单绒毛膜双羊膜囊双胎之一胎先天性心脏病的产前诊断

Prenatal diagnosis of one of the monochorionic diamniotic twins with congenital heart disease

目的探讨单合子之单绒毛膜双羊膜囊(monochorionic diamniotic,MCDA)双胎之一胎先天性心脏病(简称"先心病")产前诊断。方法 2013年1月至2017年6月在中山大学附属第一医院妇产科就诊的MCDA双胎之一胎先心病共79对,每对胎儿分别行羊膜腔穿刺,羊水标本送检染色体核型分析和染色体微阵列分析(chromosomal microarray analysis,CMA),并对其产前诊断的结果进行临床分析。结果 79对中75对共150个胎儿进行了CMA,71对共142个胎儿进行染色体核型分析。染色体核型异常检出率为7.7%(11/142);除外良性拷贝数变异(copy number variant, CNV),CMA对CNV和非整倍体的检出率为21.3%(32/150),高于核型分析(χ~2=8.025,P=0.005);核型正常胎儿异常CNV检出率为16.0%(21/131)。5对单合子双胎两个胎儿间存在不一致的染色体核型或CNV,发生率为7.0%(5/71),其中4对先心病胎儿检出异常核型或CNV,而心脏发育正常胎未检出异常。结论对于先心病的产前诊断,CMA较传统的核型分析具有更高的检出率。单绒双胎尤其单合子双胎可存在遗传异质性,当MCDA双胎出现先心病,尤其两胎表型不一致时,有必要对双胎同时进行侵入性产前诊断。

Objective To investigate the prenatal diagnosis for one of the monochorionic diamniotic(MCDA)twins with congenital heart disease(CHD).Methods From January 2013 to June 2017,79 pairs of MCDA twins with CHD were admitted at the Department of Obstetrics and Gynecology of the First Affiliated Hospital of Sun Yat-sen University.Each pair of fetuses underwent amniocentesis.Karyotype analysis and chromosome microarray analysis(CMA)were performed on amniotic fluid samples,and the results of prenatal diagnosis were analyzed.Results Totally,79 pairs of 150 fetuses were analyzed by CMA and 71 pairs of 142 fetuses were analyzed by karyotype.The detection rate of chromosome karyotype abnormalities was 7.7%(11/142);except benign copy number variation(CNV),the detection rate of CNV and aneuploidy by CMA was 21.3%(32/150),higher than that by karyotype analysis(2=8.025,P=0.005);the detection rate of CNV in normal fetuses was 16.0%(21/131).There were discordant karyotypes or CNV in 5 pairs of monozygotic twins,whose incidence was 7.0%(5/71).Abnormal karyotypes or CNV were detected in 4 pairs of CHD fetuses,but not in normal fetuses.Conclusions CMA has a higher detection rate than traditional karyotype analysis for prenatal diagnosis of CHD.MCDA,especially monozygotic twins,may have genetic heterogeneity.When CHD occurs in MCDA twins,especially the phenotypes of the two twins are discordant,it is necessary to perform invasive prenatal diagnosis for each fetus simultaneously.