Moslemi A R, Selimovic N, Bergh C H, Oldfors A
Department of Pathology, Sahlgrenska University Hospital, Göteborg, Sweden.
Cardiology. 2000;94(1):68-71. doi: 10.1159/000007049.
A 27-year-old man was admitted to hospital because of severe cardiac failure. Investigation revealed dilated cardiomyopathy with a left ventricular ejection fraction of 15-20%. During adolescence the patient had been investigated for growth retardation and he also had progressive external ophthalmoplegia. There had been no symptoms of cardiac disease until 2 weeks before admittance. An endomyocardial biopsy showed cardiomyocytes deficient in cytochrome c oxidase (COX) in a mosaic pattern. A skeletal muscle biopsy showed mitochondrial myopathy with COX-deficient ragged-red fibers. Molecular genetic analysis revealed a heteroplasmic, 3.8-kb, mitochondrial DNA (mtDNA) deletion in heart and muscle. PCR-based quantification of the proportion of mtDNA with deletion showed 47% mutated mtDNA in the myocardial biopsy and 68% in muscle. In spite of treatment, the condition deteriorated and the patient died 5 days after admittance. This case demonstrates that mtDNA deletions may occasionally be the cause of severe dilated cardiomyopathy, and that morphological and molecular genetic diagnosis may be obtained by endomyocardial biopsy.
一名27岁男性因严重心力衰竭入院。检查发现为扩张型心肌病，左心室射血分数为15% - 20%。患者青春期时曾因生长发育迟缓接受检查，还患有进行性眼外肌麻痹。入院前2周前一直没有心脏病症状。心肌内膜活检显示心肌细胞细胞色素c氧化酶（COX）呈镶嵌式缺乏。骨骼肌活检显示线粒体肌病伴COX缺乏的破碎红纤维。分子遗传学分析显示心脏和肌肉中存在异质性的3.8kb线粒体DNA（mtDNA）缺失。基于PCR的mtDNA缺失比例定量显示，心肌活检中47%的mtDNA发生突变，肌肉中为68%。尽管进行了治疗，病情仍恶化，患者入院5天后死亡。该病例表明，mtDNA缺失偶尔可能是严重扩张型心肌病的病因，并且可通过心肌内膜活检进行形态学和分子遗传学诊断。
