The most robust genetic finding on chromosome 15q25 in subjects of European ancestry is the region tagged by rs16969968, rs1051730, and other correlated variants. This finding has been replicated for smoking-related traits in multiple distinct datasets [Baker, et al. 2009; Berrettini, et al. 2008; Keskitalo, et al. 2009; Saccone, et al. 2009; Saccone, et al. 2007; Sherva, et al. 2008; Stevens, et al. 2008; Thorgeirsson, et al. 2008; Weiss, et al. 2008], and has now been reported as the most significant genome-wide association in recent meta-analyses of European ancestry subjects (e.g. rs16969968, p = 5.57×10−72, or rs1051730, p = 2.75×10−73) [Liu, et al. 2010; Saccone, et al. 2010; TAG 2010; Thorgeirsson, et al. 2010]. We will use the term “bin” to denote a group of correlated SNPs (r2 ≥0.7) that may constitute the same association signal in European ancestry samples [Carlson, et al. 2004]. Under this definition and using the 1000 Genomes Pilot 1 CEU as the European ancestry reference sample [Durbin, et al. 2010], the single bin tagged by rs16969968 and rs1051730 includes 52 known variants. This bin, which
