Hereditary hemochromatosis: progress and perspectives

Hereditary hemochromatosis is an autosomal recessive disorder of iron metabolism which leads to iron overload and organ failure. Clinical symptoms develop in mid-life and are prevalent in males. If the disease is diagnosed before the onset of cirrhosis, treatment by phlebotomy normalizes life expectancy. To demonstrate the increased iron stores, liver biopsy has been the gold standard for diagnosis. The discovery of the HFE gene and of a prevalent mutation has had a great impact on the early detection of the disorder. Molecular diagnosis is now feasible for patients using noninvasive tests. Because the molecular defect identifies only the propensity to absorb excess iron, in the presymptomatic state molecular diagnosis must be combined with other tests to demonstrate iron overload. A minority of patients with hemochromatosis have wild-type HFE. Two distinct disorders have been recognized among these patients. Young individuals with a severe iron loading may have juvenile hemochromatosis, a disorder linked to chromosome 1q. A subset of patients with adult presentation has a type of hemochromatosis linked to chromosome 7q, characterized by inactivation of transferrin receptor 2. These new findings may have an impact on diagnosis and are of relevance for a novel view of iron metabolism.