Our findings are consistent with early human genetics studies that provided no evidence of an association with variation in CHRNB2 and ND (Etter et al. 2009; Feng et al. 2004a; Li et al. 2005; Lueders et al. 2002; Silverman et al. 2000). Two distinct genetic loci in CHRNB2 have recently been associated with nicotine behaviors in multiple studies. Two highly correlated SNPs in the 3′UTR region rs2072660/rs2072661 have been associated with smoking initiation (Greenbaum et al. 2006), smoking cessation (Conti et al. 2008; Perkins et al. 2009), and ND (Wessel et al. 2010). We attempted to genotype rs2072660 in the current study, but the error rate in our sample was 1.3% thus we did not include this SNP in these analyses.
