FSH (follicle stimulating hormone) is the central hormone of mammalian reproduction, necessary for gonadal development and maturation at puberty and for gamete production during the fertile phase of life¹. Together with LH, this gonadotropin is produced and secreted by the pituitary gland as a highly heterogeneous glycoprotein². The FSH receptor belongs to the family of G-protein coupled receptors, complex transmembrane proteins characterized by seven hydrophobic helices inserted in the plasma membrane and by intracellular and extracellular domains of variable dimensions depending on the type of ligand³. The intracellular portion of the FSH receptor is coupled to a Gs protein and, upon receptor activation by the hormonal interaction with the extracellular domain it initiates a cascade of events that ultimately leads to the specific biological effects of the gonadotropin.

FSH acts by binding to specific receptors, localized exclusively in the gonads. The FSH receptor is expressed by two cell types of the gonad, namely Sertoli cells in the testis, and granulosa cells in the ovarian follicle⁴.

Mutations of FSHR may cause primary or secondary amenorrhea, infertility, premature ovarian failure (POF) and ovarian hyperstimulation syndrome (OHSS)⁵. Mutations of FSHR may also play a role in the development of granulosa cell tumors of ovaries⁶.