Amornvit Jakkrit, Pasutharnchat Nath, Pachinburavan Monvasi, Jongpiputvanich Sungkom, Joyjinda Yutthana
J Med Assoc Thai. 2014 Apr;97(4):467-72.
Mitochondrial disease is a group of rare disorders, caused by mitochondrial dysfunction. They are usually the result of mutations of either mitochondrial DNA or nuclear DNA. A3243G transition in the tRNALeu is one the most frequent mutations of the mitochondrial DNA. Phenotypic expression of this mutation varies. The most well-recognized phenotype is Mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS) syndrome. Isolated myopathy with respiratory muscle weakness in this mutation has been rarely documented. The authors reported a 20-year-old Asian female presenting with a fulminant hypoventilatory respiratory failure with mild weakness of the limbs. Electrophysiologic study showed evidences of myopathy. Restrictive physiology of the lungs was demonstrated by pulmonary function test. Subsarcolemmal accumulation of mitochondria was demonstrated by Gomori trichrome and succinate dehydrogenase stains. Genetic study revealed the A3243G mutation in mitochondrial DNA in peripheral blood Isolated mitochondrial myopathy severely affecting respiratory muscles may be considered as an uncommon clinical spectrum of A3243G mitochondrial disease.
线粒体疾病是一组由线粒体功能障碍引起的罕见疾病。它们通常是线粒体DNA或核DNA突变的结果。tRNALeu中的A3243G转换是线粒体DNA最常见的突变之一。这种突变的表型表达各不相同。最广为人知的表型是线粒体脑肌病、乳酸酸中毒和卒中样发作（MELAS）综合征。这种突变导致的孤立性肌病伴呼吸肌无力的情况鲜有文献记载。作者报告了一名20岁的亚洲女性，表现为暴发性通气不足性呼吸衰竭，伴有轻度肢体无力。电生理研究显示有肌病的证据。肺功能测试显示肺部存在限制性生理改变。Gomori三色染色和琥珀酸脱氢酶染色显示肌膜下线粒体堆积。基因研究揭示外周血线粒体DNA存在A3243G突变。严重影响呼吸肌的孤立性线粒体肌病可被视为A3243G线粒体疾病的一种罕见临床类型。
