CITED2基因在内脏反位患者中的突变分析

Mutation analysis of CITED2 gene in patients with situs inversus

目的·研究CITED2 基因突变与内脏反位的关系。方法·选取24 例内脏反位的患者和100 名健康儿童对照,从外周血提取基因组DNA,使用PCR 扩增技术和Sanger 测序技术来检测CITED2 的外显子区域;通过软件Sift、PolyPhen-2、PROVEAN 和MutationTaster 预测突变是否存在致病性;使用Y. Zhang 实验室服务器构建蛋白质的三维结构,导入SWISS-PdbViewer 查看突变对蛋白质结构的影响。结果·在1 例内脏反位的患者中发现了1 个新发的杂合错义突变c.418C>T(p.P140S),此突变在对照组中未发现。软件SIFT 和Mutation Taster 预测此突变具有致病性。SWISS-PdbViewer 显示,第140 位脯氨酸突变为丝氨酸后,第137 位天冬氨酸上的3个氢键全部断开,第140 位丝氨酸和第142 位丙氨酸重新建立了一个异常弱氢键。结论· CITED2 基因c.418C>T(p.P140S)突变可能影响CITED2 的生物学活性,与内脏反位的发生有关。

Objective · To analyze the correlation between CITED2 gene mutation and situs inversus. Methods · A total of 24 patients with situs inversus and 100 healthy controls were collected. The genomic DNA was isolated from their peripheral blood. PCR and Sanger sequecing were employed to analyze the exons of CITED2. The potential effect of the mutation was characterized by the software Sift, PolyPhen-2, PROVEAN and Mutation Taster. The Y. Zhang laboratory server was used to predict the three-dimensional structure of the protein, and the SWISS-PdbViewer was imported to see the impacts of the mutation on the protein structure. Results · A novel heterozygous CITED2 mutation c.418C>T (p.P140S) was identified in 1 patient with situs inversus, which was absent in all controls. The novel heterozygous p.P140S mutation was predicted to be pathogenic by SIFT and Mutation Taster. The SWISS-PdbViewer showed that the mutation p.P140S caused all three hydrogen bonds on the aspartic acid at position 137 to be disconnected, and an abnormal weak hydrogen bond was re-established between the serine at position 140 and the alanine at position 142. Conclusion · The novel heterozygous mutation c.418C>T (p.P140S) may affect the biological activity of CITED2 and may be related to situs inversus.