11. Hypohidrotic ectodermal dysplasia ( HED ) is the most common subtype of the disease. 12. The teeth are exoskeletal structures, partly of ectodermal , partly of dermal origin. 13. Worldwide around 7, 000 people have been diagnosed with an ectodermal dysplasia condition. 14. Two features differentiate HWS from other ectodermal displasias. 15. It is considered a kind of ectodermal dysplasia. 16. An apical ectodermal cap ( AEC ) forms on the tip of the stump. 17. Mutations in this gene have been associated with the ectodermal dysplasia / skin fragility syndrome. 18. It is a type A ectodermal dysplasia. 19. Ectodermal dysplasia is a vague term, as there are over 170 subtypes of ectodermal dysplasia.20. Ectodermal dysplasia is a vague term, as there are over 170 subtypes of ectodermal dysplasia.
