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 | 15.6% | 2.04 | 46,XX,der(21;21)(q10;q10),+ 21 | Placental biopsies had 17–53% with T21 mosaicism | Wang et al. (2013) [7] |
2 | MPSS | Not recorded | 26 | 25 | 13.4% | Normal | 46,XY,der(21;21)(q10;q10),+ 21 | Not recorded | Zhang et al. (2015) [14] |
3 | tMPS | Not recorded | Not recorded | Not recorded | Not recorded | Normal | 46,XN,der(21;21)(q10;q10),+ 21 | Not recorded | Willems et al. (2016) [24] |
4 | MPSS | 1/140 risk for T21 by serum screening | 34 | 13 + 5 | 10.5% | 0.68 | 46,XX,i(21)(q10) | Confirmed iso21q; placental trisomy mosaicism confirmed | Oepkes et al. (2016) [25] |
5 | MPSS | Not recorded | Not recorded | 10 + 6 | 7% | 0.63 | 46,XX,der(21;21)(q10;q10),+ 21 | 21q rearrangement (presumed iso21q); placenata not available for study | Huijsdens-van Amsterdam et al. (2018) [23] |
6 | MPSS | 1/300–1/700 for T21 by serum screening | Not recorded | 12 + 3 | 3% | 0.83 | 46,XX,i(21)(q10) | Confirmed iso21q; placental not available for study | Huijsdens-van Amsterdam et al. (2018) [23] |
7 | tMPS | Ultrasound markers | Not recorded | 23 + 0 | 17.2% | Normal | 46,XX,der(21;21)(q10;q10),+ 21 | 21q rearrangement (presumed iso21q); placenata not available for study | Huijsdens-van Amsterdam et al. (2018) [23] |
8 | tMPS | Ultrasound markers | Not recorded | 13 + 0 | 12.7% | Normal | 46,XX,der(21;21)(q10;q10),+ 21 | 21q rearrangement (presumed iso21q); placenata not available for study | Huijsdens-van Amsterdam et al. (2018) [23] |
9 | MPSS | 1/592 risk for T21 by serum screening | 30 | 17 + 5 | 16.9% | 0.66 | 46,XY,der(21;21)(q10;q10),+ 21 | Placenata not available for study | This study |