hidrotic ectodermal dysplasia type 1

Synopsis

 small cranial length
 frontal bossing
 hypoplastic maxilla
 small chin
 small facial height
 prominent supraorbital ridges
 scand-absent eyebrows
 periorbital wrinkles
 periorbital hyperpigmentation
 absent tears
 absent miebomian glands
 scant-absent eyelashes
 small nose
 hypoplastic alae nasi
 nasal mucosa atrophy
 ozena
 depressed nasal root and bridge (’saddle nose’)
 decreased palatal depth
 prominent lips
 hypodontia
 adontia
 microdontia
 conical teeth
 taurodontism
 respiratory difficulties
 atrophic rhinitis
 atrophic pharyngeal mucosa
 hypoplastic or absent mucous glands which may lead to dried secretions and obstruction
 atrophic mucosa causing dysphonia
 hypoplastic-absent mammary glands
 hypoplastic-absent nipples
 hypohidrosis
 anhidrosis
 sweat pore aplasia
 soft, thin skin
 dry skin
 mild localized pigmentation abnormalities
 skin peeling/scaling (newborn)
 eczema
 periorbital wrinkling
 periorbital hyperpigmentation
 hypoplastic-absent sebaceous glands
 hypoplastic-absent eccrine sweat glands
 spoon-shaped nails
 hypotrichosis
 fine, brittle hair
 scanty hair
 absent or scanty eyelashes and eyebrows
 blonde, fine scalp hair
 hoarse voice due to dry laryngeal mucosa
 intolerance to heat and fevers
 susceptible to hyperthermia

 Heterozygous females show variable expressivity (mild to severe manifestations) including hypodontia, conical teeth, reduction in scalp/body hair, and difficulty nursing
Genetic heterogeneity (autosomal recessive form 224900 and autosomal dominant form 129490)

Etiology

 X-linked hypohidrotic ectodermal dysplasia is caused by mutation in the gene encoding ectodysplasin-A (ED1) (MIM.300451)

References

 hidrotic ectodermal dysplasias

• hidrotic ectodermal dysplasia type 1 (ED1) (MIM.305100) (EDA)
• hidrotic ectodermal dysplasia type 2 (ED2) (MIM.129500) (GJB6)