A common inherited disorder in which the body absorbs and stores abnormally high amounts of iron, causing damage to certain organs. Hemochromatosis tends to coexist with diabetes, for reasons that aren’t completely clear.
Hereditary hemochromatosis is associated with a defect in the HFE gene, which helps regulate the amount of iron that gets absorbed from food. The most important mutation of this gene is known as C282Y: When a person inherits the C282Y mutation from both parents, hemochromatosis may result. As many as 5 out of 1,000 Caucasians in the United States have two copies of this mutation. (Hemochromatosis is less common in other ethnic groups.) Humans have no natural way of ridding their bodies of excess iron, so the extra iron absorbed by people with hemochromatosis gets stored in the body’s tissues, especially the liver, heart, and pancreas. Hemochromatosis can cause arthritis, liver disease, damage to the pancreas and adrenal gland, heart abnormalities, impotence, premature menopause, abnormal pigmentation of the skin (making it look gray or bronze), and thyroid deficiency.
The association between hemochromatosis and diabetes was first recognized in the late 1800’s, when doctors coined the term “bronze diabetes” in reference to the changes in skin pigmentation caused by hemochromatosis. One theory about the reason for this association is that the damage to the pancreas from excessive iron deposits can cause diabetes. Another theory is that diabetes and hemochromatosis are somehow genetically linked. Indeed, a few studies have shown the incidence of the C282Y mutation of the HFE gene to be higher in people with Type 2 diabetes than it is in the general population.
Even though people have defective hemochromatosis genes from birth, the symptoms usually don’t occur until adulthood—often between the ages of 30 and 50 in men and after age 50 in women. The symptoms associated with hemochromatosis are diverse and include joint pain, fatigue, abdominal pain, loss of libido (sex drive), and heart problems. However, it sometimes causes no symptoms.
Hemochromatosis can be diagnosed based on certain blood tests. The transferrin saturation test determines how much iron is bound to the protein that carries iron in the blood, and the serum ferritin test shows the iron level in the liver. If these tests indicate high levels of iron, the person can be given a special blood test for the HFE mutation to confirm the diagnosis. To rid the body of excess iron, people with hemochromatosis are given regular treatments of phlebotomy, or blood removal, that are simple, inexpensive, and safe.
It is best to catch hemochromatosis early, before it does much damage to organs. Health experts recommend that brothers, sisters, parents, children, and other close relatives of people with hemochromatosis be screened for the disease or the mutant gene. Doctors may additionally consider testing people with conditions such as joint disease, long-term fatigue, heart disease, elevated liver enzymes, or diabetes since these conditions can result from hemochromatosis.