The CHRNB3 region of chromosome 8in general, and this signal in particular, has been previously associated with CPD, but, of the many genome-wide association studies using CPD as the primary phenotype(8, 10, 15, 30), the only previously published genome-wide significant association with this region has been in a large meta-analysis including over 75,000 subjects(15). Specifically, rs1451240 has an r2 of 1.0 (based on 1000 genome pilot 1 data, CEU) with the two chromosome 8 SNPs published in the meta-analysis. To clarify the difference between our study of only 3,365 subjects and the large meta-analysis, we examined the effects of phenotype definition, ethnicity, and comorbid diagnoses on the association with this SNP.
