Classical mitochondrial phenotypes without mtDNA mutations: the possible role of nuclear genes

Neurology. 2003 Oct 28;61(8):1144-7. doi: 10.1212/01.wnl.0000090465.27024.3d.


The authors analyzed the total mitochondrial (mt) genome in 15 patients with classic mitochondrial phenotypes. Novel somatic mtDNA mutations in two patients with chronic progressive external ophthalmoplegia were identified. Total automated mtDNA genome analysis did not reveal other pathogenic mtDNA mutations. The authors conclude that classic mitochondrial phenotypes, including those with adult onset, may occur in the absence of mtDNA mutations. Nuclear gene mutations may be the cause.

Publication types

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

MeSH terms

  • Cell Nucleus / genetics*
  • DNA Mutational Analysis
  • DNA, Mitochondrial / genetics*
  • Electron Transport Complex IV / analysis
  • Female
  • Humans
  • Male
  • Middle Aged
  • Mitochondrial Diseases / diagnosis
  • Mitochondrial Diseases / genetics*
  • Muscle Fibers, Skeletal / chemistry
  • Muscle Fibers, Skeletal / enzymology
  • Mutation*
  • Ophthalmoplegia, Chronic Progressive External / diagnosis
  • Ophthalmoplegia, Chronic Progressive External / genetics*
  • Phenotype*
  • Polymerase Chain Reaction
  • Polymorphism, Restriction Fragment Length


  • DNA, Mitochondrial
  • Electron Transport Complex IV