房室间隔畸形患者GATA-4基因一个新的突变功能初步研究  

Preliminary functional analysis of a novel mutation in GATA-4 gene in Chinese patients with congenital cardiac septal defects

作　　者：陈名武[1] 庞玉生[1] 郭颖[2] 刘炳丽 沈捷 宋怀东 刘唐威 

机构地区：[1]广西医科大学第一附属医院儿科,南宁530021 [2]上海交通大学附属上海儿童医学中心 [3]附属瑞金医院国家基因组学重点实验室 [4]附属上海儿童医院 [5]广西心血管病研究所

出　　处：《中华医学遗传学杂志》2009年第3期277-281,共5页Chinese Journal of Medical Genetics

摘　　要：目的探讨先天性房室间隔畸形患者GATA-4基因的突变以及对所发现的突变点进行功能初步分析。方法选择的50例汉族先天性房室间隔畸形患者，用聚合酶链反应方法扩增GATA-4基因6个外显子编码区和邻近序列后分别直接测序，并与100名同民族健康者比较；利用生物信息学方法预测点突变对GATA-4蛋白结构和功能影响；以野生型pcDNA3．1-GATA4为模板，用基因定点突变的方法构建突变型GATA-4真核表达载体，在体外和ANF报告质粒共转染Hela细胞，48h后检测下游报告基因的活性。结果发现GATA-4基因一个新的杂合子H436Y突变，在NCBI的SNP数据库中未见报道，且在100名对照者中也未发现；GATA-4基因编码第436位组氨酸在生物进化过程中处于高度保守；SIFT和PolyPhen程序预测H436Y突变可能影响GATA-4蛋白质的功能；突变型GATA-4H436Y质粒激活下游报告基因活性明显下降，与野生型GATA-4质粒相比是（53．8±6．6）％，差异具有统计学意义（P〈0．01）。结论GATA-4基因H436Y杂合子突变可能是中国汉族先天性房室间隔畸形致病原因之一。Objective To perform the functional analysis of a novel H436Y mutation of GATA-4 gene identified in Han Chinese patients with congenital cardiac septal defects. Methods Using bioinformaties to predict if the H436Y mutation in the GATA-4 gene affects its protein function. H436Y mutation in the GATA-4 gene was generated by Quick Change Lightning site-directed mutagenesis kit and verified by DNA sequencing. GATA-4-wt or GATA 4-rout DNA was cotransfected into Hela cells with DNA for the luciferase reporter gene atrial natriuretic factor （ANF）, and lueiferase activity was measured by an LKB luminometer 48 h after transient transfection. Results Alignment of the GATA-4 amino acid sequence indicated that the histidine residue at position 436 was conserved, and H436Y mutation in the GATA-4 gene is expected to affect its protein function. The H436Y mutation significantly reduced the transcriptional activation of downstream reporter ANF when compared to wild-type GATA-4 （P〈0. 01）. Conclusion The mutation c. 1306C→T of the GATA-4 gene impaired the activation of the downstream target, suggesting that the H436Y mutation in the C-terminal region of the GATA-4 gene might prevent its biological function.

关 键 词：先天性心脏病 GATA-4基因 突变 细胞转染 

分 类 号：R686[医药卫生—骨科学]