CNVplex联合STR技术在复发性流产遗传学查因中的应用

Application of CNVplex combined with STR assay for genetic etiology exploration in chorionic villus of recurrent spontaneous abortion

目的运用快速检测绒毛染色体拷贝数变化的方法探讨复发性流产查因途径。方法对60例反复自然流产病例的绒毛样本(孕13周前)分别进行多重DNA拷贝数(CNVplex)和荧光原位杂交(FISH)技术检测,所有样本同时行绒毛培养核型分析验证。结果 48例培养成功的复发性流产病例,染色体异常率为60.42%。其中48例CNVplex检测结果与核型分析相一致:包括20例染色体正常者、23例常染色体三体,3例三倍体和2例45,XO(Turner综合征);而FISH检测结果中与核型分析结果相符的只有38例。对于非嵌合体和非结构异常样本,两种方法与细胞遗传学核型分析结果符合率分别为100%(CNVplex)和79.17%(FISH)。结论应用CNVplex联合短串联重复序列(STR)技术可检测绒毛染色体拷贝数及检测5 Mbp以上的重复和缺失异常,利于分析流产病因。

Objective The study is to present a novel assay for rapid detection of fetal aneuploidies in chorionic villus for spontaneous abortion. Methods Fetal chorionic villus samples were collected from 60 cases of women diagnosed with recurrent spontaneous abortion （RSA） before 13 weeks gestation. All samples were analyzed using CNVplex （copy number variations multi- plex） assay and fluorescence in situ hybridization （FISH） in addition to chromosome analysis. All villi specimens were cell cultured and karyotyped to confirm the fetal chromosomal status. Results Among 48 successfully cultured and karyotyped samples, the chromosomal abnormality rate was 60.42% The results of karyotyping and the CNVplex assay were identical, both yielding 20 ca- ses of euploidies,23 autos0mal aneuploidies,3 triplodies and 2X monosomies（Tumer Syndrome）. However, FISH obtained only 38 results identical to karyotyping. Two cases of deletion and duplication of chromosome were also identified by CNVplex but not always by karyotyping. As for non-mosaic and non-structural abnormity samples, the concordance between cytogenetics and genotyping was 100% in CNVplex and 79.17% in FISH. Conclusion With CNVplex combined with STR（short tandem repeat） assay, we can detect the aneuploidy abnormalities as effectively as routine karyotyping without the need for cell culture, while also analyzing deletions and duplications（larger than 5 Mbp） that are not always detected by karyotype analysis. Our study demonstrates that CNVplex assay is an efficient, convenient, and accurate method to explore the etiology of miscarriage.