Non‐palindromic variants with missing rates <5%, MAF >3%, and HWE p‐values >0.0001 were used for imputation. Data were imputed separately by array due to different array contents. SHAPEIT2 67 was used to phase the genotypes and Minimac3 68 was used for imputation. Originally, 1000 Genomes (Phase 3, version 5) was used as the reference panel for COGA imputation. To improve imputation quality, the COGA samples of European genetic ancestry have been re‐imputed to the Haplotype Reference Consortium (HRC) 69 reference panel using the Michigan imputation server. 68 COGA samples of African ancestry were re‐imputed using the Consortium on Asthma among African‐Ancestry Populations in the Americas (CAAPA), 70 also available on the Michigan imputation server.
