Ectodermal Dysplasia
Background
Ectodermal Dysplasia (ED) is not a single disorder, but a group of closely related conditions of which more than one hundred and sixty different syndromes have been identified. The Ectodermal Dysplasias (EDs) are genetic disorders affecting the development or function of the teeth, hair, nails and sweat glands. Depending on the particular syndrome ED can also affect the skin, the lens or retina of the eye, parts of the inner ear, the development of fingers and toes, the nerves and other parts of the body. The prevalence of the various types of ED is thought to be about 7 in 10,000 live births. EDs have been reported most often in caucasians, but they occur in all population groups. Hidrotic ED has been reported in an extensive kindred of French extraction. X-linked hypohidrotic ED has full expression predominantly in males. Female carriers outnumber affected men, but most show few, if any, signs of the condition although some do manifest it very clearly. Most of the other EDs affect males and females equally.