NEW YORK, June 26 (Praxis Press) Type 2 diabetes mellitus is a common complication of iron-overload diseases such as hereditary hemochromatosis. Recently a gene mutation was identified that strongly predisposes individuals towards hemochromatosis when present in homozygous form. Salonen and colleagues examined whether a carrier status for the mutation predicts the development of type 2 diabetes (see paper). Out of a total of 555 participants, one was homozygous and 34 heterozygous for the HFE C282Y mutation, indicating a carrier frequency of 6.9%. Four (11%) of the carriers and 23 (5%) of the 473 non-carriers developed diabetes during the four-year follow up. Carriers of the HFE C282Y mutation are at increased risk of type 2 diabetes.