Background. The acceleration of pubertal development is an important medical and social problem, as it may result in increased morbidity and mortality in later life. This systematic review summarizes relevant data about nongenetic factors, which contribute to age at menarche (AAM), and suggests those which may be the most important. Methods. The available literature from 1980 till July 2013 was searched using PubMed and Google Scholar databases. Finally, 154 papers were selected for the analysis. Results. Environmental factors, which may affect AAM, vary in populations of different ethnicity. The prenatal, infancy, and early childhood periods are the most susceptible to these factors. Body weight, high animal protein intake, family stressors (e.g., single parenting), and physical activity seem to influence AAM in most populations. Conclusions. The data about influence of nongenetic factors on AAM are still inconsistent. The factors affecting prenatal and early childhood growth seem to have a larger effect on further sexual maturation. Further studies are needed in order to validate the association between other environmental determinants and AAM in different ethnical groups.

Examine the association of genetic polymorphisms with age at menarche (AAM) in Russian women. Study design: A total of 1613 Russian females were recruited for the study. Fifty two polymorphisms were analyzed for their association with AAM, height, and BMI. The associations were analyzed assuming the additive, dominant, and recessive models and using the loglinear regression as implemented in PLINK v. 2.050. The 2-, 3-, and 4-loci models of gene-gene interactions were analyzed using the MB-MDR method and validated by the permutation test. Main outcome measures: Genetic polymorphism rs6438424 3q13.32 was independently associated with AAM in Russian women. In addition, 14 SNPs were determined as possible contributors to this trait through gene-gene interactions. Results: The obtained results suggest that 14 out of 52 studied polymorphisms may contribute to AAM in Russian women. The rs6438424 3q13.32 polymorphism was associated with AAM according to both additive and dominant models (р perm = 0.005). In total 12 two-, three-, and four-locus models of gene-gene interactions were determined as contributing to AAM (p perm ≤ 0.006). Nine of the 14 AAM-associated SNPs are also associated with height and BMI (p perm ≤ 0.003). Among 14 AAM-associated SNPs (a priori all having regulatory significance), the highest regulatory potential was determined for rs4633 COMT, rs2164808 POMC, rs2252673INSR, rs6438424 3q13.32, and rs10769908 STK33. Eleven loci are cis-eQTL and affect expression of 14 genes in various tissues and organs (FDR < 0.05). The neuropeptide-encoding genes were overrepresented among the AAM-associated genes (p bonf = 0.039). Conclusions: The rs6438424 polymorphism is independently associated with AAM in Russian females in this study. The other 14 SNPs manifest this association through gene-gene interactions. in the later life. Early menarche may increase a risk for obesity (Guo and Ji, 2011), uterine myoma (Wise and Laughlin-Tommaso, 2016), endometriosis (Nnoaham et al., 2012), breast cancer (Yermachenko and Dvornyk, 2014), cardiovascular diseases (Feng et al., 2008), type 2 diabetes mellitus, infertility and psychological problems (Yermachenko and Dvornyk, 2014).

Age at menarche (AAM) is an important marker of the pubertal development and function of the hypothalamic–pituitary–ovarian system. It was reported as a possible factor for a risk of uterine leiomyoma (UL). However, while more than 350 loci for AAM have been determined by genome-wide association studies (GWASs) to date, no studies of these loci for their association with UL have been conducted so far. In this study, we analyzed 52 candidate loci for AAM for possible association with UL in a sample of 569 patients and 981 controls. The results of the study suggested that 23 out of the 52 studied polymorphisms had association with UL. Locus rs7759938 LIN28B was individually associated with the disease according to the dominant model. Twenty loci were associated with UL within 11 most significant models of intergenic interactions. Nine loci involved in 16 most significant models of interactions between single-nucleotide polymorphism (SNP), induced abortions, and chronic endometritis were associated with UL. Among the 23 loci associated with UL, 16 manifested association also with either AAM (7 SNPs) or height and/or body mass index (BMI) (13 SNPs). The above 23 SNPs and 514 SNPs linked to them have non-synonymous, regulatory, and expression quantitative trait locus (eQTL) significance for 35 genes, which play roles in the pathways related to development of the female reproductive organs and hormone-mediated signaling [false discovery rate (FDR) ≤ 0.05]. This is the first study reporting associations of candidate genes for AAM with UL.