Alpha-1 antitrypsin (AAT) deficiency
Alpha-1 antitrypsin (AAT) deficiency is an inherited condition where a patient lacks the sufficient volumes of AAT protein to protect the alveoli (the small sacs in the lungs that exchange oxygen for carbon dioxide).
AAT is produced by the liver and released into the bloodstream.
In people with AAT deficiency, elastase (an enzyme that breaks down proteins) attacks the walls of the alveoli, causing irreversible damage. If allowed to progress, lung tissue continues to be destroyed, and eventually fatal emphysema develops.
The first signs of AAT deficiency often appear between the ages of 20 and 40. The early symptoms are usually shortness of breath, wheezing following activity, and a decreased ability to exercise.