We detected a signal of association with FEV1 extremes within the HLA region on chromosome 6 that was correlated with a previously reported signal of association with asthma.37 The signal we report was strongest in never smokers (rs9274600, p=1·26 × 10−10; table 2; appendix p 102). With an imputed proxy (rs17843604) of the asthma-associated SNP rs927334937—included as a covariate in the analysis of rs9274600—the signal for rs9274600 was attenuated (p=5·66 × 10−4), confirming that rs9274600 and rs9273359 are correlated. After exclusion of individuals with doctor-diagnosed asthma, the odds ratio for rs9274600 decreased from 1·18 (95% CI 1·11–1·25) to 1·14 (1·08–1·20), but remained significant (p=3·25 × 10−6; appendix p 103). This signal is independent of nearby signals reported for lung function,5,7,8 including rs7764819,38 which is 45 kb from rs9274600 (association for rs9274600 conditioned on rs7764819; p=6·71 × 10−11).
