We have demonstrated and replicated genetic associations between SNPs at the CHRNA3/5 locus and COPD in four study populations. The estimated population attributable risk from this locus was 12.2% and represents the discovery of a common major locus contributing to COPD in the general population. However, a potential complication with the interpretation of these findings is the possibility that differences in smoking behavior, likely related to nicotine addiction, between COPD cases and controls may drive the observed association. This is similar to the recently reported association of CHRNA3/5 SNPs with lung cancer [12]–[14].
