AB082. Association study of STin2 VNTR polymorphism of serotonin transporter gene with lifelong premature ejaculation: a case-control study in Han Chinese subjects

Background STin2 VNTR polymorphism was a variable number of tandem repeats in the intron 2 of serotonin transporter gene. We aimed to explore the relationship between STin2 VNTR polymorphism and lifelong premature ejaculation (LPE). Methods A total of 115 outpatients who complained of ejaculating prematurely and who were diagnosed as LPE, and 101 controls without PE complaint were recruited. Allelic variations of STin2 VNTR were genotyped using PCR-based technology. We evaluated the associations between STin2 VNTR allelic and genotypic frequencies and LPE, as well as the intravaginal ejaculation latency time (IELT) of different STin2 VNTR genotypes among LPE patients. Results The patients and controls did not differ significantly in terms of any characteristic except age. A significantly higher frequency of STin2.12/12 genotype was found among LPE patients versus controls (P=0.026). Frequency of patients carrying at least one copy of the 10-repeat allele was significantly lower compared to the control group (28.3% vs. 41.8%, OR =0.55; 95% CI: 0.31–0.97, P=0.040). In LPE group, the mean IELT showed significant difference in STin2.12/12 genotype when compared to those with STin2.12/10 and STin2.10/10 genotypes. The fold-increase of the mean IELT in 10-repeat allele carriers showed a 50% longer compared to STin2.12 allele homozygous. Conclusions Our results indicated the presence of STin2.10 allele is a protective factor for LPE. Men carrying the higher expression genotype STin2.12/12 have shorter IELT than those 10-repeat allele carriers.