Table 4 summarizes our findings for the top SNPs associated with WAIS Digit Symbol test. No other neurocognitive phenotypes besides WAIS digit symbol had SNPs with significant values in the CHRNB3-A6 region and none of the three neurocognitive phenotypes had a significant association with SNPs in the region of CHRNA5-A3-B4 on chromosome 15 (not shown). Of the 17 SNPs in the CHRNB3-A6 region on chromosome 8, one SNP–rs7017612—passed multiple test correction (p≤0.003) for association with the score on the WAIS Digit Symbol test (β = 0.43, p = 0.003). rs7017612 lies in the intergenic region between CHRNB3 and CHRNA6. This SNP is highly correlated with rs6474413 (r2 = 0.75; D’ = 0.95), a SNP tagging the genome-wide significant bin for decreased risk for nicotine dependence. These data suggest a modest association between genotype at these SNPs one measure of cognitive function.
