SNAI2

The SNAI2 gene (often called SLUG) provides the instructions for making a protein called snail 2. Snail 2 belongs to the snail protein family, which plays a role in the formation of tissues during embryonic development. The snail 2 protein is also found in most adult tissues, so it probably helps maintain the normal function of cells after birth. To carry out these roles, snail 2 attaches to critical regions of DNA and helps control the activity of particular genes. On the basis of this action, the protein is called a transcription factor.

Research indicates that the snail 2 protein is required during embryonic growth for the development of cells called neural crest cells. Neural crest cells migrate from the developing spinal cord to specific regions in the embryo and give rise to many tissues and cell types such as limb muscles, bones in the face and skull (craniofacial bones), some nerve tissue, and pigment-producing cells called melanocytes. Melanocytes produce the pigment melanin, which contributes to hair, eye, and skin color. Melanocytes are also found in certain regions of the brain and inner ear. The snail 2 protein probably plays a role in the formation and survival of melanocytes.

Waardenburg syndrome - caused by mutations in the SNAI2 gene

In some cases of Waardenburg syndrome, type II, both copies of the SNAI2 gene are missing. With no copies of the gene, the snail 2 protein is absent. Lack of snail 2 may disrupt the development of melanocytes in certain areas of the skin, hair, eyes, and inner ear, leading to hearing loss and the patchy loss of pigmentation that are characteristic features of Waardenburg syndrome, type II.

other disorders - caused by mutations in the SNAI2 gene

One copy of the SNAI2 gene is missing in some cases of piebaldism, a condition characterized by a white hair forelock and patches of skin without pigment. Loss of one copy of the gene probably reduces the production of the snail 2 protein. Shortage of the snail 2 protein may disrupt the development of melanocytes in certain areas of the skin and hair, causing the patchy loss of pigment.