title: A novel heteroplasmic tRNA(Ser(UCN)) mtDNA point mutation associated with progressive external ophthalmoplegia and hearing loss.
abstract: We sequenced all mitochondrial tRNA genes from a patient with sporadic external ophthalmoplegia (PEO) and 5% COX-negative fibers in muscle biopsy, who had no detectable large mtDNA deletions. Direct sequencing showed a heteroplasmic mutation at nucleotide 7506 in the dihydrouridine stem of the tRNA(Ser(UCN)) gene. RFLP analysis confirmed that 30% of muscle and 20% of urinary epithelium mtDNA harbored the mutation, which was absent in other tissues of the proband as well as in mtDNA of his mother and 100 patients with various encephalomyopathies. Several point mutations on mitochondrial tRNA genes have been reported in PEO patients without large-scale rearrangements of mtDNA but no point mutations have hitherto been found in the gene coding for tRNA(Ser(UCN)).
authors.affiliation: Department of Neurological and Behavioural Sciences, University of Siena, Viale Bracci 2, Siena 53100, Italy.
authors.forename: Elena
authors.initials: E
authors.lastname: Cardaioli
authors.forename: Paola
authors.initials: P
authors.lastname: Da Pozzo
authors.forename: Gian Nicola
authors.initials: GN
authors.lastname: Gallus
authors.forename: Alessandro
authors.initials: A
authors.lastname: Malandrini
authors.forename: Simona
authors.initials: S
authors.lastname: Gambelli
authors.forename: Carmen
authors.initials: C
authors.lastname: Gaudiano
authors.forename: Edoardo
authors.initials: E
authors.lastname: Malfatti
authors.forename: Carlo
authors.initials: C
authors.lastname: Viscomi
authors.forename: Enza
authors.initials: E
authors.lastname: Zicari
authors.forename: Gianna
authors.initials: G
authors.lastname: Berti
authors.forename: Giovanni
authors.initials: G
authors.lastname: Serni
authors.forename: Maria Teresa
authors.initials: MT
authors.lastname: Dotti
authors.forename: Antonio
authors.initials: A
authors.lastname: Federico
mesh_terms: D000328:Adult; D004252:DNA Mutational Analysis / Q000379:methods; D004272:DNA, Mitochondrial / Q000235:genetics*; D005260:Female; D034381:Hearing Loss / Q000150:complications / Q000235:genetics*; D006801:Humans; D008297:Male; D017246:Ophthalmoplegia, Chronic Progressive External / Q000150:complications / Q000235:genetics*; D017354:Point Mutation / Q000235:genetics*; D012150:Polymorphism, Restriction Fragment Length; D012362:RNA, Transfer, Ser / Q000235:genetics*; D014529:Uridine / Q000031:analogs & derivatives* / Q000737:chemistry
chemical_list: D004272:DNA, Mitochondrial; D012362:RNA, Transfer, Ser; D014529:Uridine