散发性扩张型心肌病相关ISL1基因突变分析

Mutation of the ISL1 gene associated with sporadic dilated cardiomyopathy

目的:分析散发性扩张型心肌病(DCM)相关ISL1基因突变谱。方法:收集226例散发性DCM患者和230名相匹配的健康人的血标本,抽提DNA。通过聚合酶链反应-测序分析ISL1基因的编码外显子及侧翼内含子。对所发现的ISL1基因突变,应用ClustalW2软件评估突变氨基酸在进化上的保守性,应用在线程序MutationTaster、PolyPhen-2和PROVEAN预测突变的致病性,应用双荧光素酶报告基因分析系统评估突变的功能效应。结果:在1例散发性DCM患者的ISL1基因中检测出1个新的杂合错义突变(c.706G>T即p.Asp236Tyr),该突变不存在于对照组。跨物种ISL1蛋白序列比对分析表明该被改变的氨基酸在进化上完全保守,致病性预测显示该基因突变具有致病性,生化分析表明突变体对靶基因的转录激活功能显著降低。结论:发现1个ISL1基因功能缺失性新突变,可能导致DCM,对DCM的早期个体化防治具有潜在的临床意义。

Objective:To analyze the mutation spectrum of the ISL1 gene associated with sporadic dilated cardiomyopathy(DCM).Methods:Blood samples from 226 patients with sporadic DCM and 230 healthy individuals were collected,from which DNAs were extracted.The entire coding exons and flanking introns of the ISL1 gene were analyzed by polymerase chain reaction-DNA sequencing in all participants.The ClustalW2 software was used to analyze whether the mutated amino acid was evolutionarily conserved.The disease-causing potential of the identified mutation was predicted by PROVEAN,MutationTaster and PolyPhen-2.The functional characteristics of the mutant ISL1 were assayed by the dual-luciferase reporter assay system.Results:A new heterozygous missense ISL1 mutation,c.706 G>T(p.Asp236 Tyr),was detected in one patient with sporadic DCM.The mutation was absent from the control individuals.The altered amino acid was completely conserved evolutionarily across species,and the mutation were predicted to be pathogenic.Biological analyses revealed that the mutant ISL1 was associated with significantly reduced transactivation of a target gene.Conclusions:The new ISL1 mutation is involved in the pathogenesis of DCM,which has potential clinical implications for the early prophylaxis and treatment of DCM.