Health Talk: Some people absorb too much iron
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By JOHN MESSMER - Published: July 9, 2008
Hemochromatosis is an inherited condition of abnormal iron metabolism that causes individuals with the condition to absorb too much iron from their diets.
When the metal reaches toxic levels in tissues of major organs such as the liver, heart, pituitary or thyroid, these overburdened organs stop functioning properly and eventually become diseased.
Hereditary hemochromatosis, or HH, is one of the most common genetic diseases in the United States, occurring in one in 200 caucasians, with one in 10 being a carrier — most, but not all of these having Celtic ancestry.
By contrast, sickle cell anemia occurs in one in 500 black Americans with one in 12 being carriers. Despite its prevalence, it remains relatively unknown, even among physicians.
HH causes iron to be absorbed even when it is not needed. Normally, people absorb a tiny amount of iron daily, just enough to replace what is lost from normal bodily functions.
Women absorb more during their childbearing years to replace iron loss from menstrual blood. In hemochromatosis, iron continues to be absorbed excessively.
Once the places where iron is normally stored are full, iron begins to be stored in the liver, heart, skin and other organs, damaging them.
This can lead to heart failure and rhythm disorders, diabetes, cirrhosis and liver tumors. Untreated, it can be fatal. HH is the result of genetic mutations, the most common ones called C282Y and H63D.
The mutation is believed to have developed about 40,000 years ago in what is now Ireland to compensate for an iron-poor diet.
At that time, it would have been beneficial. The mutations are passed on from parents to children. The HH genes are recessive. That means the disease occurs only when two copies of the gene are present — one from each parent.
If only one copy is passed, the person is a carrier. The full-fledged disease is seen only in those with two copies. Carriers also can store too much iron, but they rarely have organ damage. In the most common form of HH, males usually do not develop symptoms until after age 30 and women may not show problems until after menopause because they lose iron regularly during menses.
Symptoms relate to the organs that become overloaded with iron and can include arthritis, liver disease, diabetes, thyroid deficiency, bronze skin color, impotence and adrenal gland abnormalities and such nonspecific symptoms as fatigue or aches.
The problem is actually easy to diagnose before any damage occurs by measuring iron levels in the blood.
This is a different test than a blood count, the typical test for anemia. Having a normal blood count does not give any information about HH.
Blood donor centers test for too little iron; passing the test does not say anything about having too much iron.
Screening for HH is done with a serum iron level and transferrin saturation and often a ferritin level.
Transferrin is a protein that carries iron in the blood and ferritin is an iron-storage protein.
If the iron level is high and transferrin is more than 40 percent saturated or ferritin is higher than 200 or so, HH should be considered.
If a doctor tells a patient that his or her iron is great or high enough that there is no need to worry about anemia, the patient should ask how high it is and whether he or she should be tested for hemochromatosis.
To diagnose HH, a blood sample is tested for the two more common DNA mutations. Until the DNA test was available, liver biopsy was needed to test for iron deposits. Biopsy is reserved for those who have developed cirrhosis of the liver to help determine if the cause is hemochromatosis.
People with one copy of the gene should avoid taking extra iron in vitamins and supplements and should avoid using iron cookware and extra vitamin C, which enhances iron absorption.
A person with two copies of the gene has the disease and should begin a program of iron elimination. Treatment is through therapeutic phlebotomy. This is just like the process of donating blood — a unit is removed as often as weekly if needed to reduce iron levels to normal.
Treatment can be ordered by many types of medical specialists including a family physician. The family of anyone with even one HH gene should consider testing even if they have no symptoms.
Those with the disease will pass on one copy of the gene to each of their children. Carriers have a 5-0/50 chance of passing on a hemochromatosis gene to each child. Some advocate testing in childhood if one or both parents are known to carry the gene so the child's diet can be managed to keep iron levels under control.
Hereditary hemochromatosis is a fairly common disorder, but it's the luck o' the Irish to be able to diagnose and treat it effectively, especially if found early.
For more information, contact Iron Disorders Institute at www.irondisorders.org.
Original article written by John Messmer, Penn State Family and Community Medicine, Penn State Milton S. Hershey Medical Center, Penn State College of Medicine.
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