Polymorphism in the insulin-like growth factor 1 gene is associated with age at menarche in caucasian females.

BACKGROUND The insulin-like growth factor 1 (IGF1) gene, which plays a crucial role in hypothalamic-pituitary-ovarian hormone-controlled metabolic processes, may influence the onset of menarche. Our study aimed to test association between IGF1 polymorphisms with the variation of age at menarche (AAM) in Caucasian females. METHODS We recruited a sample of 1048 females from 354 Caucasian nuclear families and genotyped 19 single-nucleotide polymorphisms (SNPs) spanning the entire IGF1 gene. Pairwise linkage disequilibrium among SNPs was measured, and the haplotype blocks were inferred. Both single SNP markers and haplotypes were tested for association with AAM using the quantitative transmission disequilibrium test. RESULTS Significant association (P = 0.0153) between AAM and SNP3 (rs6214) in block1 was detected. CONCLUSIONS Our results suggested a potential effect of SNP3 in the IGF1 gene on AAM variation in Caucasian women for the first time. However, further independent studies are needed to confirm our findings.