The common MELAS mutation A3243G in mitochondrial DNA among young patients with an occipital brain infarct

Neurology. 1997 Nov;49(5):1331-4. doi: 10.1212/wnl.49.5.1331.


The syndrome of mitochondrial encephalomyopathy, lactic acidosis, and strokelike episodes (MELAS) may present with symptoms that resemble a stroke. The strokelike episodes most commonly involve the posterior part of the cerebrum. We identified retrospectively 38 patients with an occipital stroke between ages 18 to 45 years during a 19-year period in a hospital serving as the only neurologic center for a specific population. The common MELAS mutation at the base pair 3243 (A3243G) of the mitochondrial DNA (mtDNA) was analyzed in blood samples. We found four patients (10%) with a clinical or molecular diagnosis of a mitochondrial disorder. Two of the patients carried the A3243G mutation, suggesting frequencies of 6% among patients younger than 45 years of age and 14% among patients younger than 30 years for this mutation. Furthermore, we identified two patients with a clinically definite mitochondrial disorder, and sequencing of the 22 transfer RNA genes revealed the mtDNA mutation A12308G in one patient. Clinical evaluation revealed that occipital stroke was part of a more complex syndrome in these four patients. These population-based findings demonstrate that the A3243G mutation in the mtDNA, and mitochondrial disorders are not uncommon among young patients with occipital stroke.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Cerebral Infarction / etiology
  • Cerebral Infarction / genetics*
  • Cerebral Infarction / mortality
  • Cohort Studies
  • DNA Mutational Analysis
  • DNA, Mitochondrial / genetics*
  • Family Health
  • Female
  • Follow-Up Studies
  • Humans
  • MELAS Syndrome / complications
  • MELAS Syndrome / genetics*
  • Male
  • Middle Aged
  • Occipital Lobe / pathology*
  • Point Mutation*
  • Retrospective Studies


  • DNA, Mitochondrial