ABSTRACT
Pulsatile secretion of Gonadotropin-Releasing Hormone (GnRH) by the hipothalamus and its action on the pituitary gland is a complex process involving many pre and post natal events. For example, migration of GnRH neurons from the olfactory placode, GnRH release and signalling, normal anterior pituitary development and function are all needed to allow GnRH to stimulate pulsaltile pituitary secretion of follicle-stimulating hormone (FSH) and liteinizing hormone (LH). Hypogonadotropic hypogonadism can be the result of absent or inadequate GnRH secretion or action. Abnormalities in gonadotropin hormone release and function can arise from mutations in a variety of genes implicated in hypogonadotropic hypogonadism is continually growing. A given genotype at a single locus cannot reliably predict the phenotypic manifestations in any given member of affected families. Thus, the identification and characterization of these mutations are providing important information about the reproductive axis in humans and may result in improved treatment and counselling for patients with infertility.