Comparison of two superparamagnetic purification magnetic beads-based screening and enrichment techniques for isolating cell-free fetal DNA from maternal plasma for non-invasive prenatal screening
10.3760/cma.j.cn511374-20230508-00268
- VernacularTitle:超顺磁性纯化磁珠筛选胎儿游离DNA技术在无创产前筛查中的应用比较
- Author:
Wen ZENG
1
;
Jianjiang ZHU
;
Hong QI
;
Lirong CAI
;
Xiaohui WEN
;
Yao LUO
;
Qiao ZHANG
Author Information
1. 北京市海淀区妇幼保健院产前诊断科，北京 100080
- Keywords:
Non-invasive prenatal testing;
cffDNA enrichment;
Fetal DNA fraction;
False positive;
Repeated test
- From:
Chinese Journal of Medical Genetics
2024;41(7):797-802
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To assess the efficiency of modified enrichment method for cell-free fetal DNA (cffDNA) through purified superparamagnetic beads during non-invasive prenatal testing (NIPT).Methods:A total of 26 252 pregnant women undergoing NIPT at the Maternal and Child Health Care Hospital of Haidian District from December 2017 to September 2022 were recruited and randomly assigned into the conventional group ( n = 10 573) and the modified enrichment group ( n = 15 679), who were then subjected to the screening and enrichment of the cffDNA using a conventional and modified technique, respectively. High-risk pregnant women detected by NIPT were subjected to invasive prenatal diagnosis. All women were followed up for their pregnancy outcomes, and the detection efficacy of the two methods was compared in terms of fragment size, concentration of cffDNA, duplicate detection rate, and indices of clinical laboratory tests. Results:The fragment size of the main peak of the cell-free DNA library of the modified enrichment group was significantly lower than that of the conventional group [267 (264, 269) bp vs. 294 (292, 296) bp, P<0.01], while the concentration of cffDNA was significantly higher [21.86% (17.61%, 26.36%) vs. 9.08% (6.87%, 11.87%), P<0.01]. In addition, the duplicate detection rate (0.740% vs. 2.02%, χ2=83.90, P<0.01) and detection failure rate (0.006% vs. 0.057%, P<0.05) in the modified enrichment group were significantly lower than those of the conventional group. The combined positive predictive value (PPV) in both high-risk (64.3% vs. 76.1%) and low-risk (35.3% vs. 45.5%) pregnant women from the modified enrichment group was slightly lower than those from the conventional group, though no significant difference was detected. There was one false negative case for trisomy 21 among the high-risk pregnant women from the conventional group, and no false negative case was found in the modified enrichment group. Conclusion:The modified technique to screen and enrich the cffDNA has significantly enhanced the relative concentration of cffDNA and reduced the failure and duplication detection rate of NIPT, which has significantly reduced the incidence of false negative cases due to the low concentration of cffDNA, and greatly increased the overall detection efficacy of NIPT.
