Genetic polymorphisms of GnRH and gonadotrophic hormone receptors affect the phenotype of polycystic ovary syndrome

BACKGROUND Polycystic ovary syndrome (PCOS) is a complex genetic disorder. Multiple functional polymorphisms have been identified in genes that regulate the hypothalamic–pituitary–gonadal (HPG) axis that regulates ovarian function. The present study aims to examine the influence of genetic variants of the HPG-axis on the severity of clinical features of PCOS and disease susceptibility. METHODS We included 518 Caucasian PCOS women and 2996 unselected controls from the general population (the Rotterdam study). Genotype distributions were compared between patients and controls. Subsequently, associations with clinical features of PCOS were studied. Single nucleotide polymorphisms were selected in GnRH (Trp16Ser [rs6185]), the FSH-receptor (FSHR, Ala307Thr [rs6165] and Asn680Ser [rs6166]) and the LH-receptor (18insLQ, Asn291Ser [rs12470652] and Ser312Asn [rs2293275]). RESULTS FSHR Ser680 was associated with higher levels of gonadotrophic hormones (FSH: P < 0.01, LH: P = 0.01), and testosterone (P = 0.05) and a higher frequency of hyperandrogenism (P = 0.04). No differences in risk for PCOS in association with the FSH-receptor variants were observed. CONCLUSION Genetic variants of the HPG-axis were associated with a modest but significant effect on the phenotype of PCOS. FSHR variants were strongly associated with the severity of clinical features of PCOS, such as levels of gonadotrophic hormones and the presence of hyperandrogenism, but not disease risk.