Despite the limitations of this study, this meta-analysis refines the association signals with heavy smoking across samples representing European ancestry, Asian, and African American populations. In particular, for bin A, we present evidence showing rs16969968 is a likely causal variant for heavy smoking among the common SNPs in the bin. Our evidence also suggests there are additional distinct genetic variants in the chromosome 15q25 region associated with smoking, but we are unable to clearly identify these other associations across all three populations. For example, we extend the finding of association with bin B in European ancestry samples to an association in Asians, and a trend towards association in African Americans.
