无创产前基因检测技术在胎儿染色体非整倍体检测中的临床应用

Clinical application of non-invasive prenatal genetic testing technology in fetal chromosomal aneuploidy detection

目的 评价无创产前基因检测技术(NIPT)在产前胎儿染色体非整倍体筛查中的应用价值。方法 收集2017年10月至2021年6月在清远市人民医院行NIPT检测的6 535例孕妇的临床资料,高风险孕妇行羊水穿刺术进行核型确诊,低风险孕妇进行产前产后电话随访。结果 6 535例样本中共检出胎儿染色体非整倍体异常高风险88例,检出率为1.35%。其中68例进行产前诊断确诊21三体综合征(T21)、18三体综合征(T18)、13三体综合征(T13)、性染色体异常(SCA)、罕见染色体异常(RATs)的例数分别为18、5、8和1例,其阳性预测值(PPV)分别为72%(18/25)、83.3%(5/6)、40%(8/20)和7.14%(1/14)。高龄组阳性检出率大于低龄,差异有统计学意义(χ^(2)=13.005,P<0.05);唐筛高风险组阳性检出率大于临界风险或单指标异常组,差异有统计学意义(χ^(2)=18.565,P<0.05)。结论NIPT技术可快速准确地检测胎儿18、21号染色体非整倍体,但13号染色体PPV较低,而SCA及RATs的检出及有效性有待完善及优化。高龄及唐筛高风险人群患染色体异常疾病的风险升高,应重点关注NIPT在此类人群的应用。

Objective To evaluate the application of non-invasive prenatal gene detection in prenatal chromosome aneuploid detection. Methods The clinical data of 6 535 pregnant women who underwent non-invasive prenatal genetic testing(NIPT)in Qingyuan People’s Hospital from October 2017 to June 2021were collected. High-risk pregnant women underwent amniocentesis for karyotype diagnosis while low-risk pregnant women were follow-up by telephone. Results A total of 88 high-risk fetal chromosomal aneuploidy were detected in 6 535 samples,with a detection rate of 1.35%. Among them,68 cases were diagnosed with trisomy 21(T21),trisomy 18(T18),trisomy 13(T13),sex chromosomal abnormalities(SCA),and rare chromosomal abnormalities(RATs)by prenatal diagnosis. There were 18,5,8 and 1 cases,respectively,and their positive predictive value(PPV)were 72%(18/25),83.3%(5/6),40%(8/20)and 7.14%(1/14),respectively). The positive detection rate of the elderly group was higher than that of the young age group,the difference was statistically significant(χ^(2)=13.005,P<0.05). The positive detection rate of Tang screening highrisk group was higher than that of borderline risk or single-index abnormal group,and the difference was statistically significant (χ^(2)=18.565,P<0.05). Conclusion NIPT can detect fetal chromosome 18 and 21 aneuploidy quickly and accurately,but the PPV of chromosome 13 is low. And the detection and effectiveness of SCA and RATs need to be improved and optimized. The risk of chromosomal abnormalities in the elderly and high-risk population is increased. These people should be paid more attention in the application of NIPT.