title: Mitochondrial myopathy with exercise intolerance and retinal dystrophy in a sporadic patient with a G583A mutation in the mt tRNA(phe) gene.
abstract: We describe a second patient with the 583G>A mutation in the tRNA(phe) gene of mitochondrial DNA (mtDNA). This 17-year-old girl had a mitochondrial myopathy with exercise intolerance and an asymptomatic retinopathy. Muscle investigations showed occasional ragged red fibers, 30% cytochrome c oxidase (COX)-negative fibers, and reduced activities of complex I+IV in the respiratory chain. The mutation was heteroplasmic (79%) in muscle but undetectable in other tissues. Analysis of single muscle fibers revealed a significantly higher level of mutated mtDNA in COX-negative fibers. Our study indicates that the 583G>A mutation is pathogenic and expands the clinical spectrum of this mutation.
authors.affiliation: Department of Pediatrics, Sahlgrenska University Hospital, Göteborg, Sweden. niklas.darin@vgregion.se
authors.forename: N
authors.initials: N
authors.lastname: Darin
authors.forename: G
authors.initials: G
authors.lastname: Kollberg
authors.forename: A-R
authors.initials: AR
authors.lastname: Moslemi
authors.forename: M
authors.initials: M
authors.lastname: Tulinius
authors.forename: E
authors.initials: E
authors.lastname: Holme
authors.forename: M Andersson
authors.initials: MA
authors.lastname: Grönlund
authors.forename: S
authors.initials: S
authors.lastname: Andersson
authors.forename: A
authors.initials: A
authors.lastname: Oldfors
mesh_terms: D000293:Adolescent; D004252:DNA Mutational Analysis; D004579:Electron Transport / Q000235:genetics; D003576:Electron Transport Complex IV / Q000378:metabolism; D017079:Exercise Tolerance / Q000235:genetics; D005260:Female; D006801:Humans; D017240:Mitochondrial Myopathies / Q000150:complications / Q000235:genetics* / Q000503:physiopathology; D018485:Muscle Fibers, Skeletal / Q000378:metabolism / Q000473:pathology; D018908:Muscle Weakness / Q000235:genetics / Q000503:physiopathology; D009154:Mutation / Q000235:genetics*; D012313:RNA / Q000235:genetics*; D000077278:RNA, Mitochondrial; D012360:RNA, Transfer, Phe / Q000235:genetics*; D012160:Retina / Q000473:pathology / Q000503:physiopathology; D012161:Retinal Artery / Q000473:pathology / Q000503:physiopathology; D012164:Retinal Diseases / Q000150:complications / Q000235:genetics* / Q000503:physiopathology
chemical_list: D000077278:RNA, Mitochondrial; D012360:RNA, Transfer, Phe; D012313:RNA; D003576:Electron Transport Complex IV