Liu Xing-Yuan, Yang Yi-Qing, Ma Jun, Lin Xiao-Ping, Zheng Jing-Hao, Bai Kai, Chen Yi-Han
Department of Paediatrics, Tongji Hospital of Tongji University, Shanghai 200065, China.
Zhonghua Xin Xue Guan Bing Za Zhi. 2010 Aug;38(8):724-7.
To identify the genetic defects in patients with congenital atrial septal defects (ASD).
The clinical data and blood samples from 180 unrelated subjects with congenital ASD were collected and evaluated. Two hundred healthy individuals served as controls. The coding exons and the flanking introns of GATA4 gene were amplified by polymerase chain reaction and sequenced using the di-deoxynucleotide chain termination approach. The acquired sequences were aligned with the sequences publicized in GenBank by the aid of programme BLAST to identify the sequence variations. Clustal W software was applied for analysis of the conservation of altered amino acids.
Two novel heterozygous missense GATA4 mutations were identified in 2 out of 180 ASD patients. Namely, the triplet substitutions of GTC for GGC at codon 21 and TCG for CCG at codon 87 were detected, predicting the conversions of glycine into valine at amino acid residue 21 (G21V) and proline into serine at amino acid residue 87 (P87S). None of the two mutations were detected in 200 healthy controls. Across-species alignment of GATA4 encoded protein sequences displayed that the mutated amino acids were highly conserved evolutionarily. Additionally, a single nucleotide polymorphism c.99G>T was observed. However, the polymorphic frequency distribution in ASD cases was similar with that in healthy controls (for genotype GT, χ(2) = 0.7556, P = 0.3847; for allele T, χ(2) = 0.7235, P = 0.3950).
Two novel mutations of GATA4 gene are identified in two unrelated ASD patients. This finding provides new insight into the molecular etiology responsible for ASD.
确定先天性房间隔缺损（ASD）患者的基因缺陷。
收集并评估180例无亲缘关系的先天性ASD患者的临床资料和血样。200名健康个体作为对照。采用聚合酶链反应扩增GATA4基因的编码外显子及其侧翼内含子，并使用双脱氧核苷酸链终止法进行测序。借助BLAST程序将获得的序列与GenBank中公布的序列进行比对，以识别序列变异。应用Clustal W软件分析氨基酸改变后的保守性。
在180例ASD患者中的2例中鉴定出两个新的杂合错义GATA4突变。具体而言，检测到密码子21处GTC取代GGC以及密码子87处TCG取代CCG的三联体替换，预测氨基酸残基21处甘氨酸转化为缬氨酸（G21V）以及氨基酸残基87处脯氨酸转化为丝氨酸（P87S）。在200名健康对照中均未检测到这两个突变。GATA4编码蛋白序列的跨物种比对显示，突变的氨基酸在进化上高度保守。此外，观察到一个单核苷酸多态性c.99G>T。然而，该多态性在ASD病例中的频率分布与健康对照相似（对于基因型GT，χ(2)=0.7556，P=0.3847；对于等位基因T，χ(2)=0.7235，P=0.3950）。
在两名无亲缘关系的ASD患者中鉴定出两个新的GATA4基因突变。这一发现为ASD的分子病因学提供了新的见解。
