Chronic progressive external ophthalmoplegia: a correlative study of quantitative molecular data and histochemical and biochemical profile

J Neurol Sci. 1994 May;123(1-2):140-6. doi: 10.1016/0022-510x(94)90216-x.


We studied muscle biopsies of 5 patients with Kearns-Sayre syndrome and 3 patients with chronic progressive external ophthalmoplegia all with the common deletion. Steady state levels of normal and deleted mitochondrial DNA (mtDNA) measured in each patient by quantitative PCR were correlated with histochemical and biochemical features. We found that (1) normal mtDNA levels were higher in many patients than in controls; (2) as levels of deleted mtDNA increased, so did levels of normal mtDNA; (3) cytochrome c oxidase (COX) activity and the percentage of COX negative fibers were both related to the levels of deleted mtDNA; and (4) as percentage of ragged red fibers increased, so did levels of total, deleted and normal mtDNA. The quantity of deleted mtDNA plays a key role in determining the severity of COX deficiency, which is responsible for the overaccumulation of mitochondria in muscle.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Biopsy
  • Cytochrome-c Oxidase Deficiency
  • DNA Primers
  • DNA, Mitochondrial / analysis
  • DNA, Mitochondrial / genetics*
  • DNA, Mitochondrial / metabolism
  • Electron Transport Complex IV / metabolism
  • Humans
  • Kearns-Sayre Syndrome / enzymology*
  • Kearns-Sayre Syndrome / genetics*
  • Middle Aged
  • Mitochondria, Muscle / metabolism
  • Muscles / enzymology
  • Muscles / metabolism
  • Muscles / pathology
  • Ophthalmoplegia, Chronic Progressive External / genetics*
  • Ophthalmoplegia, Chronic Progressive External / metabolism*
  • Ophthalmoplegia, Chronic Progressive External / pathology
  • Polymerase Chain Reaction
  • Reference Values
  • Regression Analysis
  • Sequence Deletion


  • DNA Primers
  • DNA, Mitochondrial
  • Electron Transport Complex IV