Ectodermal dysplasia is not a single disorder, but a group of syndromes all deriving from abnormalities of the ectodermal structures. Abnormal development or growth of tissues and structures that develop from the ectoderm. Hair, teeth, etc. It is a mutation. It can be autosomal dominant, autosomal recessive, and X-linked
To make things more confusing:
ED can be classified by inheritance (autosomal dominant, autosomal recessive, and X-linked) or by which structures are involved (hair, teeth, nails, and/or sweat glands).
There are several different types with distinct genetic causes:
Hay-Wells syndrome, Rapp-Hodgkin syndrome and EEC syndrome are all associated with TP63.
Hypohidrotic ectodermal dysplasia can be associated with EDA, EDAR, and EDARADD
Margarita Island ectodermal dysplasia is associated with PVRL1
Ectodermal dysplasia with skin fragility is associated with PKP1
Clouston's hidrotic ectodermal dysplasia is associated with GJB6
Naegeli syndrome/Dermatopathia pigmentosa reticulariss is associated with KRT14
Pachyonychia congenita is caused by multiple keratins
Focal dermal hypoplasia is associated with PORCN
Ellis–van Creveld syndrome is associated with EVC
Palmoplantar ectodermal dysplasia refers to several different conditions selectively affecting the hands and feet