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Hemochromatosis is a hereditary disorder that causes the body to absorb too much iron, causing iron to build up in the body and damage organs.
In the United States, over 1 million people have hemochromatosis. Men are affected more often then women. The disorder is potentially fatal but is usually treatable.
People absorb iron from food they eat. Most of the iron is contained in red blood cells (see Iron Deficiency and Toxicity).
Hemochromatosis is hereditary. It can be caused by several different genetic mutations. The most common mutation, which involves the HFE gene, occurs in people of Northern European background. The person must inherit a mutated gene from both parents to be affected. The HFE gene makes a protein that senses the amount of iron in the body. A mutation in the gene allows too much iron to be absorbed from the diet. Other mutations cause similar disorders: ferroportin disease, juvenile hemochromatosis, transferrin receptor 2 ( TFR2 ) mutation hemochromatosis, hypotransferrinemia, and aceruloplasminemia. TFR2 mutations impair the body's ability to control iron absorption into certain cells. Although these types vary in age at which they appear, the symptoms and complications of iron overload are the same in all.
Usually, symptoms develop gradually, and the disorder may not be noticed until iron accumulation is excessive. Often no symptoms appear until middle age or later. Sometimes the first symptoms are vague, such as fatigue or weakness, and may not be noticed or may be attributed to some other disorder. In women, symptoms usually start after menopause because the loss of iron during menstrual bleeding and the increased requirement for iron during pregnancy compensate to some degree.
Symptoms vary because iron accumulation can damage any part of the body, including the brain, liver, pancreas, lungs, or heart. The first symptoms, particularly in men, may be those of cirrhosis (due to liver damage) or those of diabetes (due to pancreas damage). Or, the first symptoms, particularly in women, may be vague and affect the whole body. Fatigue is an example. Liver disease is the most common problem. The following problems can also occur:
In many men, levels of male hormones decrease. Erectile dysfunction may occur. Hemochromatosis can worsen neurologic disorders that are already present.
Identifying hemochromatosis based on symptoms may be difficult. However, blood tests to measure the levels of iron and two proteins involved in handling iron, can identify people who should have further evaluation. These proteins are ferritin, a protein that stores iron, and transferrin, the protein that carries iron in blood when iron is not inside red blood cells. If the ferritin level and percentage of iron in transferrin are high, genetic testing is usually done to confirm the diagnosis. A liver biopsy may be necessary to determine whether the liver has been damaged
Genetic testing is recommended for people with hemochromatosis, and all of their first-degree relatives (siblings, parents, and children) should be screened for hemochromatosis by measuring their iron levels.
Usually, removing blood (phlebotomy) is the best treatment. It prevents additional organ damage but does not reverse existing damage. Phlebotomy is initially done once or sometimes twice a week. Each time, about 500 milliliters (1 pint or 1 unit) of blood is removed until the iron level and percentage of iron in transferrin are normal. Phlebotomy is then done periodically to keep iron stores at normal levels.
People can eat a normal, healthy diet, including iron-containing foods. Doctors may tell people to limit alcohol consumption because alcohol can increase iron absorption and also increases the risk of cirrhosis.
With early diagnosis and treatment of hemochromatosis, a long, healthy life is expected.
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