Question: What are the genetic changes related to Kallmann syndrome ?
Answer: Mutations in the ANOS1, FGFR1, PROKR2, and PROK2 genes cause Kallmann syndrome. ANOS1 gene mutations are responsible for Kallmann syndrome 1. Kallmann syndrome 2 results from mutations in the FGFR1 gene. Mutations in the PROKR2 and PROK2 genes cause Kallmann syndrome types 3 and 4, respectively. The genes associated with Kallmann syndrome play a role in the development of certain areas of the brain before birth. Although some of their specific functions are unclear, these genes appear to be involved in the formation and movement (migration) of a group of nerve cells that are specialized to process smells (olfactory neurons). These nerve cells come together into a bundle called the olfactory bulb, which is critical for the perception of odors. The ANOS1, FGFR1, PROKR2, and PROK2 genes also play a role in the migration of neurons that produce a hormone called gonadotropin-releasing hormone (GnRH). GnRH controls the production of several other hormones that direct sexual development before birth and during puberty. These hormones are important for the normal function of the gonads (ovaries in women and testes in men). Studies suggest that mutations in the ANOS1, FGFR1, PROKR2, or PROK2 gene disrupt the migration of olfactory nerve cells and GnRH-producing nerve cells in the developing brain. If olfactory nerve cells do not extend to the olfactory bulb, a person's sense of smell will be impaired or absent. Misplacement of GnRH-producing neurons prevents the production of certain sex hormones, which interferes with normal sexual development and causes the characteristic features of hypogonadotropic hypogonadism. It is unclear how gene mutations lead to the other possible signs and symptoms of Kallmann syndrome. Because the features of this condition vary among individuals, researchers suspect that additional genetic and environmental factors may be involved. Together, mutations in the ANOS1, FGFR1, PROKR2, and PROK2 genes account for 25 percent to 30 percent of all cases of Kallmann syndrome. In cases without an identified mutation in one of these genes, the cause of the condition is unknown. Researchers are looking for other genes that can cause this disorder.
Source: GHR

Question: What are the treatments for Kallmann syndrome ?
Answer: These resources address the diagnosis or management of Kallmann syndrome: - Gene Review: Gene Review: Isolated Gonadotropin-Releasing Hormone (GnRH) Deficiency - Genetic Testing Registry: Hypogonadism with anosmia - Genetic Testing Registry: Kallmann syndrome 1 - Genetic Testing Registry: Kallmann syndrome 2 - Genetic Testing Registry: Kallmann syndrome 3 - Genetic Testing Registry: Kallmann syndrome 4 - MedlinePlus Encyclopedia: Hypogonadotropic Hypogonadism - MedlinePlus Encyclopedia: Smell - Impaired These resources from MedlinePlus offer information about the diagnosis and management of various health conditions: - Diagnostic Tests - Drug Therapy - Surgery and Rehabilitation - Genetic Counseling - Palliative Care
Source: GHR