Ectodermal dysplasias: not only 'skin' deep.

The ectodermal dysplasias (EDs) are a large and complex nosologic group of diseases; more than 170 different pathologic clinical conditions have been identified. Despite the great number of EDs described so far, few causative genes have been identified. We review EDs in the light of the most recent molecular findings and propose a new classification of EDs integrating both molecular-genetic data and corresponding clinical findings of related diseases.