Mitochondrial tRNA(Cys) gene mutation (A5814G): a second family with mitochondrial encephalopathy

Neuromuscul Disord. 1997 May;7(3):156-9. doi: 10.1016/s0960-8966(97)00444-6.


We report an Italian family with maternally inherited encephalomyopathy including progressive external ophthalmoplegia, seizures, and neurophysiological evidence of brainstem dysfunction. Mitochondrial DNA analysis showed a heteroplasmic point mutation at position 5814 in the tRNA gene for cysteine (A5814G), previously reported in a 5-year-old girl of Portuguese origin. The mutation was very abundant (> 95%) in both muscle and blood from the proposita and was present in lower proportions (average 85 +/- 6%) in blood from three less severely affected maternal relatives. This observation confirms pathogenicity for the A5814G mutation.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adult
  • Blotting, Southern
  • Family Health
  • Female
  • Humans
  • Italy
  • Male
  • Mitochondria / genetics*
  • Mitochondrial Encephalomyopathies / genetics*
  • Pedigree
  • Point Mutation*
  • Polymorphism, Restriction Fragment Length
  • RNA, Transfer, Cys / genetics*


  • RNA, Transfer, Cys