HFE-haemochromatosis is the most frequent genetic disposition for iron overload in ethnic Danes: 20,000 persons are homozygous for the C282Y mutation. The disorder has a long preclinical phase with increasing body iron overload, and 30% of males will develop clinically overt disease, presenting with symptoms of fatigue, arthralgias, reduced libido, erectile dysfunction, cardiac disease, diabetes and liver disease, later progressing into cirrhosis, cardio-myo-pathy, pancreatic fibrosis and osteoporosis. Treatment consists of phlebotomies, which in the preclinical and early clinical phases ensure normal survival.