Table 4.

Ectodermal Dysplasias in the Differential Diagnosis of Hidrotic Ectodermal Dysplasia 2

Gene(s)DisorderMOIClinical CharacteristicsComment / Distinguishing Features
Hypohidrotic ectodermal dysplasia (HED) 1XL
  • Hypotrichosis: thin, lightly pigmented, slow-growing scalp hair
  • Hypohidrosis: deficient sweating w/episodes of hyperthermia
  • Hypodontia: few & abnormally formed teeth erupt, later than average
  • Hypohidrosis & dental abnormalities are the major distinguishing features.
  • Eyelid papules may develop in WNT10A-HED.
GJB2 Keratitis-ichthyosis-deafness syndrome (OMIM 148210)AD
  • Sensorineural deafness
  • Photophobia, corneal ulceration & scarring
  • Progressive hyperkeratotic plaques & palmoplantar hyperkeratosis
  • Sparse hair & nail dystrophy: less pronounced than in HED2
Sensorineural deafness & ocular changes are the major differentiating features.
HOXC13 Ectodermal dysplasia 9, hair/nail type (OMIM 614931)AR Absent palmoplantar keratoderma
Pachyonychia congenita (PC)AD
  • Hypertrophic nail dystrophy w/subungual hyperkeratosis
  • Painful focal palmoplantar keratoderma & blistering
  • Variably present: oral leukokeratosis, pilosebaceous cysts, palmoplantar hyperhidrosis, follicular keratoses on the trunk & extremities, natal teeth
  • Absence of hypotrichosis or atrichia is the main distinguishing feature.
  • Palmoplantar keratoderma is focal in PC (vs diffuse in most cases of HED2).
KRT74 Ectodermal dysplasia 7, hair/nail type (OMIM 614929)AR
  • Generalized hypotrichosis or atrichia
  • Nail dystrophy
Absent palmoplantar keratoderma
KRT85 Ectodermal dysplasia 4, hair/nail type (OMIM 602032)AR
  • Sparse or absent scalp hair
  • Absent eyebrows, eyelashes, pubic & axillary hair
  • Nail dystrophy
Absent palmoplantar keratoderma

EDA pathogenic variants are associated with X-linked HED. EDAR, EDARADD, and WNT10A pathogenic variants are associated with autosomal dominant and autosomal recessive HED.

From: Hidrotic Ectodermal Dysplasia 2

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