LAUSR

INTRODUCTION Previous studies have found serotonergic pathway genes have inhibitory effects on dopamine system which may influence smoking addiction. This study examined the associations of serotonergic pathway genes (serotonergic receptor genes, solute carrier family 6 member4 and tryptophan hydroxylase gene) with smoking cessation. MATERIALS AND METHODS Male current and former smokers (n=819) were recruited from 17 villages of three counties in Shandong province, China. DNA was extracted from the blood samples. Eleven single nucleotide polymorphisms (SNPs) in serotonergic pathway genes were genotyped. Multiple logistic regression was used to assess associations between SNPs and smoking cessation. Pearson's χ2 test was performed to explore associations of haplotypes with smoking cessation. Multiple logistic regression was used to detect the interaction between SNPs on smoking cessation. RESULTS In multiple logistic regression, rs1042173 of Solute carrier family 6 member 4 was significantly related to smoking cessation in additive and dominant model (p=0.03 and 0.02, respectively). Rs4570625 of tryptophan hydroxylase 2 was significantly associated with smoking cessation in dominant model (p=0.03). Nine significant interactions were detected between SNPs in serotonergic pathway genes. CONCLUSIONS The present study reveals that serotonergic pathway genes were significantly related to smoking cessation. Future research should expand upon these findings to confirm them.