Quantitative determination of heteroplasmy in Leber's hereditary optic neuropathy by single-strand conformation polymorphism

Invest Ophthalmol Vis Sci. 1995 Jul;36(8):1714-20.


Purpose: The maternal inheritance of Leber's hereditary optic neuropathy (LHON) is caused by defects in the genes of mitochondrial DNA (mtDNA). The most prevalent mtDNA mutation, present in 40% to 90% of families with this disease, is a G to A substitution at nucleotide position 11778. The rapid and accurate quantification of heteroplasmy of this mutation will help determine the relative risk for disease expression.

Methods: The authors conducted screening tests for heteroplasmy in 44 visually affected patients with the 11778 mutation and 34 unaffected members of 36 Japanese families with LHON using the single-strand conformation polymorphism analysis. This method can detect even a single base difference between the sequences of wild type and mutant DNA strands. The percentage of mutant mtDNA was calculated using an image analyzer.

Results: Single-strand conformation polymorphism analysis allowed the detection of heteroplasmy ranging from 5% to 95%. Five (14%) of the 36 families showed heteroplasmy, and 14 (18%) of the 78 persons tested had heteroplasmy ranging from 10% to 94%. Seven patients with heteroplasmy with visual loss had mutant mtDNA ranging from 62% to 94%.

Conclusions: Single-strand conformation polymorphism analysis is rapid, efficient, and accurate for detecting point mutations and quantifying heteroplasmy in mtDNA. Individuals with heteroplasmy with less than 60% of mutant mtDNA in circulating leukocytes are probably at lesser risk for developing optic atrophy.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Base Sequence
  • DNA / analysis
  • DNA Mutational Analysis
  • DNA Primers / chemistry
  • DNA, Mitochondrial / genetics*
  • Electrophoresis, Agar Gel
  • Female
  • Humans
  • Male
  • Middle Aged
  • Molecular Sequence Data
  • Optic Atrophies, Hereditary / genetics*
  • Pedigree
  • Point Mutation / genetics*
  • Polymerase Chain Reaction
  • Polymorphism, Single-Stranded Conformational*


  • DNA Primers
  • DNA, Mitochondrial
  • DNA