Alpha-1 Antitrypsin Deficiency
Source: MedlinePlus Health Topics, U.S. National Library of Medicine
What is alpha-1 antitrypsin deficiency (AAT deficiency)? Alpha-1 antitrypsin deficiency (AAT deficiency, or AATD) is an inherited condition that raises your risk for lung and liver disease. If you have this condition, your body doesn't make enough alpha-1 antitrypsin (AAT). AAT is made by your liver. It helps protect your lungs from inflammation and irritating substances you might breathe in, such as smoke. If your liver doesn't make enough AAT, your lungs may be more easily damaged from smoking , pollution , or dust from the environment. This can lead to a serious lung condition called chronic obstructive pulmonary disease ( COPD ). AAT deficiency may also cause a liver disease called cirrhosis . This is more common in children who have AAT deficiency. What causes alpha-1 antitrypsin deficiency (AAT deficiency)? AAT deficiency is a genetic disorder . That means it's caused by changes in your genes, which may also be called gene variants or mutations. Your genes carry information that controls what you look like and how your body works. AAT deficiency is caused by changes in the SERPINA1 gene , which carries instructions for making the AAT protein. These gene changes are inherited from your parents, so AAT deficiency tends to run in families: If you have two mutated copies of the gene, it means you have a condition called AAT deficiency. People with this disorder have a higher risk of getting lung disease or liver damage before the age of 45. If you have one mutated copy of the gene, you are a carrier of AAT deficiency. In these cases, this means you are at slightly higher risk of developing lung disease, especially if you have other risk factors, such as being a smoker. You could still pass the mutated gene on to your children. There are a few gene changes that cause AAT deficiency. These gene changes can: Decrease the amount of AAT protein your liver makes. Prevent your liver from making any AAT. Affect the shape of the AAT protein so that it can't move out of you