A novel heteroplasmic tRNA Ser(UCN) mtDNA point mutation associated with progressive ophthalmoplegia and dysphagia

Diagn Mol Pathol. 2010 Mar;19(1):28-32. doi: 10.1097/PDM.0b013e3181b00f02.


We report a novel heteroplasmic mitochondrial DNA mutation in the tRNA gene at nucleotide 7458 (m.7458G>A) in a 26-year-old patient affected with sporadic progressive external ophthalmoplegia associated with dysphagia. Muscle biopsy showed a strong succinate dehydrogenase staining, ragged red fibers, and 15% of cytochrome c oxidase-negative fibers. Activities of mitochondrial respiratory chain complexes I+III and IV were reduced. The mutation was heteroplasmic (75%) in the muscle, but undetectable in accessible tissues from the patient and his maternal relatives. This report expands the molecular heterogeneity of progressive external ophthalmoplegia.

Publication types

  • Case Reports

MeSH terms

  • Adult
  • Biopsy
  • DNA, Mitochondrial / genetics*
  • Deglutition Disorders / complications*
  • Deglutition Disorders / genetics*
  • Humans
  • Male
  • Mitochondrial Diseases
  • Muscles / pathology
  • Ophthalmoplegia / complications*
  • Ophthalmoplegia / genetics*
  • Point Mutation*
  • Polymorphism, Single Nucleotide*
  • RNA, Transfer, Ser / genetics*


  • DNA, Mitochondrial
  • RNA, Transfer, Ser