For example, low hepcidin production is a major cause of haemochromatosis,15 whereas high hepcidin expression leads to iron-refractory iron deficient anemia (IRIDA).16 Low hepcidin expression has also been associated with severely impaired erythropoiesis in β-thalassemia17 with tissue iron deposition. This evidence concerns the gene HAMP and hereditary hemochromatosis.