!Hypohidrotic Ectodermal Dysplasia (HED)

  • Etiology
    • Mutation in genes encoding components of the ectodysplasin A (EDA) signaling pathway, which is critical for the initiation of sweat gland, hair follicule and tooth morphogenesis
      • Because gene only required for initiation → prime target for pre natal or neonatal treatment with recombinant EDA protein
    • XLR (EDA1) 58% → responsible for full blown disease in males and areas of skin involving the lines of Blashko in heterozygous females
    • AD/AR (EDAR, EDARDD), WNT10a
  • Clinical findings
    • Hypohidrosis (recurrent fevers can be initial presentation)
    • Hypotrichosis
    • Hypodontia: Dental abnormalities (peg shaped/conical incisors)
    • Increased bronchopulmonary, infection & rhinitis, recurrent otitis
    • Square forehead with frontal bossing, large conspicuous nostrils, wide cheekbones with flat malar ridges, thick everted lower lip, prominent chin
    • Ears low lying, anteriorly places, periorbital darkening with periorbital dermatitis
    • No nail involvement
  • Treatment for all forms of HED
    • Cool baths and drenching with water, air conditioning
    • Light clothing, cooling suits
    • Minoxidil
    • Dental prostheses and implants at age 2
    • Speech development

Hypohidrotic Ectodermal Dysplasia with immunodeficiency (HED-ID)

  • 1:250.000
  • NEMO mutation
  • Usually XLD
  • Serious pyogenic infections in 86% and mycobacterial infections (atypical mycobacterium avium) in 44%
  • Lung infections → bronchiectasis
  • Intractable diarrhea, FTT
  • 60% hypogammaglobulinemia, 15% increased IgM