title: Association of GSTP1 -313A/G polymorphisms and endometriosis risk: a meta-analysis of case-control studies.
abstract: OBJECTIVE
  In view of the controversies surrounding the association of glutathione S-transferases (GST) P1 with endometriosis, a meta-analysis of GSTP1 -313A/G polymorphism with endometriosis risk was performed.
  
  
  METHODS
  The relevant studies were identified through a search of PubMed, Excerpta Medica Database (Embase), Elsevier Science Direct and Chinese Biomedical Literature Database (CBM) until March 2013. The association between GSTP1 -313A/G polymorphism and endometriosis risk was pooled by odds ratios (ORs) together with their 95% confidence intervals (95% CIs).
  
  
  RESULTS
  A total of eight case-control studies were eventually identified. We found that GSTP1-313A/G polymorphism was not associated with endometriosis risk in the overall population (A vs. G: OR=1.02, 95% CI=0.97-1.07, P=0.511; AA vs. GG: OR=1.02, 95% CI=0.98-1.06, P=0.359; GA vs. GG: OR=1.03, 95% CI=0.98-1.08, P=0.299; AA vs.
  OR=1.01, 95% CI=0.96-1.07, P=0.621; AA/GA vs. GG: OR=1.00, 95% CI=0.97-1.03, P=0.972). In the sub-group analysis based on ethnicity, a significant association was found in Caucasians under the recessive model (AA vs.
  OR=1.28, 95% CI=1.08-1.53, P=0.006).
  
  
  CONCLUSIONS
  GSTP1 -313A/G polymorphism may not be associated with endometriosis risk, while the observed increase in risk of endometriosis may be due to small-study bias. Considering the limited sample size and ethnicity included in our meta-analysis, an updated meta-analysis will be urgently needed when further larger and well-designed studies are published.
authors.affiliation: Department of Clinical Laboratory, First Affiliated Hospital of Guangxi Medical University, Nanning 530021, Guangxi, People's Republic of China. Electronic address: chenxu16300@163.com.
authors.forename: Xu
authors.initials: X
authors.lastname: Chen
authors.forename: Yulan
authors.initials: Y
authors.lastname: Yan
authors.forename: Ping
authors.initials: P
authors.lastname: Li
authors.forename: Zheng
authors.initials: Z
authors.lastname: Yang
authors.forename: Lingyan
authors.initials: L
authors.lastname: Qin
authors.forename: Wuning
authors.initials: W
authors.lastname: Mo
mesh_terms: D044466:Asian People / Q000235:genetics; D016022:Case-Control Studies; D004715:Endometriosis / Q000235:genetics*; D005260:Female; D020022:Genetic Predisposition to Disease; D051549:Glutathione S-Transferase pi / Q000235:genetics*; D006801:Humans; D020641:Polymorphism, Single Nucleotide
chemical_list: D051549:Glutathione S-Transferase pi
keywords: Endometriosis; GSTP1; Meta-analysis; Polymorphism