Red cells II: acquired anaemias and polycythaemia

Iron deficiency affects 30% of the world's population. Iron metabolism is tightly regulated, with both gut transport and storage b eing coordinated. Hereditary haemochromatosis due to mutations in the HFE gene loads to incre ased absorption of iron and multiple end-organ damage. Myelodysplastic disorders are acquired clonal stem-cell disorders that caus e ineffective erythropoiesis. Aplastic anaemia is caused by an intrinsic defect of haemopoietic stem cell s; both inherited and acquired forms occur. Primary polycythaemia is a myeloproliferative disorder, a non-malignant ste m-cell disease.