title: Interaction effects between estrogen receptor alpha and vitamin D receptor genes on age at menarche in Chinese women.
abstract: OBJECTIVE
  To evaluate whether estrogen receptor alpha (ER-alpha) and vitamin D receptor (VDR) genes are associated with the age at menarche in Chinese women.
  
  
  METHODS
  A total of 390 pre-menopausal Chinese women were genotyped at the ER-alpha PvuII, XbaI, and VDR ApaI loci using polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP).
  
  
  RESULTS
  Neither the ER-alpha gene nor the VDR gene individually had significant effects on the age at menarche in our subjects (P>0.10). However, evidence of interaction effects between the two genes were observed: with the aa genotype at the VDR ApaI locus, subjects with haplotype PX at the ER-alpha gene had, on average, 6 months later onset of menarche than the non-carriers (P=0.01).
  
  
  CONCLUSIONS
  We found that neither the ER-alpha gene or the VDR gene had a significant association with the age at menarche individually. However, potential interaction effects between the two genes were observed in Chinese women.
authors.affiliation: Laboratory of Molecular and Statistical Genetics, College of Life Sciences, Hu-nan Normal University, Changsha 410081, China.
authors.forename: Hong
authors.initials: H
authors.lastname: Xu
authors.forename: Ji-Rong
authors.initials: JR
authors.lastname: Long
authors.forename: Miao-Xin
authors.initials: MX
authors.lastname: Li
authors.forename: Hong-Wen
authors.initials: HW
authors.lastname: Deng
mesh_terms: D000328:Adult; D000367:Age Factors; D044466:Asian People; D002681:China; D047628:Estrogen Receptor alpha / Q000235:genetics*; D005260:Female; D005787:Gene Frequency; D005838:Genotype; D006801:Humans; D008572:Menarche / Q000235:genetics*; D012150:Polymorphism, Restriction Fragment Length; D017697:Premenopause; D018167:Receptors, Calcitriol / Q000235:genetics*
chemical_list: D047628:Estrogen Receptor alpha; D018167:Receptors, Calcitriol