Genetic biochemical and pathophysiological characterization of a familial mitochondrial encephalomyopathy (MERRF)

摘要: Abstract Myoclonic epilepsy with ragged-red fibers (MERRF) syndrome is a neuromuscular disorder characterized by mitochondrial myopathy and progressive myoclonus epilepsy. A heteroplasmic to G transition mutation in the encoded tRNA Lys gene at nucleotide pair 8344 has been suggested be linked MERRF-syndrome. We have investigated biochemically histochemically muscle biopsies studied genomes of hair, blood tissue family including three cases MERRF-syndrome as well unaffected relatives within maternal lineage. Sequence analysis mtDNAs, performed after amplification polymerase chain reaction (PCR), confirmed position 8344. The additional point 750 12 S rRNA gene, which was also found Shoffner et al. (1990), however, absent all tissues. Quantitative percentage mutated mtDNA mispairing PCR (Seibel al., 1990) revealed variable contents different tissues individuals, members. Mitochondrial protein synthesis cultured fibroblasts from MERRF patients diminished incorporation 35 S-methionine into lysine-containing peptides.