Morbidity, risk of cancer and mortality in 3645 HFE mutations carriers

Background & Aims Mutations in the HFE gene can lead to hereditary haemochromatosis (HH) and have been suggested to increase the risk of extra‐hepatic diseases, especially breast and colorectal cancer. Here we investigated long‐term outcomes of Swedish patients with HFE mutations. Methods We identified 3645 patients with a homozygous p.C282Y (62%) or a compound heterozygous p.C282Y/p.H63D (38%) mutation from eight centres in Sweden between 1997 and 2017. These were matched 1:10 by age, sex and county of residence to reference individuals from the general population. We ascertained incident outcomes until the end of 2017 by linkage to national registers. Studied outcomes were HH, cirrhosis, hepatocellular carcinoma (HCC), breast cancer (in women), colorectal cancer, type 1 and 2 diabetes, hypothyroidism, Parkinson’s disease and mortality. Cox proportional hazards regression was used to estimate hazard ratios for these outcomes. Results Median age at diagnosis was 52 years, 44% were females. During a mean follow‐up of 7.9 years, we found an increased risk for HCC, HH, cirrhosis, type 2 diabetes, osteoarthritis and death. Excess mortality was only seen in men. No increased risk was seen for colorectal or breast cancer. Liver‐related outcomes were rare, with a cumulative incidence of