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The ectodermal dysplasias (EDs) is a large, heterogeneous group of inherited disorders due to primary defects in the development. The tissues primarily involved are the skin, hair, nails, eccrine glands, and teeth.
The ectodermal dysplasias are congenital, diffuse, and nonprogressive.
To date, more than 192 distinct disorders have been described. The most common ectodermal dysplasias are X-linked recessive hypohidrotic ectodermal dysplasia (Christ-Siemens-Touraine syndrome) and hidrotic ectodermal dysplasia (Clouston syndrome).
The frequency of the different ectodermal dysplasias in a given population is highly variable. The prevalence of hypohidrotic ectodermal dysplasia, the most common variant, is estimated to be 1 case per 100,000 births.
Beyond early childhood, life expectancy ranges from normal to slightly reduced