What is it?
- Hereditary hemochromatosis, an inherited condition, causes your body to absorb too much iron from the food you eat. The excess iron is stored in your organs, especially your liver, heart and pancreas. If you have hereditary hemochromatosis, the stored iron damages these organs, leading to life-threatening conditions such as cancer, heart problems and liver disease.
- Signs and symptoms of hereditary hemochromatosis usually appear in midlife, although they may occur earlier. The most common complaint is joint pain, but hereditary hemochromatosis can also cause a number of other signs and symptoms, including fatigue, abdominal pain and impotence.
Some people with hereditary hemochromatosis never have symptoms. Others experience a wide range of problems. These can vary considerably from person to person and may be different for men and women.
When signs and symptoms typically appear
Although the genetic defect that causes hereditary hemochromatosis is present at birth, most people don't experience signs and symptoms until later in life — usually between the ages of 30 and 50 in men and after age 50 in women. Women are more likely to have symptoms after menopause, when they no longer lose iron with menstruation and pregnancy.
Early-stage signs and symptoms
Early signs and symptoms of hereditary hemochromatosis mimic those of many other common conditions, making it difficult to diagnose. Signs and symptoms include:
- Arthritis, especially in your hands
- Chronic fatigue
- Loss of sex drive (libido) or impotence
- Lack of normal menstruation (amenorrhea)
- Abdominal pain
- High blood sugar levels
- Low thyroid function (hypothyroidism)
- Abnormal liver function tests, even if no other symptoms are present
Advanced-stage signs and symptoms
In later stages of the disease, you may develop serious conditions such as:
- Cirrhosis — a condition marked by irreversible scarring of the liver
- Liver failure
- Liver cancer
- Congestive heart failure
- Cardiac arrhythmia
- Discolored skin that's bronze or gray in appearance
Iron plays an essential role in several body functions, including helping with the formation of blood. Most people absorb about 10 percent of the iron they ingest. When these stores are adequate, the body reduces the amount of iron absorbed by the intestine to avoid accumulating excess amounts.
But if you have hereditary hemochromatosis, you may absorb as much as 30 percent of the iron you ingest. Because your body can't use or eliminate this extra iron, it's stored in the tissues of major organs, especially your liver. Eventually you may accumulate five to 20 times as much iron as normal. Over a period of years, the stored iron can severely damage many organs, leading to organ failure and chronic diseases such as cirrhosis and diabetes.
The genetics of hemochromatosis
Genes are information centers in your cells that control your body's growth, development and function. A mutation in just one gene can drastically alter the way your body works.
The gene that controls the amount of iron you absorb from food is called HFE. The HFE gene has two common mutations, C282Y and H63D. In the United States, most people with hemochromatosis have inherited two copies of C282Y — one from each parent.
Inheriting just one gene with the C282Y mutation means you're a carrier. You aren't likely to develop the disease yourself, although you may absorb more iron than normal. About one in every 10 Caucasians carries one gene for hemochromatosis. If both your parents are carriers, you have a 25 percent chance of inheriting two mutated genes. Complicating things is the fact that not everyone with two copies of C282Y will experience symptoms.
A few people inherit one copy of C282Y and one of H63D. Of these, a small number develop symptoms of hemochromatosis. An even smaller number of people inherit two copies of H63D. Whether they're at risk of hereditary hemochromatosis is a matter of debate.
Other types of hemochromatosis
Other forms of hemochromatosis include:
- Juvenile hemochromatosis. This causes the same problems in young people that hereditary hemochromatosis causes in adults. But iron accumulation begins much earlier and symptoms usually appear between the ages of 15 and 30. Common complications include diabetes and problems with sexual development — which may lead to impotence, amenorrhea and infertility. Complications may also include an irregular heartbeat (heart arrhythmia) and heart failure — a condition in which your heart can't circulate enough blood to meet your body's needs. When not treated, juvenile hemochromatosis can be fatal. Although juvenile hemochromatosis is an inherited disease, the genetic abnormalities that cause it don't involve the HFE gene. Instead, it's caused by a mutation in a gene called hemojuvelin.
- Neonatal hemochromatosis. In this severe disorder, iron builds up in a baby's liver so rapidly that he or she may be stillborn or die within a few days of birth. Just what causes neonatal hemochromatosis isn't known.
- Having two copies of a mutated HFE gene. This is the greatest risk factor for hereditary hemochromatosis.
- Family history. If you have a close relative — a parent or sibling — with hemochromatosis, you're more likely to develop the disease.
- Ethnicity. People of Northern European descent — British, Dutch, German, Irish and French — are more prone to hereditary hemochromatosis than are people of other ethnic backgrounds. Hemochromatosis is less common in African-Americans, Hispanics and Asian-Americans.
- Being a man. Men are more likely to develop signs and symptoms of hemochromatosis at an earlier age. Because women lose iron with menstruation and pregnancy, they tend to store less of the mineral than men do. After menopause or a hysterectomy, the risk for women increases.
Untreated, hereditary hemochromatosis can lead to a number of complications, especially in your joints and in organs where excess iron tends to be stored — your liver, pancreas and heart. Many of these complications are serious and some may be life-threatening:
- Cirrhosis. Because your liver is a primary storage area for excess iron, it's especially likely to be damaged by long-term iron overload. Cirrhosis — permanent scarring of the liver — is just one of the problems that may occur. Cirrhosis itself may lead to serious complications, including bleeding from dilated veins in your esophagus and stomach (varices) and severe fluid retention in your abdomen (ascites). Toxins that accumulate in your blood can affect your mental functioning, leading to confusion and even coma (hepatic encephalopathy). A number of factors other than hereditary hemochromatosis also can cause cirrhosis — the most common are long-term alcohol abuse and chronic hepatitis.
- Liver cancer. If you have both cirrhosis and hereditary hemochromatosis, your risk of liver cancer increases greatly. Because liver cancer must be diagnosed and treated early for the best outcome, your doctor will likely monitor you for any liver problems.
- Diabetes. This disease affects the way your body uses blood sugar (glucose). Diabetes is the leading cause of adult-onset blindness and can contribute to serious health problems such as kidney failure and cardiovascular disease.
- Congestive heart failure. This potentially life-threatening condition may occur when excess iron in your heart interferes with its ability to circulate enough blood to meet your body's needs. Untreated congestive heart failure can be fatal, but the condition may be reversible when hereditary hemochromatosis is treated and excess iron stores reduced.
- Heart arrhythmias. Abnormal heart rhythms can cause heart palpitations, chest pain and lightheadedness. In some cases, they may be life-threatening. Like congestive heart failure, arrhythmias can often be reversed with treatment for hereditary hemochromatosis.
- Pigment changes. Deposits of iron in skin cells can turn your skin a bronze or gray color.
Hereditary hemochromatosis can be difficult to diagnose. Early symptoms such as stiff joints and fatigue can result from a number of conditions that are more common than hemochromatosis.
At any stage — even before symptoms appear — doctors can detect iron overload with two blood tests:
- Serum transferrin saturation. This test measures the amount of iron bound to a protein (transferrin) that carries iron in your blood. Transferrin saturation values greater than 45 percent are considered too high.
- Serum ferritin. This test measures the amount of iron stored in your body. If the results of your serum transferrin saturation test are higher than normal, your doctor will check your serum ferritin. Because a number of infectious and inflammatory conditions other than hereditary hemochromatosis can cause elevated ferritin, both tests are needed to diagnose the disorder. You may need the tests repeated for the most accurate results.
Serum transferrin saturation and serum ferritin tests aren't a part of routine medical testing. Public health officials recommend that you be tested for hemochromatosis if you have a parent, child or sibling with the disease, or if you have any of the following signs and symptoms:
- Joint disease
- Severe fatigue
- Heart disease
- Elevated liver enzymes
Blood tests may also suggest iron overload if you abuse alcohol, have had multiple blood transfusions or have had hepatitis C. To confirm a diagnosis of hereditary hemochromatosis, your doctor may suggest other tests, including:
- Genetic testing. The discovery of the HFE gene made genetic testing for hemochromatosis possible. This test can help your doctor confirm a diagnosis of hereditary hemochromatosis. Some researchers advocate universal screening for HFE gene mutations. They point out that hemochromatosis is a common condition that can cause serious complications when it's not treated and that a simple, inexpensive and effective treatment exists. Other doctors, as well as the Centers for Disease Control and Prevention, recommend this type of testing only for adult family members of someone with hemochromatosis. If you're considering genetic testing for hemochromatosis, discuss the pros and cons with your doctor or a genetic counselor.
- Liver biopsy. Until recently, this test was the only way to confirm a diagnosis of hereditary hemochromatosis. During the procedure, your doctor removes a sample of tissue from your liver, using a thin needle. The sample is sent to a laboratory where it's checked for the presence of iron as well as for evidence of liver damage, especially scarring or cirrhosis. Risks of biopsy include bruising, bleeding and infection.