Table 2.
Genetic workup performed for all cases of NIHF
| Test | Number cases receiving test | Number cases with abnormal result | Abnormal findings (number of cases with each finding) |
|---|---|---|---|
| Karyotype | 40 | 11 | Turner syndrome (6), trisomy 21 (3), trisomy 18 (1), chromosome 2 inversion (1) |
| Chromosomal microarray | 30 | 2 | Trisomy 21 (2) |
| Exome sequencing | 2 | 1 | Compound heterozygous PIEZO1 variants (1)a |
| Targeted genetic testing | 3 | 3 | PTPN11 pathogenic variant (2),b Compound heterozygous PIEZO1 variants (1)a |
| Hydrops gene panel | 2 | 0 | — |
| RASopathy gene panel | 3 | 0 | — |
| Lysosomal storage enzyme assay panel | 1 | 0 | — |
a
Exome sequencing identified compound heterozygous PIEZO1 variants (c.3206G>A of paternal inheritance, and c.6208A>C of maternal inheritance) in the second hydropic fetus for one woman. Remaining DNA from the first hydropic fetus was sequenced, and found to have the same compound heterozygous PIEZO1 variants.
b
Pathogenic variants identified in PTPN11 were c.417G>C for one case, and c.317A>C for the other
CMA chromosomal microarray analysis, NIHF nonimmune hydrops fetalis.