title: Polymorphisms of estrogen-biosynthesis genes CYP17 and CYP19 may influence age at menarche: a genetic association study in Caucasian females.
abstract: Variation in age at menarche (AAM) is known to be substantially influenced by genetic factors, but the true causal genes remain largely unidentified. Because the increased amplitude of estrogen exposure of tissues initiates the onset of menarche, the genes involved in estrogen biosynthesis are natural candidate genes underlying AAM. Our study aimed to identify whether the CYP17 and CYP19, the two key genes involved in the biosynthesis of estrogen, are associated with AAM variation in 1048 females from 354 Caucasian nuclear families. We genotyped 38 SNPs and established the linkage disequilibrium blocks and haplotype structures that covered the full transcript length of those two genes. Family-based and population-based statistical analyses were used to test for associations with all of the single SNPs and haplotypes. Both methods consistently detected significant associations for five SNPs of CYP19 with AAM. Haplotype analyses corroborated our single-SNP results by showing that the haplotypes in block 1 were highly significant to AAM in population-based analyses. However, we could not find any association of CYP17 with AAM. Our study is the first to suggest the important effect of CYP19 on AAM variation in Caucasian females. It will be valuable to replicate and confirm these findings in other independent studies, aiming at eventually finding the hidden genetic mechanisms underlying the variation in AAM.
authors.affiliation: Key Laboratory of Biomedical Information Engineering, Ministry of Education and Institute of Molecular Genetics, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an 710049, People's Republic of China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Guo
authors.forename: Dong-Hai
authors.initials: DH
authors.lastname: Xiong
authors.forename: Tie-Lin
authors.initials: TL
authors.lastname: Yang
authors.forename: Yan-Fang
authors.initials: YF
authors.lastname: Guo
authors.forename: Robert R
authors.initials: RR
authors.lastname: Recker
authors.forename: Hong-Wen
authors.initials: HW
authors.lastname: Deng
mesh_terms: D000293:Adolescent; D001141:Aromatase / Q000235:genetics*; D004967:Estrogens / Q000096:biosynthesis*; D005260:Female; D008040:Genetic Linkage; D006239:Haplotypes; D006801:Humans; D015810:Linkage Disequilibrium; D008297:Male; D008572:Menarche / Q000235:genetics*; D008875:Middle Aged; D008954:Models, Biological; D011110:Polymorphism, Genetic; D013254:Steroid 17-alpha-Hydroxylase / Q000235:genetics*; D044465:White People / Q000235:genetics
chemical_list: D004967:Estrogens; D001141:Aromatase; D013254:Steroid 17-alpha-Hydroxylase