DENND1A and polycystic ovary syndrome: Previously in 2011 and 2012, two genome-wide association studies (GWAS) on PCOS in Chinese have identified 11 susceptibility loci mapping to genes functioning in metabolism (INSR, HMGA2, THADA, RAB5B/SUOX), follicle maturation and ovulation (LHCGR, FSHR) and cell proliferation (DENND1A, C9orf3, YAP1, TOX3, SUMO1P1)3, 4et al. Among them, several loci, such as 19p13.3 (INSR), 2p21 (THADA), 12q13.2 (RAB5B/SUOX), 2p16.3 (LHCGR), and 9q33.3 (DENND1A), have been replicated in European, Egyptian and Indian populations5, 6, 7.