Both B type natriuretic peptide (BNP) and the inactive N-terminal chain of the pro-BNP (NT-proBNP) have good accuracy in the differential diagnosis of dyspnea in emergency rooms(1,2), both in a suspected diagnosis of heart failure (HF) in primary care(3), and in a prognostic evaluation of patients with acute HF(4). This evidence concerns the gene NPPB and hydrops fetalis.