The inherited iron disorder hemochromatosis is most common in people from Ireland and in people from the Hebrides in Scotland, shows a comprehensive study from the U.K.
Hereditary hemochromatosis is a genetic condition affecting around one million people in the U.S. Often caused by mutations in the HFE gene, it causes the body to accumulate too much iron. If left unchecked it can cause organ damage and conditions such as cancer and heart disease.
Despite it being one of the most common inherited genetic conditions, it is not something included in standard screening programs such as newborn heel prick testing. This is largely because organ damage from the condition often does not occur until later in life, and even if someone inherits two copies of the genetic mutation, it is not guaranteed they will go on to develop the condition as penetrance is incomplete.
“The highest European frequencies of this allele are observed in the formerly Celtic-speaking populations in Ireland and in the United Kingdom, hence hemochromatosis is sometimes called the Celtic Curse,” write lead author Jim Wilson, DPhil, a professor at the University of Edinburgh, and colleagues in Nature Communications.
Wilson and colleagues carried out a study in 440,000 people who were from across the U.K. and Ireland to look at the prevalence of C282Y, the main genetic variant of HFE linked to hereditary hemochromatosis.
Participants were recruited from both the UK Biobank, approximately 430,000 people from across the country and Ireland, and the Viking Genes cohort—around 10,000 people from Orkney, Shetland, and the Northern or Western Isles in Scotland.
The team found that people from Northwest Ireland and the Outer Hebrides islands in Scotland had the highest risk for hereditary hemochromatosis with a one in 54 and one in 62 chance of carrying two copies of C282Y, respectively.
White Irish individuals had a 3.7-fold higher risk of being C282Y homozygotes compared with White British participants.
People from mainland Scotland had a one in 117 chance of carrying two copies of C282Y, which was lower than those from the Hebrides, but higher than people from Southern England who had a one in 212 chance of being C282Y homozygotes.
“We have shown that the risk in the Hebrides and Northern Ireland is much higher than previously thought, with about one in every 60 people at risk, about half of whom will develop the disease. Early detection prevents most of the adverse consequences and a simple treatment—giving blood—is available,” said Wilson in a press statement.
“The time has come to plan for community-wide genetic screening in these high-risk areas, to identify as many people as possible whose genes mean they are at high risk of this preventable illness.”
