title: Variants of the EPPIN gene affect the risk of idiopathic male infertility in the Han-Chinese population.
abstract: BACKGROUND
  It has been identified that human epididymal protease inhibitor (EPPIN) plays a critical role in sperm function and male fertility. The aim of this study was to determine whether variants of the EPPIN gene are risk factors for idiopathic male infertility.
  
  
  METHODS
  All subjects, including 473 idiopathic infertile men and 198 fertile controls, underwent complete historical and physical examinations. Each subject donated 5 ml of peripheral blood for genomic DNA extraction and serum testosterone evaluation and an ejaculate for semen analysis. The semen analysis was performed by computer-assisted semen analysis system. The serum testosterone level was evaluated by radioimmunoassay. Four tagging single-nucleotide polymorphisms were analyzed by polymerase chain reaction-restriction fragment length polymorphism.
  
  
  RESULTS
  We have demonstrated a significant decreased risk of idiopathic infertility with abnormal semen parameters in association with the variant rs2231829, and an increased risk of idiopathic infertility with abnormal semen parameters in association with the variant rs11594. However, among men with normal semen parameters, there were no differences in risk for these genotypes. Furthermore, no significant differences were found for the other variants, rs6124715 and rs2227290, on the risk of male infertility with normal or abnormal semen parameters. Similar serum testosterone levels among different EPPIN genotypes were observed for each group.
  
  
  CONCLUSIONS
  These results suggest that different variants in the EPPIN gene may have different relationships with idiopathic male infertility and men carrying these variants have a decreased or increased risk of abnormal semen parameters associated with male infertility.
authors.affiliation: Key Laboratory of Reproductive Medicine, Institute of Toxicology, Nanjing Medical University, Nanjing 210029, China.
authors.forename: Xinliang
authors.initials: X
authors.lastname: Ding
authors.forename: Jie
authors.initials: J
authors.lastname: Zhang
authors.forename: Juan
authors.initials: J
authors.lastname: Fei
authors.forename: Zenghui
authors.initials: Z
authors.lastname: Bian
authors.forename: Yingchun
authors.initials: Y
authors.lastname: Li
authors.forename: Yankai
authors.initials: Y
authors.lastname: Xia
authors.forename: Chuncheng
authors.initials: C
authors.lastname: Lu
authors.forename: Lin
authors.initials: L
authors.lastname: Song
authors.forename: Shoulin
authors.initials: S
authors.lastname: Wang
authors.forename: Xinru
authors.initials: X
authors.lastname: Wang
mesh_terms: D044466:Asian People / Q000235:genetics; D016022:Case-Control Studies; D002681:China / Q000208:ethnology; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006801:Humans; D007248:Infertility, Male / Q000208:ethnology / Q000235:genetics*; D008297:Male; D020641:Polymorphism, Single Nucleotide; D053491:Proteinase Inhibitory Proteins, Secretory / Q000235:genetics*; D012307:Risk Factors; D055101:Semen Analysis; D013739:Testosterone / Q000097:blood
chemical_list: C431553:Eppin protein, human; D053491:Proteinase Inhibitory Proteins, Secretory; D013739:Testosterone