Key Points

• Alpha-1 antitrypsin (AAT) deficiency is a condition that raises your risk for certain types of lung disease, especially if you smoke. A small number of people who have AAT deficiency develop liver disease and a rare skin disease.
• Alpha-1 antitrypsin, also called AAT, is a protein made in the liver. Normally, the protein goes into the bloodstream and helps protect the body's organs from the harmful effects of other proteins. One of the main organs it protects is the lungs.
• In AAT deficiency, the AAT proteins made in the liver aren't the right shape. They get stuck inside liver cells and can't get into the bloodstream. This means that the organs don't get enough protection, and the liver has too much AAT protein in it.
• AAT deficiency is an inherited condition. "Inherited" means it's passed from parents to children. If you have close relatives with AAT deficiency, you're more likely to have the condition.
• You may not have any serious complications if you have AAT deficiency, and you may live a normal lifespan. Many nonsmokers who have AAT deficiency don't develop any serious related lung diseases.
• You may have AAT deficiency if you have signs and symptoms of serious lung disease without any obvious cause. Another sign of AAT deficiency is if you develop emphysema at age 45 years or younger.
• Your doctor will diagnose AAT deficiency based on your medical and family histories, any risk factors you have, and results from diagnostic tests.
• AAT deficiency has no cure. However, the lung diseases linked to this inherited condition have many treatments. These include lifestyle changes, medicines, vaccines, rehabilitation, and surgery.
• You can't prevent AAT deficiency, because the condition is inherited. If you inherit two altered AAT genes, you will have AAT deficiency. However, you can take steps to prevent or delay the lung diseases linked to this condition. Quitting smoking and avoiding places with dust, fumes, and other toxic substances are important steps.
• Researchers continue to look for new treatments for AAT deficiency.