以心肌病和呼吸肌受累为主要表现的线粒体病

摘要

目的 线粒体基因3243A＞G突变是导致经典性线粒体病的常见突变,临床表现以神经肌肉损害为主,现就1例以心脏损害和呼吸肌受累为主要表现的儿童线粒体病进行研究.方法 回顾患儿临床特点和诊治过程,并总结临床表现与病理、遗传学特点的关系.结果 患儿,女,10岁发病,以心力衰竭和呼吸衰竭为主要临床特征.骨骼肌肉病理分析见破碎红纤维;外周血白细胞线粒体基因3243A＞G突变率为94％,为tRNA Leu(UUR)突变.经过呼吸支持、纠正心力衰竭和大剂量磷酸肌酸钠、左卡尼汀等改善线粒体能量代谢治疗后好转出院,长期口服左卡尼汀、辅酶Q10及夜间无创通气,随访2年余病情未再反复,生长发育明显进步,现在12岁,正常上学.结论 以心脏损害和呼吸肌受累同时为首发临床表现的儿童线粒体病并不多见,并且罕有以心肌病为主的线粒体基因3243A＞G突变患者;肌肉组织病理及基因分析是疾病诊断的关键手段,改善线粒体能量代谢和辅助通气治疗有一定疗效.%Objective The 3243A ＞ G mutation in mitochondrial DNA is a common cause of the classical mitochondrial diseases characterized by neuro-muscular disorders.This study reports a rare case with the main manifestations of mitochondrial disease in children of mitochondrial cardiomyopathy and respiratory muscle damage.Methods The clinical characteristics,diagnosis and treatment,biochemical,pathological and genetic features of a 10-year-old girl were studied.Results The girl was admitted because of heart failure and respiratory failure at the age of 10.Ragged red fibers in skeletal muscles had been noticed.On her mitochondrial gene,3243A ＞ G mutation,Leu tRNA (UUR),was detected.The mutation rate in the peripheral blood cells was 94％.After the treatment with a high dose of creatine phosphate sodium,coenzyme Q10 and L-carnitine with assisted ventilation,the patient improved rapidly.The child was followed up for 2 years without recurrence.Meanwhile the growth,development and daily life were normal.Conclusions Cardiac and respiratory muscle impairments that appeared at the same time as the first manifestations of the children's mitochondrial disease is not common,and it is rare to have cardiomyopathy based mitochondrial gene 3243A ＞ G mutation is seldom seen clinically.Skeletal muscle biopsy and genetic test is the key for accurate diagnosis.Improving mitochondrial metabolism and assisted ventilation appear to be helpful treatments.