The age at which girls reach sexual maturity is influenced by ‘imprinted’ genes, a small sub-set of genes whose activity differs depending on which parent passes on that gene, according to new research published today in the journal Nature.
See more at: http://www.cam.ac.uk/research/news/age-of-puberty-in-girls-influenced-by-which-parent-their-genes-are-inherited-from#sthash.sbDVP2sc.dpuf
Reference article: John R. B. Perry et al. “Parent-of-origin-specific allelic associations among 106 genomic loci for age at menarche”. Nature. July 2014. http://dx.doi.org/10.1038/nature13545