INVITED COMMENTARY Mutations of the G protein-coupled receptors of the hypothalamo–pituitary–gonadal axis. Where do we stand?

Gonadal function is controlled by the two gonadotropins luteinizing hormone (LH) and follicle-stimulating hormone (FSH), produced by the pituitary gland under regulation of the hypothalamic hormone gonadotropin-releasing hormone (GnRH). LH, FSH and GnRH act through binding to specific receptors, which are members of the G protein-coupled receptor family. In recent years, it has become evident that germline mutations of the gonadotropin and GnRH receptors are involved in some forms of hypogonadism and pathologic pubertal maturation. Moreover, as these hormones have tropic and growth-promoting roles in their target organ, it has been hypothesized that somatic activating mutation of their receptors might be involved in the generation of gonadal an