A novel heteroplasmic tRNA Ser(UCN) mtDNA point mutation associated with progressive ophthalmoplegia and dysphagia.
We report a novel heteroplasmic mitochondrial DNA mutation in the tRNA gene at nucleotide 7458 (m.7458G>A) in a 26-year-old patient affected with sporadic progressive external ophthalmoplegia associated with dysphagia. Muscle biopsy showed a strong succinate dehydrogenase staining, ragged red fibers, and 15% of cytochrome c oxidase-negative fibers. Activities of mitochondrial respiratory chain complexes I+III and IV were reduced. The mutation was heteroplasmic (75%) in the muscle, but undetectable in accessible tissues from the patient and his maternal relatives. This report expands the molecular heterogeneity of progressive external ophthalmoplegia.
Souilem
Sihem
S
Department of Molecular Neurobiology and Neuropathology La Rabta, National Institute of Neurology, Tunis, Tunisia. sihemsouilem@yahoo.fr
Kefi
Mounir
M
Mancuso
Michelangelo
M
Nesti
Claudia
C
Hentati
Faycal
F
Amouri
Rim
R
D000328:Adult; D001706:Biopsy; D004272:DNA, Mitochondrial / Q000235:genetics*; D003680:Deglutition Disorders / Q000150:complications* / Q000235:genetics*; D006801:Humans; D008297:Male; D028361:Mitochondrial Diseases; D009132:Muscles / Q000473:pathology; D009886:Ophthalmoplegia / Q000150:complications* / Q000235:genetics*; D017354:Point Mutation; D020641:Polymorphism, Single Nucleotide; D012362:RNA, Transfer, Ser / Q000235:genetics*
D004272:DNA, Mitochondrial; D012362:RNA, Transfer, Ser