基于高通量测序技术应用于孕期无创产前筛查人群的结果分析

Value of high throughput sequencing in noninvasive prenatal screening

目的评价基于高通量测序技术对孕妇外周血胎儿DNA行胎儿染色体无创筛查的临床效能。方法回顾性分析在华中科技大学同济医学院附属武汉儿童医院(武汉市妇幼保健院)就诊的2 256例需要进行无创产前筛查的单胎孕妇。采用高通量测序技术检测母血浆胎儿游离DNA并进行生物信息学分析,对无创筛查高风险病例进一步行产前诊断,比较无创技术筛查胎儿染色体高风险结果与产前诊断结果的符合情况。结果 2 256例样本采用无创技术均检测成功,共检出35例胎儿染色体高风险,检出率为0.58%,其中21-三体高风险、18-三体高风险、13-三体高风险、性染色体高风险以及其他染色体结构高风险者分别有13例,1例,1例,15例以及5例。1例13-三体高风险孕妇直接引产并拒绝行进一步检查,另34例均进一步行产前诊断,经细胞核型和(或)单核苷酸多态性基因芯片技术确诊病例分别为21-三体12例、18-三体1例、性染色体异常者5例以及1例3号染色体断臂存在缺失。无创筛查技术与产前诊断技术阳性符合率分别为92.85%,100%,33.33%以及20%。结论高通量测序技术应用于无创筛查在胎儿21、18、13三体非整倍体的检测与产前诊断结果具有较高的阳性符合率,可信度较高,但对于性染色体以及其他染色体的筛查仍需进一步完善与优化。

Objective To assess the clinical value of high throughput seuencing(HTS)in noninvasive prenatal testing(NIPT). Methods The results of NIPT of 2 256 cases of women with singleton pregnancy were retrospectively reviewed. Free fetal DNA in maternal peripheral blood was sequenced using HTS,and bioinformatic analysis techniques. Prenatal diagnosis was performed through amniocentesis when NIPT indicated high risks. High risk results from non-invasive screening of fetal chromosomal and prenatal diagnosis were compared. Results All of the 2,256 specimens were successfully analyzed and 35 cases were found with fetal chromosomal high risks, with an overall detection rate of 0.58%,including 13 cases with high risk for trisomy 21,1 with trisomy 18,1 with trisomy 13,15 with sex chromosome abnormality and 5 with other chromosomal structures abnormality. All the 34 cases had further prenatal diagnosis except 1 case of pregnant woman with high-risk 13-trisomy who took abortion directly and refused further examination. Among 12 cases with high risk for 21-trisomy,1 with 18-trisomy,5 with sex chromosome abnormalities and 1 with the deletion of chromosome,3 were confirmed by traditional karyotyping and/or single nucleotide polymorphism microarray(SNP-array)technology. The coincidence rate of abnormally high risk results of NIPT detection in fetal chromosomal and prenatal diagnosis were 92.85%,100%,33.33% and 20% respectively. Conclusion There is a relatively high positive coincidence rate when compared HTS for screening of high risk for trisomy 21,18,13 aneuploidy and prenatal diagnosis and HTS is reliable. While when it comes to the screening of sex chromosome and other chromosomal structures abnormality,HTS still need to be improved and optimized.