What are the frequencies of HFE genotypes in the general population and among hemochromatosis patients?
General Population

A recent review of published HFE genotype frequencies that focused on non-Hispanic North American Caucasians reported that about 9% of tested individuals are carriers of the C282Y mutation and about 0.5% are C282Y homozygotes (Hanson EH 2001).

A large cross-sectional population-based study of DNA samples from the Third National Health and Nutrition Examination Survey estimated the overall C282Y homozygote prevalence to be about 0.3% in non-Hispanic Caucasians, 0.06% in non-Hispanic blacks, and 0.03% in Mexican Americans (Steinberg KK, 2001).

Although it is rare to find HFE mutations in African Americans who have iron overload (McNamara L, 1998), these mutations have been found in a few individuals (Barton JC, 2000 and 2001). It has been suggested that their appearance is due to admixture. Current research suggests that genes other than HFE are responsible for the majority of iron overload in African and Mexican Americans.

Among Hemochromatosis Patients

A pooled analysis of major HFE prevalence studies among diagnosed hemochromatosis patients estimated that about 75% have the C282Y/C282Y genotype. A range of other HFE genotypes was found in the remaining cases, including C282Y/H63D (~5.0%) and H63D/H63D (~1.5%); some cases carried a single HFE mutation or no HFE mutations.

This finding suggests that non-genetic influences, additional HFE mutations, or variations in additional or modifying genes that affect iron metabolism may also lead to hemochromatosis (Hanson EH, 2001).