Definition of Alpha-1 antitrypsin deficiency:

Alpha-1 antitrypsin deficiency is a lack of a liver protein that blocks the destructive effects of certain enzymes. The condition may lead to emphysema and liver disease, and in rare cases, skin disease.

Causes, incidence, and risk factors:

Alpha-1 antitrypsin deficiency results from a genetic defect. The mechanism that causes associated liver disease and emphysema in some people with this deficiency is not known. However, some evidence suggests that it may be related to inflammation.

Studies now show that Alpha-1 antitrypsin deficiency may be more common than once thought. Approximately 75% of adults with severe deficiency will develop emphysema, which often begins before 40 years of age. Smoking can increase the risk.