Ophthalmoplegia due to mitochondrial DNA disease: the need for genetic diagnosis

Muscle Nerve. 2005 Jul;32(1):104-7. doi: 10.1002/mus.20319.


We describe a patient with chronic progressive external ophthalmoplegia (CPEO) who underwent muscle biopsy for suspected mitochondrial disease. In spite of normal histocytochemical cytochrome c oxidase (COX) activity and respiratory chain enzyme measurements in muscle, subsequent molecular genetic analysis revealed the presence of a single, large-scale deletion of mitochondrial DNA (mtDNA). The case serves to illustrate the importance of pursuing the proposed mitochondrial genetic abnormality, even in patients with normal biopsy findings.

Publication types

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

MeSH terms

  • Adult
  • Biopsy
  • DNA, Mitochondrial / genetics*
  • Electron Transport
  • Electron Transport Complex IV / metabolism
  • Female
  • Genetic Testing
  • Histocytochemistry
  • Humans
  • Mitochondrial Diseases / genetics*
  • Mitochondrial Diseases / pathology*
  • Ophthalmoplegia, Chronic Progressive External / genetics*
  • Ophthalmoplegia, Chronic Progressive External / pathology*


  • DNA, Mitochondrial
  • Electron Transport Complex IV