Asthma cases, unaffected controls, asthmacase parent trios, and extended families were recruited in clinics in the U.S, Mexico, and Barbados. Twelve samples with GWAS data were included in this study (Table 1). Detailed descriptions of the individual studies, ascertainment schemes, genotyping platforms, quality control (QC) protocols, and statistical analyses for the primary association testing are described in the Supplementary Note online.