Table 3 Published cases of false negative NIPT results due to T21
From: Two cases of placental trisomy 21 mosaicism causing false-negative NIPT results
Case number | cfDNA screening technology | Indication for NIPT | Pregnant woman age (yrs) | Blood drawn at GA (wk + d) | Fetal DNA fraction | Z-score for T21 | Karyotype | Explanation for false negative NIPT result | Study [reference] |
|---|---|---|---|---|---|---|---|---|---|
1 | MPSS | 1/370 risk for T21 by serum screening | 32 | 18 + 0 | 15.60% | 2.04 | 46,XX,der(21;21)(q10;q10), + 21 | Placental biopsies had 17–53% with T21 mosaicism | Wang et al. (2013) [9] |
2 | MPSS | 1/529 risk for T21 by serum screening | 23 | 15 | 15.67% | − 0.201 | 46,XY,der(21;21)(q10;q10), + 21 | Placental biopsies had 13–88% with T21 mosaicism | This study |
3 | MPSS | Ultrasound markers | 35 | 17 | 19.70% | 0.932 | 47,XY, + 21 | Placental biopsies had 17–30% with T21 mosaicism | This study |
4 | MPSS | Ultrasound markers | 35 | 18 | 19.72 | 1.33 | 47,XY, + 21 | Placental biopsies had 2.6–76% with T21 mosaicism | Wang et al. (2013) [9] |
5 | tMPS | a history of multiple adverse pregnancy outcomes | 37 | 16 + 5 | 7.52% | 2.503 | Placental biopsies had about 42.9%% with T21 mosaicism | Kang et al. (2022) [19] |