无创产前基因检测筛查胎儿性染色体异常

Fetal Chromosomal Abnormalities Screened by Non-invasive Prenatal Genetic Testing

目的探讨无创产前基因检测产前筛查胎儿性染色体异常的临床意义。方法对在我院进行无创产前基因检测的6 283例孕妇采集外周血,提取纯化胎儿游离DNA。在Bioelectron Seq 4000上利用半导体芯片技术应用碱基互补原理对所有测序信号进行分析,对测序信号分析结果显示性染色体高危的孕妇进行侵入性产前诊断。结果 6 283例患者中筛查出性染色体异常14例,筛查阳性率为0.22%。其中3例患者拒绝诊断,其余11例患者进行了核型分析。11例患者中,5例XO高危中有2例确诊为胎儿性染色体异常(其中1例确诊为XO/XXX嵌合体,另外1例确诊为XO),3例确诊为正常核型;5例XXY高危均确诊为XXY;1例XXX高危确诊为XXX。无创产前基因检测性染色体的准确率为73%(8/11)。与2011年至2014年未开展无创产前基因检测相比,2015年至2016年我院胎儿性染色体异常检出率增加,差异有统计学意义(P<0.05)。结论无创产前基因检测对性染色体异常的筛查准确率较高,在提高胎儿性染色体异常检出率上起到关键作用。

Objective To explore the clinical significance of non-invasive prenatal genetic testing to screen prenatal fetal chromosomal abnormalities. Methods Peripheral blood was collected from 6 283 pregnant women who underwent non-invasive prenatal genetic testing at our hospital,and fetal DNA was extracted and purified for analysis. The complementary base principle of semiconductor chip technology was used to analyze all sequenced signals with Bioelectron Seq 4000. Invasive prenatal diagnosis was performed in high-risk pregnant women according to the results of the sex chromosome sequencing signal analysis. Results Of the 6 283 pregnant women screened,14 were found to have chromosomal abnormalities,and the positive rate was 0.22%. Karyotype analysis was performed on 11 of the women;the remaining 3 refused to be diagnosed. Of these 11 women,2 of the 5 patients with a high risk of XO were diagnosed with fetal chromosomal abnormalities（diagnosed as XO/XXX chimera and XO,respectively）,and 3 were diagnosed with a normal karyotype;5 patients with a high risk of XXY were diagnosed as XXY;and 1 patient with a high risk of XXX was confirmed as XXX. NIPT accuracy was measured to be 73%（8/11）. The detection rate of fetal chromosomal abnormalities by non-invasive prenatal genetic testing was significantly higher in the years 2015-2016 than in 2011-2014（P 0.05）. Conclusion Non-invasive prenatal genetic testing for screening chromosomal abnormalities has a high accuracy rate and could improve the detection rate of fetal chromosomal abnormalities.