title: Association between ubiquitin-specific protease USP26 polymorphism and male infertility in Chinese men.
abstract: BACKGROUND
  Increased sperm ubiquitin was inversely associated with sperm count and motility. Ubiquitin-specific protease 26 (USP26), which is an X-linked gene, has been studied as a potential infertility gene. There are conflicting reports on whether variations in USP26 are associated with spermatogenesis.
  
  
  METHODS
  In order to assess that USP26 polymorphisms contribute to male infertility, we screened 221 infertile men with azoospermia, oligozoospermia, asthenozoospermia, or oligoasthenozoospermia, and 101 control fertile men using DNA sequencing.
  
  
  RESULTS
  There were six polymorphisms identified, including an unreported variation (508G>A, G170R). Only the allele frequency of 576G>A was significantly higher in fertile men than infertile patients (p<0.001), although this variant does not result in an amino acid change. The major haplotypes in fertile and infertile men were TGATC (76.2% vs 47.5% of the population, p<0.001) and TGGTC (14.9% vs 39.4%, p<0.001). The haplotype TGATC was under-transmitted, whereas the haplotype TGGTC was over-transmitted in infertile men with asthenozoospermia and oligoasthenozoospermia.
  
  
  CONCLUSIONS
  Our results indicated the variation of USP26 was not directly associated with human sperm count but suggested it might be a potential role in sperm motility. The 576G>A synonymous single nucleotide polymorphism (SNP) might have a role in improving the sperm motility.
authors.affiliation: Department of Reproduction and Genetics, Jinling Hospital, Nanjing University School of Medicine, Nanjing, PR China.
authors.forename: Yi-chao
authors.initials: YC
authors.lastname: Shi
authors.forename: Li
authors.initials: L
authors.lastname: Wei
authors.forename: Ying-xia
authors.initials: YX
authors.lastname: Cui
authors.forename: Xue-jun
authors.initials: XJ
authors.lastname: Shang
authors.forename: Hao-yang
authors.initials: HY
authors.lastname: Wang
authors.forename: Xin-yi
authors.initials: XY
authors.lastname: Xia
authors.forename: Yu-chun
authors.initials: YC
authors.lastname: Zhou
authors.forename: Hong
authors.initials: H
authors.lastname: Li
authors.forename: Hai-tao
authors.initials: HT
authors.lastname: Jiang
authors.forename: Wei-ming
authors.initials: WM
authors.lastname: Zhu
authors.forename: Yu-feng
authors.initials: YF
authors.lastname: Huang
mesh_terms: D000328:Adult; D001483:Base Sequence; D016022:Case-Control Studies; D003546:Cysteine Endopeptidases / Q000235:genetics*; D017931:DNA Primers; D005787:Gene Frequency; D006801:Humans; D007248:Infertility, Male / Q000235:genetics*; D008297:Male; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic
chemical_list: D017931:DNA Primers; C501866:USP26 protein, human; D003546:Cysteine Endopeptidases