Hemochromatosis Gene Mutation and Erythrocytosis

In a patient group presenting with either increased Hgb level or high RBC count HFE gene mutations occured in two-third of the patients. The explanation for this phenomenon is still missing. These patients had normal erythropoietin levels and had no JAK2 mutation. Out of the 22 patients, 12 had the H63D mutation in heterozygous / homozygous or compound heterozygous forms, 2 had C282Y mutation and 7 had wild type HFE gene. In contrast to the classical form of type I Hemochromatosis with C282Y homozygous mutation, characterised by high serum iron, transferrin saturation and ferritin levels, patients with the H63D mutation had normal iron content. In the second part of the study authors analysed iron and red cell parameters of patients available from their Hemochromatosis registry. The results were similar: those who had the H63D mutation, had more red cells and less iron content. It seems like in those having this mutation more iron is consumed for the red blood cell production. The role of H63D mutation in this process should still be clarified.