In the context of PCOS, this theory proposes that a hyperandrogenic intrauterine environment has epigenetic consequences affecting the expression of genes that regulate the future endocrine and metabolic functions of the fetus (i.e., GnRH pulsatility, folliculogenesis, the ovarian production of sex steroids, insulin resistance). The gene discussed is GNRH1; the disease is polycystic ovary syndrome.