Candidate SNPs from the nicotinic acetylcholine receptor locus on chromosome 15q25 (rs578776, rs588765, rs8034191, rs1051730 and rs16969968) were significantly (p<0.05) associated with lifetime average CPD with the same direction of effect as seen in previous GWAS on CPD (table 2). The synonymous rs1051730 SNP was the top associated SNP in this locus (figure 2).
