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
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).