Wise, MD, Johns Hopkins Asthma and Allergy Center Reviewed / Revised Jun 2022 | Modified Sep 2022 View Patient Education Pathophysiology Classification Symptoms and Signs Diagnosis Prognosis Treatment Key Points Topic Resources Expression of Phenotype in... Alpha-1 antitrypsin deficiency is congenital lack of a primary lung antiprotease, alpha-1 antitrypsin, which leads to increased protease-mediated tissue destruction and emphysema in adults.