The effect of transferrin polymorphisms on iron metabolism.

The effect of five different transferrin variants (TFv1, TFv2, TFv3, TFv4, and TFv5) on the hemoglobin level, mean corpuscular volume (MCV), ferritin level, percent transferrin saturation (%TS), and the unsaturated iron binding capacity (UIBC) was investigated in subjects with defined HFE haplotypes, 919 persons undergoing health screening and 113 patients with clinical hemochromatosis. The most common variant is TFv4; the population distribution of this variant was also studied. None of the variants were found to have an effect on any of the parameters of iron metabolism that were investigated. Moreover, the frequency of these variants in patients with clinically significant hemochromatosis was no different from that in the general population. We conclude that these polymorphisms in transferrin do not play a role in the expression of hemochromatosis, nor do they produce any other significant changes in iron metabolism.