A novel mutation (8342G-->A) in the mitochondrial tRNA(Lys) gene associated with progressive external ophthalmoplegia and myoclonus.

TitleA novel mutation (8342G-->A) in the mitochondrial tRNA(Lys) gene associated with progressive external ophthalmoplegia and myoclonus.
Publication TypeJournal Article
Year of Publication1999
AuthorsTiranti, V, Carrara, F, Confalonieri, P, Mora, M, Maffei, RM, Lamantea, E, Zeviani, M
JournalNeuromuscul Disord
Volume9
Issue2
Pagination66-71
Date Published1999 Mar
ISSN0960-8966
KeywordsAdenine, Adult, Autoanalysis, Base Sequence, Epilepsies, Myoclonic, Female, Guanine, Humans, Molecular Sequence Data, Nucleic Acid Conformation, Ophthalmoplegia, Chronic Progressive External, Pedigree, Point Mutation, RNA, RNA, Mitochondrial, RNA, Transfer, Lys
Abstract

We describe a patient who suffered from impaired ocular motility from age 10 years and at 16 years developed ptosis, proximal weakness and progressive fatigability. At 35 years she developed massive myoclonic jerks, and head and distal tremor. A muscle biopsy showed a high percentage of cytochrome c oxidase negative fibers but no ragged-red fibers. A novel heteroplasmic mutation (8342G-->A) was found in the mitochondrial transfer RNA(Lys) gene by single-strand conformation polymorphism screening, followed by sequence and restriction fragment length polymorphism analysis. Approximately 80% of muscle mitochondrial DNA (mtDNA) harbored the mutation, while the mutation was absent in lymphocyte DNA of the proband, as well as of her mother, daughter and a maternal aunt. However, the pathogenicity of the mutation was confirmed by restriction fragment length polymorphism analysis of single muscle fibers, which revealed a significantly greater level of mutant mtDNA in cytochrome c oxidase negative over cytochrome c oxidase positive fibers.

DOI10.1016/s0960-8966(98)00103-5
Alternate JournalNeuromuscul. Disord.
Citation Key10.1016/s0960-8966(98)00103-5
PubMed ID10220860