For the SNPs significant after multiple test correction, the odds ratios (ORs) for the primary genetic model are modest, ranging up to 1.4 (for SNPs in CHRNB3) for the effect of a single copy of the risk allele. Among the SNPs covering the CHRNA5-CHRNA3-CHRNB4 region, the strongest alternative odds ratio is found for rs16969968 when modeled recessively, with an OR of 1.83 for the effect of having 2 copies of the risk allele (Table S1). This OR is similar to but larger than the OR for two risk alleles under the primary model: (1.31)2 = 1.7. For rs16969968, both the recessive-model and primary model ORs are higher than the corresponding ORs for the eight additional correlated SNPs in bin 4, further suggesting the importance of this non-synonymous variant relative to these alternative loci.
