[Hypohidrotic ectodermal dysplasias]

Ectodermal dysplasias form a heterogeneous group of hereditary diseases associating dysplastic abnormalities of four tissues which derive from the ectoderm. The frequency of these congenital diseases is estimated at 7 out of 100,000 newborns. More than 150 different syndromes have been described. Solomon and Keuer, then Freire Maya and Pinheiro established a classification of these diseases dividing them in 6 groups depending on the presence of the four main clinical disorders: trichodysplasia, onychodysplasia, hypodontia and hypohidrosis. We focus on the fundamental clinical features of the hypohidrotic ectodermal dysplasias and propose an overview of the most frequent forms based on a review of the literature.