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
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.
What Causes Hereditary Hemochromatosis?
Hereditary
hemochromatosis is a
genetic disorder called an
autosomal recessive 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)
testing is done to check to see if a person is likely to develop hereditary
hemochromatosis. This test checks whether you are a carrier of the
defective gene that causes hemochromatosis. HFE testing locates gene mutations that are called
C282Y and H63D. The test can usually confirm whether a person has an increased
chance for having hereditary hemochromatosis.
HFE testing identifies a genetic risk rather than the
disease itself. Even if you have one or more HFE gene mutations, you may never get sick.
Who Should Be Screened?
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. The test may be ordered if you have
a close family member—parent, brother, sister, or child—with the
condition. It is best to get tested
when you are age 18 to 30 when tests can usually detect the disease before
serious organ damage occurs.
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 Screening is not recommended for the general population because hemochromatosis is not common. 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 if you have the gene mutation too.
- You want to see how likely it will be that you will pass
the disease on to your children.
Is Screening Accurate?
The HFE screening test is very accurate in finding the common mutations in the HFE gene. But only about 85% of hemochromatosis is caused by the mutations found by the HFE screening.2, 3 Even if you have HFE mutations, you may not have the
disease. Or, you may have the disease, but gene testing did not find the mutations that are causing the disease.
Should I Be Screened?
The decision to have
hereditary hemochromatosis carrier screening is a personal one.
This testing is used to find out if a
person has an increased chance for having hemochromatosis. It may be
recommended for people who have a close family member—parent, brother, sister,
or child—with this disease.
Carrier
testing is expensive. If you are paying for the test, you will want to consider whether the cost of the testing is worth the results.
The discovery of a genetic disease that is not causing symptoms now should not affect your future ability to gain employment or health insurance coverage. A law in the United States, called the Genetic Information Nondiscrimination Act of 2008 (GINA), protects people who have DNA differences that may affect their health. This law does not cover life insurance, disability insurance, or long-term care insurance.
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 of African or Asian descent. 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
Organizations
|
Genetics Home Reference, U.S. National Library of
Medicine
|
| 8600 Rockville Pike |
| Bethesda, MD 20894 |
| Phone: |
1-888-FIND-NLM (1-888-346-3656) |
| Fax: |
(301) 402-1384 |
| TDD: |
1-800-735-2258 |
| Web Address: |
www.ghr.nlm.nih.gov |
| |
|
The Genetics Home Reference provides information on hundreds of genetic conditions. The website has many tools for learning about human genetics and the way genetic changes can cause
disease. It 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 |
| Phone: |
1-888-565-IRON (1-888-565-4766) (864) 292-1175 |
| Fax: |
(864) 292-1878 |
| Email: |
patientservices@irondisorders.org |
| Web Address: |
www.irondisorders.org |
| |
|
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
|
| 2 Information Way |
| Bethesda, MD 20892-3570 |
| Phone: |
1-800-891-5389 |
| Fax: |
(703) 738-4929 |
| TDD: |
1-866-569-1162
toll-free |
| Email: |
nddic@info.niddk.nih.gov |
| Web Address: |
www.digestive.niddk.nih.gov |
| |
|
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 |
| Phone: |
(301) 592-8573 |
| Fax: |
(240) 629-3246 |
| TDD: |
(240) 629-3255 |
| Email: |
nhlbiinfo@nhlbi.nih.gov |
| Web Address: |
www.nhlbi.nih.gov |
| |
|
The U.S. National Heart, Lung, and Blood Institute
(NHLBI) information center offers information and publications about preventing
and treating:
- Diseases affecting the heart and circulation, such as heart
attacks, high cholesterol, high blood pressure, peripheral artery disease, and
heart problems present at birth (congenital heart diseases).
- Diseases that affect the lungs, such as asthma, chronic
obstructive pulmonary disease (COPD), emphysema, sleep apnea, and
pneumonia.
- Diseases that affect the blood, such as anemia,
hemochromatosis, hemophilia, thalassemia, and von Willebrand disease.
|
|
References
Citations
-
U.S. Preventive Services Task Force (2006). Screening for hemochromatosis. Available online: http://www.ahrq.gov/clinic/uspstf06/hemochromatosis/hemochrs.htm.
-
Powell LW (2012). Hemochromatosis. In DL Longo et al., eds., Harrison's Principles of Internal Medicine, 18th ed., vol. 2, pp. 3162–3167. New York: McGraw-Hill.
-
National Human Genome Research Institute (2010). Learning about hereditary hemochromatosis. Available online: http://www.genome.gov/page.cfm?pageID=10001214.
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.
- Beutler E (2010). Disorders of iron metabolism. In K Kaushanksy et al., eds., Williams Hematology, 8th ed., pp. 565–606. New York: McGraw-Hill.
- Powell LW (2012). Hemochromatosis. In DL Longo et al., eds., Harrison's Principles of Internal Medicine, 18th ed., vol. 2, pp. 3162–3167. New York: McGraw-Hill.
- 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.
Credits
|
By
|
Healthwise Staff |
|
Primary Medical Reviewer
|
Kathleen Romito, MD - Family Medicine |
|
Specialist Medical Reviewer
|
Brian Leber, MDCM, FRCPC - Hematology |
|
Last Revised
|
October 15, 2012 |
U.S. Preventive Services Task Force (2006). Screening for hemochromatosis. Available online: http://www.ahrq.gov/clinic/uspstf06/hemochromatosis/hemochrs.htm.
Powell LW (2012). Hemochromatosis. In DL Longo et al., eds., Harrison's Principles of Internal Medicine, 18th ed., vol. 2, pp. 3162–3167. New York: McGraw-Hill.
National Human Genome Research Institute (2010). Learning about hereditary hemochromatosis. Available online: http://www.genome.gov/page.cfm?pageID=10001214.