G-protein β3 subunit gene 825C/T polymorphism and its association with the presence, severity, and duration of vasculogenic erectile dysfunction

ObjectiveTo investigate the association between G-protein β3 (GNB3) subunit gene 825C/T polymorphism and vasculogenic ED (VED).DesignCase-control study.SettingPrivate urology and andrology clinic.Patient(s)The study included 246 patients with VED and 492 healthy controls, Caucasians of Iranian descent.Intervention(s)Typing of the polymorphism was performed using the polymerase chain reaction restriction fragment length polymorphism technique.Main Outcome Measure(s)To test the hypothesis of whether the presence of the 825T allele of the GNB3 gene is associated with an increased risk of VED.Result(s)The CT genotype was more prevalent in VED patients relative to healthy controls (adjusted odds ratio [OR] = 2.34; 95% confidence interval [CI], 1.10-4.26). Interaction between T allele carriership and VED was significant. The dominant model CT + TT variant was associated with a 3.74-fold increase in the adjusted risk (OR = 3.74; 95% CI, 1.11-12.4) for the occurrence of VED. Our results indicate that the GNB3 polymorphism is associated with higher systolic blood pressure, higher dyslipidemia, and higher body mass index. The 825TT genotype was associated with a more than five-fold increased risk of severe VED compared with the 825CC genotype (OR = 5.62; 95% CI, 3.54-9.25). Significantly different onset of age of VED was not found between the genotypes for the GNB3 polymorphism.Conclusion(s)The GNB3 polymorphism is an independent risk factor for VED in Iranian males. Our findings confirm a role of GNB3 in the genetic susceptibility of VED and suggest that GNB3 polymorphism should be taken into consideration to improve the assessment of an individual's risk of VED.