Atypical MELAS associated with mitochondrial tRNA(Lys) gene A8296G mutation

Pediatr Neurol. 2002 Nov;27(5):397-400. doi: 10.1016/s0887-8994(02)00456-3.


We report on a unique patient with mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) presenting optic atrophy, cardiomyopathy, and bilateral striatal necrosis before stoke-like episodes became apparent. Skeletal muscle total mitochondrial DNA analysis identified a heteroplasmic A to G point mutation in the tRNA(Lys) gene at position 8296. Skeletal muscle pathology revealed typical MELAS findings, including ragged-red fibers cytochrome c oxidase positive strongly succinate dehydrogenase-reactive blood vessels. Recent reports describe the 8296 mutation identified in patients with diabetes mellitus or myoclonus epilepsy with ragged-red fibers, not MELAS. We conclude that the 8296 mutation is likely to be pathogenic and that it may be not only a mutation responsible for diabetes mellitus or myoclonus epilepsy with ragged-red fibers but also for MELAS.

Publication types

  • Case Reports

MeSH terms

  • Adolescent
  • Biopsy
  • Cardiomyopathies / diagnosis
  • Cardiomyopathies / etiology
  • Corpus Striatum / pathology
  • DNA Mutational Analysis
  • DNA, Mitochondrial / genetics*
  • Echocardiography
  • Humans
  • MELAS Syndrome / diagnosis*
  • MELAS Syndrome / genetics*
  • MELAS Syndrome / pathology
  • Magnetic Resonance Imaging
  • Male
  • Muscle Fibers, Fast-Twitch / pathology
  • Muscle, Skeletal / blood supply
  • Muscle, Skeletal / pathology
  • Optic Atrophy / diagnosis
  • Optic Atrophy / etiology
  • Point Mutation / genetics*
  • RNA, Transfer, Lys / genetics*


  • DNA, Mitochondrial
  • RNA, Transfer, Lys