Idiopathic hypogonadotropic hypogonadism: Diagnosis, pathogenesis, genetics, and treatment

Idiopathic hypogonadotropic hypogonadism (IHH) is a heterogeneous disorder displaying a range of phenotypic, genetic, and endocrinologic features. Current evidence suggests a deficiency in the hypothalamic release of pulsatile gonadatropin-releasing hormone (GnRH) in most patients. No genetic defects in the genes for GnRH, LHβ, or FSHβ have been described, although a deletion in the steroid sulfatase gene has been reported in X-linked Kallmann's syndrome with associated ichthyosis. Treatment with GnRH administered in a pulsatile fashion has been successful in inducing steroidogenesis and gametogenesis.