 The prevalence of mutations in iron-metabolism genes varies in different populations.A study of 3,011 unrelated white Australians found that 14% were heterozygous carriers of an HFE mutation, 0.5% were homozygous for an "HFE" mutation, and only 0.25% of the study population had clinically relevant iron overload.Most patients who are homozygous for "HFE" mutations do not manifest clinically relevant haemochromatosis (see Genetics above).