Tanno Y, Yoneda M, Nonaka I, Tanaka K, Miyatake T, Tsuji S
Department of Neurology, Niigata University, Japan.
Biochem Biophys Res Commun. 1991 Sep 16;179(2):880-5. doi: 10.1016/0006-291x(91)91900-w.
An A to G transition at nucleotide position 8,344 in tRNALys of mitochondrial DNA has been recently identified as a causative mutation of myoclonus epilepsy associated with ragged-red fibers (MERRF). To investigate if the degree of heteroplasmy of mitochondrial DNA is correlated with the severity of MERRF, we have developed a novel method for quantitation of the mutant mitochondrial DNA by polymerase chain reaction using a mismatched primer. With the method, populations of mutant mtDNAs from 5 cases of MERRF carrying the tRNALys mutation were analyzed. The tight linkage of the severity of symptoms and the degree of heteroplasmies is not necessarily observed for all cases, though there is a tendency that patients with less wild type mtDNAs show severer clinical symptoms and earlier onset.
线粒体DNA中赖氨酸转运RNA（tRNALys）第8344位核苷酸处的A到G转换最近被确定为与肌阵挛性癫痫伴破碎红纤维（MERRF）相关的致病突变。为了研究线粒体DNA异质性程度是否与MERRF的严重程度相关，我们开发了一种新方法，通过使用错配引物的聚合酶链反应来定量突变的线粒体DNA。利用该方法，分析了5例携带tRNALys突变的MERRF患者的突变型线粒体DNA群体。虽然存在野生型线粒体DNA较少的患者临床症状更严重且发病更早的趋势，但并非所有病例都必然观察到症状严重程度与异质性程度的紧密联系。
