Stage B HF, now termed “pre-HF”, describes patients with no symptoms of HF, but evidence of one of the following: (1) structural heart abnormalities (e.g., reduced ventricular compliance, chamber enlargement, ventricular hypertrophy, reduced contractility, or valvular disease); (2) elevated filling pressures detected invasively or non-invasively (e.g., echocardiography); or (3) Stage A risk factors accompanied by elevated B-type natriuretic peptide (BNP) levels or persistently elevated cardiac troponin [5]. The gene discussed is NPPB; the disease is hydrops fetalis.