In hereditary hemochromatosis, mutations in genes such as HFE, TFR2, HJV, HAMP cause a hepcidin deficiency due to the reduced activity of the hepatic BMP-SMAD-signaling pathway or hepcidin synthesis per se, resulting in increased iron adsorption and iron release into the bloodstream [5]. Here, HAMP is linked to hyperinsulinemic hypoglycemia, familial, 4.