The genes and intergenic SNPs identified in the relevant literature were evaluated in the SpiroMeta dataset using an extended region of +/−10 kilobases (kb) from the gene coordinates downloaded from the UCSC genome browser (we used the SNP coordinate +/−10 kb for intergenic SNPs). Meta-analysis association results for SNPs in these (+/−10 kb extended) regions were extracted from the SpiroMeta dataset for both FEV1 and FEV1/FVC in all individuals and separately in ever–smokers. The complete cohort descriptions, study design and methods have been previously reported [7], but we provide here a brief summary. At study level, non-genotyped SNPs were imputed using standard approaches [18], [20] to facilitate meta-analysis of studies employing different genotyping platforms. Thus up to 2,705,257 SNPs were tested for association with FEV1 and FEV1/FVC using additive models and adjusting for age, sex, height and ancestry principal components. Then, the results were meta-analysed across studies using inverse variance weighting. Genomic control was applied at the study level and after the meta-analysis to correct for test inflation due to population stratification [21]. We excluded SNPs which were not well
