TABLE 5.
SNP-array results of 1199 samples with abnormal result on maternal serum screening.
| Abnormality | Number | Normal | Aneuploidy | LOH | CNV | CNVa | |||
| P | LP | VOUS | LB | ||||||
| High risk of trisomy 21 syndrome (Down syndrome, DS) (≥1/300) | 998 (83.2%) | 917 (91.9%) | 11 (1.2%) | 3 (0.3%) | 66 (6.6%) | 17(1.7%) | 5 | 22 | 22 |
| High risk of trisomy 18 syndrome (Edwards syndrome, ES) (≥1/350) | 68 (5.7%) | 57 (83.8%) | 4 (5.9%) | 0 (0.0%) | 7 (10.3%) | 3(4.4%) | 1 | 0 | 3 |
| High risk of open neural tube defects (ONTD) (AFP ≥ 2.5 MoM)b | 24 (2.0%) | 22 (91.7%) | 0 (0.0%) | 0 (0.0%) | 2 (8.3%) | 0(0.0%) | 0 | 1 | 1 |
| Intermediate risk of trisomy 21 syndrome (Down syndrome, DS) (1/301–1/1000) | 109 (9.1%) | 95 (87.2%) | 4 (3.7%) | 0 (0.0%) | 10 (9.2%) | 5(4.6%) | 0 | 1 | 4 |
| Total | 1199 [100%] | 1091 (91.0%) | 20 (1.7%) | 3 (0.3%) | 85 (7.1%) | 25(2.1%) | 6 | 24 | 30 |
aCNVs were classified into four groups according to interpretation: P, pathogenic; LP, likely pathogenic; VOUS, variation of uncertain significance; LB, likely benign. For cases with 2 CNVs including a pathogenic CNV and a VOUS CNV were listed in the P group.
bAFP and freeβ-HCG levels in maternal serum were converted to MoM (multiples of median).