Hamazaki S, Koshiba M, Sugiyama T
Department of Pathology, Faculty of Medicine, Kyoto University, Japan.
Acta Pathol Jpn. 1993 Apr;43(4):187-91. doi: 10.1111/j.1440-1827.1993.tb01130.x.
Point mutations in the mitochondrial tRNA(leu(UUR)) gene have been recently reported in patients with mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes (MELAS). To investigate the relationship between the degree of heteroplasmy and the organ damage, the ratio of mutant and wildtype genes was quantitated in 14 different organs obtained at an autopsy case of MELAS. The percentages of mitochondrial tRNA(leu(UUR)) gene carrying an A to G transition mutation at nucleotide 3243 were determined by the restriction enzyme digestion of the polymerase chain reaction products. The organs largely depending on oxidative phosphorylation for the sources of energy contained higher proportions of the mutant tRNA(leu(UUR)) gene than organs with a lower oxygen demand. However, the percentage of the mutant genes was similar in both symptomatic and asymptomatic organs with a higher oxygen demand.
线粒体肌病、脑病、乳酸酸中毒和卒中样发作（MELAS）患者中最近报道了线粒体tRNA（leu（UUR））基因的点突变。为了研究异质性程度与器官损伤之间的关系，在一例MELAS尸检病例中，对取自14个不同器官的突变型和野生型基因的比例进行了定量分析。通过聚合酶链反应产物的限制性酶切来确定携带核苷酸3243处A到G转换突变的线粒体tRNA（leu（UUR））基因的百分比。与对氧需求较低的器官相比，在很大程度上依赖氧化磷酸化作为能量来源的器官含有更高比例的突变型tRNA（leu（UUR））基因。然而，在对氧需求较高的有症状和无症状器官中，突变基因的百分比相似。
