Interaction effects between estrogen receptor α and vitamin D receptor genes on age at menarche in Chinese women.

To evaluate whether estrogen receptor α(ER-α) and vitamin D receptor (VDR) genes are associated with the age at menarche in Chinese women. A total of 390 pre-menopausal Chinese women were genotyped at the ER-α PvuII, X baI, and VDR ApaI loci using polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP). Neither the ER-αgene 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-αgene had, on average, 6 months later onset of menarche than the non-carriers ( P=0.01). We found that neither the ER-αgene 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. [ABSTRACT FROM AUTHOR]