NPPB and hydrops fetalis: At the molecular level, the onset of HF is associated with reprogramming of gene expression, including down regulation of the α-myosin heavy chain (α-MHC) gene and sarcoplasmic reticulum calcium ATPase genes and reactivation of specific fetal cardiac genes such as atrial natriuretic factor (ANF) and brain natriuretic peptide (BNP) [76].