Association of hereditary spherocytosis and idiopathic hemochromatosis. A synergistic effect in determining iron overload.

Two siblings, both splenectomized at an early age for hereditary spherocytosis, had a severe hemochromatosis develop. The human leukocyte antigen (HLA) system typing showed that they were half HLA identical. All the other members of the family who did not have evidence of hereditary spherocytosis, including those who displayed identical HLA haplotypes with the two patients, did not have any increase in iron stores. These results suggest that the two siblings are heterozygous for idiopathic hemochromatosis and that the coexistence of this condition with hereditary spherocytosis can cause a severe iron overload.