Ineffective erythropoiesis is observed in hemoglobinopathies such as thalassemia, hereditary sideroblastic anemias, and certain myelodysplastic syndromes, in which anemia is associated with iron overload, the latter resulting from increased iron absorption and mobilization of iron from the stores mediated by relative hepcidin deficiency.20, 21. This evidence concerns the gene HAMP and hyperinsulinemic hypoglycemia, familial, 4.