title: +1730 G/A polymorphism of the estrogen receptor beta gene (ERbeta) may be an important genetic factor predisposing to endometriosis.
abstract: OBJECTIVE
  To determine the frequency of the estrogen receptor gene (ERbeta) +1730 G/A polymorphism in Brazilian women with endometriosis.
  
  
  METHODS
  Case-control study.
  
  
  METHODS
  Endometriosis Outpatient Clinic and Family Planning Outpatient Clinic of ABC Faculty of Medicine.
  
  
  METHODS
  A total of 108 patients with endometriosis and a control group consisting of 210 fertile women.
  
  
  METHODS
  The ERbeta gene +1730 G/A polymorphism was identified by restriction fragment length polymorphism-polymerase chain reaction.
  
  
  METHODS
  Genotype distribution and allele frequency of the +1730 G/A polymorphism in the ERbeta gene.
  
  
  RESULTS
  Genotypes GG, GA and AA of the ERbeta gene presented frequencies of 50.9%, 47.2% and 1.9%, respectively, in the women with endometriosis. Among the patients with stage I/II endometriosis, 47% presented the normal homozygous genotype GG; 51% had a GA heterozygous genotype and 2% had a homozygous mutated genotype AA. Among the patients with stage III/IV endometriosis, genotypes GG, GA and AA were present in 54.3%, 44% and 1.7%, respectively. In the control group, 74.3% presented the normal homozygous genotype GG, 24.3% the heterozygous genotype GA and 1.4% the homozygous mutated genotype AA.
  
  
  CONCLUSIONS
  The data suggest that the ERbeta gene +1730 G/A polymorphism can be associated with the risk of endometriosis development, regardless of the stage of the disease.
authors.affiliation: Division of Genetics and Human Reproduction - Department of Gynecology and Obstetrics, ABC Faculty of Medicine, Santo André, São Paulo, Brazil. bianca.bianco@hotmail.com
authors.forename: Bianca
authors.initials: B
authors.lastname: Bianco
authors.forename: Denise Maria
authors.initials: DM
authors.lastname: Christofolini
authors.forename: Fernanda Abani
authors.initials: FA
authors.lastname: Mafra
authors.forename: Ariel
authors.initials: A
authors.lastname: Brandes
authors.forename: Karina
authors.initials: K
authors.lastname: Zulli
authors.forename: Caio Parente
authors.initials: CP
authors.lastname: Barbosa
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D004247:DNA / Q000737:chemistry / Q000235:genetics; D004715:Endometriosis / Q000235:genetics*; D047629:Estrogen Receptor beta / Q000235:genetics*; D005260:Female; D020022:Genetic Predisposition to Disease; D014644:Genetic Variation; D005838:Genotype; D006801:Humans; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length; D020641:Polymorphism, Single Nucleotide
chemical_list: D047629:Estrogen Receptor beta; D004247:DNA