Münscher C, Rieger T, Müller-Höcker J, Kadenbach B
Fachbereich Chemie (Biochemie), Philipps-Universität, Marburg, Germany.
FEBS Lett. 1993 Feb 8;317(1-2):27-30. doi: 10.1016/0014-5793(93)81484-h.
The A-to-G transition mutation in the tRNA(Lys) gene of mitochondrial DNA (mtDNA), characteristic for the maternally inherited MERRF syndrome (myoclonic epilepsy with ragged red fibers), has been identified by point mutation-specific polymerase chain reaction in extraocular muscle from 11 of 16 healthy people of different ages. No mutation was found in navel-string samples from 5 newborns, in HeLa cells, and in 2 individuals younger than 20 years. On the other hand, the mutation is present in all 5 tested 74-89-year-old individuals and in 6 of 9 20-70-year-old individuals. The amount of mutated from total mtDNA was estimated by 'mispairing PCR' in extraocular muscle of 2 individuals of 74 and 89 years to 2.0 and 2.4%, respectively. In most tissue samples the MERRF mutation occurs together with the 'common deletion' of mtDNA, which was previously shown to accumulate in healthy individuals with increasing age. It is proposed that during aging, deletions and point mutations of mtDNA accumulate, which could impair mitochondrial energetics.
线粒体DNA（mtDNA）的tRNA（Lys）基因中的A到G转换突变是母系遗传的肌阵挛性癫痫伴蓬毛样红纤维（MERRF）综合征的特征性突变，通过点突变特异性聚合酶链反应在16名不同年龄的健康人的眼外肌中，有11人被检测到。在5名新生儿的脐带样本、HeLa细胞以及2名20岁以下的个体中未发现突变。另一方面，在所有5名年龄在74 - 89岁的受测个体以及9名年龄在20 - 70岁的个体中的6人中发现了该突变。通过“错配PCR”估计，在2名年龄分别为74岁和89岁个体的眼外肌中，突变型mtDNA占总mtDNA的比例分别为2.0%和
