A GABRIEL Consortium Large-Scale Genome-Wide Association Study of Asthma

Study Description

European cases and population-matched controls were obtained from clinics and cohort and cross-sectional population surveys. We included some family-based studies, cases and controls from our first-generation genome-wide association study, and cases and controls of European descent from Canadian, Australian and US surveys. Asthma was considered present if diagnosed by a physician. We defined childhood-onset asthma as being present below the age of 16 years and adult-onset asthma to have started at 16 years or older. Some surveys contributed samples to both age-of-onset groups. Other subgroups were made up of cases of unknown age of onset, cases with occupational asthma or cases of severe asthma. All participants or their parents provided signed informed consent to participate in the study, according to the rules of local ethics committee. After quality control and filtering, we retained genotype on 582,892 SNPs on 10,365 cases and 16,110 controls from 23 different studies as described in the Table below. ¹