Congenital hypogonadotropic hypogonadism (CHH) is caused by impaired production, secretion, or action of gonadotropin-releasing hormone (GnRH). Hypogonadotropic hypogonadism presents clinically as incomplete or absent puberty and infertility in males and females. CHH may be isolated or be associated with other developmental anomalies such as cleft lip or palate, dental agenesis, ear anomalies, congenital hearing impairment, renal agenesis, bimanual synkinesis, or skeletal anomalies. When CHH is accompanied by a defective sense of smell (anosmia or hyposmia), it is termed Kallmann syndrome (KS) and results from incomplete embryonic migration of GnRH-synthesizing neurons.
CHH/KS is genetically heterogeneous, and causative genes include X-linked, autosomal dominant, and recessive inheritance. The Hypogonadotropic Hypogonadism/Kallman Syndrome Panel includes sequence and deletion/duplication analysis of over 40 genes associated with CCH/KS.
