Alpha-1-antitrypsin deficiency (https://omim.org/entry/613490) is an autosomal recessive disorder. The most common manifestation is emphysema, which becomes evident by the third to fourth decade. A less common manifestation of the deficiency is liver disease, which occurs in children and adults, and may result in cirrhosis and liver failure. Environmental factors, particularly cigarette smoking, greatly increase the risk of emphysema at an earlier age (Crystal, 1990).