Accumulated evidence shows that serum or plasma levels of three natriuretic peptides, namely brain natriuretic peptide (BNP), amino-terminal proBNP (NT-proBNP), and midregion pro-atrial natriuretic peptide (MR-proANP), are powerful diagnostic tools for HF [7–13]. The gene discussed is NPPB; the disease is hydrops fetalis.