Iron is important because it is part of hemoglobin, a molecule in the blood that transports oxygen from the lungs to all body tissues. Normal iron absorption occurs in the proximal small intestine at a rate of 1-2 mg per day. In people with hereditary hemochromatosis, this absorption rate can reach 4–5 mg per day with progressive accumulation to 15–40 grams of iron in the body.
Humans have no physiologic pathway to excrete iron. Therefore, iron can accumulate in any body tissue, although depositions are most common in the liver, thyroid, heart, pancreas, gonads, hypothalamus and joints. Hemochromatosis causes or exacerbates arthritis, diabetes, impotence, heart failure, cirrhosis of the liver and liver cancer.
Excessive alcohol intake and viral hepatitis accelerate the pathology associated with hemochromatosis, especially with respect to liver and pancreatic toxicity. Diabetes is the primary manifestation of pancreatic iron deposition. The incidence of diabetes is approximately 50% in symptomatic patients, and the risk is increased in heterozygotes for hereditary hemochromatosis.
The three types of hemochromatosis are primary hemochromatosis, also called hereditary hemochromatosis; secondary hemochromatosis; and neonatal hemochromatosis.
The most common cause of secondary hemochromatosis is frequent blood transfusions in people with severe anemia.
Hemochromatosis
