For the first time, researchers have mapped the genetic risk of haemochromatosis, dubbed the 'Celtic curse', in the UK and Ireland. They discovered outbreaks in northwest Ireland and the Outer Hebrides in Scotland. In some regions, about one in 60 people carry the high-risk gene variant. This iron overload condition can take decades to show symptoms. Untreated hemochromatosis can lead to liver cancer and arthritis. In total, one in 54 people in these areas is at risk.