Abstract
The marked variability in individual susceptibility to the detrimental effects of smoking on lung function and other findings suggest a significant genetic contribution to chronic obstructive pulmonary disease (COPD). The only known genetic risk factor for COPD, severe a1-antitrypsin (AAT) deficiency, explains only 1% to 2% of cases of this disease. Screening for severe AAT should be done in all cases of COPD. There is considerable interest in identifying susceptibility genes for COPD unrelated to severe AAT deficiency, as this could greatly enhance efforts to prevent, diagnose, and treat COPD by yielding novel insights into its pathogenesis.