MITOCHONDRIAL ENCEPHALOMYOPATHY WITH A-TRANSITION TO G-TRANSITION OF MITOCHONDRIAL TRANSFER RNA(LEU)(UUR) 3,243 PRESENTING HYPERTROPHIC CARDIOMYOPATHY

In a 24-year-old woman with mitochondrial encephalomyopathy presenting hypertrophic cardiomyopathy, microscopical examination of myocardial biopsy specimen disclosed severe vacuolar degeneration of myocardium a nd aggregates of enlarged mitochondria with proliferated cristae. Limb muscle biopsy specimen showed ''ragged-red fibers'' light microscopic ally and enlarged abnormal mitochondria with markedly increased crista e ultrastructurally, Mitochondrial DNA analysis by polymerase chain re action (PCR) revealed an A-to-G transition in the mitochondrial transf er RNA(Leu(UUR)) gene at nucleotide position 3,243 which is reported t o be associated with mitochondrial myopathy, encephalopathy, lactic ac idosis, and stroke-like episodes (MELAS), However, the clinical featur es of this case, presenting mainly cardiac abnormalities, were not con sistent with the typical MELAS.