MELAS, Myoclonus, Ataxia and Deficiencies of Complexes I and IV in Muscle Mitochondria

A 13-year-old Japanese girl developed convulsions, periodic attacks of coma with hyperpyrexia, visual disturbance, aphasia, myoclonus, cerebellar symptoms and dementia. A muscle biopsy four years previously had shown ragged-red fibers. Biochemical studies showed NADH CoQ reductase and cytochrome c oxidase deficiencies in biopsied muscle at 13 years of age, although normal activity of cytochrome c oxidase had been histochemically detected at 9 years of age. A therapeutic trial of citrate administration produced transient improvement in the clinical features and in the hyperlactic and pyruvic acidemia.