A Case of Myoclonus Epilepsy and Ragged-red Fiber Syndrome

J Korean Neurol Assoc > Volume 14(2); 1996 > Article

Journal of the Korean Neurological Association 1996;14(2): 595-600.

김병곤, 전범석

서울대 신경과

A Case of Myoclonus Epilepsy and Ragged-red Fiber Syndrome

Byung Gon Kim, M.D., Beom Seok Jeon, M.D.

Department of Neurology, College of Medicine, Seoul National University

Abstract

Myoclonus epilepsy and ragged-red fiber (MERRF) syndrome is one of the common etiologies of progressive myoclonus epilepsy. The clinical features of MERRF syndrome are myoclonus, seizure, dementia, ataxia, neuropathy, myopathy, deafness, and lipouta. The patients with MERRF syndrome have a point mutation in mitochondrial DNA at 8344 or 8356 nucleotide. We are reporting a patient who developed myoclonus and seizure at the age of eighteen. He later showed cerebellar ataxia, peripheral neuropathy, and cognitive dysfunction. Skeletal muscle biopsy failed to demonstrate ragged-red fibers. He was diagnosed as MERRF syndrome by the mitochondrial DNA analysis. He had 86% mutant mitochondrial genomes (A-)G(8%) mutation) in leukocytes, and his asymptomatic mother had 66%. The absence of ragged-red fibers does not rule out the possibility of MERRF syndrome. Demonstration of mitochondrial DNA mutation is the most convincing method for establishing the diagnosis of MERRF.