Hemochromatosis, also known as iron overload, is caused by an accumulation of iron in the body, with excessive storage of iron in the liver, skin, pancreas, heart, joints, and testes. In untreated individuals, early symptoms may include: abdominal pain, weakness, lethargy, and weight loss; the risk of cirrhosis is significantly increased when the serum ferritin is higher than 1,000 ng/mL; other findings may include progressive increase in skin pigmentation, diabetes mellitus, congestive heart failure, and/or arrhythmias, arthritis, and hypogonadism. The mutation or polymorphism most commonly associated with hereditary hemochromatosis is C282Y. About 1/200 of people of Northern European origin have two copies of this variant; they, particularly males, are at high risk. The H63D variant rarely causes clinical problems in the homozygous or compound heterozygous ([Cys282Tyr]+[His63Asp]) state and is relatively common in the heterozygous state in most populations. Considering the high frequency of heterozygotes for the C282Y and H63D alleles, approximately one third of the northern European population is heterozygous for either one or the other of these two variant alleles.