J Korean Neurol Assoc.  1996 Jun;14(2):595-600.

A Case of Myoclonus Epilepsy and Ragged-red Fiber Syndrome

• Kim BG
• Jeon BS

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.

MeSH Terms

Ataxia
Biopsy
Cerebellar Ataxia
Deafness
Dementia
Diagnosis
DNA, Mitochondrial
Epilepsies, Myoclonic*
Genome, Mitochondrial
Humans
Leukocytes
MERRF Syndrome
Mothers
Muscle, Skeletal
Muscular Diseases
Myoclonic Epilepsies, Progressive
Myoclonus*
Peripheral Nervous System Diseases
Point Mutation
Seizures
DNA, Mitochondrial