Diagnosing alpha 1-antitrypsin deficiency.

Alpha 1-antitrypsin deficiency is a genetically transmitted disorder associated with an increased risk of emphysema and liver disease. The highest incidence occurs in whites of Northern European descent; the disorder affects between 70,000 and 100,000 individuals in the United States. Most persons with alpha 1-antitrypsin deficiency are misdiagnosed or undiagnosed. The laboratory tests used to screen for and diagnose the disorder are simple, inexpensive, and provide an opportunity to prevent the development of clinical disease through education about cofactor avoidance. This article provides a review of the epidemiology, genetics, and clinical presentation of this disorder.