A novel mutation in the mitochondrial tRNA(Phe) gene associated with mitochondrial myopathy.
We report a novel heteroplasmic T-->C mutation at nt position 582 within the mitochondrial tRNA(Phe) gene of a 70-year-old woman with mitochondrial myopathy. No other family members were affected, suggesting that our patient was a sporadic case. The muscle showed frequent ragged red fibers and 43% cytochrome c oxidase deficient fibers. The mutation alters a conserved base pairing in the aminoacyl acceptor stem. The mutation load was 70% in muscle homogenate and varied from 0 to 95% in individual muscle fiber segments. Cytochrome c oxidase-negative fibers showed significantly higher levels of mutated mtDNA (>75%) than Cytochrome c oxidase-positive fibers (<55%). This mutation adds to the previously described four pathogenic mutations in the tRNA(Phe) gene.
Moslemi
A-R
AR
Department of Pathology, Sahlgrenska University Hospital, 41345 Göteborg, Sweden. ali-reza.moslemi@path.gu.se
Lindberg
C
C
Toft
J
J
Holme
E
E
Kollberg
G
G
Oldfors
A
A
D000368:Aged; D019943:Amino Acid Substitution / Q000235:genetics; D000604:Amino Acyl-tRNA Synthetases / Q000235:genetics; D019069:Cell Respiration / Q000235:genetics; D004252:DNA Mutational Analysis; D004272:DNA, Mitochondrial / Q000235:genetics*; D003576:Electron Transport Complex IV / Q000378:metabolism; D005260:Female; D006801:Humans; D008928:Mitochondria / Q000235:genetics* / Q000378:metabolism; D017240:Mitochondrial Myopathies / Q000175:diagnosis / Q000235:genetics* / Q000473:pathology; D018482:Muscle, Skeletal / Q000378:metabolism* / Q000473:pathology; D017354:Point Mutation / Q000235:genetics*; D012360:RNA, Transfer, Phe / Q000235:genetics*; D012689:Sequence Homology, Nucleic Acid
D004272:DNA, Mitochondrial; D012360:RNA, Transfer, Phe; D003576:Electron Transport Complex IV; D000604:Amino Acyl-tRNA Synthetases