title: Combined estrogen receptor alpha and estrogen receptor beta genotypes influence the age of menarche.
abstract: BACKGROUND
  Age at menarche has a strong genetic influence. We reported recently an association between the XbaI (351A-->C)and PvuII (397T-->C) polymorphisms of the estrogen receptor (ER)alpha gene with the age of menarche in Greek adolescents. In the present study, we examined whether ERbeta genotypes alone, or in combination with ERalpha genotypes, may also influence onset of menarche.
  
  
  METHODS
  We performed genotyping for the single nucleotide polymorphisms 1730A-->G and 1082G-->A of the ERbeta gene and examined their association with the age of menarche in the same cohort of 145 Greek girls. We then looked for a possible effect of combined ERalpha and beta genotypes on the age of menarche.
  
  
  RESULTS
  Menarche occurred 7 months later in girls with the AA genotype of the 1730A-->G polymorphism than in girls with the AG genotype (mean +/- SD: 13.23 +/- 1.24 versus 12.66 +/- 1.26 years, respectively; P = 0.005). The 1082G-->A polymorphism was not detected in any of the girls examined. A significant effect of combined ERalpha and beta genotypes was also apparent. Menarche occurred 11 months later in girls bearing the AA/TT,AA (ERalpha, ERbeta) genotypes compared with girls with the CC/CC,AG genotype (13.30 +/- 1.27 nersus 12.41 +/- 1.28 years; P = 0.042). The difference remained significant after adjusting for body mass index (P = 0.034).
  
  
  CONCLUSIONS
  Combined ERalpha and ERbeta polymorphisms may influence the age of menarche.
authors.affiliation: Department of Endocrinology and Laboratory of Reproductive Genetics, University of Ioannina, 45110 Ioannina, Greece.
authors.forename: I
authors.initials: I
authors.lastname: Stavrou
authors.forename: C
authors.initials: C
authors.lastname: Zois
authors.forename: A
authors.initials: A
authors.lastname: Chatzikyriakidou
authors.forename: I
authors.initials: I
authors.lastname: Georgiou
authors.forename: A
authors.initials: A
authors.lastname: Tsatsoulis
mesh_terms: D000293:Adolescent; D002648:Child; D047628:Estrogen Receptor alpha / Q000235:genetics*; D047629:Estrogen Receptor beta / Q000235:genetics*; D005260:Female; D005787:Gene Frequency; D005838:Genotype; D006115:Greece; D006801:Humans; D008572:Menarche / Q000235:genetics*; D020641:Polymorphism, Single Nucleotide
chemical_list: D047628:Estrogen Receptor alpha; D047629:Estrogen Receptor beta