For TTC12-ANKK1-DRD2, the most significantly associated SNP was rs10502172 (P=9.1×10−6) mapping in TTC12. Also ANKK1-rs2734849 and DRD2-rs1076563 were significantly associated (Table S3 in Supplement 1). In adolescence, TTC12-rs10502172[G] conferred increased risk of both smoking regularly [OR(95%CI):1.33(1.11–1.60)] and occasionally [OR(95%CI):1.29(1.12–1.48)]. TTC12-rs10502172[G] effect was weaker at age 31 [ORs~1.13–1.14] than 14, but still significant (Table 1).
