Heterogeneous clinical presentation of the mtDNA NARP/T8993G mutation

Neurology. 1997 Jul;49(1):270-3. doi: 10.1212/wnl.49.1.270.


To obtain a better molecular definition of patients with syndromic retinitis pigmentosa, we screened for mitochondrial DNA (mtDNA) alterations of the two ATPase genes and 22 tRNA-coding sequences in 10 patients whose features resembled NARP (neuropathy, ataxia, and retinitis pigmentosa) syndrome. In two patients, one of whom showed features mimicking Kearns-Sayre syndrome, we identified a heteroplasmic T8993G mutation (average 80%) in the mitochondrial ATPase 6 gene. There was no mutated mtDNA in muscle and leukocytes from the mother of one patient or in leukocytes from his brother, suggesting a rapid segregation of the mutated nucleotide. MtDNA analysis should be considered in the differential diagnosis of patients with syndromic retinitis pigmentosa.

Publication types

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

MeSH terms

  • Adult
  • DNA, Mitochondrial / genetics*
  • Female
  • Humans
  • Male
  • Mutation / genetics
  • Polymorphism, Genetic / genetics*
  • Retinitis Pigmentosa / genetics*


  • DNA, Mitochondrial