SERPINA1 and hydrops fetalis: SERPINA1. In our study, three different heterozygous variants of the SERPINA1 gene were identified, and the two most prevalent were p.E288V (rs17580) (HF was 2.65%, which was 55% among all detected SERPINA1 variants) and p.E366K (rs28929474) (HF was 2.1% and 43.3% among all detected SERPINA1 variants).