A new mutation in the mitochondrial tRNA(Ala) gene in a patient with ophthalmoplegia and dysphagia

We describe a new mutation in the tRNA(Ala) gene, a T-->C transition at nuc leotide position 5628, in a 62-year-old woman with late onset chronic progr essive external ophthalmoplegia. dysphagia and mild proximal myopathy. The mutation is heteroplasmic and disrupts a highly conserved A-U base pair wit hin the anticodon stem of the tRNA(Ala). Cytochrome c oxidase-negative fibe rs harbor a significantly higher level of mutated mtDNA than cytochrome c o xidase-positive fibers. This is the first mutation in the tRNA(Ala) gene wh ich satisfies accepted criteria for pathogenicity. (C) 2001 Elsevier Scienc e B.V. All rights reserved.