Adult-onset Mitochondrial Myopathy, Encephalopathy, Lactic Acidosis, and Stroke (MELAS)-like Encephalopathy Diagnosed Based on the Complete Sequencing of Mitochondrial DNA Extracted from Biopsied Muscle without any Myopathic Changes

Intern Med. 2017;56(1):95-99. doi: 10.2169/internalmedicine.56.7301. Epub 2017 Jan 1.


The clinical features of mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) are not uniform. We herein report a male patient with unusual MELAS-like encephalopathy who had been experiencing isolated recurrent stroke-like episodes since he was 33 years old without any particular family history. Despite an extensive investigation, he had no other signs suggestive of MELAS. Although the muscle pathology showed a normal appearance, a mitochondrial genome sequence analysis of the biopsied muscle revealed a heteroplasmic m.10158T>C mutation in the mitochondrial complex I subunit gene, MT-ND3. To prevented further deterioration of the higher brain function, the early diagnosis and treatment of mitochondrial stroke-like episodes is important.

Publication types

  • Case Reports

MeSH terms

  • Acidosis, Lactic / diagnosis*
  • Acidosis, Lactic / genetics
  • Adult
  • Biopsy
  • Brain Diseases / diagnosis*
  • Brain Diseases / genetics
  • DNA, Mitochondrial / genetics*
  • Early Diagnosis
  • Humans
  • MELAS Syndrome / diagnosis*
  • MELAS Syndrome / genetics
  • Male
  • Mitochondrial Myopathies / diagnosis*
  • Mitochondrial Myopathies / genetics
  • Muscular Diseases / genetics*
  • Muscular Diseases / pathology*
  • Mutation


  • DNA, Mitochondrial