Goto Y
Department of Ultrastructural Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry.
Nihon Rinsho. 1997 Dec;55(12):3259-64.
Mitochondrial DNA (mtDNA) mutations were discovered during a few years around 1990 and thought to be assigned to the three major clinical forms of mitochondrial myopathies. Then, several mtDNA mutations were detected in each disease and the common mutations were found in more than one disease, suggesting genotype and phenotype heterogeneity. Heteroplasmy, tissue/cellular specificity and threshold effect have been extensively studied using skeletal muscle and culture cells from the patients, but the major part of the relations up between mtDNA genotype and clinical phenotype remains unknown. Because of the facts that mtDNA mutations have been found in other clinical forms (not myopathies), and frataxin, the product of the responsible gene for Freidreich ataxia, may be associated with mtDNA biogenesis, disease entity accompanied by mtDNA abnormalities could expand more in the future.
线粒体DNA（mtDNA）突变于1990年前后的几年间被发现，并被认为与线粒体肌病的三种主要临床类型有关。随后，在每种疾病中都检测到了几种mtDNA突变，并且在不止一种疾病中发现了常见突变，这表明基因型和表型存在异质性。利用患者的骨骼肌和培养细胞，对异质性、组织/细胞特异性和阈值效应进行了广泛研究，但mtDNA基因型与临床表型之间的主要关系仍不清楚。由于在其他临床类型（非肌病）中也发现了mtDNA突变，并且弗里德赖希共济失调致病基因的产物frataxin可能与mtDNA生物合成有关，未来伴有mtDNA异常的疾病实体可能会进一步扩大。
