Different effects of novel mtDNA G3242A and G3244A base changes adjacent to a common A3243G mutation in patients with mitochondrial disorders

Mitochondrion. 2009 Apr;9(2):115-22. doi: 10.1016/j.mito.2009.01.005. Epub 2009 Jan 21.


Two novel mitochondrial DNA base changes were identified at both sides of the 3243A>G mutation, the most common mutation associated with mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS). One was a 3244G>A transition in a girl with MELAS. The other was a 3242G>A transition in a girl with a mitochondrial disorder without a MELAS phenotype. Although the two base changes were adjacent to the 3243A>G mutation, they had different effects on the clinical phenotype, muscle pathology, and respiratory chain enzyme activity. Investigations of the different effects of the 3244G>A and 3242G>A base changes may provide a better understanding of tRNA dysfunction in mitochondrial disorders.

Publication types

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

MeSH terms

  • Child
  • Child, Preschool
  • DNA, Mitochondrial / genetics*
  • Female
  • Humans
  • MELAS Syndrome / genetics
  • Mitochondrial Diseases / genetics*
  • Point Mutation*
  • Polymorphism, Genetic*


  • DNA, Mitochondrial