Hemochromatosis gene (HFE) testing is a blood test used to check for hereditary hemochromatosis, an inherited disorder that causes the body to absorb too much iron. The iron then builds 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 at ages 40 to 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.
Why It Is Done
HFE testing is used to find out if a person has an increased chance of having hemochromatosis. It is often recommended for people who have a close family member—parent, brother, sister, or child—with this disease.
This test might be done if you have high iron levels in your blood. This test helps to find out if you have hemochromatosis.
HFE testing locates and identifies mutations in the HFE genes. These gene mutations are called C282Y and H63D.
How To Prepare
Generally, no special preparation is required before having a hemochromatosis gene test.
Genetic test results often have ethical, legal, or social implications. You may want to talk to a genetic counsellor before making a decision about testing. Genetic counsellors are trained to explain the test and its results clearly. A genetic counsellor can help you make well-informed decisions.
Talk to your doctor about any concerns you have regarding the need for the test, its risks, how it will be done, or what the results will mean. To help you understand the importance of this test, fill out the medical test information form ( What is a PDF document? ).
How It Is Done
You might have a cheek test or a blood test.
For a cheek test, a health professional will gently swab or scrape the inside of your cheek to get a sample of cells.
For a blood test, the health professional taking a sample of your blood will:
- Wrap an elastic band around your upper arm to stop the flow of blood. This makes the veins below the band larger so it is easier to put a needle into the vein.
- Clean the needle site with alcohol.
- Put the needle into the vein. More than one needle stick may be needed.
- Attach a tube to the needle to fill it with blood.
- Remove the band from your arm when enough blood is collected.
- Put a gauze pad or cotton ball over the needle site as the needle is removed.
- Put pressure on the site and then put on a bandage.
How It Feels
The blood sample is taken from a vein in your arm. An elastic band is wrapped around your upper arm. It may feel tight. You may feel nothing at all from the needle, or you may feel a quick sting or pinch.
If you get a cheek test, you will feel gentle pressure on the inside of your cheek from the swab.
You may worry or feel nervous before you have the test or while you are waiting for the results.
There is very little chance of a problem from having a cheek test or from having a blood sample taken from a vein. If you have a blood test:
- You may get a small bruise at the site. You can lower the chance of bruising by keeping pressure on the site for several minutes.
- In rare cases, the vein may become swollen after the blood sample is taken. This problem is called phlebitis. A warm compress can be used several times a day to treat this.
Hemochromatosis gene (HFE) testing is a blood test used to check for hereditary hemochromatosis, a disorder that is passed from a parent to a child (inherited) and causes the body to absorb too much iron. This HFE gene test is usually not used to check for other, less common causes of inherited hemochromatosis.
Mutations (C282Y or H63D) are not found in the HFE gene. Normal results are called negative.
Mutations (C282Y or H63D) are found in the HFE gene test. Abnormal results are called positive.
An abnormal test result does not mean that you have hemochromatosis or that you will have hemochromatosis. It means that you have a mutation in the HFE gene. Ask your doctor or a genetic counsellor to help you understand your test results.
What Affects the Test
There is a very small chance that the results of a hemochromatosis gene test may not be accurate if you have had a blood transfusion done within a week of the test.
What To Think About
- If you are thinking about having genetic testing, talk with your doctor about the benefits as well as the possibility of insurance, employment, or other discrimination based on test results. You can also contact the Canadian Coalition for Genetic Fairness at 1-800-998-7398. Or visit its website at www.ccgf-cceg.ca.
- The information obtained from an HFE test can have a big impact on your life. Genetic counsellors are trained to help you understand your chance for having a child with an inherited (genetic) disease. A genetic counsellor can help you make well-informed decisions. Ask to have genetic counselling before making a decision about HFE testing.
- HFE testing is not able to predict whether you will have hemochromatosis. Although the test locates the most common HFE mutations, there may be other HFE mutations that the test does not find. You may have HFE mutations and not have the diseases or you may have symptoms of the disease but gene testing is does not find any mutations.
- HFE gene testing may identify the cause of high iron levels and eliminate the need for other tests, such as a liver biopsy.
- Iron and ferritin levels may also be checked at the same time as a hemochromatosis gene test.
Other Works Consulted
- Bacon, BR et al. (2011). Diagnosis and management of hemochromatosis: 2011 practice guideline by the American Association for the Study of Liver Diseases. Hepatology, 54(1): 328–343.
- National Human Genome Research Institute (2010). Learning about hereditary hemochromatosis. Available online: http://www.genome.gov/page.cfm?pageID=10001214.
- Pagana KD, Pagana TJ (2010). Mosby's Manual of Diagnostic and Laboratory Tests, 4th ed. St. Louis: Mosby Elsevier.
- Powell LW (2015). Hemochromatosis. In DL Kasper et al., eds., Harrison's Principles of Internal Medicine, 19th ed., vol. 2, pp. 2514–2519. New York: McGraw-Hill Education.
- 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.
- U.S. Preventive Services Task Force (2006). Screening for hemochromatosis. Available online: http://www.ahrq.gov/clinic/uspstf06/hemochromatosis/hemochrs.htm.
Current as ofMay 6, 2018
Author: Healthwise Staff
Medical Review: Kathleen Romito, MD - Family Medicine
Brian O'Brien, MD, FRCPC - Internal Medicine
E. Gregory Thompson, MD - Internal Medicine
Adam Husney, MD - Family Medicine
Martin J. Gabica, MD - Family Medicine
Elizabeth T. Russo, MD - Internal Medicine
Brian Leber, MDCM, FRCPC - Hematology
Current as of: May 6, 2018
Author: Healthwise Staff
Medical Review:Kathleen Romito, MD - Family Medicine & Brian O'Brien, MD, FRCPC - Internal Medicine & E. Gregory Thompson, MD - Internal Medicine & Adam Husney, MD - Family Medicine & Martin J. Gabica, MD - Family Medicine & Elizabeth T. Russo, MD - Internal Medicine & Brian Leber, MDCM, FRCPC - Hematology