,
Mo. USA). For cytochrome c reduction by superoxide, xanthine oxidase (0.01
IU/mL)
(Sigma, St. Louis, Mo. USA) is used in presence of xanthine (501.1M).
[0779] Total Cellular ATP Concentration Assay: The reductions of mitochondrial

respiratory chain activity in CoQ10 deficient patients have been reported
(Quinzii G et al.,
FASEB J. 22:1874-1885 (2008)). Briefly, lymphocytes (2x105 cell/mL), are
plated (1 mL
in 12-well plates) and treated with chroman derivatives at final
concentrations of 5, 10
M, and 25 [iM and incubated at 37 C for 48 hours in a humidified atmosphere
containing 5% CO2 in air. Chroman derivatives are prepared by first making 20
mM stock
solutions in DMSO. Cells are transferred (100 pt) to 96-well microtiter black-
walled cell
culture plates (Costar, Corning, N.Y.). The total intracellular ATP level is
measured in a
luminator (ClarityTM luminescence microplate reader) with the ATP
Bioluminescence
Assay Kit (ViaLight Plus ATP monitoring reagent kit, Lonza) following the
manufacturer's instructions. The standard curve of ATP is obtained by serial
dilution of 1
mM ATP solution. After calibration against the ATP standard, the ATP content
of the cell
extract is determined and normalized for protein content in the cell.
[0780] Mitochondrial Bioenergetics Assessment: The use of chroman derivatives
and
methylene blue analogues (positive control) to normalize and restore the
respiratory chain
activities in cultured cells derived from subjects with a mitochondrial
disease or disorder
are assessed. Lymphocytes are cultured under glucose-free media supplemented
with
galactose for two weeks to force energy production predominantly through
oxidative
phosphorylation rather than glycolysis. Lymphocytes are cultured in RPMI 1640
medium
glucose-free supplemented with 25 mM galactose, 2 mM glutamine and 1%
penicillin-
streptomycin, and 10%, dialyzed fetal bovine serum FBS (<0.5 lg/mL). Briefly,
lymphocytes (2x105 cell/mL), are plated (1 mL in 12-well plates) and treated
with the
chroman derivatives at final concentrations of 50, 125, 250, 1000, and 5000
nM, and
incubated at 37 C for 48 hours in a humidified atmosphere containing 5% CO2
in air.
Cells are transferred (100 L) to 96-well microtiter black-walled cell culture
plates. The
227

CA 02920246 2016-02-09
total intracellular ATP level is measured in a luminator (ClarityTM
luminescence
microplate reader) with the ATP Bioluminescence Assay Kit (ViaLight -Plus ATP
monitoring reagent kit, Lonza) following the manufacturer's instructions.
Carbonyl
cyanide-p-trifluormethoxy-phenylhydrazone (FCCP) and oligomycin are used as
controls
for inhibition of ATP synthesis.
[0781] Results ¨ It is anticipated that cells derived from subjects suspected
of having or
diagnosed as having a mitochondrial disease or disorder will show one or more
alterations
associated with mitochondrial dysfunction such as decreased cell viability,
loss of
mitochondrial membrane potential, decreased cytochrome c reduction, decreased
cellular
content of ATP, and reduced efficiency of oxidative phosphorylation. It is
expected that
treatment with chroman derivatives will reduce the severity or eliminate one
or more of
these alterations associated with mitochondrial dysfunction.
[0782] These results will show that the chroman derivatives of the present
technology
are useful in methods for normalizing and restoring mitochondrial
bioenergetics generally.
Example 20 ¨ Use of Chroman Derivatives in Combination with an Additional
Therapeutic Agent in Ameliorating Symptoms of a Mitochondrial Disease or
Disorder in
Subjects Diagnosed with a Mitochondrial Disease or Disorder
[0783] This Example will demonstrate the use of chroman derivatives of the
present
technology, in combination with one or more additional therapeutic agents
(e.g., one or
more of vitamins, cofactors, antibiotics, hormones, antineoplastic agents,
steroids,
immunomodulators, dermatologic drugs, antithrombotic, antianemic, and
cardiovascular
agents) to alleviate or ameliorate one or more symptoms in a subject diagnosed
with a
mitochondrial disease. Suitable test subjects diagnosed with a mitochondrial
disease will
exhibit one or more of the following symptoms: poor growth, loss of muscle
coordination,
muscle weakness, neurological deficit, seizures, autism, autistic spectrum,
autistic-like
features, learning disabilities, heart disease, liver disease, kidney disease,
gastrointestinal
disorders, severe constipation, diabetes, increased risk of infection, thyroid
dysfunction,
adrenal dysfunction, autonomic dysfunction, confusion, disorientation, memory
loss,
failure to thrive, poor coordination, sensory (vision, hearing) problems,
reduced mental
functions, hypotonia, disease of the organ, dementia, respiratory problems,
hypoglycemia,
apnea, lactic acidosis, seizures, swallowing difficulties, developmental
delays, movement
disorders (dystonia, muscle spasms, tremors, chorea), stroke, and brain
atrophy.
228

CA 02920246 2016-02-09
[0784] Subjects diagnosed with any mitochondrial disease or disorder described
herein
and exhibiting one or more of the above symptoms are divided into 4 groups
(N=20) as
follows: Group I is administered a daily dose of 0.5 mg/kg/day of the chroman
derivatives;
Group II is administered a daily dose of between 0.01-10 mg/k/day of one or
more of
vitamins, cofactors, antibiotics, hormones, antineoplastic agents, steroids,
immunomodulators, dermatologic drugs, antithrombotic, antianemic, and
cardiovascular
agents; Group III is administered a combination of a daily dose of 0.5
mg/kg/day of the
chroman derivatives and a daily dose of between 0.01-10 mg/k/day of one or
more of
vitamins, cofactors, antibiotics, hormones, antineoplastic agents, steroids,
immunomodulators, dermatologic drugs, antithrombotic, antianemic, and
cardiovascular
agents; and Group IV is administered saline vehicle (control). Each group will
receive
therapy for six weeks. At the end of the six-week test period, subjects are
evaluated for
amelioration or attenuation of one or more of the symptoms described above.
[0785] It is anticipated that subjects in groups I and II will show an
improvement (e.g.,
alleviation, amelioration) in at least one or more of the signs and symptoms
of the
mitochondrial disease or disorder as compared to the control group, Group IV.
It is
anticipated that subjects in Group III will exhibit a synergistic effect with
respect to the
combination therapy, and will exhibit a greater improvement in one or more
signs or
symptoms of the mitochondrial disease or disorder than the subjects of Group I
and II.
[0786] These results will show that combination therapy, i.e., chroman
derivatives of the
present technology in combination with one or more additional therapeutic
agents, is
useful in reducing, alleviating or ameliorating one or more of the signs and
symptoms
associated with a mitochondrial disease or disorder.
EQUIVALENTS
[0787] The present technology is not to be limited in terms of the particular
embodiments described in this application, which are intended as single
illustrations of
individual aspects of the present technology. Many modifications and
variations of the
present technology can be made without departing from its spirit and scope, as
will be
apparent to those skilled in the art. Functionally equivalent methods and
apparatuses
within the scope of the present technology, in addition to those enumerated
herein, will be
apparent to those skilled in the art from the foregoing descriptions. Such
modifications
and variations are intended to fall within the scope of the appended claims.
The present
229

CA 02920246 2016-02-09
technology is to be limited only by the terms of the appended claims, along
with the full
scope of equivalents to which such claims are entitled. It is to be understood
that the
present technology is not limited to particular methods, reagents, compounds
compositions
or biological systems, which can, of course, vary. It is also to be understood
that the
terminology used herein is for the purpose of describing particular
embodiments only, and
is not intended to be limiting.
[0788] In addition, where features or aspects of the disclosure are described
in terms of
Markush groups, those skilled in the art will recognize that the disclosure is
also thereby
described in terms of any individual member or subgroup of members of the
Markush
group.
[0789] As will be understood by one skilled in the art, for any and all
purposes,
particularly in terms of providing a written description, all ranges disclosed
herein also
encompass any and all possible subranges and combinations of subranges
thereof. Any
listed range can be easily recognized as sufficiently describing and enabling
the same
range being broken down into at least equal halves, thirds, quarters, fifths,
tenths, etc. As
a non-limiting example, each range discussed herein can be readily broken down
into a
lower third, middle third and upper third, etc. As will also be understood by
one skilled in
the art all language such as "up to," "at least," "greater than," "less than,"
and the like,
include the number recited and refer to ranges which can be subsequently
broken down
into subranges as discussed above. Finally, as will be understood by one
skilled in the art,
a range includes each individual member. Thus, for example, a group having 1-3
cells
refers to groups having 1, 2, or 3 cells. Similarly, a group having 1-5 cells
refers to groups
having 1, 2, 3, 4, or 5 cells, and so forth.
[0790] All patents, patent applications, provisional applications, and
publications
referred to or cited herein are incorporated by reference in their entirety,
including all
figures and tables, to the extent they are not inconsistent with the explicit
teachings of this
specification.
[0791] Other embodiments are set forth within the following claims.
230

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Claims 2016-02-09 9 447
Drawings 2016-02-09 5 67
Cover Page 2016-09-26 1 31
New Application 2016-02-09 3 88