Patients with Cd 41/42 (-TTCT) (β0), IVS 1-5 (G>C) (β+), and Cd 26 (G>A) HbE (βE) also have severe anaemia with significant thrombocytosis and leukocytosis, as well as significantly increased serum ferritin levels and decreased serum hepcidin levels, compared to patients with other mutations. Here, HAMP is linked to thrombocytosis disease.