先天性房间隔缺损相关TBX5基因新突变研究

Mutation of the TBX5 gene associated with congenital atrial septal defect

目的:研究先天性房间隔缺损(ASD)相关TBX5基因新突变。方法:从中国汉族人群入选62例ASD患者和108名健康对照者,提取基因组DNA。对全部研究对象的TBX5基因的整个编码区进行测序分析以发现新的致病突变。构建野生型及突变型TBX5的真核表达载体,利用脂质体转染COS-7细胞,同时转染报告质粒心房利钠因子-荧光素酶及内对照质粒,应用双荧光素酶报告基因分析试剂研究突变型TBX5的转录活性。结果:在1例散发型ASD患者中发现了1个杂合性TBX5基因新突变,即c.318C>G(p.Y106X)突变。该无义突变不存在于108名健康对照者。功能分析表明突变型TBX5对靶基因的转录激活功能丧失。结论:发现1个ASD相关TBX5基因功能缺失性新突变,对ASD的个体化防治具有潜在的临床意义。

Objective:To study a novel TBX5 mutation involved in congenital atrial septal defect(ASD).Methods:A total of 62 patients of Han nationality with ASD and 108 healthy individuals were recruited,from which genomic DNA were extracted.The entire coding regions of the TBX5 gene were sequenced and analyzed for identification of novel mutation.The eukaryotic expression plasmid expressing wild-type and mutant TBX5 was constructed,respectively,and was transfected into COS-7 cells using lipofectamine,together with luciferase reporter plasmid of atrial natriuretic factor and internal control plasmid.The transcriptional activity of mutant TBX5 was measured by utilizing dual-luciferase reporter gene assay kit.Results:A novel heterozygous TBX5 mutation c.318 C>G(p.Y106 X),was discovered in a patient with sporadic ASD.The nonsense mutation was absent from the 108 healthy control subjects.Functional analysis demonstrated that mutant TBX5 lost the ability of transcriptional activation at target gene.Conclusions:The novel TBX5 loss-of-function mutation is involved in ASD,which has potential clinical implications for the personalized prophylaxis and treatment of ASD.