Unusual adult-onset Leigh syndrome presentation due to the mitochondrial m.9176T>C mutation

Biochem Biophys Res Commun. 2011 Aug 26;412(2):245-8. doi: 10.1016/j.bbrc.2011.07.076. Epub 2011 Jul 27.


Leigh syndrome (LS) is an incurable, nearly always fatal, neurodegenerative, pediatric disorder that results from respiratory chain failure. The most common mitochondrial DNA (mtDNA) mutations that result in LS are m.8993T→C/G and m.9176T→C/G, which were previously found in several patients with early-onset Leigh syndrome. Here, we describe clinical and molecular features of a novel pedigree, where LS developed in two siblings. The proband was a young woman with an unusual adult-onset LS. She harbored a homoplasmic m.9176T→C mutation, based on analysis of a muscle biopsy. In contrast, the brother died at a young age. This novel case report and literature review highlights the variability of phenotypic expression of the m.9176T→C mutation.

Publication types

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

MeSH terms

  • Adult
  • Age of Onset
  • DNA, Mitochondrial / genetics*
  • Female
  • Genes, Mitochondrial*
  • Humans
  • Leigh Disease / genetics*
  • Leigh Disease / pathology
  • Muscle, Skeletal / pathology
  • Mutation
  • Pedigree


  • DNA, Mitochondrial