先心病相关微缺失的快速筛查和诊断方法

Fast screening and diagnosis of CHD-associated microdeletion

目的建立简便易行的用于筛查先心病病因的诊断技术平台。方法在单核苷酸多态数据库中选择先心病相关的22q11染色体区段内和锌指蛋白4基因编码区内的单核苷酸多态位点,采用多聚酶链式反应—限制性片段长度多态性法对单核苷酸多态标记在116个正常人群中基因型的杂合度进行测定,检测14例心脏畸形胎儿家系等位基因的基因型,并利用连锁分析间接诊断微缺失的发生情况。结果22q11染色体区段上的单核苷酸多态rs4819523基因型杂合度为0.431,锌指蛋白4基因单核苷酸多态基因型杂合度为0.569。筛查到1例锌指蛋白4单等位基因缺失的畸形胎儿。结论多聚酶链式反应-限制性片段长度多态性法应用于22q11染色体微缺失和锌指蛋白4基因缺失的检测方便快捷,适用于先天性心脏畸形病因的初步筛查和遗传诊断。

Objective To establish a feasible and effective diagnostic technique platform to screen cause of congenital heart disease （CHD）. Methods Through extensive screening of dbSNP, single nucleotide polymorphism （SNP） markers located in coding area of zinc finger protein 4 （ZICA） and 22ql I chromosomal region that were considered to be related to congenital heart defects were selected. Heterozygosities of 116 normal individuals and 14 families of congenital heart defects were detected by using PCR-RFLP assay. Leakage analysis was used to diagnose indirectly incidence of microdeletion. Results The heterozygosities of genotype of SNP rs4819523 located in 22ql 1 region and genotype of SNP rs2279830 located in ZIC 4 among normal population were 0.43 and 0.569, respectively. Single allele deletion in ZICA of 1 malformed fetus suffering from Dandy-Walker syndrome as well as congenital heart malformation was found. Conclusion PCR-RFLP used in detection of microdeletion in 22ql 1 chromosome and gene deletion of ZICA is convenient and fast for preliminary etiological screening and genetic diagnosis of congenital heart malformation.