单纯性房间隔缺损患儿GATA4和GATA6基因突变筛查

The mutations of GATA4 and GATA6 in children with isolated atrial septal defect

目的探讨GATA4和GATA6基因在单纯房间隔缺损(ASD)患儿中的突变情况。方法收集2012年11月至2013年11月就诊并拟行封堵术的101例单纯ASD患儿(99例非家族性患儿及一对双胞胎ASD患儿),同时以100例种族匹配并排除先天性心脏病、血液系统疾病及染色体异常儿童作为对照组,采集静脉血,应用PCR扩增GATA4和GATA6基因的全部编码区及其侧翼部分序列,采用双脱氧核苷链末端合成终止法对扩增片段进行测序,然后与Gen Bank中的基因编码序列进行比对。结果在ASD患儿中发现两个新的GATA6错义突变c.145 G>A和c.151 G>A,其均未在对照组中出现;这两个突变导致编码区第49位的甘氨酸和第51位的谷氨酸分别变为丝氨酸和赖氨酸。在9例ASD患儿和7例对照组儿童中发现一个GATA6突变c.43 G>C,引起第15位的甘氨酸变为精氨酸。此外在GATA4编码区中发现一个不引起氨基酸改变的单核苷酸多态性变化,即c.99G>T。结论 GATA6基因作为心脏发育过程中重要的转录因子,其点突变可能引起GATA6蛋白功能的改变并造成其转录活性的变化,从而导致单纯ASD的发生。

Objective To identify mutations of GATA4 and GATA6 genes in children with isolated congenital atrial septal defect（ASD）.Methods From November 2012 to November 2013,101 patients with ASD（99 unrelated patients and one twin） who were submitted to catheter-based intervention and 100 ethnicity-matched children without congenital heart disease,blood disorders and chromosomal abnormalities were enrolled.The blood was collected.The coding regions and flanking regions of the GATA4 and GATA6 genes were amplified by polymerase chain reaction and sequenced using the dideoxvnucleotide chain termination technique,and then compared with the normal sequence in the Genbank.Results Two novel heterozygous missense GATA6 mutations,c.G145 A and c.G151 A,were identified in 2 unrelated ASD patients,which were not present in the controls.These two mutations predicted the conversion of glycine into serine at amino acid residue 49（G49S） and glutamate into lysine at amino acid residue 52（K52E）.A heterozygous missense GATA6 mutation c.43 G〉C,which caused a conversion from glycine to arginine,was found in 9 ASD patients and 7 controls.A single nucleotide polymorphism c.99G〉T,which did not cause amino acid conversion in GATA4 gene,was found.Conclusions GATA6 gene is an important transcription factor in heart development.The mutation of GATA6 gene may cause the change of its transcriptional activity,and lead to ASD.