کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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1914614 | 1535170 | 2010 | 4 صفحه PDF | دانلود رایگان |
Mitochondrial disorders are often associated with mutations in mitochondrial tRNA. Independent observation of the same molecular defect in unrelated subjects is a generally required proof of pathogenicity. A sporadic case of chronic external ophthalmoplegia (cPEO) with ragged red fibres (RRFs) has been previously related to an m.12316G>A substitution in tRNALeu(CUN).Sequencing muscle-derived mtDNA, we found the m.12316G>A substitution in an adult woman with mitochondrial myopathy and respiratory impairment. Her muscle biopsy presented several cytochrome c oxidase-negative (COX−) fibres, and RRFs as signs of mitochondrial proliferation. Restriction-fragment length polymorphism (RFLP) analysis of the mutation in isolated muscle fibres showed a threshold of at least 60% of mutated mtDNA to determine a COX deficiency phenotype. This second report of the m.12316G>A mutation in a sporadic patient consolidates its pathogenic nature and provides further elements for genetic counselling.
Journal: Journal of the Neurological Sciences - Volume 292, Issues 1–2, 15 May 2010, Pages 107–110