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EDAR gene
Reviewed by Medicinsk Expert•Last updated: 2026-10-22•Gene

EDAR gene

The EDAR gene provides instructions for making the ectodysplasin A receptor, a protein essential for the development of ectodermal structures like hair, teeth, and sweat glands.

Normal Function

The EDAR gene provides instructions for making a protein called the ectodysplasin A receptor. This protein is part of a signaling pathway that plays an important role in development before birth. Specifically, it is critical for interactions between two embryonic cell layers called the ectoderm and the 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 formation of several structures that arise from the ectoderm, including the skin, hair, nails, teeth, and sweat glands.

The ectodysplasin A receptor interacts with a protein called ectodysplasin A1 (produced from the EDA gene). On the cell surface, ectodysplasin A1 attaches to this receptor like a key in a lock. When these two proteins are connected, they trigger a series of chemical signals that affect cell activities such as division, growth, and maturation. Starting before birth, this signaling pathway controls the formation of ectodermal structures such as hair follicles, sweat glands, and teeth.

Studies suggest that common variations (polymorphisms) in the EDAR gene are associated with the thickness and straightness of scalp hair, particularly in East Asian populations. EDAR appears to be one of many genes that influence these hair traits.

Health Conditions Related to Genetic Changes

Hypohidrotic ectodermal dysplasia

More than 50 mutations in the EDAR gene have been found to cause hypohidrotic ectodermal dysplasia, the most common form of ectodermal dysplasia. Starting before birth, ectodermal dysplasias result in the abnormal development of the skin, hair, nails, teeth, and sweat glands. Hypohidrotic ectodermal dysplasia is characterized by a reduced ability to sweat (hypohidrosis), sparse scalp and body hair (hypotrichosis), and several missing teeth (hypodontia) or teeth that are malformed. EDAR gene mutations account for about 10 percent of all cases of hypohidrotic ectodermal dysplasia.

Most of the EDAR gene mutations associated with hypohidrotic ectodermal dysplasia change a single protein building block (amino acid) in the receptor protein. Some of the mutations that cause this condition lead to the production of an abnormal version of the ectodysplasin A receptor. Other mutations prevent cells from producing any functional receptor. All of these genetic changes prevent the receptor from interacting with ectodysplasin A1, which impairs chemical signaling needed for interactions between the ectoderm and the mesoderm in early development. Without these signals, hair follicles, teeth, sweat glands, and other ectodermal structures do not form properly, which leads to the characteristic features of hypohidrotic ectodermal dysplasia.

Other disorders

EDAR gene mutations have also been reported in some people with a condition called nonsyndromic tooth agenesis. This condition causes one or more teeth not to form. Although missing teeth is a common feature of ectodermal dysplasias, "nonsyndromic" suggests that in these cases tooth agenesis occurs without the other signs and symptoms of those conditions.

Other Names for This Gene

  • DL
  • ectodysplasin 1, anhidrotic receptor
  • ectodysplasin A1 isoform receptor
  • ectodysplasin receptor
  • ED1R
  • ED3
  • ED5
  • EDA-A1R
  • EDA1R
  • EDA3
  • EDAR_HUMAN

Frequently Asked Questions

The V370A polymorphism is considered a benign, population‑specific allele that primarily influences hair morphology. It does not impair the receptor’s signaling enough to cause ectodermal dysplasia, nor is it associated with increased risk of skin, dental, or sweat‑gland abnormalities. Therefore, carriers of V370A experience the cosmetic trait of thicker, straighter hair without known adverse health effects.
Most pathogenic EDAR variants that lead to hypohidrotic ectodermal dysplasia (HED) follow an autosomal‑recessive inheritance pattern. Both parents must carry one copy of the altered gene; each pregnancy then has a 25 % chance of producing an affected child, a 50 % chance of a carrier, and a 25 % chance of an unaffected, non‑carrier child. Rarely, certain gain‑of‑function EDAR changes can act in a dominant‑negative fashion, but this is uncommon.
Key red‑flag signs include: (1) sparse, fine, or absent scalp hair (often described as “lanugo”); (2) missing or peg‑shaped teeth, especially the incisors; (3) reduced or absent sweating leading to heat intolerance or recurrent fevers; (4) dry, thin skin with absent or reduced eccrine glands; and (5) a family history of similar findings. When two or more of these ectodermal signs are present, especially in a child with a suggestive pedigree, sequencing of the EDAR gene (often as part of an ectodermal dysplasia panel) is recommended.
Because the underlying defect is structural, the sweat glands cannot be restored, but several supportive measures help: (1) maintain a cool environment—air‑conditioned rooms, fans, and breathable clothing; (2) schedule regular, short “cool‑down” breaks during physical activity and avoid strenuous exercise in hot weather; (3) use oral or topical antipyretics promptly for fever; (4) encourage adequate hydration (water, electrolyte solutions); and (5) educate caregivers on early signs of heat exhaustion. In severe cases, a pediatric neurologist may prescribe a low‑dose oral pilocarpine to stimulate residual sweat glands, though efficacy varies.
Source: MedlinePlus, National Library of Medicine

MedlinePlus brings together authoritative health information from the National Library of Medicine (NLM), the National Institutes of Health (NIH), and other government agencies and health-related organizations.

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