A mitochondrial tRNA(Lys) gene mutation (T8316C) in a patient with mitochondrial myopathy, lactic acidosis, and stroke-like episodes

Neuromuscul Disord. 2000 Oct;10(7):493-6. doi: 10.1016/s0960-8966(00)00107-3.


We studied a patient with mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes who had morphologically and biochemically abnormal muscle mitochondria. Molecular analysis revealed a T8316C transition in the mitochondrial DNA tRNA(Lys) gene. The mutation was homoplasmic in muscle from the proposita, heteroplasmic in her blood, and still less abundant in blood from her asymptomatic maternal relatives. The T8316C mutation affects a highly conserved base pair and was not found in controls, thus satisfying the accepted criteria for pathogenicity. Our data document the genetic heterogeneity in mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes syndrome, underlining that the same syndrome may be associated with mutations of different genes.

Publication types

  • Case Reports
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acidosis, Lactic / complications
  • Acidosis, Lactic / genetics*
  • Adolescent
  • Base Sequence
  • DNA, Mitochondrial / genetics*
  • Family Health
  • Female
  • Humans
  • MELAS Syndrome / complications
  • MELAS Syndrome / genetics*
  • Mitochondria / enzymology
  • Molecular Biology
  • Molecular Sequence Data
  • Nucleic Acid Conformation
  • Pedigree
  • Point Mutation*
  • RNA, Transfer, Lys / chemistry
  • RNA, Transfer, Lys / genetics*
  • Stroke / complications
  • Stroke / genetics*
  • Succinate Dehydrogenase / analysis


  • DNA, Mitochondrial
  • RNA, Transfer, Lys
  • Succinate Dehydrogenase