At least 26 replicated PCOS risk genes have emerged from studies of human populations [24,28,39,40,41,42], regulating a variety of reproductive functions, including gonadotropin secretion (FSHB), gonadotropin action and ovarian function (AMH and AMHR2; LHCGR, STON1 and GTF2A1L; FSHR; DENND1A; RAB5B and SUOX: HMGA2; C9orf3; YAP1; TOX3; RAD50; FBN3) as well as metabolic (THADA, GATA4 and NEIL2, ERBB2, ERBB3, ERBB4, SUMO1P1, INSR, KRR1) and neural (KCNA4) function. This evidence concerns the gene DENND1A and polycystic ovary syndrome.