A novel heteroplasmic tRNA(Ser(UCN)) mtDNA point mutation associated with progressive external ophthalmoplegia and hearing loss.
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)).
Cardaioli
Elena
E
Department of Neurological and Behavioural Sciences, University of Siena, Viale Bracci 2, Siena 53100, Italy.
Da Pozzo
Paola
P
Gallus
Gian Nicola
GN
Malandrini
Alessandro
A
Gambelli
Simona
S
Gaudiano
Carmen
C
Malfatti
Edoardo
E
Viscomi
Carlo
C
Zicari
Enza
E
Berti
Gianna
G
Serni
Giovanni
G
Dotti
Maria Teresa
MT
Federico
Antonio
A
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
D004272:DNA, Mitochondrial; D012362:RNA, Transfer, Ser; D014529:Uridine