ANOS1

ANOS1 (also known as Kallmann syndrome 1 or KAL1) is a gene that in humans is located on the X chromosome. It is associated with Kallmann syndrome, a genetic condition that affects the development of the hypothalamus, a part of the brain that controls many important functions including the release of hormones from the pituitary gland.

Function

The ANOS1 gene provides instructions for making a protein called anosmin-1. This protein is involved in the development of the nervous system, particularly the formation and movement (migration) of nerve cells (neurons). Anosmin-1 is thought to play a critical role in the development of the olfactory system, which is involved in the sense of smell, and the hypothalamic-pituitary-gonadal axis, which is involved in sexual development and reproduction.

Clinical significance

Mutations in the ANOS1 gene cause Kallmann syndrome, a disorder characterized by the combination of hypogonadotropic hypogonadism (a condition affecting the production of hormones that direct sexual development) and anosmia (the inability to smell). Most of the mutations delete or disrupt the ANOS1 gene, preventing the cell from making any functional anosmin-1. A lack of this protein disrupts the normal development of the brain, preventing the migration of neurons that are important for the sense of smell and the regulation of hormone production.

See also

• Kallmann syndrome
• Hypogonadotropic hypogonadism
• Anosmia