Alpha 1 antitrypsin (A1AT) deficiency (A1ATD) is a common autosomal co-dominant genetic disorder caused by mutations on the SERPINA1 gene (chromosome 14) that may be clinically characterized by lung (emphysema, chronic obstructive pulmonary disease-COPD) and/or liver (cirrhosis) disease. Here, SERPINA1 is linked to chronic obstructive pulmonary disease.