CAJ | 학술논문

目的研究线粒体呼吸链复合物活性缺陷导致心脏损害患儿的临床、生化和基因特点.方法 3例患儿分别于8、4、3岁时因心律失常和心脏增大,于2009年1月至2012年5月在北京大学第一医院就诊.经过生化、尿有机酸分析、血氨基酸与酯酰肉碱谱分析、溶酶体酶活性测定等检查排除了炎症、免疫性疾病及氨基酸、有机酸、脂肪酸、溶酶体代谢病导致的心脏疾病.采用外周血白细胞分光光度法测定线粒体呼吸链酶复合物活性,并进行线粒体全基因序列分析.结果 2例为肥厚型心肌病；心功能Ⅰ～Ⅱ级.1例为心律失常；心功能Ⅰ级.血清磷酸肌酸激酶、肌酸激酶同工酶增高.3例患儿均有不同类型的线粒体呼吸链酶复合物活性缺陷,例1为呼吸链复合物Ⅲ和Ⅴ缺陷,复合物Ⅰ+Ⅲ活性18.7 nmol/(min·mg线粒体总蛋白),复合物Ⅴ活性20.4 nmol/(min·mg线粒体总蛋白).线粒体基因分析显示tRNAGluA14693G突变,D-loop区T16519C突变.例2为单纯呼吸链复合物Ⅰ缺陷,活性为22.0 nmol/(min·mg线粒体总蛋白).D-loop区A16183C、T16189C、G15043A突变.例3为呼吸链复合物Ⅳ和Ⅴ缺陷,分别是21.0 nmol/(min·mg线粒体总蛋白)和23.2 nmol/(min·mg线粒体总蛋白).D-loop区C253T、C16187T突变.单倍型分析3例患儿均属H2a2a.结论表现为心脏损害的线粒体病临床上可表现为心肌病、心律失常等,有多种线粒体呼吸链复合物缺陷类型,线粒体基因tRNAGlu A14693G突变为病因之一.
목적 연구선립체호흡련복합물활성결함도치심장손해환인적림상、생화화기인특점.방법 3례환인분별우8、4、3세시인심률실상화심장증대,우2009년1월지2012년5월재북경대학제일의원취진.경과생화、뇨유궤산분석、혈안기산여지선육감보분석、용매체매활성측정등검사배제료염증、면역성질병급안기산、유궤산、지방산、용매체대사병도치적심장질병.채용외주혈백세포분광광도법측정선립체호흡련매복합물활성,병진행선립체전기인서렬분석.결과 2례위비후형심기병；심공능Ⅰ～Ⅱ급.1례위심률실상；심공능Ⅰ급.혈청린산기산격매、기산격매동공매증고.3례환인균유불동류형적선립체호흡련매복합물활성결함,례1위호흡련복합물Ⅲ화Ⅴ결함,복합물Ⅰ+Ⅲ활성18.7 nmol/(min·mg선립체총단백),복합물Ⅴ활성20.4 nmol/(min·mg선립체총단백).선립체기인분석현시tRNAGluA14693G돌변,D-loop구T16519C돌변.례2위단순호흡련복합물Ⅰ결함,활성위22.0 nmol/(min·mg선립체총단백).D-loop구A16183C、T16189C、G15043A돌변.례3위호흡련복합물Ⅳ화Ⅴ결함,분별시21.0 nmol/(min·mg선립체총단백)화23.2 nmol/(min·mg선립체총단백).D-loop구C253T、C16187T돌변.단배형분석3례환인균속H2a2a.결론 표현위심장손해적선립체병림상상가표현위심기병、심률실상등,유다충선립체호흡련복합물결함류형,선립체기인tRNAGlu A14693G돌변위병인지일.
Objective Mitochondrial disease is a group of energy metabolic disorders,characterized by involvement of multisystem with high energy requirements.Encephalomyopathies are common clinical findings of the mitochondrial diseases.However,mitochondrial cardiac damage is not rare.In this study,the clinical,biological,and genetic analyses were performed in three patients with mitochondrial cardiac damage,in order to understand the characteristics of mitochondrial diseases.Method Three girls presented with arrhythmia and cardiac enlargement from the age of 3,4 and 8 years respectively.They were admitted into the Peking University First Hospital.Infection,autoimmune diseases,aminoacidopathies,organic acidurias,mitochondrial-fatty acid oxidation defects,and lysosomal storage disease were excluded by routine laboratory examinations and metabolic analysis for blood amino acids,acylcarnitines,urinary organic acids,and lysosome activity assay.Peripheral leukocytes mitochondrial respiratory chain enzyme Ⅰ to Ⅴ activities were measured by spectrophotometry.The entire sequence of the mitochondrial DNA was analyzed.Result In two patients (case 1 and case 3),hypertrophic cardiomyopathy and grade Ⅰ to grade Ⅱ of cardiac function were found.One patient (case 2) was diagnosed with arrhythmia and grade Ⅰ of cardiac function.Increased creatine phosphokinase and creatine kinase isoenzyme MB were observed.Mitochondrial respiratory chain complex deficiencies were indentified in the three patients.Patient 1 had combined deficiencies of complex Ⅲ and Ⅴ.The activity of complex Ⅰ + Ⅲ was 18.7 nmol/(min · mg mitochondrial protein)(control 84.4 ± 28.5).The activity of complex Ⅴ was 20.4 nmol/(min · mg mitochondrial protein)(control 103.7 ± 29.2).In her mitochondrial gene,A14693G on tRNAGlu and T16519C on D-loop were found.Patient 2 had an isolated complex Ⅰ deficiency.The activity was 22.0 nmol/(min · mg mitochondrial protein) (control 44.0 ± 5.4).A16183C,T16189C and G15043A mutations on D-loop were found.Patient 3 had a combined deficiency of complex Ⅳ and Ⅴ.The activity of complex Ⅳ was 21.0 nmol/(min · mg mitochondrial protein) (control 54.1 ± 12.3).The activity of complex Ⅴ was 23.2 nmol/(min · mg mitochondrial protein) (control 103.7 ± 29.2).C253T and C16187T mutations on D-loop were detected.Haplotype analysis showed that three patients belong to H2a2a.Improvement was observed after the treatment with L-carnitine,coenzyme Q10,vitamin C and E.At present,the patients are 7,5 and 8 years old.Although excise intolerance still persists,they had a good general condition with normal school life.Conclusion The mitochondrial diseases with cardiac damage show cardiomyopathy,arrhythmia and exercise intolerance.Many kinds of mitochondrial respiratory chain deficiency were observed.A14693G in mitochondrial tRNAGlu gene is probably one of the causes in China.