Myoclonus epilepsy, retinitis pigmentosa, leukoencephalopathy and cerebral calcifications associated with a novel m.5513G>A mutation in the MT-TW gene

Biochem Biophys Res Commun. 2018 Jun 2;500(2):158-162. doi: 10.1016/j.bbrc.2018.04.009. Epub 2018 Apr 13.


We sequenced the mitochondrial genome from a 40-year-old woman with myoclonus epilepsy, retinitis pigmentosa, leukoencephalopathy and cerebral calcifications. Histological and biochemical features of mitochondrial respiratory chain dysfunction were present. Direct sequencing showed a novel heteroplasmic mutation at nucleotide 5513 in the MT-TW gene that encodes tRNATrp. Restriction Fragment Length Polymorphism analysis confirmed that about 80% of muscle mtDNA harboured the mutation while it was present in minor percentages in mtDNA from other tissues. The mutation is predicted to disrupt a highly conserved base pair within the aminoacyl acceptor stem of the tRNA. This is the 17° mutation in MT-TW gene and expands the known causes of late-onset mitochondrial diseases.

Keywords: MT-TW gene; Mitochondrial disease; New mutation; mtDNA; tRNA(Trp).

MeSH terms

  • Adult
  • Base Sequence
  • Epilepsies, Myoclonic / blood
  • Epilepsies, Myoclonic / diagnostic imaging
  • Epilepsies, Myoclonic / genetics*
  • Female
  • Genetic Predisposition to Disease*
  • Humans
  • Leukoencephalopathies / blood
  • Leukoencephalopathies / diagnostic imaging
  • Leukoencephalopathies / genetics*
  • Mutation / genetics*
  • RNA, Transfer, Trp / genetics*
  • Retinitis Pigmentosa / blood
  • Retinitis Pigmentosa / diagnostic imaging
  • Retinitis Pigmentosa / genetics*
  • Sequence Analysis, DNA
  • Tomography, X-Ray Computed
  • Vascular Calcification / genetics*


  • RNA, Transfer, Trp