No difference in 5-HTTLPR and Stin2 polymorphisms frequency between premature ejaculation patients and controls.

Introduction: Premature ejaculation (PE) is defined as the inability of men to control ejaculation and it is the most prevalent male sexual dysfunction. The neurobiogenesis of ejaculation is very complex and involves the serotoninergic (5-hydroxytryptamine [5-HT]) system. A genetic etiology of PE in humans was stated accounting for around 30%. Recently, genetic polymorphisms located on SLC6A4 gene codifying for 5-HT transporter (5-HTT or serotonin transporter [SERT]), the major regulator of serotonergic neurotransmission, have been linked with the pathogenesis of PE and associated with the clinical response to therapy with contrasting results.

Aim: In order to establish a possible pathogenetic link between PE and SLC6A4 polymorphisms, we analyzed the 5-HTT-linked polymorphic region (5-HTTLPR), rs25531, and STin2 polymorphisms in 121 patients affected by lifelong and acquired PE.

Methods: Polymerase chain reaction (PCR)-based technology followed by restriction fragment length polymorphism (RFLP) analysis.

Main Outcome Measures: Intravaginal ejaculatory latency time was measured by stopwatch in order to diagnose PE, and the results of the SLC6A4 polymorphisms analysis in PE patients was compared with the control group.

Results: Genotype frequencies for 5-HTTLPR, rs25531, and STin2 for both patients and controls showed no significant deviation from Hardy-Weinberg equilibrium. No statistically significant differences were found in the frequency of SLC6A4 gene polymorphisms in PE patients vs. controls, or in lifelong PE patients vs. controls, or acquired PE patients vs. controls, or lifelong PE vs. acquired PE patients. The obtained data were contrasting with three out of four previously published reports.

Conclusions: The present results indicate that no difference exists in SLC6A4 polymorphisms frequency between PE patients and controls. A comparison with the previously published reports on this field is reported.