To our knowledge, this is the first meta-analysis of GWAS data for smoking behaviors in African Americans. The single genome-wide significant association we observed between rs2036527 and CPD is the same signal that was reported previously at 15q25.1 for nicotine dependence, smoking intensity and lung cancer in European ancestry samples.4, 5, 6, 42, 43 The strong association that we found for this SNP supports studies suggesting that it is highly correlated with the functional allele(s) in populations of African ancestry. The fact that we did not observe a strong second association signal in this region after conditioning on rs2036527 suggests that rs2036527 and correlated SNPs in the African ancestry populations may define a single common haplotype at chr15q25.1 with sufficient effect size to be detected in our sample. After back transformation of the beta estimate, mean CPD values for each rs2036527 genotype were 14.6 for AA, 13.5 for AG and 12.8 for GG, suggesting that there is an increase of less than one cigarette smoked per day for each copy of the A allele. This SNP accounted for approximately 0.20%
