Haptoglobin Polymorphism and Iron Homeostasis

BACKGROUND: There is a marked difference in the degree of expression of the homozygous C282Y HFE genotype that is associated with hereditary hemochromatosis. It has been reported that individuals with the haptoglobin 2-2 type manifest increased iron concentrations, including serum iron, transferrin saturation, and ferritin. METHODS: We studied 232 patients, 115 homozygous for the c.845G-->A (C282Y) mutation and 117 matched controls with the wild-type HFE genotype, for haptoglobin phenotypes. Haptoglobin types were determined by electrophoresis of the denatured protein. The HFE genotype was determined by allele-specific oligonucleotide hybridization. Ferritin and transferrin saturation were measured by standard methods. RESULTS: There was no relationship between haptoglobin type and ferritin concentration or transferrin saturation. CONCLUSIONS: The effect of haptoglobin type on iron homeostasis cannot account for the marked phenotypic variation that is seen in patients homozygous for the HFE C282Y mutation.