The m.3244G>A mutation in mtDNA is another cause of progressive external ophthalmoplegia.
We sequenced all mitochondrial tRNA genes in a 61-year-old man with chronic progressive external ophthalmoplegia and mitochondrial myopathy but without mtDNA rearrangements, and identified a heteroplasmic m.3244G>A mutation in the tRNA(Leu(UUR)) gene. This mutation had been previously associated with the MELAS phenotype, but not described in any detail. The mutation load in muscle was 84% and COX-negative fibers harbored greater levels of mutant genomes than COX-positive fibers. The m.3244G>A mutation affects a highly conserved nucleotide in the dihydrouridine loop and has been associated with a wobble modification deficiency of the mutant tRNA.
Sotiriou
Evangelia
E
Department of Neurology, Columbia University Medical Center, New York, NY 10032, USA.
Coku
Jorida
J
Tanji
Kurenai
K
Huang
Hua-bin
HB
Hirano
Michio
M
DiMauro
Salvatore
S
D001483:Base Sequence; D017124:Conserved Sequence / Q000235:genetics; D004252:DNA Mutational Analysis; D004272:DNA, Mitochondrial / Q000235:genetics*; D018450:Disease Progression; D020022:Genetic Predisposition to Disease / Q000235:genetics*; D006801:Humans; D008297:Male; D008875:Middle Aged; D028361:Mitochondrial Diseases / Q000235:genetics* / Q000378:metabolism / Q000503:physiopathology; D018485:Muscle Fibers, Skeletal / Q000378:metabolism / Q000473:pathology; D009154:Mutation / Q000235:genetics*; D009711:Nucleotides / Q000235:genetics; D009801:Oculomotor Muscles / Q000378:metabolism / Q000503:physiopathology; D017246:Ophthalmoplegia, Chronic Progressive External / Q000235:genetics* / Q000378:metabolism / Q000503:physiopathology; D052097:Quadriceps Muscle / Q000378:metabolism / Q000473:pathology; D012356:RNA, Transfer, Leu / Q000235:genetics*
D004272:DNA, Mitochondrial; D009711:Nucleotides; D012356:RNA, Transfer, Leu