Relationship between premature ejaculation and genetic polymorphisms of the dopamine transporter gene (SLC6A3).

OBJECTIVE

• To investigate the possible relationships between premature ejaculation (PE) polymorphisms in the dopamine transporter (DAT) gene (SLC6A3, DAT1), which has a polymorphic 40 base pair (40 bp) variable number of tandem repeats (VNTR) sequence in the 3'-untranslated region (3' VNTR).

PATIENTS AND METHODS

• Cohorts of 270 Iranian men with PE and 266 age-matched healthy Iranian subjects were genotyped for the DAT1-VNTR polymorphism.

RESULTS

• The 10-repeat allele frequencies were similar in the control (90.2%) and patient groups (88.5%) (P = 0.8). • A statistically significant association was observed between the presence of the nine-repeat allele and PE (chi-squared test = 4.346, odds ratio [OR] = 2.46, 95% confidence interval [CI] = 1.57-3.15, P = 0.026). • The frequencies of the 9/10 genotype were also significantly higher in the PE patients than in normal controls (chi-squared test = 4.466, OR = 2.47, 95% CI = 1.52-3.21, P = 0.028). The presence of the seven-repeat allele had a protective effect against PE (chi-squared test = 2.324, OR = 0.62, 95% CI = 0.47-0.89, P = 0.034).

CONCLUSIONS

• The findings of the present study suggest that DAT1-VNTR polymorphisms resulting in higher dopamine concentrations were associated with vulnerability to PE. • Further studies are needed to replicate these results and to evaluate the role of inconsistency in the DAT genes and how this affects the development of PE.