Genes closest to the association peaks were enriched for genes regulating haematological functions 14, 15, and for genes causative for Mendelian blood disorders (Tables S1–S2) such as haemolytic anaemia (HK1, G6PD), sickle cell disease (BCL11A, HBB, HBSx1L‐MYB), thrombocytopenia (MPL), leukaemia (PTPN11) and bone marrow failure (TERT). The gene discussed is HBB; the disease is sickle cell disease.