NIPT在胎儿染色体非整倍体产前筛查中的应用

The Application of NIPT in prenatal screening of fetal chromosome aneuploidy

目的利用高通量测序技术(NGS)对2336例孕妇进行无创DNA产前检测(NIPT),结合染色体核型分析比对实验结果,评估NIPT能否对胎儿染色体非整倍体疾病进行精准筛查。方法 2015年7月到2017年6月,我院共收集了2336例孕妇血液标本。其中包括孕中期血清学筛查高风险或临界风险孕妇1145例;高龄(≥35岁)孕妇733例;超声异常(NT≥2.5mm)363例;试管孕妇87例;双胎8例。研究发现,每一条染色体的呈现都与其GC含量存在线性关系。参与研究的每一位NIPT阳性孕妇都自愿进行了羊水穿刺核型比照分析,并对每位孕妇均进行妊娠结局随访,追踪出生婴儿生长发育情况。结果 2336例NIPT检测中,发现16例21-三体;8例18-三体;1例13-三体;1例20-三体;2例45,X和5例47,XXY,[n=33/23369(1.41%)]。染色体非整倍体检测的灵敏度为100%,研究中出现2例假阳性样本,特异性为99.91%。结论利用NIPT技术可精准地对胎儿染色体非整倍体进行有效筛查进而降低母婴损害,具有较高的灵敏度和特异性,适宜广泛应用。

Objective:Non-invasive prenatal testing(NIPT)was performed on 2336 pregnant volunteers using next generation sequencing(NGS),and the accuracy of NIPT in screening fetal chromosomal aneuploidy was evaluated by combining the results of karyotype analysis. Methods:From July 2015 to June 2017,a total of 2,336 pregnant women′s blood samples were collected in our hospital. Among them,1145 cases with high or critical risk of serum screening in the second trimester;733 pregnant were aged ≥35 years old;ultrasonic abnormality(NT≥2.5 mm)was detected in 363 cases;87 cases of testtube pregnant women and 8 women were twins. It was found that there was a linear relationship between the expression of each chromosome and its GC content. Each NIPT-positive pregnant woman who participated in this study voluntarily carried out comparative analysis of amniocentesis karyotype,and everyone was followed up for pregnancy outcome to track the growth and development of the baby. Results:Among the 2336 cases of NIPT detection,16 cases were found to be 21-trisomy;8 were 18-trisomy;1 was 13-trisomy;1 was 20-trisomy;2 was 45,X and 5 were 47,XXY,[n=33/23369(1.41%)]. The sensitivity of chromosome aneuploidy detection was 100% and the specificity was 99.91%. Conclusion:By using NIPT technology can accurately screen fetal chromosome aneuploidy to reduce mother and infant damage,which has high sensitivity and specificity,so it is suitable for wide application.