We constructed 3-SNP weighted genetic risk scores (wGRS) using the independent 19q13.2 SNPs from the meta-analysis (rs56113850, rs113288603, esv2663194) by summing the number of major alleles (0/1/2) for each of the three SNPs weighted by their estimated effect sizes obtained from the GWAS meta-analysis. In addition, a 4-SNP wGRS comprising of the four independent SNPs in FINRISK2007 (rs56113850, rs113288603, esv2663194, rs12461964) was constructed. We then tested whether the wGRSs predict smoking behavior using two independent Finnish samples. In the FINRISK sample (no overlap with the FINRISK2007 sample used in NMR GWAS), logistic regression was used to model current daily (N = 3138) vs. former (abstinence of ≥6 months; N = 2710) smoking, and hurdle regression was used to model smoking quantity among current smokers (quantitative CPD; N = 3138). In the family-based NAG-FIN sample, mixed effects logistic regression was used to model current daily (N = 816) vs. former (abstinence of ≥6 months; N = 833) smoking, and a mixed effects poisson regression was used to model smoking quantity among current smokers (quantitative CPD; N = 816). Odds ratios (ORs)
