GnRH neurons originate in the nasal placode, migrating through the forebrain to the hypothalamus.[18] Failure of migration has been linked to hypogonadotropic hypogonadism in many studies to date,[19] whereas an excess of GnRH neurons in the hypothalamus has been demonstrated to drive premature pubertal development in mice.[20] Appropriate regulation of both GnRH neuronal migration and activity is thus crucial for the physiological function of the neuroendocrine axis. The gene discussed is GNRH1; the disease is hypogonadotropic hypogonadism.