A novel mutation in the mitochondrial tRNA(Ala) gene (m.5636T>C) in a patient with progressive external ophthalmoplegia.
We report a heteroplasmic novel mutation m.5636T>C in the mt-tRNA(Ala) in a patient with bilateral ptosis and ophthalmoparesis in whom a muscle biopsy showed cytochrome c oxdidase (COX) negative and ragged red fibers. Using laser capture microdissection we have isolated COX negative fibers and COX positive fibers from the muscle of the patient and determined that the mutation load was clearly increased in COX negative muscle fibers. Additionally, the mutated m.5636T nucleotide is conserved in all the mammal and non-mammal species analyzed and might be structurally relevant as it is located in a position involved in the formation of tertiary structure of canonical mitochondrial tRNAs.
Pinós
Tomàs
T
Unitat de Patologia Mitocondrial i Neuromuscular, Institut de Recerca Hospital Universitari Vall d'Hebron, Universitat Autònoma de Barcelona, Barcelona, Spain. tpinos@ir.vhebron.net
Marotta
Mario
M
Gallardo
Eduard
E
Illa
Isabel
I
Díaz-Manera
Jorge
J
Gonzalez-Vioque
Emiliano
E
García-Arumí
Elena
E
Andreu
Antoni L
AL
Martí
Ramon
R
D000328:Adult; D001706:Biopsy; D004272:DNA, Mitochondrial / Q000235:genetics; D050259:Genes, Mitochondrial; D006801:Humans; D008297:Male; D042282:Microdissection / Q000379:methods; D008928:Mitochondria / Q000378:metabolism / Q000473:pathology; D018482:Muscle, Skeletal; D009154:Mutation; D017246:Ophthalmoplegia, Chronic Progressive External / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D012344:RNA, Transfer, Ala / Q000235:genetics*
D004272:DNA, Mitochondrial; D012344:RNA, Transfer, Ala