title: Mitochondrial myopathies.
abstract: Mitochondrial myopathies are clinically heterogeneous disorders that can affect multiple systems besides skeletal muscle (mitochondrial encephalomyopathies or cytopathies) and are usually defined by morphological abnormalities of muscle mitochondria. There are a few distinctive syndromes, such as the Kearns-Sayre syndrome; myoclonus epilepsy with ragged-red fibers; and mitochondrial myopathy, encephalopathy, lactic acidosis, and strokelike episodes. Biochemically, mitochondrial myopathies can be divided into defects of substrate utilization, oxidation-phosphorylation coupling, and the respiratory chain. Because mitochondria have their own DNA and their own translation and transcription apparatuses, mitochondrial myopathies can be due to defects of either a nuclear or mitochondrial genome and can be transmitted by mendelian or maternal inheritance.
mesh_terms: D002331:Carnitine / Q000172:deficiency; D002334:Carnitine O-Palmitoyltransferase / Q000172:deficiency; D003580:Cytochromes; D004272:DNA, Mitochondrial / Q000378:metabolism; D006801:Humans; D008854:Microscopy, Electron; D008928:Mitochondria / Q000378:metabolism; D008931:Mitochondria, Muscle / Q000648:ultrastructure*; D009132:Muscles / Q000378:metabolism; D009135:Muscular Diseases / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D010085:Oxidative Phosphorylation; D010101:Oxygen Consumption; D015324:Pyruvate Carboxylase Deficiency Disease; D015325:Pyruvate Dehydrogenase Complex Deficiency Disease; D013577:Syndrome
chemical_list: D003580:Cytochromes; D004272:DNA, Mitochondrial; D002334:Carnitine O-Palmitoyltransferase; D002331:Carnitine