Mitochondrial cytopathies are clinically and biochemically heterogeneous disorders affecting energy production.
clinically heterogeneous multisystem disease characterized by defects of brain–mitochondrial encephalopathies and/or muscle–mitochondrial myopathies due to alterations in the protein complexes of the electron transport chain of oxidative phosphorylation.
Group 1 Progressive external ophthalmoplegias
• Kearns-Sayre disease Ophthalmoplegia plus syndrome
• Ocular myopathy
• Leber’s hereditary optic neuropathy–due to a point mutation
Group 2 Mitochondrial encephalomyopathies
• Mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes
• Myoclonus epilepsy with ragged red fibers
• Leigh syndrome
Group 3 Undefined mitochondrial encephalomyopathies, eg congenital lactic acidosis
Group 4 Mitochondrial myopathies
• Luft syndrome
• Enzyme defects, eg ATPase, cytochrome oxidase
McGraw-Hill Concise Dictionary of Modern Medicine. © 2002 by The McGraw-Hill Companies, Inc.