Ectodysplasin A receptor

Ectodysplasin A receptor (EDAR) is a is_associated_with::protein that in humans is encoded by the EDAR is_associated_with::gene. EDAR is a is_associated_with::cell surface receptor for is_associated_with::ectodysplasin A which plays an important role in the development of ectodermal tissues such as the is_associated_with::skin. It is structurally related to members of the is_associated_with::TNF receptor superfamily.

Function
EDAR and other genes provide instructions for making proteins that work together during is_associated_with::embryonic development. These proteins form part of a is_associated_with::signaling pathway that is critical for the interaction between two cell layers, the is_associated_with::ectoderm and the is_associated_with::mesoderm. In the early embryo, these cell layers form the basis for many of the body's organs and tissues. Ectoderm-mesoderm interactions are essential for the proper formation of several structures that arise from the ectoderm, including the skin, hair, nails, teeth, and sweat glands.

Clinical significance
Mutation in this gene have been associated with is_associated_with::hypohidrotic ectodermal dysplasia, a disorder characterized by a lower density of is_associated_with::sweat glands.

East Asian characteristics
A point mutation in EDAR, 370A, found in most is_associated_with::East Asians but not common in is_associated_with::African or European populations, is thought to be responsible for a number of differences between these populations, including the thicker hair, more numerous sweat glands, smaller breasts, and dentition characteristic of East Asians. The difference in dentition was not visible in mice due to the radically different structure of mice from human teeth, but it is considered reasonable that that difference also is due to the mutation. The 370A mutation arose in humans approximately 30,000 years ago, and now is found in 93% of Han Chinese and in the majority of people in nearby Asian populations.