DENND1A and adenoma: The first GWAS of PCOS was performed in Han Chinese women and identified important susceptibility single nucleotide polymorphisms (SNPs) on chromosomes 2p16.3, 2p21 and 9p33.3; these SNPs were located in genes that included the thyroid adenoma-associated gene (THADA), DENN/MADD domain-containing 1A (DENND1A) and luteinizing hormone/choriogonadotropin receptor (LHCGR) [10].