CLCNKA and hydrops fetalis: Although other genes in this region including HSPB757 and ZBTB1758 have been implicated in HF, our results provide support for a role of CLCNKA. Other highly prioritized genes included CDKN1A (p = 7.56 × 10−17 in the atrial appendage), an important cell-cycle regulator of cardiomyocyte proliferation during terminal differentiation;59,60SYNPO2L (p = 9.15 × 10−13 in the atrial appendage and p = 9.64 × 10−12 in the left ventricle), a Z-disc protein previously linked to atrial fibrillation61,62.