LAUSR

To investigate the association between the human 8‐oxoguanine DNA glycosylase 1 (hOGG1) gene Ser326Cys polymorphism and male subfertility in Taiwanese patients with varicocele, we made a prospective study. Ninety young male patients with varicocele (group 1), 50 young male patients with subclinical varicocele (group 2) and 30 normal young male patients without varicocele (group 3) were recruited in this study. The hOGG1 null homozygous genotype (Cys/Cys) and the occurrence of a 4,977‐bp deletion in mitochondrial DNA and mitochondrial copy number in spermatozoa were determined by polymerase chain reaction. The 8‐hydroxy‐2′‐deoxyguanosine (8‐OHdG) content of DNA in the spermatozoa was measured using high‐performance liquid chromatography, and total antioxidant capacity (TAC) of seminal plasma was detected electrochemically. The rates of male subfertility were 31.1% (28/90) in group 1 and 22% (11/50) in group 2. Of 39 subfertile men, 74.4% (29/39) had the hOGG1 Cys/Cys genotype. Patients in groups 1 and 2 with hOGG1 Cys/Cys genotype had significantly higher 8‐OHdG content in sperm DNA, lower mitochondrial copy number in spermatozoa and lower TAC in seminal plasma than those with Ser/Ser or Ser/Cys genotype. Clinicians should pay more attention to patients with varicocele with the hOGG1 Cys/Cys genotype.