A novel mitochondrial tRNAPhe mutation causes MERRF syndrome

Neurology. 2004 Jun 8;62(11):2119-21. doi: 10.1212/01.wnl.0000127608.48406.f1.


A woman with typical features of myoclonic epilepsy with ragged red fibers (MERRF) had a novel heteroplasmic mutation (G611A) in the mitochondrial DNA tRNA phenylalanine gene. The mutation was heteroplasmic (91%) in muscle but undetectable in accessible tissues from the patient and her maternal relatives. Single-fiber PCR analysis showed that the proportion of mutant genomes was higher in cytochrome c oxidase (COX)-negative ragged red fibers (RRFs) than in COX-positive non-RRFs. This report shows that typical MERRF syndrome is not always associated with tRNA lysine mutations.

Publication types

  • Case Reports
  • Comparative Study
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adolescent
  • Adult
  • Amino Acid Substitution
  • DNA, Mitochondrial / genetics*
  • Electron Transport Complex IV / analysis
  • Genetic Heterogeneity
  • Humans
  • MERRF Syndrome / genetics*
  • MERRF Syndrome / pathology
  • Mitochondria / chemistry
  • Muscles / chemistry
  • Muscles / ultrastructure
  • Mutation, Missense
  • Organ Specificity
  • Point Mutation
  • Polymerase Chain Reaction
  • Polymorphism, Restriction Fragment Length
  • RNA, Transfer, Phe / genetics*


  • DNA, Mitochondrial
  • RNA, Transfer, Phe
  • Electron Transport Complex IV