What Is Hemochromatosis?
Hemochromatosis is a condition in which too much iron is absorbed from food and retained in the body. This is called iron overload. The excess iron is stored in the critical organs, where it gradually builds up and causes damage.
The organs most often affected are the liver, heart, pancreas, and skin; the pituitary gland and joints of the body also can be affected. The excess iron can cause cirrhosis, heart failure, diabetes, erectile dysfunction, and arthritis. If hemochromatosis is not treated, can even lead to death.
Hemochromatosis usually occurs in adults. It is the most common genetic disorder among people of Northern European ancestry— British, Dutch, German, Irish and French. It also occurs among African Americans, Asian Americans and Hispanic Americans.
It is more common in men than in women. Iron rarely builds up in women before menopause because of the monthly loss of blood through menstruation.
Iron is an important micronutrient that the body can't make on its own. It helps carry oxygen in red blood cells and is needed for proper functioning of the immune system, brain, muscles, and many important enzymes. Iron is absorbed from foods when they reach the small intestine. In healthy adults, the body maintains a constant level of iron by absorbing only as much as is needed to replace iron lost through body processes. Healthy adult men and women lose about 1 mg of iron daily through normal body functions; during childbearing years, healthy women lose an average of 2 mg of iron daily during their menstrual period.
Most people eat about 10 mg of iron a day, but the body absorbs only 1 to 2 mg iron a day, storing most of what is not immediately needed in red blood cells, bone marrow, the spleen and the liver using a protein called ferritin. When the body has stored enough iron, it stops or decreases the amount of iron absorbed from food in the intestine so that excess iron does not accumulate. In hemochromatosis, the body continues to absorb iron even if sufficient iron is already stored. The body can’t eliminate the excess iron, so it continues to try to store it. Over time, the iron overload damages organs and causes chronic diseases.
Iron is carried in the blood by several proteins; the chief one is transferrin. When there is too much iron in the body, the transferrin protein cannot carry all of it, so some iron circulates freely in the blood. This free iron is highly destructive and dangerous. It can trigger chemical reactions that can kill cells, destroy DNA and increase the risk for serious infections from bacteria and parasites.
Researchers have identified two common types of hemochromatosis: primary (hereditary) and secondary. Each type has a different cause.
Primary, or hereditary, hemochromatosis
This is the more common type. It is caused by an inherited defect in a gene, called HFE, that controls how much iron is absorbed from food. A person must inherit two damaged copies of the gene—one from each parent—for the disease to occur. This genetic situation is called autosomal recessive. If you inherit only one copy of a defective HFE gene, you are a carrier, which means you can pass the gene onto your children. About 1 in 10 people in the United States are believed to be hemochromatosis carriers. If both parents have a defective HFE gene, their children have a 1 in 4 chance of getting the disease. Some people who have two defective HFE genes don't seem to get the disease, but they can still pass the gene on to their children.
This type is caused by another disease or condition that allows too much iron to accumulate in the body. These diseases and conditions can lead to secondary hemochromatosis:
Anemias, such as thalassemia and aplastic anemia
A condition called African iron overload (previously known as African siderosis), which is a combination of an inherited disorder and a diet high in iron
Chronic liver disease, such as hepatitis, alcoholic liver disease or nonalcoholic fatty liver disease
Occasionally, hemochromatosis can be caused by blood transfusions, long-term kidney dialysis or medications or supplements that contain iron.
Other, less common types include juvenile hemochromatosis and neonatal hemochromatosis. A person with juvenile hemochromatosis begins to accumulate iron in childhood or adolescence, and symptoms usually appear by age 30. If not treated, it can be fatal. Like primary hemochromatosis, juvenile hemochromatosis is an inherited disease, but the cause is a mutation in the hemojuvelin gene. In neonatal hemochromatosis, iron builds up in a baby's liver before birth, and he or she may be stillborn or die within a few days of birth. The cause is not known.
For people with an abnormally high level of iron in the blood and a positive genetic test, a liver biopsy may be unnecessary.
Iron overload occurs slowly, and symptoms appear only after years of accumulation. Because hemochromatosis can affect many parts of the body, it can cause different signs and symptoms that vary in severity. Many of the symptoms are also symptoms of other diseases, so diagnosis can be difficult.
Almost 70 percent of people develop their first symptoms between ages 40 and 60. The condition is usually not diagnosed until after age 40 in men and after menopause in women. Menstruation delays the accumulation of iron in women.
These are symptoms of early to mid-stage hemochromatosis:
Chronic fatigue and weakness that has no explanation
Joint pains, usually in the hands
Palpitations, or a fluttering sensation in the chest
As more iron builds up in the body, signs and symptoms of mid-stage hemochromatosis occur:
Arthritis from damage to joints
An enlarged liver
Problems with reproductive organs such as shrinkage of the testicles, loss of sex drive, infertility, absence of the menstrual cycle and early menopause
Heart problems such as chest pain, shortness of breath and abnormal heart rhythms
Abnormal skin color; this includes yellowish skin, tan skin not caused by the sun, or reddish palms with no apparent cause
In advanced hemochromatosis, signs and symptoms depend on which organs are failing.
Your health care provider can usually make a hemochromatosis diagnosis based on your medical and family history, your signs and symptoms, and several blood tests. One blood test measures the levels of transferrin, the protein that carries iron in the blood. A second blood test measures serum ferritin, to find out how much iron is stored in the body.
Genetic testing is available for two of the more common genes associated with this disorder (found in up to 90 percent of people with hemochromatosis), but not everyone who has the genes develops the disease. A liver biopsy is sometimes needed to confirm the diagnosis.
If you are diagnosed with hemochromatosis, you should tell your blood relatives. They may be at risk for the condition and should have the iron level in their blood checked. Your health care provider may also recommend genetic testing.
It's important to reduce the amount of iron in your body to prevent or delay organ damage. The usual treatment is to remove some of your blood, a process called therapeutic phlebotomy. Blood is removed because it is the place where most of the iron is stored. How much and how often blood is removed depends on your age, your overall health and how much excess iron you have. At the beginning of treatment, your doctor may remove about a pint of blood once or twice a week. When your iron levels have returned to normal, you may need this treatment only every three months. The blood removal and iron-level tests must be done on a periodic basis for the rest of your life. (The blood that's removed can be donated to a blood bank approved by the Food and Drug Administration.)
If you have developed complications such as diabetes or heart failure from hemochromatosis, those complications also must be treated. If you have liver cirrhosis from hemochromatosis, you may need to be tested periodically for liver cancer.
Some people cannot undergo repeated blood removal. For them, iron chelation therapy is an option. Iron chelation therapy uses either oral or injected medication to remove excess iron from the body.
These are precautions that people with hemochromatosis should take:
Don't take iron supplements, including multivitamins with iron. This is particularly important for men and postmenopausal women.
Avoid foods high in iron such as red meat, dried peas and beans. Red meat contains the most easily absorbed form of iron.
Limit the amount of vitamin C from dietary supplements to no more than 200 mg a day. Do not take a vitamin C supplement with food, because the supplement increases absorption of iron. Eating fruits and vegetables that contain vitamin C is safe.
If you don't have liver damage, you can drink alcohol, but limit how much you consume because it increases the amount of iron absorbed. If you have liver damage or elevated liver enzymes, avoid all alcohol, even red wine, which has tannins that inhibit absorption of iron. For people with liver damage, alcohol increases the risk for liver damage and liver cancer.
Avoid eating raw or improperly cooked fish or shellfish. People with hemochromatosis are susceptible to infections caused by bacteria, such as Yersinia, Listeria and Vibrio, found in raw seafood. In people with high free-iron levels, these bacteria can cause life-threatening infections.
Some foods and beverages can block absorption of iron. These include tea, coffee and chocolate, all of which contain tannates; fiber; eggs; spinach, which contains oxalates; and dairy products that contain calcium and phosphates.