The age at menarche (AAM) precisely and the secular trend of decadal declining AAM, has been subject matter of several researches associated with health differential, in terms of early and late AAM. Nevertheless, oestrous cycle to menarche as a macro-evolutionary feature, AAM could be conceived as micro-evolutionary feature and appraised the confluence of biology (genetic configuration) and Social-Cultural (socio-demographic) aspects i.e., extrinsic factors, which enact as epigenetic modulation in AAM, as switching off (methylation) or switching on (acetylation) the expression with regard to timing of AAM. Nevertheless, researches on association of AAM and post-natal extrinsic factors such as socio-demographic variables results are found to be indistinctive and varied cross-culturally, but the genetic effect for example Turner’s syndrome (45, XO) universally distinctively evident with primary amenorrhea to no menarche, therefore, infertile and given birth by normal parents. In this background, present review attempted to highlight aspects of AAM and the associative biological (genetic polymorphism) and extrinsic (Social-cultural) factors on the basis of literatures pertaining to relevant keywords, covering GWAS, candidate genes, socio-demographic aspects. Literatures from Google Scholar, PubMed was searched with the relevant keywords published till 2022. The cardinal features, envisaged GWAS and a number of candidate gene association nearly 25 genes (such as ESRα, ESRβ, VDR, LIN28B, CYP19, LOC107986022, LEPR, IGF1, SHBG, DARC) associated with AAM with considerable population variation of gene polymorphism in ESRα, ESRβ, VDR, PGR, LIN28B, CYP19 genes. However, effects of variable outcome on AAM associated with SNPs of the same gene in different populations, as well as in different geographical locations are evident and pertinently indicate the need of the hour research stimulation of urgent reproductive health issues.
