A novel mitochondrial tRNA Arg mutation resulting in an anticodon swap in a patient with mitochondrial encephalomyopathy.
We report a mutation in the anticodon of the tRNA(Arg) gene (m.10437 G>A), resulting in an anticodon swap from GCU to ACU, which is the anticodon of tRNA(Trp), in a boy with mitochondrial encephalomyopathy. Enzyme histochemical analysis of muscle tissue and biochemical analysis of isolated muscle mitochondria demonstrated cytochrome c oxidase (COX) deficiency. Restriction fragment length polymorphism analysis showed that 90% of muscle and 82% of urinary epithelium mtDNA harbored the mutation. The mutation was not identified in blood, fibroblasts, hair roots, or buccal epithelial cells and it was absent in the asymptomatic mother, suggesting that it was a de novo mutation. Single-fiber PCR analysis showed that the proportion of mutated mtDNA correlated with enzyme histochemical COX deficiency. This mutation adds to the three previously described disease-causing mutations in tRNA(Arg), but it is the first mutation occurring in the anticodon of tRNA(Arg).
Department of Pathology, Institute of Biomedicine, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden. sara.roos@gu.se
Sara
S
Roos
Niklas
N
Darin
Gittan
G
Kollberg
Marita
M
Andersson Grönlund
Mar
M
Tulinius
Elisabeth
E
Holme
Ali-Reza
AR
Moslemi
Anders
A
Oldfors
D000293:Adolescent; D000926:Anticodon / Q000235:genetics; D020029:Base Pairing; D001483:Base Sequence; D019069:Cell Respiration / Q000502:physiology; D030401:Cytochrome-c Oxidase Deficiency / Q000235:genetics; D006652:Histological Techniques; D006801:Humans; D008297:Male; D017237:Mitochondrial Encephalomyopathies / Q000235:genetics* / Q000473:pathology; D008969:Molecular Sequence Data; D018482:Muscle, Skeletal / Q000473:pathology*; D009154:Mutation / Q000235:genetics; D010641:Phenotype; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length; D012347:RNA, Transfer, Arg / Q000235:genetics*; D017422:Sequence Analysis, DNA; D013548:Sweden
D000926:Anticodon; D012347:RNA, Transfer, Arg