In addition, we found that rs1044394, another synonymous SNP in exon 5, was nominally significantly associated with ND and FTND in the combined sample, as well as in AAs and in EAs separately. However, only the association of rs1044394 with ND in the combined sample remained significant after correction for multiple testing (Pcorrected = 0.033). We are aware of only one other study that investigated the role of rs1044394 in smoking-related behaviors; that yielded a negative result (Etter et al., 2009). Interestingly, the correlation between rs2236196 and rs1044394 was low in both AAs and EAs, suggesting that multiple independent variants within this gene could be associated with different dimensions of smoking behavior. However, all of the published studies investigated a very limited number of variants in this gene, thus we would speculate that other independent variants associated with smoking behavior may have been missed.
