TABLE 2.
Summary of chromosomal aberrations among the 320 fetuses with nasal bone abnormality.
| Genetic results | First-trimester | Second-/Third trimester | ||
|---|---|---|---|---|
| Isolated | Non-isolated | Isolated | Non-isolated | |
| Aneuploidies | ||||
| T21 | 0 | 12 | 7 | 34 |
| T18 | 0 | 1 | 0 | 3 |
| T13 | 0 | 0 | 1 a | 0 |
| XXY | 1 | 1 | 0 | 0 |
| XO | 0 | 1 | 1 a | 0 |
| T2 | 0 | 0 | 1 a | 0 |
| CNVs | ||||
| P | 0 | 1 | 6 b | 8 d |
| LP | 1 | 1 | 2 | 4 |
| VOUS | 0 | 0 | 6 c | 1 |
| Normal | 8 | 4 | 156 | 63 |
| Total | 10 | 21 | 178 | 111 |
CNVs, copy number variations; P, pathogenic; LP, likely pathogenic; VOUS, variants of unknown/uncertain significance.
a
Mosaic.
b
Including 1 case of T21 combined with X-linked DMD carrier and 1 case of X-linked STS carrier.
c
Including 1 case of mosaic XO combined with VOUS-CNV.
d
Including 1 case of T21 combined with P-CNV and 1 case contained two P-CNVs.