What Is AAT Deficiency?
Alpha1-antitrypsin (AAT) deficiency, also known as Alpha-1, is an inherited disorder that causes significant reduction in the naturally occurring protein alpha1 antitrypsin. Scientists also call this protein alpha1-proteinase inhibitor (A1-PI) because it inhibits not only trypsin but also other enzymes called proteinases. AAT deficiency is inherited, which means it is a genetic disorder, and it can lead to emphysema, a serious and progressive lung disease. AAT deficiency develops when the body has a lower than normal level of the protein AAT. A low level of AAT allows certain enzymes to attack healthy tissues in the body, primarily in the lungs. This destruction is prevented when the AAT level is normal. The Role of Heredity in AAT Deficiency Since AAT deficiency is inherited, blood relatives of anyone with AAT deficiency have an increased chance of having the disease. Brothers and sisters of someone with AAT deficiency have a 1-in-4 chance of inheriting the genes that cause AAT defici
