HFE Hereditary Haemochromatosis - Epidemiology

Epidemiology

Haemochromatosis is one of the most common heritable genetic conditions in people of northern European extraction with a prevalence of 1 in 200. The disease has a variable penetration and about 1 in 10 people of this demographic carry a mutation in one of the genes regulating iron metabolism, the most common allele being the C282Y allele in the HFE gene. 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 will not manifest clinically relevant haemochromatosis (see Genetics below). Other populations have a lower prevalence of both the genetic mutation and the clinical disease.

Genetic studies suggest the original haemochromatosis mutation arose in a single person, possibly of Celtic ethnicity, who lived 60–70 generations ago. At that time when dietary iron may have been scarcer than today, the presence of the mutant allele may have provided an evolutionary or natural selection reproductive advantage by maintaining higher iron levels in the blood.