Some ectodermal dysplasias are here classified as congenital disorders characterized by abnormal development in 2 or more ectodermal structures (hair, nails, teeth, and sweat glands) without other systemic findings.
Hypohidrotic, or anhidrotic, ectodermal dysplasia is characterized ... Some ectodermal dysplasias are here classified as congenital disorders characterized by abnormal development in 2 or more ectodermal structures (hair, nails, teeth, and sweat glands) without other systemic findings. Hypohidrotic, or anhidrotic, ectodermal dysplasia is characterized by a triad of signs comprising sparse hair (hypotrichosis), abnormal or missing teeth (anodontia or hypodontia), and inability to sweat (anhidrosis or hypohidrosis). Typical clinical manifestations also include dryness of the skin, eyes, airways, and mucous membranes presumably due to the defective development of several exocrine glands. Hypohidrotic ectodermal dysplasia can be associated with dysmorphic features (forehead bumps, rings under the eyes, everted nose, and prominent lips) and occasionally with absent nipples (summary by Cluzeau et al., 2011). For a discussion of genetic heterogeneity of hypohidrotic/anhidrotic ectodermal dysplasia, see 305100.
Bal et al. (2007) reported a large Moroccan family in which 7 members had the clinical triad of hypohidrotic ectodermal dysplasia, i.e., hypotrichosis, hypodontia, and anhidrosis.
In 7 affected members of a large Moroccan family with autosomal dominant anhidrotic ectodermal dysplasia, Bal et al. (2007) identified a heterozygous mutation in the EDARADD gene (606603.0002). The findings indicated that mutations in the EDARADD gene can ... In 7 affected members of a large Moroccan family with autosomal dominant anhidrotic ectodermal dysplasia, Bal et al. (2007) identified a heterozygous mutation in the EDARADD gene (606603.0002). The findings indicated that mutations in the EDARADD gene can cause autosomal dominant and autosomal recessive HED (see 614941). In a male patient with oligodontia, Bergendal et al. (2011) identified a heterozygous missense mutation in the EDARADD gene that was predicted to be functionally relevant. The patient, who was not clinically ascertained, did not report any ectodermal symptoms besides the teeth.