【摘要】 目的探讨无创产前检测(NIPT)对筛查胎儿染色体拷贝数变异(CNVs)和微缺失/微重复综合征(MDs)的临床价值。方法收集2012年1月至2017年7月在云南省第一人民医院遗传诊断中心、产前诊断中心10 005例中孕期(15～20+6周)进行NIPT的孕妇资料,对检测提示胎儿CNVs孕妇中选择介入性产前诊断者的羊水/脐血染色体G显带核型分析及高通量测序(NGS)基因组拷贝数分析,相关CNVs到相应数据库查找分析,分析NIPT所发现的CNVs与介入性产前诊断结果的一致性。结果中孕期进行NIPT的10 005例孕妇中提示胎儿CNVs 32例,筛查阳性率为0.32%(32/10 005)。知情同意接受介入性产前诊断25例,其中确诊胎儿CNVs14例,阳性预测值(PPV)为56%(14/25),包括微缺失9例、微重复5例,片段大小在587.75kb～36.05Mb之间。胎儿细胞DNA样本NGS检测到的片段大小和起止位置与NIPT筛查时所见CNVs基本吻合。在14例CNVs中确诊MDs 11例,临床意义不明CNVs 3例。对11例MDs胎儿的父母亲进行CNVs检测和外周血染色体核型分析,证实新发病CNVs 10例,其中父系染色体异常来源致病CNVs 2例;8例致病CNVs胎儿合并有染色体结构异常。经遗传咨询,这11例致病变异有10例夫妇知情选择终止妊娠;1例知情选择继续妊娠,分娩1例活产新生儿。结论 NIPT作为一种高精度筛查手段,能够筛查出部分有临床意义的胎儿CNVs,可望成为常规筛查手段,检测致病风险大的较大片段的染色体微缺失和微重复CNVs(≥5Mb);NIPT检测到胎儿CNVs高风险时需进行介入性产前诊断。更多还原

【Abstract】 Objective To explore the clinical value of non-invasive prenatal testing(NIPT)for screening fetal chromosomal copy number variations(CNVs) and microdeletion/microduplication syndromes(MDs).Methods Retrospective analysis was made in the 10 005 women who received NIPT during the first trimester(15-20+ 6 weeks)from January,2012 to July,2017,at First People’s Hospital of Yunnan Province,Department of Genetic Diagnosis Center.Among them 32 pregnant women were indicated fetal CNVs,25 of 32 pregnant women selected interventional prenatal diagnosis.Statistical analysis was made on the amniotic fluid/cord blood chromosome G band karyotype and high-throughput sequencing(NGS)genome copy number analysis was made,and relevant CNVs were searched and analyzed in the corresponding database;the consistency of CNVs found in NIPT with interventional prenatal diagnosis was statistically analyzed.Results During the second trimester(15-20+ 6 weeks),in the 10 005 pregnant women who received NIPT testing 32 cases were shown to have high risks of fetal CNVs,and the screening positive rate was 0.32%(32/10 005).In 25 high risk pregnant women who accepted invasive prenatal diagnosis via informed choice,14 women wereconfirmed as fetal CNVs,the positive predictive value(PPV)of NIPT being 56%(14/25),including 9 cases of microdeletion and 5 cases of microduplication.The sizes were between 587.75 kb and 36.05 Mb.The size and the start and end positions of CNVs found by NIPT were similar to those of fetal DNA samples detected by NGS.Among 14 cases of fetal CNVs,11 cases were identified as MDs,3 cases as unknown clinical significance.In 11 cases of MDs,8 cases were observed fetal chromosome structure abnormalities by karyotype analysis,10 cases were confirmed as de novo abbreviations,and 2 cases as originated from paternal same MD.After genetic counseling,10 pregnant women in 11 cases of MDs chose informed terminations,and one case chose continuing pregnancy.Conclusion As a high-precision screening method,NIPT is expected to be an effective mean to screen for fetal CNVs,which can be used to detect highrisk chromosome microdeletion and microduplication CNVs of larger segments.High risk cases of fetal CNVs found by NIPT require invasive prenatal diagnosis for validation.更多还原