ETHYLMALONIC ACIDURIA ASSOCIATED WITH PROGRESSIVE NEUROLOGICAL DISEASE AND PARTIAL CYTOCHROME-C-OXIDASE DEFICIENCY

Persistent excretion of elevated amounts of ethylmalonic acid (EMA) with or without concomitant acylglycinuria is a relatively frequent finding during selective screening for inborn errors of metabolism in our laboratory. One is struck by the number of cases within this group that show similar clinical features: muscular hypotonia, motor retardation, ataxia, spastic diplegia or tetraparesis develop gradually after febrile infections with vomiting and somnolence. In 3 out of 20 patients initially observed, in whom we have succeeded in obtaining the appropriate material, partial cytochrome c oxidase (COX) deficiency (McKusick 220110) was detected in muscle biopsies.