In the LF group 68 fixed genome windows containing 113 candidate genes in the HF group were selected including, PROK1 (prokineticin 1), CHD7 (Chromodomain helicase DNA binding protein 7), KDM6A (lysine K-specific demethylase 6A), TENM1 (teneurin transmembrane protein 1), and SWI5 (SWI5 homologous recombination repair protein). Here, PROK1 is linked to hydrops fetalis.