Pharmacogenetics in ovarian stimulation - Current concepts

Ovarian response to follicle-stimulating hormone (FSH) action differs considerably among women; this has prompted researchers to determine which factors modify this response. The challenge is to identify the genes that affect the response to FSH stimulation by the application of pharmacogenetics to assisted reproduction techniques (ARTs). Recently, new insights have been gained in the investigation of the variability in the gene that encodes the FSH receptor (FSHR) gene or genes of the estrogen pathway. Several polymorphisms of the FSHR gene have been discovered, but Ser680Asn and Thr307Ala are the two most studied. The Ser680Asn polymorphism of the FSHR gene has been found to influence the ovarian response to FSH stimulation in women undergoing in vitro fertilization (IVF), and in women with the genotype Ser/Ser, the FSHR appears to be more resistant to FSH action. The clinical implications of this finding are highly important; the ultimate goal is to apply genetic markers as routine diagnostic tests before ovarian stimulation to predict ovarian response, determine the required FSH dose, and avoid the possible complications related to FSH stimulation.