Ectodermal dysplasias: clinical and molecular review.

Ectodermal dysplasias (EDs) as defined by Freire-Maia [Freire-Maia (1971); Hum Hered 21: 309-312; Freire-Maia (1977); Acta Genet Med Gemellol 26: 121-131] are congenital disorders characterized by alterations in two or more ectodermal structures, at least one of these involving alterations in hair, teeth, nails, or sweat glands. Suggestions for a new definition and, consequently, for a new classification of EDs have being proposed lately, mainly with the purpose of connecting clinical knowledge with recent discoveries of gene mutations responsible for about 30% of EDs. The aim of this review was to update the clinical classification of EDs with recent molecular (64 genes and 3 chromosome regions) and clinical data, mainly of EDs of the A group (N = 186), in order to contribute information for the evaluation of the ED definition proposed by Freire-Maia.