COPD is expected to be the third leading cause of worldwide mortality and the fifth leading cause of morbidity by the year 2020 [1]. Cigarette smoking is the major risk factor for COPD but smokers show considerable variation in their risk of developing airflow obstruction. Familial aggregation studies suggest a strong genetic component to this risk [2]–[8]. However the only proven genetic risk factor for COPD is severe deficiency of α1-antitrypsin [9], which is present in only 1–2% of individuals with COPD. This suggests that other genes have yet to be identified that predispose smokers to airflow obstruction. We report the first genome wide association study (GWAS) for COPD. Our primary discovery sample was a case-control population collected from Bergen, Norway, and we used three independent study cohorts to further evaluate the top associations emerging from the GWAS analysis.
