Yang C C, Hwang C C, Pang C Y, Wei Y H
Department of Neurology, National Taiwan University Hospital, Taipei, Taiwan.
J Formos Med Assoc. 1998 Oct;97(10):715-9.
We report a patient with the A3243G point mutation of mitochondrial DNA (mtDNA) who presented with severe impairment of respiratory function and only mild involvement of limb muscles. This 55-year-old woman had a history of repeated episodes of respiratory failure unexplained by lung disease or central nervous system lesions. Needle electromyography suggested myopathy and muscle biopsy showed many ragged-red fibers. Molecular analysis of mtDNA in blood and muscle cells showed an A3243G point mutation in the tRNA(Leu(UUR))gene; the percentages of mutant mtDNA in blood and muscle cells were 65% and 71%, respectively. These findings suggest that mitochondrial myopathy should be considered as a cause of respiratory failure due to neuromuscular disorders, and that pure myopathy with predominant respiratory dysfunction is one of the heterogeneous phenotypic features associated with the A3243G point mutation of mtDNA.
我们报告了一名线粒体DNA（mtDNA）发生A3243G点突变的患者，该患者出现严重呼吸功能障碍，而肢体肌肉仅有轻度受累。这名55岁女性有反复发生呼吸衰竭的病史，肺部疾病或中枢神经系统病变无法解释其病因。针极肌电图提示肌病，肌肉活检显示许多破碎红纤维。血液和肌肉细胞中mtDNA的分子分析显示，tRNA（Leu（UUR））基因存在A3243G点突变；血液和肌肉细胞中突变型mtDNA的百分比分别为65%和71%。这些发现表明，线粒体肌病应被视为神经肌肉疾病导致呼吸衰竭的一个原因，且以呼吸功能障碍为主的单纯性肌病是与mtDNA的A3243G点突变相关的异质性表型特征之一。
