Severe \documentclass[12pt]{minimal}\usepackage{amsmath}\usepackage{wasysym}\usepackage{amsfonts}\usepackage{amssymb}\usepackage{amsbsy}\usepackage{mathrsfs}\usepackage{upgreek}\setlength{\oddsidemargin}{-69pt}\begin{document}$${\mathrm{\alpha }}_{1}$$\end{document}α1-antitrypsin (AAT) deficiency is the best known genetic risk factor for COPD6, and genome-wide association studies (GWAS) have identified multiple promising candidate genes for COPD, including FAM13A, HTR4, RIN3, HHIP, ADAM19, CHRNA3/5, AGER, and EEFSEC6–8. The gene discussed is SERPINA1; the disease is chronic obstructive pulmonary disease.