alpha-1 antitrypsin deficiency What Is Alpha-1 Antitrypsin Deficiency?. NHLBI. alpha-1 antitrypsin deficiency AAT deficiency http://www.nhlbi.nih.gov/health/health-topics/topics/aat National Heart Lung and Blood Association: AATD Alpha-1 antitrypsin deficiency alpha-1 antitrypsin deficiency http://www.nhlbi.nih.gov/health/health-topics/topics/aat/ Alpha-1 Antitrypsin Deficiency raise the risk Alpha-1 antitrypsin (AAT) deficiency alpha-1 antitrypsin deficiency Alpha1 antitrypsin deficiency National Institute of Health Alpha-1-Antitripsin deficiency