Hemochromatosis

DEFINITION

Hereditary hemochromatosis (he-moe-kroe-muh-TOE-sis) 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. The excess iron can poison these organs, leading to life-threatening conditions such as cancer, heart arrhythmias and cirrhosis.

Many people inherit the faulty genes that cause hemochromatosis — it is the most common genetic disease in Caucasians. But only a minority of those with the genes develop serious problems. Hemochromatosis is more likely to be serious in men.

Signs and symptoms of hereditary hemochromatosis usually appear in midlife. Iron can be dropped to safe levels by regularly removing blood from your body.

CAUSES

Hereditary hemochromatosis is caused by a mutation in a gene that controls the amount of iron your body absorbs from the food you eat. The mutations that cause hereditary hemochromatosis are passed from parents to children.

Gene mutations that cause hemochromatosis

The gene that is mutated most often in people with hereditary hemochromatosis is called HFE. You inherit one HFE gene from each of your parents. The HFE gene has two common mutations, C282Y and H63D. One of these mutations is found in about 85 percent of people who have hereditary hemochromatosis. Genetic testing can reveal whether you have these mutations in your HFE gene.

If you inherit 2 abnormal genes, you may develop hemochromatosis. About 70 percent of people who inherit two genes develop evidence of iron overload of hemochromatosis. You can also pass the mutation on to your children.

If you inherit 1 abnormal gene, you won’t develop hemochromatosis. You are considered a gene mutation carrier and can pass the mutation on to your children. They would not develop disease unless they also inherit another abnormal gene from another parent.

How hemochromatosis affects your organs

Iron plays an essential role in several body functions, including helping in the formation of blood. A peptide hormone called hepcidin, secreted by the liver, plays a key role in the body’s use of iron. It controls how much iron is absorbed by the intestines, how iron is used in various body processes and how it’s stored in various organs.

In hemochromatosis, the normal role of hepcidin is disrupted and your body absorbs more iron that it needs. This excess iron is stored in the tissues of major organs, especially your liver. Too much iron is toxic to your body, and over a period of years, the stored iron can severely damage many organs, leading to organ failure and chronic diseases such as cirrhosis, diabetes and heart failure.

Though many people have faulty genes that cause hemochromatosis, only about 10 percent of them have iron overload to the degree that causes tissue and organ damage.

Other types of hemochromatosis

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. This disorder is caused by a mutation in the HJV gene.

Neonatal hemochromatosis. In this severe disorder, iron builds up rapidly in the liver of the developing fetus. It is thought to be an autoimmune disease, in which the body attacks itself.

Secondary hemochromatosis. This form of the disease is not inherited. The iron deposits are due to another disease, such as anemia, chronic liver disease or an infection.

SYMPTOMS

Some people with hereditary hemochromatosis never have symptoms. Early signs and symptoms often are nonspecific, mimicking those of other common conditions. Common symptoms include:

• Joint pain
• Fatigue
• Weakness

First signs and symptoms of the disease in men are often from organ damage. They include:

• Joint pain
• Diabetes
• Loss of sex drive (libido)
• Impotence
• Heart failure

When signs and symptoms typically appear

Although hereditary hemochromatosis is present at birth, most people don’t experience signs and symptoms until later in life — usually between the ages of 50 and 60 in men and after age 60 in women. Women are more likely to develop symptoms after menopause, when they no longer lose iron with menstruation and pregnancy.

When to see a doctor

See your doctor if you experience any of the signs and symptoms of hereditary hemochromatosis. If you have an immediate family member who has hemochromatosis, ask your doctor about genetic tests that can determine if you have inherited the gene that increases your risk of hemochromatosis.