People from the northwest of Ireland have the highest risk in the British Isles of developing a genetic disease that causes a dangerous build-up of iron in the body, a new study suggests.
Often referred to as the “Celtic curse”, haemochromatosis is an inherited genetic disorder that causes the body to absorb too much iron from food, with this excess iron building up and causing organ damage.
The disorder is recognised as being most common in people from Scotland and Ireland, and the study from the University of Edinburgh is the first time the genetic risk has been mapped across the UK and Ireland.
The condition is caused by small changes in DNA, known as genetic variants, which can be passed down through families. The most important risk factor in the UK and Ireland is a genetic variant called C282Y.
The Scottish scientists analysed genetic data from more than 400,000 people in the UK BioBank and Viking Genes studies to determine the prevalence of the variant across 29 regions.
They found that people with ancestry from the northwest of Ireland have the highest risk of developing haemochromatosis, with one in 54 people estimated to carry the variant. This is followed by Outer Hebrideans (one in 62) and those from Northern Ireland (one in 71).
The high combined risk across these locations suggests that focusing genetic screening at these key areas would discover the largest number of people with the condition, the researchers said.
Early diagnosis and treatment – such as regular blood donation to reduce iron levels – is key to preventing liver damage, liver cancer and arthritis, they added.
The study, funded by the charity Haemochromatosis-UK and carried out in collaboration with RCSI University of Medicine and Health Sciences, is published in the journal Nature Communications.
Prof Jim Flett Wilson, chair of human genetics at the University of Edinburgh, said the research shows the risk in the Hebrides and Northern Ireland is much higher than previously thought.