Myo-leukoencephalopathy in twins: study of 3243-myopathy, encephalopathy, lactic acidosis, and strokelike episodes mitochondrial DNA mutation

Ann Neurol. 1994 Mar;35(3):365-70. doi: 10.1002/ana.410350321.


Two dizygotic twins with myopathy and leukoencephalopathy are described. The female twin had an incomplete form of MELAS syndrome (myopathy, encephalopathy, lactic acidosis, and strokelike episodes) with severe myopathy, epileptic seizures without strokelike episodes. The male twin presented clinical features exclusively of myopathy and subclinical leukoencephalopathy. The MELAS mitochondrial DNA point mutation (MELAS-3243) was found by southern blot and polymerase chain reaction in muscle, skin fibroblasts, and blood of the female twin and was not detected in the skin fibroblasts nor in the blood of the mother, nor in any of the tissues tested in the male twin. The absence of mutation in male twin tissues raises questions about the pathogenetic significance of the mutation in this family.

Publication types

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

MeSH terms

  • Adult
  • Base Sequence
  • Blotting, Southern
  • DNA, Mitochondrial / genetics*
  • Diseases in Twins / genetics*
  • Female
  • Humans
  • MELAS Syndrome / diagnosis
  • MELAS Syndrome / genetics*
  • Magnetic Resonance Imaging
  • Male
  • Molecular Sequence Data
  • Muscles / ultrastructure
  • Pedigree
  • Point Mutation*
  • Polymerase Chain Reaction
  • Twins, Dizygotic


  • DNA, Mitochondrial