Chronic progressive external ophthalmoplegia: a new heteroplasmic tRNA(Leu(CUN)) mutation of mitochondrial DNA

J Neurol Sci. 2008 Sep 15;272(1-2):106-9. doi: 10.1016/j.jns.2008.05.005. Epub 2008 Jul 7.


We sequenced all genes of mitochondrial tRNAs of a patient with chronic progressive external ophthalmoplegia with 5% ragged red fibres and 15% COX-negative fibres but without macrorearrangements of mitochondrial DNA (mtDNA). Direct sequencing showed a novel heteroplasmic G>A substitution in position 12316 of tRNA(Leu(CUN)) gene. This change destroys a highly conserved G-C base coupling in tRNA TpsiC branch. By RFLP analysis we could demonstrate different degrees of heteroplasmy in different patient's tissues. This alteration, absent in a population of 110 patients with different encephalomyopathies, can be considered pathogenic: it is the tenth tRNA(Leu(CUN)) pathogenic mutation described up to date.

Publication types

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

MeSH terms

  • DNA Mutational Analysis
  • DNA, Mitochondrial / genetics*
  • Female
  • Humans
  • Middle Aged
  • Muscle, Skeletal / pathology
  • Mutation*
  • Ophthalmoplegia, Chronic Progressive External / genetics*
  • Ophthalmoplegia, Chronic Progressive External / pathology
  • RNA, Transfer, Leu / genetics*


  • DNA, Mitochondrial
  • RNA, Transfer, Leu