[A case of childhood onset myoclonus epilepsy with ragged-red fibers--with special reference to various clinical manifestations].

There are few descriptions about the clinical course of children with myoclonus epilepsy with ragged-red fibers (MERRF). We reported a girl who was diagnosed as having MERRF at 10 years of age and developed various clinical manifestations including chronic respiratory failure, paralytic ileus and pancytopenia at 18 years of age. Administration of cytochrome c worsened lactic acidosis and muscle weakness, while intravenous hyperalimentation with copper supplementation gradually improved these findings as well as pancytopenia. Cytochrome c oxidase is a copper dependent enzyme. Its activity is extremely low in MERRF patients. It was suspected that deficiency of serum copper and supplementation of cytochrome c worsened the clinical symptoms of our patient.