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Home > Health Library > Alpha-1 Antitrypsin Deficiency Genetic Testing
Alpha-1 antitrypsin (AAT) is a proteinnormally found in the lungs and the bloodstream. It helps protect the lungs from diseases such as emphysemaand chronic obstructive pulmonary disease (COPD). Some people do not make enough of this protein or they make an abnormal type of AAT, either of which can cause AAT deficiency. These people are more likely to have lung diseases and will get them at a younger-than-normal age (30 to 40 years old). Some types of abnormal AAT can also damage the liver. AAT deficiency is a rare disorder and is the only known genetic(inherited) factor that increases your chances for developing emphysema.
Alpha-1 antitrypsin deficiency is caused by a change, or mutation, in the genethat tells the body how to make alpha-1 antitrypsin. There are many kinds of possible changes in this gene, but only a few cause problems. To have this condition, you have to get the changed gene from both parents.
If you receive only one changed gene, you do not have the disease but are a carrier. The good copy of the gene you received from your other parent is enough to tell your body how to properly make alpha-1 antitrypsin. Some people who carry the changed gene may have very mild symptoms of the deficiency.
Treatment for alpha-1 antitrypsin deficiency involves avoiding substances-especially cigarette smoke-that could harm your lungs. Also try to avoid dust and workplace chemicals. You also may want to avoid alcohol because of the risk of liver damage. Exercise can improve your stamina and overall health. You may also need medicines and other treatments to help you breathe easier and stay as healthy and strong as you can.
The only treatment available for the lack of the protein is plasmacontaining alpha-1 antitrypsin. This is usually given only to people who have very low levels of AAT in their blood. It is not clear that this treatment is any better than avoiding smoke and other lung-damaging chemicals. The plasma is made from the blood of many donors and is treated to reduce the chance of spreading an infectious disease. You receive the plasma through an IV, usually every 3 to 4 weeks for life.
A blood test can measure the amount of alpha-1 antitrypsin (AAT) in your blood. You may have AAT deficiency if your levels are low or if the blood test is not able to find any AAT in your blood. If your AAT level is lower than normal, the blood sample can be tested to look for abnormal types of alpha-1 antitrypsin. People who carry the changed gene may be more at risk for symptoms if they have certain types of alpha-1 antitrypsin.
100-200 mg/dLor 1.0-2.0 g/L
Although this blood test is highly reliable, no test is 100% accurate. This test cannot predict when-or whether-you will develop symptoms or how severe they will be.
The decision to have the test is personal. You may have emotional, financial, and family reasons for taking or not taking the test.
You may choose to have the test because:
You may decide not to be tested because:
Information from genetic testing can have a big impact on your life. Ask to have genetic counselingbefore making a decision about testing. Genetic counselors are trained to explain the test and its results, but you make the decision about whether to have the test. A genetic counselor can help you make well-informed decisions. Genetic counseling can help you and your family:
Genetic counselors are trained to help you and your family make informed decisions. They are sensitive to the physical and emotional aspects of these decisions. Your privacy and confidentiality are carefully protected.
Fischbach FT, Dunning MB III, eds. (2009). Manual of Laboratory and Diagnostic Tests, 8th ed. Philadelphia: Lippincott Williams and Wilkins.
Other Works Consulted
Pagana KD, Pagana TJ (2010). Mosby's Manual of Diagnostic and Laboratory Tests, 4th ed. St. Louis: Mosby.
ByHealthwise StaffPrimary Medical ReviewerE. Gregory Thompson, MD - Internal MedicineAdam Husney, MD - Family MedicineElizabeth T. Russo, MD - Internal MedicineSpecialist Medical ReviewerKen Y. Yoneda, MD - Pulmonology, Critical Care Medicine
Current as ofDecember 6, 2017
Current as of:
December 6, 2017
E. Gregory Thompson, MD - Internal Medicine & Adam Husney, MD - Family Medicine & Elizabeth T. Russo, MD - Internal Medicine & Ken Y. Yoneda, MD - Pulmonology, Critical Care Medicine
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