Hemochromatosis Genetic Screening
What Is Hereditary Hemochromatosis?
Hereditary hemochromatosis is a disorder that causes the body to absorb too much iron. This causes iron to build up in the blood, liver, heart, pancreas, joints, skin, and other organs.
In its early stages, hemochromatosis can cause joint and belly pain, weakness, lack of energy, and weight loss. It can also cause scarring of the liver (cirrhosis), darkening of the skin, diabetes, infertility, heart failure, irregular heartbeats (arrhythmia), and arthritis. But many people do not have symptoms in the early stages.
In men, hereditary hemochromatosis is usually found between the ages of 40 and 60. In women, it is not usually found until after menopause because, until that time, women regularly lose blood and iron during their monthly periods.
What Causes Hereditary Hemochromatosis?
Hereditary hemochromatosis is a genetic disorder. It is passed from a parent to a child (inherited). Most people who have hemochromatosis inherit defective genes from both parents. In rare cases, a person can have hemochromatosis by inheriting defective genes from just one parent.
A person who has inherited only one defective gene will most likely be a carrier of hemochromatosis and will not have the disease. A carrier can pass the defective gene on to his or her children.
- If only one parent is a carrier of a defective gene, the child will not have hemochromatosis. But there is a 50% chance that the child will be a carrier.
- If both parents are carriers, there is only a 25% chance that the child will have both defective genes and so will have a higher risk of getting hemochromatosis. But there is a 50% chance that the child will be a carrier.
What Is Hemochromatosis Genetic (HFE) Screening?
Screening tests help your doctor look for a certain disease or condition before any symptoms appear. This can increase your chance of finding the problem at a curable or more treatable stage.
Hemochromatosis gene (HFE) screening is a blood test that finds out whether you are a carrier of the defective gene that causes hemochromatosis. The test may be ordered if you have a close family member—parent, brother, sister, or child—with the condition.
HFE testing identifies a genetic risk rather than the disease itself. Even if you have one or more HFE genes, you may never get sick. Screening is only recommended for people who have an increased chance of having the disease, such as those with other family members who have hereditary hemochromatosis.
Who Should Be Screened?
Hemochromatosis gene (HFE) testing is done to check to see if a person is likely to develop hereditary hemochromatosis. HFE testing locates common gene mutations (which are called C282Y and H63D). The test can usually confirm whether a person has an increased chance of having hereditary hemochromatosis.
This type of genetic testing allows parents to find out if they have increased chances of having a child with hemochromatosis. Genetic counseling to help you understand the meaning and possible results of the test is recommended before having genetic testing.
The U.S. Preventive Services Task Force (USPSTF) does not recommend genetic screening for hemochromatosis in the general population.1 The general population includes people who do not have symptoms of hemochromatosis and who do not have a parent, brother, sister, or child with the disease.
Anyone can have the test, but a doctor must order it. You may decide to have HFE testing:
- If other people in your family have hereditary hemochromatosis and you want to see how likely it will be that you will pass the disease on to your children. Information from screening can help you make decisions about your health care.
- If two separate blood tests, which include a ferritin level and transferrin saturation, are done and they show that you have high iron levels in your blood (iron overload). More than half of people with iron overload have HFE gene mutations.
- To find out whether you have hemochromatosis before you develop related problems, such as liver disease. Early treatment can help prevent later problems.
Is Screening Accurate?
HFE screening accurately locates the gene that causes hereditary hemochromatosis about 85% of the time.2 You may have HFE mutations and not have the disease, or you may have symptoms of the disease but gene testing does not find any mutations.
Should I Be Screened?
The decision to have hereditary hemochromatosis carrier screening is a personal one.
You might decide to be tested if you have had 2 or more blood tests that show that you have high iron levels in your blood (iron overload). More than half of people with iron overload have HFE gene mutations. If screening shows that you have hereditary hemochromatosis, early treatment can prevent later problems, such as scarring of the liver (cirrhosis).
Carrier testing is expensive. You may be more likely to have the test if your insurance pays for it.
Why Not Be Screened?
There may be reasons you would choose not to have carrier testing.
- You think that your risk of being a carrier is low. This may be true if you are an African American or an Asian-American. Fewer people in these groups have hereditary hemochromatosis.
- Carrier testing is expensive. You may decide not to have testing if your insurance does not pay for it.
- Testing is not always able to predict if you will have hereditary hemochromatosis. Although the test detects the most common hemochromatosis gene (HFE) mutations, there may be other HFE mutations that the test does not detect. There is a small chance that you are a carrier even if the results are normal because there may be other HFE mutations that the test does not find. HFE gene testing is usually not used to check for other, less common causes of inherited hemochromatosis.
Other Places To Get Help
|Genetics Home Reference, U.S. National Library of Medicine|
|8600 Rockville Pike|
|Bethesda, MD 20894|
The Genetics Home Reference provides information on more than 250 genetic conditions. It also contains a glossary, a handbook, and other tools for learning about human genetics and the way genetic changes can cause disease. The Web site also has links to additional resources for people who have genetic conditions and for their families.
|Iron Disorders Institute|
|P.O. Box 675|
|Taylors, SC 29687|
The Iron Disorders Institute is a national voluntary health agency that provides information about iron disorders such as hemochromatosis, acquired iron overload, sickle cell anemia, thalassemia, iron deficiency anemia, and anemia of chronic disease. The organization works with a scientific review board as well as various medical professional groups. A free newsletter, idInsight, is available.
|National Digestive Diseases Information Clearinghouse (NDDIC)|
|2 Information Way|
|Bethesda, MD 20892-3570|
This clearinghouse is a service of the U.S. National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), part of the U.S. National Institutes of Health. The clearinghouse answers questions; develops, reviews, and sends out publications; and coordinates information resources about digestive diseases. Publications produced by the clearinghouse are reviewed carefully for scientific accuracy, content, and readability.
|National Heart, Lung, and Blood Institute (NHLBI)|
|P.O. Box 30105|
|Bethesda, MD 20824-0105|
The U.S. National Heart, Lung, and Blood Institute (NHLBI) information center offers information and publications about preventing and treating:
- U.S. Preventive Services Task Force (2006). Screening for hemochromatosis. Available online: http://www.ahrq.gov/clinic/uspstf06/hemochromatosis/hemochrs.htm.
- National Human Genome Research Institute (2008). Learning about hereditary hemochromatosis. Available online: http://www.genome.gov/page.cfm?pageID=10001214.
Other Works Consulted
- Qaseem A, et al. (2005). Screening for hereditary hemochromatosis: A clinical practice guideline from the American College of Physicians. Annals of Internal Medicine, 143(7): 517–521.
|Author||Robin Parks, MS|
|Editor||Kathleen M. Ariss, MS|
|Associate Editor||Tracy Landauer|
|Primary Medical Reviewer||E. Gregory Thompson, MD - Internal Medicine|
|Specialist Medical Reviewer||Brian Leber, MDCM, FRCPC - Hematology|
|Last Updated||April 20, 2009|
Last Updated: April 20, 2009