The first GWAS on nicotine dependence was conducted by Bierut and colleagues.30 The study compared 1050 nicotine-dependent subjects and 879 controls (who smoked but did not become dependent). Although no individual SNPs reached genome-wide significance, the data were reanalyzed for a targeted association study with 3713 SNPs in 348 candidate genes.31 Several cholinergic nicotinic receptor genes dominated the top signals after controlling for multiple testing.
