Mitochondrial myopathies.
The mitochondrial myopathies or encephalomyopathies with known biochemical defects can be divided into 5 groups: (1) defects of mitochondrial transport, such as CPT deficiency or carnitine deficiencies; (2) defects of substrate utilization, such as PDHC deficiency or defects of beta-oxidation; (3) defects of the Krebs cycle, such as fumarase deficiency; (4) defects of oxidation-phosphorylation coupling, such as Luft disease, and (5) defects of the respiratory chain. These disorders are reviewed, with particular emphasis on the defects of the respiratory chain. Defects of complex I, III and IV show remarkable clinical and biochemical heterogeneity. All 3 complexes contain some subunits encoded by mtDNA and others encoded by nuclear DNA. At least some of the cytoplasmically made subunits appear to be tissue specific and may be developmentally regulated, thus explaining the genetic heterogeneity of these disorders.
DiMauro
S
S
H. Houston Merritt Clinical Research Center for Muscular Dystrophy and Related Diseases, Columbia-Presbyterian Medical Center, New York, NY 10032.
Bonilla
E
E
Zeviani
M
M
Servidei
S
S
DeVivo
D C
DC
Schon
E A
EA
D000251:Adenosine Triphosphatases / Q000172:deficiency; D001692:Biological Transport; D002331:Carnitine / Q000172:deficiency; D002952:Citric Acid Cycle; D030401:Cytochrome-c Oxidase Deficiency; D042963:Electron Transport Complex II; D014450:Electron Transport Complex III / Q000172:deficiency; D006801:Humans; D008661:Metabolism, Inborn Errors / Q000201:enzymology / Q000235:genetics; D008931:Mitochondria, Muscle / Q000201:enzymology; D009097:Multienzyme Complexes / Q000172:deficiency; D016660:NAD(P)H Dehydrogenase (Quinone); D010085:Oxidative Phosphorylation; D010088:Oxidoreductases / Q000172:deficiency; D010101:Oxygen Consumption; D011773:Pyruvates / Q000378:metabolism; D019289:Pyruvic Acid; D011808:Quinone Reductases / Q000172:deficiency; D013385:Succinate Dehydrogenase / Q000172:deficiency
D009097:Multienzyme Complexes; D011773:Pyruvates; D019289:Pyruvic Acid; D010088:Oxidoreductases; D042963:Electron Transport Complex II; D013385:Succinate Dehydrogenase; D016660:NAD(P)H Dehydrogenase (Quinone); D011808:Quinone Reductases; D000251:Adenosine Triphosphatases; D014450:Electron Transport Complex III; D002331:Carnitine