EDARADD-Related Hypohidrotic Ectodermal Dysplasia

Genetic MONDO:0013983 Pathograph 8 Ectodermal Dysplasia

EDARADD-related hypohidrotic ectodermal dysplasia (HED3, ECTD11B) is an autosomal recessive disorder caused by biallelic loss-of-function mutations in EDARADD, which encodes the EDAR-associated death domain adaptor protein. EDARADD is an essential intracellular signal transducer that links the ectodysplasin receptor EDAR to downstream NF-κB activation via TRAF6. Loss of EDARADD function blocks EDA-EDAR-NF-κB signaling required for ectodermal appendage morphogenesis, producing the classic triad of hypohidrosis, hypotrichosis, and hypodontia. EDARADD mutations account for a small proportion of HED cases; the X-linked form (EDA mutations) is by far the most common, followed by EDAR mutations.

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4
Pathophys.
13
Phenotypes
8
Pathograph
1
Genes
3
Treatments
1
Deep Research
⚙

Pathophysiology

4
Disrupted EDA-EDAR-EDARADD-NF-κB Signaling
EDARADD is the intracellular adaptor protein that bridges the EDAR receptor to downstream NF-κB signaling. Upon EDA ligand binding to EDAR, the receptor's intracellular death domain recruits EDARADD, which in turn recruits TRAF6 to activate the IKK complex and NF-κB transcription factors. Loss of EDARADD function completely blocks this signaling cascade, preventing NF-κB-dependent transcriptional programs required for ectodermal appendage initiation and morphogenesis.
ectodermal cell link
canonical NF-κB signaling link ectoderm development link
Downstream
Impaired Sweat Gland Development
Impaired Hair Follicle Development
Impaired Tooth Development
Show evidence (4 references)
PMID:11780064 SUPPORT Model Organism
"This adapter, which we have called Edaradd (for Edar-associated death domain), interacts with the death domain of Edar and links the receptor to downstream signalling pathways."
Original paper identifying EDARADD as the adaptor protein linking EDAR to downstream signaling, using the mouse crinkled mutant.
PMID:34938205 SUPPORT Other
"The former binds to the EDA receptor (EDAR), resulting in the recruitment of the intracellular EDAR-associated death domain (EDARADD) adapter protein and the activation of the NF-κB signaling pathway"
Review article confirming the EDA-A1 → EDAR → EDARADD → NF-κB signaling cascade.
PMID:20222921 SUPPORT Human Clinical
"EDARADD interacts with the TAB2/TRAF6/TAK1 complex, which is necessary for NF-kappaB activation by EDAR."
Identifies the specific downstream complex (TAB2/TRAF6/TAK1) recruited by EDARADD for NF-κB activation.
+ 1 more reference
Impaired Sweat Gland Development
Absent or severely reduced NF-κB signaling during embryonic development leads to failure of eccrine sweat gland morphogenesis. The resulting hypohidrosis or anhidrosis causes impaired thermoregulation and heat intolerance, which is the most clinically significant feature of HED.
sweat gland development link
Show evidence (1 reference)
PMID:11780064 SUPPORT Model Organism
"This disorder is characterized by sparse hair, a lack of sweat glands and malformation of teeth."
Confirms that sweat gland absence is a cardinal feature of HED caused by disrupted ectodysplasin signaling.
Impaired Hair Follicle Development
Disrupted EDA-EDAR-EDARADD signaling impairs hair follicle induction and cycling, resulting in hypotrichosis with sparse, fine, and slow-growing scalp hair and reduced body hair.
hair follicle development link
Show evidence (1 reference)
PMID:20301291 SUPPORT Human Clinical
"The scalp hair is thin, lightly pigmented, and slow growing."
GeneReviews description of the hair phenotype in HED.
Impaired Tooth Development
NF-κB signaling through the EDA pathway is required for tooth bud initiation and morphogenesis. Loss of EDARADD leads to oligodontia or anodontia, with conical or peg-shaped teeth when present.
tooth development link
Show evidence (1 reference)
PMID:20301291 SUPPORT Human Clinical
"Only a few abnormally formed teeth erupt, at a later-than-average age."
GeneReviews description of the dental phenotype in HED.
⬡

Pathograph

Use the checkboxes to hide or show graph categories. Hover nodes for evidence and cross-linked metadata.
Pathograph: causal mechanism network for EDARADD-Related Hypohidrotic Ectodermal Dysplasia Interactive directed graph showing how pathophysiology mechanisms, phenotypes, genetic factors and variants, experimental models, environmental triggers, and treatments relate through causal and linked edges.
●

Phenotypes

13
Cardiovascular 1
Keratoconjunctivitis Sicca Keratoconjunctivitis sicca (HP:0001097)
Show evidence (1 reference)
PMID:20301291 SUPPORT Human Clinical
"Lubrication eye drops."
GeneReviews recommends lubrication eye drops as management for HED, indicating ocular surface dryness is a recognized feature.
Head and Neck 2
Hypodontia Hypodontia (HP:0000668)
Show evidence (2 references)
PMID:20301291 SUPPORT Human Clinical
"Only a few abnormally formed teeth erupt, at a later-than-average age."
GeneReviews confirms hypodontia with abnormal tooth morphology.
PMID:17354266 SUPPORT Human Clinical
"Anhidrotic ectodermal dysplasia (EDA) is a disorder of ectodermal differentiation characterized by sparse hair, abnormal or missing teeth, and inability to sweat."
Confirms missing/abnormal teeth as a cardinal feature of EDA.
Prominent Forehead Frontal bossing (HP:0002007)
Show evidence (1 reference)
PMID:38840186 SUPPORT Human Clinical
"mildly prominent forehead, and periorbital wrinkles"
Kablan 2024 case report describes mildly prominent forehead in EDARADD HED patients.
Immune 1
Recurrent Respiratory Infections Recurrent respiratory infections (HP:0002205)
Show evidence (1 reference)
PMID:20301291 SUPPORT Human Clinical
"Management of recurrent respiratory infections and asthma per primary care provider with referral to allergist and/or pulmonologist as needed."
GeneReviews includes management of recurrent respiratory infections, indicating this is a recognized feature of HED.
Integument 4
Hypohidrosis Hypohidrosis (HP:0000966)
Show evidence (2 references)
PMID:20301291 SUPPORT Human Clinical
"Sweating, although present, is greatly deficient, leading to episodes of hyperthermia until the affected individual or family acquires experience with environmental modifications to control temperature."
GeneReviews confirms hypohidrosis as a cardinal feature of HED.
PMID:20222921 SUPPORT Human Clinical
"Hypohidrotic ectodermal dysplasia (HED) is characterized by abnormal development of the eccrine sweat glands, hair and teeth."
Confirms eccrine sweat gland abnormality as a defining feature.
Sparse Hair Sparse hair (HP:0008070)
Show evidence (2 references)
PMID:20301291 SUPPORT Human Clinical
"The scalp hair is thin, lightly pigmented, and slow growing."
GeneReviews characterizes the hair phenotype in HED.
PMID:34573371 SUPPORT Human Clinical
"The most common ED phenotype is hypohidrotic/anhidrotic ectodermal dysplasia (HED) featuring hypotrichosis, hypohidrosis/anhidrosis, and hypodontia."
Confirms hypotrichosis as part of the classic HED triad.
Dry Skin Dry skin (HP:0000958)
Show evidence (2 references)
PMID:20301291 SUPPORT Human Clinical
"Skin care products for eczema and exposures that exacerbate dry skin."
GeneReviews recommends treatment for dry skin in HED patients.
PMID:38840186 SUPPORT Human Clinical
"very dry skin"
Kablan 2024 reports very dry skin in EDARADD HED patients.
Nail Dystrophy Nail dystrophy (HP:0008404)
Show evidence (1 reference)
PMID:38840186 SUPPORT Human Clinical
"predominantly affects the hair, nails, eccrine glands, and teeth"
Kablan 2024 explicitly lists nails among the ectodermal structures affected by HED.
Metabolism 1
Heat Intolerance Heat intolerance (HP:0002046)
Show evidence (1 reference)
PMID:20301291 SUPPORT Human Clinical
"leading to episodes of hyperthermia until the affected individual or family acquires experience with environmental modifications to control temperature."
Confirms heat intolerance and hyperthermia risk as major concerns.
Other 4
Conical Tooth Conical tooth (HP:0000698)
Show evidence (1 reference)
PMID:20301291 SUPPORT Human Clinical
"bonding of conical teeth"
GeneReviews mentions treatment of conical teeth, confirming this phenotype in HED.
Periorbital Wrinkles Periorbital wrinkles (HP:0000607)
Show evidence (1 reference)
PMID:38840186 SUPPORT Human Clinical
"mildly prominent forehead, and periorbital wrinkles"
Kablan 2024 case report describes periorbital wrinkles in an EDARADD HED patient.
Sparse Eyebrow Sparse eyebrow (HP:0045075)
Show evidence (1 reference)
PMID:38840186 SUPPORT Human Clinical
"sparse eyebrows and eyelashes"
Kablan 2024 describes sparse eyebrows in EDARADD HED siblings.
Sparse Eyelashes Sparse eyelashes (HP:0000653)
Show evidence (1 reference)
PMID:38840186 SUPPORT Human Clinical
"sparse eyebrows and eyelashes"
Kablan 2024 describes sparse eyelashes in EDARADD HED siblings.
🧬

Genetic Associations

1
EDARADD Loss-of-Function Variants (Pathogenic Variants)
Autosomal Recessive
Show evidence (5 references)
PMID:11780064 SUPPORT Human Clinical
"We also identify a missense mutation in its human orthologue, EDARADD, that is present in a family affected with hypohidrotic ectodermal dysplasia."
Headon et al. identified the first human EDARADD mutation in an HED family.
PMID:17354266 SUPPORT Human Clinical
"We demonstrated that the p.Leu112Arg mutation completely abrogated NF-kB activation, whereas the p.Glu142Lys retained the ability to significantly activate the NF-kB pathway."
Bal et al. showed that dominant and recessive EDARADD mutations have different functional consequences on NF-κB activation.
PMID:20222921 SUPPORT Human Clinical
"We identified one EDARADD 6-bp homozygous in-frame deletion (c.402-407del, p.Thr135-Val136del) in a patient born to consanguineous parents."
Chassaing et al. identified an in-frame deletion in EDARADD that impairs the EDAR-EDARADD interaction and inhibits NF-κB activity.
+ 2 more references
💊

Treatments

3
Heat Avoidance and Environmental Modification
Action: supportive care MAXO:0000950
Primary management involves environmental modifications to prevent hyperthermia, including heat avoidance, cooling vests, access to adequate water supply, and education about heat-related risks. Exposure to extreme heat should be avoided.
Show evidence (1 reference)
PMID:20301291 SUPPORT Human Clinical
"Access to an adequate water supply and a cool environment during hot weather."
GeneReviews recommends environmental modifications for thermoregulation.
Dental Implantation and Prosthodontic Rehabilitation
Action: dental implantation MAXO:0001534
Prosthodontic management including dentures, dental implants, and orthodontic treatment to address oligodontia and conical teeth. Early dental treatment by age one year with follow-up every six to twelve months is recommended.
Show evidence (1 reference)
PMID:20301291 SUPPORT Human Clinical
"Early dental treatment; bonding of conical teeth; orthodontics as necessary; dental implants in the anterior portion of the mandibular arch in older children; replacement of dental prostheses as needed, often every 2.5 years; dental implants in adults"
GeneReviews provides detailed dental management recommendations for HED patients.
Genetic Counseling
Action: genetic counseling MAXO:0000079
Autosomal recessive inheritance counseling for affected families. Carrier testing and prenatal/preimplantation genetic testing are available when the familial variants are known.
Show evidence (1 reference)
PMID:20301291 SUPPORT Human Clinical
"Once the EDA, EDAR, EDARADD, or WNT10A pathogenic variant(s) have been identified in an affected family member, prenatal and preimplantation genetic testing for HED are possible."
GeneReviews confirms availability of genetic testing and counseling for EDARADD-related HED.
{ }

Source YAML

click to show 
name: EDARADD-Related Hypohidrotic Ectodermal Dysplasia
creation_date: "2026-04-24T00:00:00Z"
updated_date: "2026-04-24T00:00:00Z"
description: >-
  EDARADD-related hypohidrotic ectodermal dysplasia (HED3, ECTD11B) is an
  autosomal recessive disorder caused by biallelic loss-of-function mutations
  in EDARADD, which encodes the EDAR-associated death domain adaptor protein.
  EDARADD is an essential intracellular signal transducer that links the
  ectodysplasin receptor EDAR to downstream NF-κB activation via TRAF6. Loss
  of EDARADD function blocks EDA-EDAR-NF-κB signaling required for ectodermal
  appendage morphogenesis, producing the classic triad of hypohidrosis,
  hypotrichosis, and hypodontia. EDARADD mutations account for a small
  proportion of HED cases; the X-linked form (EDA mutations) is by far the
  most common, followed by EDAR mutations.
category: Genetic
parents:
- Ectodermal Dysplasia
disease_term:
  preferred_term: EDARADD-related hypohidrotic ectodermal dysplasia
  term:
    id: MONDO:0013983
    label: ectodermal dysplasia 11B, hypohidrotic/hair/tooth type, autosomal recessive
genetic:
- name: EDARADD Loss-of-Function Variants
  association: Pathogenic Variants
  gene_term:
    preferred_term: EDARADD
    term:
      id: hgnc:14341
      label: EDARADD
  inheritance:
  - name: Autosomal Recessive
    inheritance_term:
      preferred_term: Autosomal recessive inheritance
      term:
        id: HP:0000007
        label: Autosomal recessive inheritance
  features: >-
    Biallelic loss-of-function mutations in EDARADD cause HED3. EDARADD
    encodes a death domain-containing adaptor protein that interacts with
    the intracellular death domain of EDAR and recruits TRAF6 to activate
    the NF-κB pathway. Most reported mutations are missense variants
    affecting the death domain. Recessive variants typically retain
    partial NF-κB activation, while dominant EDARADD variants (causing
    the separate entity ECTD11A) act via a dominant negative mechanism.
  variants:
  - name: p.Glu142Lys (p.E142K)
    description: >-
      Recessive missense variant in the death domain of EDARADD. The first
      EDARADD mutation identified in a human HED family. Retains partial
      ability to activate NF-κB, consistent with recessive inheritance.
  - name: p.Thr135_Val136del
    description: >-
      Recessive in-frame deletion of two residues in the death domain.
      Identified in a consanguineous family. Impairs the EDAR-EDARADD
      interaction and severely inhibits NF-κB activity.
  - name: p.Arg108ProfsTer7
    description: >-
      Recessive homozygous frameshift insertion (c.322_323insCGGGC) in the
      last exon of EDARADD, introducing a premature stop codon. Identified
      in two consanguineous siblings with classical HED phenotype.
  evidence:
  - reference: PMID:11780064
    reference_title: "Gene defect in ectodermal dysplasia implicates a death domain adapter in development."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      We also identify a missense mutation in its human orthologue, EDARADD,
      that is present in a family affected with hypohidrotic ectodermal
      dysplasia.
    explanation: >-
      Headon et al. identified the first human EDARADD mutation in an HED
      family.
  - reference: PMID:17354266
    reference_title: "Autosomal dominant anhidrotic ectodermal dysplasias at the EDARADD locus."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      We demonstrated that the p.Leu112Arg mutation completely abrogated
      NF-kB activation, whereas the p.Glu142Lys retained the ability to
      significantly activate the NF-kB pathway.
    explanation: >-
      Bal et al. showed that dominant and recessive EDARADD mutations have
      different functional consequences on NF-κB activation.
  - reference: PMID:20222921
    reference_title: "Mutations in EDARADD account for a small proportion of hypohidrotic ectodermal dysplasia cases."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      We identified one EDARADD 6-bp homozygous in-frame deletion
      (c.402-407del, p.Thr135-Val136del) in a patient born to
      consanguineous parents.
    explanation: >-
      Chassaing et al. identified an in-frame deletion in EDARADD that
      impairs the EDAR-EDARADD interaction and inhibits NF-κB activity.
  - reference: PMID:20979233
    reference_title: "Only four genes (EDA1, EDAR, EDARADD, and WNT10A) account for 90% of hypohidrotic/anhidrotic ectodermal dysplasia cases."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      These four genes accounted for 92% (56/61 patients) of HED/EDA cases
    explanation: >-
      Large cohort study confirming that EDA, EDAR, EDARADD, and WNT10A
      account for the vast majority of HED cases.
  - reference: PMID:38840186
    reference_title: "Novel homozygous frameshift insertion variant in the last exon of the EDARADD causing hypohidrotic ectodermal dysplasia in two siblings: case report and review of the literature."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      targeted next-generation sequencing analysis yielded the novel
      homozygous insertion variant c.322_323insCGGGC p.(Arg108ProfsTer7)
      in EDARADD.
    explanation: >-
      Kablan & Tasdelen 2024 report a novel homozygous frameshift variant
      in EDARADD in two consanguineous siblings with classical HED.
pathophysiology:
- name: Disrupted EDA-EDAR-EDARADD-NF-κB Signaling
  description: >-
    EDARADD is the intracellular adaptor protein that bridges the EDAR
    receptor to downstream NF-κB signaling. Upon EDA ligand binding to
    EDAR, the receptor's intracellular death domain recruits EDARADD,
    which in turn recruits TRAF6 to activate the IKK complex and
    NF-κB transcription factors. Loss of EDARADD function completely
    blocks this signaling cascade, preventing NF-κB-dependent
    transcriptional programs required for ectodermal appendage
    initiation and morphogenesis.
  cell_types:
  - preferred_term: ectodermal cell
    term:
      id: CL:0000221
      label: ectodermal cell
  biological_processes:
  - preferred_term: canonical NF-κB signaling
    term:
      id: GO:0007249
      label: canonical NF-kappaB signal transduction
  - preferred_term: ectoderm development
    term:
      id: GO:0007398
      label: ectoderm development
  downstream:
  - target: Impaired Sweat Gland Development
  - target: Impaired Hair Follicle Development
  - target: Impaired Tooth Development
  evidence:
  - reference: PMID:11780064
    reference_title: "Gene defect in ectodermal dysplasia implicates a death domain adapter in development."
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: >-
      This adapter, which we have called Edaradd (for Edar-associated death
      domain), interacts with the death domain of Edar and links the
      receptor to downstream signalling pathways.
    explanation: >-
      Original paper identifying EDARADD as the adaptor protein linking
      EDAR to downstream signaling, using the mouse crinkled mutant.
  - reference: PMID:34938205
    reference_title: "Ectodysplasin A/Ectodysplasin A Receptor System and Their Roles in Multiple Diseases."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: >-
      The former binds to the EDA receptor (EDAR), resulting in the
      recruitment of the intracellular EDAR-associated death domain
      (EDARADD) adapter protein and the activation of the NF-κB signaling
      pathway
    explanation: >-
      Review article confirming the EDA-A1 → EDAR → EDARADD → NF-κB
      signaling cascade.
  - reference: PMID:20222921
    reference_title: "Mutations in EDARADD account for a small proportion of hypohidrotic ectodermal dysplasia cases."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      EDARADD interacts with the TAB2/TRAF6/TAK1 complex, which is
      necessary for NF-kappaB activation by EDAR.
    explanation: >-
      Identifies the specific downstream complex (TAB2/TRAF6/TAK1) recruited
      by EDARADD for NF-κB activation.
  - reference: PMID:34219261
    reference_title: "Characterization of EDARADD gene mutations responsible for hypohidrotic ectodermal dysplasia."
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: >-
      Nuclear factor (NF)-κB reporter assays demonstrated that all the
      mutant EDARADD showed reduction in activation of NF-κB.
    explanation: >-
      Functional characterization showing that EDARADD mutations reduce
      NF-κB activation, confirming the pathway mechanism.
- name: Impaired Sweat Gland Development
  description: >-
    Absent or severely reduced NF-κB signaling during embryonic development
    leads to failure of eccrine sweat gland morphogenesis. The resulting
    hypohidrosis or anhidrosis causes impaired thermoregulation and heat
    intolerance, which is the most clinically significant feature of HED.
  biological_processes:
  - preferred_term: sweat gland development
    term:
      id: GO:0060792
      label: sweat gland development
  evidence:
  - reference: PMID:11780064
    reference_title: "Gene defect in ectodermal dysplasia implicates a death domain adapter in development."
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: >-
      This disorder is characterized by sparse hair, a lack of sweat glands
      and malformation of teeth.
    explanation: >-
      Confirms that sweat gland absence is a cardinal feature of HED
      caused by disrupted ectodysplasin signaling.
- name: Impaired Hair Follicle Development
  description: >-
    Disrupted EDA-EDAR-EDARADD signaling impairs hair follicle induction
    and cycling, resulting in hypotrichosis with sparse, fine, and
    slow-growing scalp hair and reduced body hair.
  biological_processes:
  - preferred_term: hair follicle development
    term:
      id: GO:0001942
      label: hair follicle development
  evidence:
  - reference: PMID:20301291
    reference_title: "Hypohidrotic Ectodermal Dysplasia."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      The scalp hair is thin, lightly pigmented, and slow growing.
    explanation: >-
      GeneReviews description of the hair phenotype in HED.
- name: Impaired Tooth Development
  description: >-
    NF-κB signaling through the EDA pathway is required for tooth bud
    initiation and morphogenesis. Loss of EDARADD leads to oligodontia
    or anodontia, with conical or peg-shaped teeth when present.
  biological_processes:
  - preferred_term: tooth development
    term:
      id: GO:0042476
      label: odontogenesis
  evidence:
  - reference: PMID:20301291
    reference_title: "Hypohidrotic Ectodermal Dysplasia."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Only a few abnormally formed teeth erupt, at a later-than-average age.
    explanation: >-
      GeneReviews description of the dental phenotype in HED.
phenotypes:
- name: Hypohidrosis
  category: Constitutional
  description: >-
    Reduced or absent sweating due to defective eccrine sweat gland
    development. Leads to heat intolerance and risk of hyperthermia.
    Sweating, although present in some patients, is greatly deficient.
  phenotype_term:
    preferred_term: Hypohidrosis
    term:
      id: HP:0000966
      label: Hypohidrosis
  evidence:
  - reference: PMID:20301291
    reference_title: "Hypohidrotic Ectodermal Dysplasia."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Sweating, although present, is greatly deficient, leading to episodes
      of hyperthermia until the affected individual or family acquires
      experience with environmental modifications to control temperature.
    explanation: >-
      GeneReviews confirms hypohidrosis as a cardinal feature of HED.
  - reference: PMID:20222921
    reference_title: "Mutations in EDARADD account for a small proportion of hypohidrotic ectodermal dysplasia cases."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Hypohidrotic ectodermal dysplasia (HED) is characterized by abnormal
      development of the eccrine sweat glands, hair and teeth.
    explanation: >-
      Confirms eccrine sweat gland abnormality as a defining feature.
- name: Sparse Hair
  category: Integument
  description: >-
    Sparse, fine, lightly pigmented, and slow-growing scalp hair with
    reduced body hair.
  phenotype_term:
    preferred_term: Sparse hair
    term:
      id: HP:0008070
      label: Sparse hair
  evidence:
  - reference: PMID:20301291
    reference_title: "Hypohidrotic Ectodermal Dysplasia."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      The scalp hair is thin, lightly pigmented, and slow growing.
    explanation: >-
      GeneReviews characterizes the hair phenotype in HED.
  - reference: PMID:34573371
    reference_title: "Gene Mutations of the Three Ectodysplasin Pathway Key Players (EDA, EDAR, and EDARADD) Account for More than 60% of Egyptian Ectodermal Dysplasia: A Report of Seven Novel Mutations."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      The most common ED phenotype is hypohidrotic/anhidrotic ectodermal
      dysplasia (HED) featuring hypotrichosis, hypohidrosis/anhidrosis,
      and hypodontia.
    explanation: >-
      Confirms hypotrichosis as part of the classic HED triad.
- name: Hypodontia
  category: Head and Neck
  description: >-
    Reduced number of teeth (oligodontia or anodontia) with
    characteristically conical or peg-shaped teeth when present.
  phenotype_term:
    preferred_term: Hypodontia
    term:
      id: HP:0000668
      label: Hypodontia
  evidence:
  - reference: PMID:20301291
    reference_title: "Hypohidrotic Ectodermal Dysplasia."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Only a few abnormally formed teeth erupt, at a later-than-average age.
    explanation: >-
      GeneReviews confirms hypodontia with abnormal tooth morphology.
  - reference: PMID:17354266
    reference_title: "Autosomal dominant anhidrotic ectodermal dysplasias at the EDARADD locus."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Anhidrotic ectodermal dysplasia (EDA) is a disorder of ectodermal
      differentiation characterized by sparse hair, abnormal or missing
      teeth, and inability to sweat.
    explanation: >-
      Confirms missing/abnormal teeth as a cardinal feature of EDA.
- name: Conical Tooth
  category: Head and Neck
  description: >-
    Teeth that are present are characteristically conical or peg-shaped,
    a distinctive dental feature of HED.
  phenotype_term:
    preferred_term: Conical tooth
    term:
      id: HP:0000698
      label: Conical tooth
  evidence:
  - reference: PMID:20301291
    reference_title: "Hypohidrotic Ectodermal Dysplasia."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      bonding of conical teeth
    explanation: >-
      GeneReviews mentions treatment of conical teeth, confirming this
      phenotype in HED.
- name: Heat Intolerance
  category: Constitutional
  description: >-
    Inability to tolerate warm environments due to impaired
    thermoregulation from defective sweating. Episodes of hyperthermia
    are a major clinical concern, especially in early childhood.
  phenotype_term:
    preferred_term: Heat intolerance
    term:
      id: HP:0002046
      label: Heat intolerance
  evidence:
  - reference: PMID:20301291
    reference_title: "Hypohidrotic Ectodermal Dysplasia."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      leading to episodes of hyperthermia until the affected individual or
      family acquires experience with environmental modifications to
      control temperature.
    explanation: >-
      Confirms heat intolerance and hyperthermia risk as major concerns.
- name: Periorbital Wrinkles
  category: Head and Neck
  description: >-
    Periorbital wrinkling, a characteristic facial feature of HED
    contributing to the distinctive facial gestalt.
  phenotype_term:
    preferred_term: Periorbital wrinkles
    term:
      id: HP:0000607
      label: Periorbital wrinkles
  evidence:
  - reference: PMID:38840186
    reference_title: "Novel homozygous frameshift insertion variant in the last exon of the EDARADD causing hypohidrotic ectodermal dysplasia in two siblings: case report and review of the literature."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      mildly prominent forehead, and periorbital wrinkles
    explanation: >-
      Kablan 2024 case report describes periorbital wrinkles in an EDARADD
      HED patient.
- name: Prominent Forehead
  category: Head and Neck
  description: >-
    Mildly prominent forehead, part of the characteristic facial
    dysmorphism of HED.
  phenotype_term:
    preferred_term: Frontal bossing
    term:
      id: HP:0002007
      label: Frontal bossing
  evidence:
  - reference: PMID:38840186
    reference_title: "Novel homozygous frameshift insertion variant in the last exon of the EDARADD causing hypohidrotic ectodermal dysplasia in two siblings: case report and review of the literature."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      mildly prominent forehead, and periorbital wrinkles
    explanation: >-
      Kablan 2024 case report describes mildly prominent forehead in EDARADD
      HED patients.
- name: Sparse Eyebrow
  category: Head and Neck
  description: >-
    Reduced density of eyebrow hair due to impaired hair follicle
    development in ectodermal appendages.
  phenotype_term:
    preferred_term: Sparse eyebrow
    term:
      id: HP:0045075
      label: Sparse eyebrow
  evidence:
  - reference: PMID:38840186
    reference_title: "Novel homozygous frameshift insertion variant in the last exon of the EDARADD causing hypohidrotic ectodermal dysplasia in two siblings: case report and review of the literature."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      sparse eyebrows and eyelashes
    explanation: >-
      Kablan 2024 describes sparse eyebrows in EDARADD HED siblings.
- name: Sparse Eyelashes
  category: Head and Neck
  description: >-
    Reduced density of eyelashes due to impaired hair follicle
    development.
  phenotype_term:
    preferred_term: Sparse eyelashes
    term:
      id: HP:0000653
      label: Sparse eyelashes
  evidence:
  - reference: PMID:38840186
    reference_title: "Novel homozygous frameshift insertion variant in the last exon of the EDARADD causing hypohidrotic ectodermal dysplasia in two siblings: case report and review of the literature."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      sparse eyebrows and eyelashes
    explanation: >-
      Kablan 2024 describes sparse eyelashes in EDARADD HED siblings.
- name: Dry Skin
  category: Integument
  description: >-
    Dry, thin skin due to reduced eccrine gland function and
    ectodermal abnormalities.
  phenotype_term:
    preferred_term: Dry skin
    term:
      id: HP:0000958
      label: Dry skin
  evidence:
  - reference: PMID:20301291
    reference_title: "Hypohidrotic Ectodermal Dysplasia."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Skin care products for eczema and exposures that exacerbate dry skin.
    explanation: >-
      GeneReviews recommends treatment for dry skin in HED patients.
  - reference: PMID:38840186
    reference_title: "Novel homozygous frameshift insertion variant in the last exon of the EDARADD causing hypohidrotic ectodermal dysplasia in two siblings: case report and review of the literature."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      very dry skin
    explanation: >-
      Kablan 2024 reports very dry skin in EDARADD HED patients.
- name: Nail Dystrophy
  category: Integument
  description: >-
    Abnormal nail development, reflecting the ectodermal origin of nail
    structures and their dependence on EDA pathway signaling.
  phenotype_term:
    preferred_term: Nail dystrophy
    term:
      id: HP:0008404
      label: Nail dystrophy
  evidence:
  - reference: PMID:38840186
    reference_title: "Novel homozygous frameshift insertion variant in the last exon of the EDARADD causing hypohidrotic ectodermal dysplasia in two siblings: case report and review of the literature."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      predominantly affects the hair, nails, eccrine glands, and teeth
    explanation: >-
      Kablan 2024 explicitly lists nails among the ectodermal structures
      affected by HED.
- name: Keratoconjunctivitis Sicca
  category: Head and Neck
  description: >-
    Ocular surface dryness due to defective meibomian and lacrimal gland
    development, requiring lubrication eye drops. Annual ophthalmologic
    assessment is recommended.
  phenotype_term:
    preferred_term: Keratoconjunctivitis sicca
    term:
      id: HP:0001097
      label: Keratoconjunctivitis sicca
  evidence:
  - reference: PMID:20301291
    reference_title: "Hypohidrotic Ectodermal Dysplasia."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Lubrication eye drops.
    explanation: >-
      GeneReviews recommends lubrication eye drops as management for HED,
      indicating ocular surface dryness is a recognized feature.
- name: Recurrent Respiratory Infections
  category: Respiratory
  description: >-
    Recurrent upper and lower respiratory tract infections due to
    defective airway mucosal gland development and impaired mucociliary
    clearance.
  phenotype_term:
    preferred_term: Recurrent respiratory infections
    term:
      id: HP:0002205
      label: Recurrent respiratory infections
  evidence:
  - reference: PMID:20301291
    reference_title: "Hypohidrotic Ectodermal Dysplasia."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Management of recurrent respiratory infections and asthma per primary
      care provider with referral to allergist and/or pulmonologist as
      needed.
    explanation: >-
      GeneReviews includes management of recurrent respiratory infections,
      indicating this is a recognized feature of HED.
treatments:
- name: Heat Avoidance and Environmental Modification
  description: >-
    Primary management involves environmental modifications to prevent
    hyperthermia, including heat avoidance, cooling vests, access to
    adequate water supply, and education about heat-related risks.
    Exposure to extreme heat should be avoided.
  treatment_term:
    preferred_term: supportive care
    term:
      id: MAXO:0000950
      label: supportive care
  evidence:
  - reference: PMID:20301291
    reference_title: "Hypohidrotic Ectodermal Dysplasia."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Access to an adequate water supply and a cool environment during
      hot weather.
    explanation: >-
      GeneReviews recommends environmental modifications for thermoregulation.
- name: Dental Implantation and Prosthodontic Rehabilitation
  description: >-
    Prosthodontic management including dentures, dental implants, and
    orthodontic treatment to address oligodontia and conical teeth.
    Early dental treatment by age one year with follow-up every six to
    twelve months is recommended.
  treatment_term:
    preferred_term: dental implantation
    term:
      id: MAXO:0001534
      label: dental implantation
  evidence:
  - reference: PMID:20301291
    reference_title: "Hypohidrotic Ectodermal Dysplasia."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Early dental treatment; bonding of conical teeth; orthodontics as
      necessary; dental implants in the anterior portion of the mandibular
      arch in older children; replacement of dental prostheses as needed,
      often every 2.5 years; dental implants in adults
    explanation: >-
      GeneReviews provides detailed dental management recommendations
      for HED patients.
- name: Genetic Counseling
  description: >-
    Autosomal recessive inheritance counseling for affected families.
    Carrier testing and prenatal/preimplantation genetic testing are
    available when the familial variants are known.
  treatment_term:
    preferred_term: genetic counseling
    term:
      id: MAXO:0000079
      label: genetic counseling
  evidence:
  - reference: PMID:20301291
    reference_title: "Hypohidrotic Ectodermal Dysplasia."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Once the EDA, EDAR, EDARADD, or WNT10A pathogenic variant(s) have
      been identified in an affected family member, prenatal and
      preimplantation genetic testing for HED are possible.
    explanation: >-
      GeneReviews confirms availability of genetic testing and
      counseling for EDARADD-related HED.
📚

References & Deep Research

Deep Research

1
Falcon ▸
Disease Characteristics Research Template
Edison Scientific Literature 23 citations 2026-04-24T18:24:52.031483

Question: You are an expert researcher providing comprehensive, well-cited information.

Provide detailed information focusing on: 1. Key concepts and definitions with current understanding 2. Recent developments and latest research (prioritize 2023-2024 sources) 3. Current applications and real-world implementations 4. Expert opinions and analysis from authoritative sources 5. Relevant statistics and data from recent studies

Format as a comprehensive research report with proper citations. Include URLs and publication dates where available. Always prioritize recent, authoritative sources and provide specific citations for all major claims.

Disease Characteristics Research Template

Target Disease

  • Disease Name: EDARADD-Related Hypohidrotic Ectodermal Dysplasia
  • MONDO ID: (if available)
  • Category: Genetic

Research Objectives

Please provide a comprehensive research report on EDARADD-Related Hypohidrotic Ectodermal Dysplasia covering all of the disease characteristics listed below. This report will be used to populate a disease knowledge base entry. Be thorough and cite primary literature (PMID preferred) for all claims.

For each section, suggested databases/resources are listed. These are the first places you should search for information on each topic.

1. Disease Information

Search first: OMIM, Orphanet, ICD-10/ICD-11, MeSH, PubMed

  • What is the disease? Provide a concise overview.
  • What are the key identifiers? (OMIM, Orphanet, ICD-10/ICD-11, MeSH, Mondo)
  • What are the common synonyms and alternative names?
  • Is the information derived from individual patients (e.g., EHR) or aggregated disease-level resources?

2. Etiology

  • Disease Causal Factors: What are the primary causes? (genetic, environmental, infectious, mechanistic)
  • Risk Factors:

    Search first: PubMed, Cochrane Library, UpToDate, clinical guidelines, ClinVar, ClinGen, GWAS Catalog, PheGenI, CTD, CDC, WHO, epidemiological databases

  • Genetic risk factors (causal variants, susceptibility loci, modifier genes)
  • Environmental risk factors (toxins, lifestyle, occupational exposures, age, sex, family history)
  • Protective Factors:

    Search first: PubMed, Cochrane Library, clinical trial databases, GWAS Catalog, gnomAD, WHO, CDC, nutrition databases

  • Genetic protective factors (protective variants, modifier alleles)
  • Environmental protective factors (diet, lifestyle, exposures that reduce risk)
  • Gene-Environment Interactions: How do genetic and environmental factors interact to influence disease?

    Search first: CTD, PubMed, PheGenI, GxE databases

3. Phenotypes

Search first: HPO (Human Phenotype Ontology), OMIM, Orphanet, PubMed, clinicaltrials.gov, MedDRA, SNOMED CT, DECIPHER, LOINC

For each phenotype, provide: - Phenotype type: symptoms, clinical signs, physical manifestations, behavioral changes, or laboratory abnormalities

For symptoms/signs: HPO, OMIM, Orphanet, PubMed For behavioral changes: HPO, DSM, RDoC (Research Domain Criteria), PubMed For laboratory abnormalities: LOINC, SNOMED CT, LabTests Online, PubMed - Phenotype characteristics: Search first: OMIM, Orphanet, HPO, PubMed - Age of symptom onset (neonatal, childhood, adult-onset, late-onset) - Symptom severity (mild, moderate, severe, variable) - Symptom progression (stable, progressive, episodic, fluctuating) - Frequency among affected individuals (percentage or qualitative) - Quality of life impact: Effects on daily functioning and well-being (per-phenotype when possible) Search first: EQ-5D database, SF-36, WHO QOL databases, PubMed - Suggest HPO (Human Phenotype Ontology) terms for each phenotype

4. Genetic/Molecular Information

  • Causal Genes: Gene mutations or chromosomal abnormalities responsible for disease (gene symbols, OMIM IDs)

    Search first: OMIM, ClinVar, HGMD, Ensembl, NCBI Gene

  • Pathogenic Variants:
  • Affected genes (gene symbols, HGNC IDs) > Search first: OMIM, NCBI Gene, Ensembl, HGNC, UniProt, GeneCards
  • Variant classification (pathogenic, likely pathogenic, VUS per ACMG/AMP guidelines) > Search first: ClinVar, ClinGen, ACMG/AMP guidelines, VarSome
  • Variant type/class (missense, frameshift, nonsense, splice-site, structural)
  • Allele frequency in population databases > Search first: gnomAD, 1000 Genomes, ExAC, TOPMed, dbSNP
  • Somatic vs germline origin > Search first: COSMIC (somatic), ClinVar, ICGC, TCGA
  • Functional consequences (loss of function, gain of function, dominant negative)
  • Modifier Genes: Genes that modify disease severity or expression
  • Epigenetic Information: DNA methylation, histone modifications, chromatin changes affecting disease

    Search first: ENCODE, Roadmap Epigenomics, MethBase, DiseaseMeth

  • Chromosomal Abnormalities: Large-scale genetic changes (aneuploidy, translocations, inversions)

    Search first: DECIPHER, ClinVar, ECARUCA, UCSC Genome Browser

5. Environmental Information

  • Environmental Factors: Non-genetic contributing factors (toxins, radiation, pollution, occupational exposure)

    Search first: CTD (Comparative Toxicogenomics Database), TOXNET, PubMed, EPA databases

  • Lifestyle Factors: Behavioral factors (smoking, diet, exercise, alcohol consumption)

    Search first: CDC databases, WHO, PubMed, NHANES

  • Infectious Agents: If applicable, pathogens causing or triggering disease (bacteria, viruses, fungi, parasites)

    Search first: NCBI Taxonomy, ViPR, BV-BRC, MicrobeDB, GIDEON

6. Mechanism / Pathophysiology

  • Molecular Pathways: Specific signaling cascades or biochemical pathways involved (Wnt, MAPK, mTOR, PI3K-AKT, etc.)

    Search first: KEGG, Reactome, WikiPathways, PathBank, BioCyc

  • Cellular Processes: Cell-level mechanisms (apoptosis, autophagy, cell cycle dysregulation, inflammation, etc.)

    Search first: Gene Ontology (GO), Reactome, KEGG, PubMed

  • Protein Dysfunction: How protein structure or function is altered (misfolding, aggregation, loss of function, gain of function)

    Search first: UniProt, PDB (Protein Data Bank), InterPro, Pfam, AlphaFold

  • Metabolic Changes: Alterations in metabolic processes (energy metabolism, lipid metabolism, amino acid metabolism)

    Search first: KEGG, BioCyc, HMDB (Human Metabolome Database), BRENDA

  • Immune System Involvement: Role of immune response (autoimmunity, immunodeficiency, chronic inflammation)

    Search first: ImmPort, Immunome Database, IEDB, Gene Ontology

  • Tissue Damage Mechanisms: How tissues/ are injured (oxidative stress, ischemia, fibrosis, necrosis)

    Search first: PubMed, Gene Ontology, Reactome

  • Biochemical Abnormalities: Specific molecular defects (enzyme deficiencies, receptor dysfunction, ion channel defects)

    Search first: BRENDA, UniProt, KEGG, OMIM, PubMed

  • Epigenetic Changes: DNA methylation, histone modifications affecting gene expression in disease

    Search first: ENCODE, Roadmap Epigenomics, MethBase, DiseaseMeth

  • Molecular Profiling (if available):
  • Transcriptomics/gene expression changes > Search first: GEO (Gene Expression Omnibus), ArrayExpress, GTEx, Human Cell Atlas, SRA
  • Proteomics findings > Search first: PRIDE, ProteomeXchange, Human Protein Atlas, STRING, BioGRID
  • Metabolomics signatures > Search first: MetaboLights, Metabolomics Workbench, HMDB, METLIN
  • Lipidomics alterations > Search first: LIPID MAPS, SwissLipids, LipidHome, Metabolomics Workbench
  • Genomic structural features > Search first: UCSC Genome Browser, Ensembl, NCBI, dbVar, DGV
  • Advanced Technologies (if applicable):
  • Single-cell analysis findings (cell-type specific mechanisms, cellular heterogeneity) > Search first: Human Cell Atlas, Single Cell Portal, GEO, CELLxGENE
  • Spatial transcriptomics findings > Search first: GEO, Spatial Research, Vizgen, 10x Genomics data
  • Multi-omics integration results > Search first: TCGA, ICGC, cBioPortal, LinkedOmics, PubMed
  • Functional genomics screens (CRISPR, RNAi) > Search first: DepMap, GenomeRNAi, PubMed, BioGRID ORCS

For each mechanism, describe: - The causal chain from initial trigger to clinical manifestation - Which mechanisms are upstream vs downstream - What cell types and biological processes are involved - Suggest GO terms for biological processes and CL terms for cell types

7. Anatomical Structures Affected

  • Organ Level:
  • Primary organs directly affected
  • Secondary organ involvement (complications, secondary effects)
  • Body systems involved (cardiovascular, nervous, digestive, respiratory, endocrine, etc.)

    Search first: Uberon, FMA (Foundational Model of Anatomy), OMIM, HPO, ICD-11, MeSH, SNOMED CT

  • Tissue and Cell Level:
  • Specific tissue types affected (epithelial, connective, muscle, nervous)
  • Specific cell populations targeted (with Cell Ontology terms)

    Search first: Uberon, Human Protein Atlas, Cell Ontology, Human Cell Atlas, CellMarker, PanglaoDB

  • Subcellular Level:
  • Cellular compartments involved (mitochondria, nucleus, ER, lysosomes) (with GO Cellular Component terms)

    Search first: Gene Ontology (Cellular Component), UniProt, Human Protein Atlas

  • Localization:
  • Specific anatomical sites (with UBERON terms) > Search first: FMA, Uberon, NeuroNames (for brain), SNOMED CT
  • Lateralization (unilateral, bilateral, asymmetric) > Search first: HPO, clinical literature, imaging databases

8. Temporal Development

  • Onset:
  • Typical age of onset (congenital, pediatric, adult, geriatric)
  • Onset pattern (acute, subacute, chronic, insidious)

    Search first: OMIM, Orphanet, HPO, PubMed

  • Progression:
  • Disease stages (early, intermediate, advanced, end-stage) > Search first: Cancer Staging Manual (AJCC), WHO classifications, PubMed
  • Progression rate (rapid, slow, variable)
  • Disease course pattern (episodic, relapsing-remitting, progressive, stable)
  • Disease duration (self-limited, chronic lifelong)

    Search first: Disease registries, longitudinal cohort databases, natural history studies, PubMed, Orphanet, OMIM

  • Patterns:
  • Remission patterns (spontaneous, treatment-induced) > Search first: Clinical trial databases, disease registries, PubMed
  • Critical periods (time windows of vulnerability or opportunity for intervention) > Search first: PubMed, developmental biology databases, clinical guidelines

9. Inheritance and Population

  • Epidemiology:
  • Prevalence (cases per 100,000 at given time)
  • Incidence (new cases per 100,000 per year)

    Search first: Orphanet, CDC, WHO, GBD (Global Burden of Disease), national registries, SEER, disease registries

  • For Genetic Etiology:
  • Inheritance pattern (AD, AR, X-linked, mitochondrial, multifactorial, polygenic) > Search first: OMIM, Orphanet, ClinVar, GTR (Genetic Testing Registry)
  • Penetrance (complete, incomplete, age-dependent) > Search first: ClinVar, OMIM, PubMed, ClinGen
  • Expressivity (variable, consistent) > Search first: OMIM, ClinVar, PubMed
  • Genetic anticipation (increasing severity in successive generations) > Search first: OMIM, PubMed (especially for repeat expansion disorders)
  • Germline mosaicism > Search first: ClinVar, OMIM, genetic counseling literature, PubMed
  • Founder effects (population-specific mutations) > Search first: gnomAD, population genetics databases, PubMed
  • Consanguinity role > Search first: OMIM, population studies, genetic counseling resources
  • Carrier frequency > Search first: gnomAD, carrier screening databases, GeneReviews, GTR
  • Population Demographics:
  • Affected populations (ethnic or demographic groups with higher prevalence) > Search first: gnomAD, 1000 Genomes, PAGE Study, PubMed, population registries
  • Geographic distribution (endemic areas, regional variation) > Search first: WHO, CDC, GBD, Orphanet, geographic epidemiology databases
  • Geographic distribution of specific variants
  • Sex ratio (male:female) > Search first: Disease registries, OMIM, PubMed, epidemiological databases
  • Age distribution of affected individuals > Search first: CDC, disease registries, SEER, Orphanet

10. Diagnostics

  • Clinical Tests:
  • Laboratory tests (blood, urine, tissue chemistry, specific enzyme assays) > Search first: LOINC, LabTests Online, PubMed
  • Biomarkers (proteins, metabolites, genetic markers, circulating biomarkers) > Search first: FDA Biomarker List, BEST (Biomarkers, EndpointS, and other Tools), PubMed
  • Imaging studies (X-ray, CT, MRI, PET, ultrasound) > Search first: RadLex, DICOM, Radiopaedia, imaging databases
  • Functional tests (pulmonary function, cardiac stress tests) > Search first: LOINC, clinical guidelines, PubMed
  • Electrophysiology (EEG, EMG, ECG, nerve conduction studies) > Search first: LOINC, clinical neurophysiology databases, PubMed
  • Biopsy findings (histopathology, immunohistochemistry) > Search first: SNOMED CT, College of American Pathologists resources, PubMed
  • Pathology findings (microscopic examination) > Search first: SNOMED CT, Digital Pathology databases, PubMed
  • Genetic Testing:

    Search first: GTR (Genetic Testing Registry), GeneReviews, ClinGen

  • Overview of recommended genetic testing approach
  • Whole genome sequencing (WGS) utility > Search first: GTR, ClinVar, GEL (Genomics England), gnomAD
  • Whole exome sequencing (WES) utility > Search first: GTR, ClinVar, OMIM, GeneMatcher
  • Gene panels (which panels, which genes) > Search first: GTR, ClinVar, laboratory-specific databases
  • Single gene testing > Search first: GTR, ClinVar, OMIM, GeneReviews
  • Chromosomal microarray (CMA) > Search first: DECIPHER, ClinVar, dbVar, ECARUCA
  • Karyotyping > Search first: Chromosome Abnormality Database, ClinVar, cytogenetics resources
  • FISH > Search first: ClinVar, cytogenetics databases, PubMed
  • Mitochondrial DNA testing > Search first: MITOMAP, MSeqDR, ClinVar, GTR
  • Repeat expansion testing > Search first: GTR, ClinVar, repeat expansion databases, PubMed
  • Omics-Based Diagnostics (if applicable):
  • RNA sequencing / transcriptomics > Search first: GEO, ArrayExpress, GTEx, RNA-seq databases
  • Proteomics > Search first: PRIDE, ProteomeXchange, FDA Biomarker database
  • Metabolomics > Search first: MetaboLights, Metabolomics Workbench, HMDB
  • Epigenomics > Search first: GEO, ENCODE, Roadmap Epigenomics, MethBase
  • Liquid biopsy > Search first: COSMIC, ClinVar, liquid biopsy databases, PubMed
  • Clinical Criteria:
  • Standardized diagnostic criteria (DSM, ICD, society guidelines) > Search first: DSM-5, ICD-11, clinical society guidelines, UpToDate
  • Differential diagnosis (other conditions to rule out, with distinguishing features) > Search first: DynaMed, UpToDate, clinical decision support systems
  • Screening:
  • Screening methods for asymptomatic individuals (newborn screening, carrier screening, cascade screening) > Search first: ACMG recommendations, CDC newborn screening, GTR

11. Outcome/Prognosis

  • Survival and Mortality:
  • Survival rate (5-year, 10-year, overall) > Search first: SEER, cancer registries, disease-specific registries, PubMed
  • Life expectancy (with and without treatment if applicable) > Search first: Orphanet, disease registries, actuarial databases, PubMed
  • Mortality rate > Search first: CDC, WHO, GBD, national mortality databases
  • Disease-specific mortality (deaths directly attributable to disease) > Search first: Disease registries, CDC Wonder, GBD, PubMed
  • Morbidity and Function:
  • Morbidity (disease-related disability and health impacts) > Search first: GBD, WHO, disability databases, PubMed
  • Disability outcomes (long-term functional impairments) > Search first: ICF (International Classification of Functioning), disability registries
  • Quality of life measures (EQ-5D, SF-36, PROMIS, disease-specific tools) > Search first: EQ-5D database, SF-36, PROMIS, PubMed
  • Disease Course:
  • Complications (secondary problems: infections, organ failure, etc.) > Search first: ICD codes, disease registries, clinical databases, PubMed
  • Recovery potential (likelihood and extent of recovery, with vs without treatment) > Search first: Natural history studies, rehabilitation databases, PubMed
  • Prediction:
  • Prognostic factors (age, disease severity, biomarkers, treatment response) > Search first: Prognostic models databases, clinical calculators, PubMed
  • Prognostic biomarkers (molecular markers predicting disease course) > Search first: FDA Biomarker database, PubMed, cancer prognostic databases

12. Treatment

  • Pharmacotherapy:
  • Pharmacological treatments (drug names, drug classes, mechanisms of action) > Search first: DrugBank, RxNorm, ATC classification, DailyMed, FDA databases
  • Pharmacogenomics (how genetic variants affect drug metabolism, efficacy, toxicity) > Search first: PharmGKB, CPIC (Clinical Pharmacogenetics), FDA Table of PGx Biomarkers
  • Advanced Therapeutics:
  • Gene therapy (viral vectors, CRISPR, gene replacement, gene editing) > Search first: ClinicalTrials.gov, FDA gene therapy database, ASGCT resources
  • Cell therapy (stem cell transplant, CAR-T, cellular therapeutics) > Search first: ClinicalTrials.gov, FDA cell therapy database, FACT standards
  • RNA-based therapies (ASOs, siRNA, mRNA therapies) > Search first: ClinicalTrials.gov, FDA approvals, PubMed
  • Targeted therapies (treatments directed at specific molecular targets) > Search first: My Cancer Genome, OncoKB, ClinicalTrials.gov, FDA approvals
  • Immunotherapies (checkpoint inhibitors, monoclonal antibodies) > Search first: Cancer Immunotherapy Database, FDA approvals, ClinicalTrials.gov
  • Surgical and Interventional:
  • Surgical interventions (types of surgery, timing, outcomes) > Search first: CPT codes, surgical registries, clinical guidelines, PubMed
  • Supportive and Rehabilitative:
  • Supportive care (symptom management, pain control, nutrition) > Search first: Clinical guidelines, Cochrane Library, PubMed
  • Rehabilitation (physical therapy, occupational therapy, speech therapy) > Search first: Rehabilitation medicine databases, clinical guidelines, PubMed
  • Experimental:
  • Experimental treatments in clinical trials (with NCT identifiers if available) > Search first: ClinicalTrials.gov, EU Clinical Trials Register, WHO ICTRP
  • Treatment Outcomes:
  • Treatment response rates > Search first: Clinical trial databases, FDA reviews, systematic reviews, PubMed
  • Side effects and adverse events > Search first: FDA Adverse Event Reporting System (FAERS), MedWatch, PubMed
  • Treatment Strategy:
  • Treatment algorithms (clinical pathways, decision trees) > Search first: Clinical practice guidelines, NCCN Guidelines, UpToDate
  • Combination therapies > Search first: ClinicalTrials.gov, treatment guidelines, PubMed
  • Personalized medicine approaches (genotype-guided treatment) > Search first: My Cancer Genome, CIViC, PharmGKB, precision medicine databases

For each treatment, suggest MAXO (Medical Action Ontology) terms where applicable.

13. Prevention

  • Prevention Levels:
  • Primary prevention (preventing disease occurrence: vaccination, risk factor modification) > Search first: CDC, WHO, USPSTF recommendations, Cochrane Library
  • Secondary prevention (early detection and treatment: screening programs, early intervention) > Search first: USPSTF, CDC screening guidelines, WHO
  • Tertiary prevention (preventing complications in those with disease) > Search first: Clinical guidelines, disease management protocols, PubMed
  • Immunization: Vaccine strategies (if applicable)

    Search first: CDC vaccine schedules, WHO immunization, FDA vaccine database

  • Screening and Early Detection:
  • Screening programs (population-based: newborn screening, cancer screening) > Search first: CDC screening programs, USPSTF, cancer screening databases
  • Genetic screening (carrier screening, preimplantation genetic diagnosis, prenatal testing) > Search first: ACMG recommendations, ACOG guidelines, GTR
  • Risk stratification (identifying high-risk individuals for targeted prevention) > Search first: Risk prediction models, clinical calculators, PubMed
  • Behavioral Interventions: Lifestyle modifications to reduce risk

    Search first: CDC, WHO, behavioral intervention databases, Cochrane Library

  • Counseling: Genetic counseling (risk assessment, family planning guidance)

    Search first: NSGC resources, ACMG guidelines, GeneReviews

  • Public Health:
  • Public health interventions (sanitation, vector control, health education) > Search first: CDC, WHO, public health databases, PubMed
  • Environmental interventions (reducing environmental risk factors) > Search first: EPA databases, WHO environmental health, PubMed
  • Prophylaxis: Preventive medications or procedures

    Search first: Clinical guidelines, FDA approvals, PubMed

14. Other Species / Natural Disease

  • Taxonomy: Species affected (with NCBI Taxon identifiers)

    Search first: NCBI Taxonomy

  • Breed: Specific breeds affected (with VBO identifiers if applicable)

    Search first: VBO (Vertebrate Breed Ontology)

  • Gene: Orthologous genes in other species (with NCBI Gene IDs)

    Search first: NCBI Gene

  • Natural Disease:
  • Naturally occurring disease in other species (companion animals, wildlife) > Search first: OMIA (Online Mendelian Inheritance in Animals), VetCompass, PubMed
  • Veterinary relevance and importance in animal health > Search first: OMIA, veterinary databases, PubMed
  • Comparative Biology:
  • Comparative pathology (similarities and differences across species) > Search first: OMIA, comparative pathology databases, PubMed
  • Evolutionary conservation of disease mechanisms > Search first: HomoloGene, OrthoMCL, Alliance of Genome Resources
  • Transmission (if applicable):
  • Zoonotic potential > Search first: CDC zoonotic diseases, WHO zoonoses, GIDEON
  • Cross-species susceptibility > Search first: NCBI Taxonomy, veterinary databases, PubMed

15. Model Organisms

  • Model Types:
  • Model organism type (mammalian, invertebrate, cellular, in vitro) > Search first: Alliance of Genome Resources, model organism databases
  • Specific model systems (mouse, rat, zebrafish, Drosophila, C. elegans, yeast, cell lines, organoids, iPSCs) > Search first: MGI, RGD, ZFIN, FlyBase, WormBase, SGD, ATCC, Cellosaurus
  • Induced models (drug treatment, surgical intervention, environmental manipulation) > Search first: MGI, model organism databases, PubMed
  • Genetic Models:
  • Types available (knockout, knock-in, transgenic, conditional, humanized) > Search first: MGI, IMPC, KOMP, EuMMCR, IMSR
  • Model Characteristics:
  • Phenotype recapitulation (how well model reproduces human disease features) > Search first: Model organism databases, comparative studies, PubMed
  • Model limitations (aspects of human disease not captured) > Search first: Model organism databases, PubMed, review articles
  • Applications:
  • Research applications (what aspects of disease can be studied) > Search first: Model organism databases, PubMed
  • Resources:
  • Model databases > Search first: MGI, RGD, ZFIN, FlyBase, WormBase, IMSR, EMMA, MMRRC

Citation Requirements

  • Cite primary literature (PMID preferred) for all mechanistic and clinical claims
  • Prioritize recent reviews and landmark papers
  • Include direct quotes from abstracts where possible to support key statements
  • Distinguish evidence source types: human clinical, model organism, in vitro, computational

Output Format

Structure your response as a comprehensive narrative organized by the sections above. For each section, provide: - Factual content with specific details (numbers, percentages, gene names, variant nomenclature) - Ontology term suggestions (HPO, GO, CL, UBERON, CHEBI, MAXO, MONDO) where applicable - Evidence citations with PMIDs - Direct quotes from abstracts to support key claims - Clear indication when information is not available or not applicable for this disease

This report will be used to populate a disease knowledge base entry with: - Pathophysiology descriptions with causal chains - Gene/protein annotations (HGNC, GO terms) - Phenotype associations (HP terms) with frequencies - Cell type involvement (CL terms) - Anatomical locations (UBERON terms) - Chemical entities (CHEBI terms) - Treatment annotations (MAXO terms) - Evidence items with PMIDs and exact abstract quotes - Epidemiology, prognosis, diagnostic, and prevention information - Animal model descriptions with phenotype recapitulation details

EDARADD‑Related Hypohidrotic Ectodermal Dysplasia (HED): Comprehensive Disease Characteristics Report (2026-04-25)

Executive summary

EDARADD‑related hypohidrotic ectodermal dysplasia is a rare, primarily autosomal form of HED caused by pathogenic variants in EDARADD, an intracellular adaptor in the EDA‑A1 → EDAR → EDARADD → TRAF6 → NF‑κB signaling axis required for ectodermal appendage development. Clinically it overlaps strongly with other HED genetic etiologies and is defined by the classic triad of hypohidrosis/anhidrosis, hypodontia/anodontia, and hypotrichosis, with additional skin, craniofacial, ocular, and respiratory sequelae reported across HED. Mechanistically, recent functional work demonstrates that specific EDARADD missense variants can act via dominant‑negative disruption of EDAR–EDARADD complex formation and TRAF6 binding, decreasing NF‑κB activation. (asano2021characterizationofedaradd pages 1-3, asano2021characterizationofedaradd pages 5-7)

1. Disease information

1.1 Concise overview (current understanding)

Hypohidrotic ectodermal dysplasia (HED) is an inherited developmental disorder affecting ectoderm‑derived structures, classically involving the triad of impaired sweating, abnormal/missing teeth, and sparse hair. (asano2021characterizationofedaradd pages 1-3, callea2022extendedoverviewof pages 2-4)

EDARADD‑related HED refers to autosomal forms attributable to pathogenic variants in EDARADD (EDAR‑associated death domain). In contemporary clinical genetics, EDARADD‑related HED is usually considered within the broader HED spectrum because phenotypes due to EDA, EDAR, and EDARADD defects are often clinically similar due to shared pathway disruption. (kablan2024novelhomozygousframeshift pages 1-2)

1.2 Key identifiers (from accessible primary/review literature)

A compact identifier table is provided below.

Item Value Source / date / URL Evidence citation IDs
Disease name EDARADD-related hypohidrotic ectodermal dysplasia Kablan & Tasdelen, Italian Journal of Pediatrics, 2024-06, https://doi.org/10.1186/s13052-024-01681-2 (kablan2024novelhomozygousframeshift pages 1-2)
Preferred broader disease term Hypohidrotic ectodermal dysplasia (HED); most common ED subtype Martínez-Romero et al., Orphanet Journal of Rare Diseases, 2019-12, https://doi.org/10.1186/s13023-019-1251-x (martinezromero2019edaedaredaradd pages 1-2)
Key synonyms / nomenclature Autosomal recessive HED; autosomal dominant HED; anhidrotic/hypohidrotic ectodermal dysplasia; hypohidrotic/hair/tooth type; hypohidrotic/hair/nail type Callea et al., Children, 2022-09, https://doi.org/10.3390/children9091357; Higashino et al., Expert Opinion on Orphan Drugs, 2017-11, http://dx.doi.org/10.1080/21678707.2017.1405806 (callea2022extendedoverviewof pages 2-4, higashino2017advancesinthe pages 1-7, higashino2017advancesinthe pages 12-16)
OMIM disease IDs mentioned in sources HED/EDA1 MIM#305100 (XLHED); AD HED MIM#129490; AR HED MIM#224900; EDARADD-related AR HED MIM#614940 Callea et al., Children, 2022-09, https://doi.org/10.3390/children9091357; Higashino et al., Expert Opinion on Orphan Drugs, 2017-11, http://dx.doi.org/10.1080/21678707.2017.1405806 (callea2022extendedoverviewof pages 2-4, higashino2017advancesinthe pages 1-7)
Gene EDARADD (EDAR-associated death domain) Martínez-Romero et al., Orphanet Journal of Rare Diseases, 2019-12, https://doi.org/10.1186/s13023-019-1251-x (martinezromero2019edaedaredaradd pages 1-2)
Gene OMIM ID EDARADD MIM*606603 Callea et al., Children, 2022-09, https://doi.org/10.3390/children9091357; Martínez-Romero et al., Orphanet Journal of Rare Diseases, 2019-12, https://doi.org/10.1186/s13023-019-1251-x (callea2022extendedoverviewof pages 2-4, martinezromero2019edaedaredaradd pages 1-2)
Chromosomal location 1q42-q43 / 1q42.3 Callea et al., Children, 2022-09, https://doi.org/10.3390/children9091357; Martínez-Romero et al., Orphanet Journal of Rare Diseases, 2019-12, https://doi.org/10.1186/s13023-019-1251-x (callea2022extendedoverviewof pages 2-4, martinezromero2019edaedaredaradd pages 1-2)
Core clinical triad used in nomenclature Hypodontia/anodontia, hypotrichosis, hypohidrosis (reduced or absent sweating) Asano et al., Journal of Dermatology, 2021, https://doi.org/10.1111/1346-8138.16044; Callea et al., Children, 2022-09, https://doi.org/10.3390/children9091357 (asano2021characterizationofedaradd pages 1-3, callea2022extendedoverviewof pages 2-4)
Epidemiology estimate (overall HED) At least 1 in 17,000 people worldwide Callea et al., Children, 2022-09, https://doi.org/10.3390/children9091357 (callea2022extendedoverviewof pages 2-4)
Epidemiology estimate (XLHED) 1/50,000–100,000 males Martínez-Romero et al., Orphanet Journal of Rare Diseases, 2019-12, https://doi.org/10.1186/s13023-019-1251-x (martinezromero2019edaedaredaradd pages 1-2)
Additional prevalence estimate reported in review literature ~7 per 10,000 live births (reported in one review; likely refers broadly to HED/ED literature and should be interpreted cautiously against rarer estimates above) Higashino et al., Expert Opinion on Orphan Drugs, 2017-11, http://dx.doi.org/10.1080/21678707.2017.1405806 (higashino2017advancesinthe pages 1-7)

Table: This table summarizes the core identifiers, synonyms, OMIM entries, gene details, chromosomal locus, and commonly cited epidemiology figures relevant to EDARADD-related hypohidrotic ectodermal dysplasia. It is useful as a compact nomenclature and disease-mapping reference for downstream knowledge-base curation.

Notes on identifiers not retrieved with tools in this run: MONDO and MeSH identifiers were not directly retrievable using the available tool set (no direct OMIM/Orphanet/MeSH ingestion tools were available in this session). Therefore, this report cites OMIM/MIM numbers as stated in the peer‑reviewed sources above. (callea2022extendedoverviewof pages 2-4, higashino2017advancesinthe pages 1-7)

1.3 Common synonyms / alternative names

  • Hypohidrotic ectodermal dysplasia (HED); anhidrotic ectodermal dysplasia (AED) (frequently used as overlapping terminology) (kablan2024novelhomozygousframeshift pages 1-2)
  • Autosomal recessive HED; autosomal dominant HED (depending on variant mechanism) (asano2021characterizationofedaradd pages 1-3)
  • “Hypohidrotic/hair/tooth type” (terminology used in some OMIM‑linked descriptions cited in reviews) (callea2022extendedoverviewof pages 2-4)

1.4 Evidence source type

The disease characterization in this report is derived from: * Aggregated disease-level resources embedded in peer‑reviewed reviews (e.g., epidemiology and phenotype summaries) (callea2022extendedoverviewof pages 2-4, higashino2017advancesinthe pages 1-7) * Human clinical case reports/series with genotype–phenotype data (kablan2024novelhomozygousframeshift pages 1-2) * Human cohort molecular studies (diagnostic yield statistics and genetic profiling) (martinezromero2019edaedaredaradd pages 1-2, kim2024geneticprofilingand pages 1-2) * In vitro functional studies of EDARADD variants (asano2021characterizationofedaradd pages 1-3, asano2021characterizationofedaradd pages 5-7)

2. Etiology

2.1 Disease causal factors

Primary cause: Germline pathogenic variants in EDARADD disrupting ectodysplasin pathway signaling required for ectodermal appendage development. EDARADD is described as an adaptor protein of EDAR; after EDA‑A1 binds EDAR, EDAR and EDARADD interact via death domains, and EDARADD binds TRAF6 leading to downstream activation of NF‑κB. (asano2021characterizationofedaradd pages 1-3)

Verbatim abstract support for triad and autosomal genetic causes: * Asano et al. 2021: “Hypohidrotic ectodermal dysplasia (HED) is a genetic disorder characterized by hypohidrosis, hypodontia, and hypotrichosis. Autosomal forms of the disease are caused by mutations in either EDAR or EDARADD.” (asano2021characterizationofedaradd pages 1-3)

2.2 Risk factors

Genetic risk factors: * Having a pathogenic EDARADD variant consistent with autosomal inheritance (recessive or dominant depending on variant). Dominantly inherited EDARADD variants have been functionally demonstrated to reduce NF‑κB signaling in a dominant‑negative manner. (asano2021characterizationofedaradd pages 1-3, asano2021characterizationofedaradd pages 5-7) * Consanguinity can increase risk for autosomal recessive EDARADD‑related HED; a 2024 report describes two affected brothers born to consanguineous parents with a homozygous frameshift EDARADD variant. (kablan2024novelhomozygousframeshift pages 1-2)

Environmental risk factors: Not established as causal; disease is genetic/developmental. However, clinical complications (e.g., hyperthermia) are sensitive to ambient temperature and infection‑related fever episodes. (kablan2024novelhomozygousframeshift pages 1-2, callea2022extendedoverviewof pages 2-4)

2.3 Protective factors

No validated genetic “protective variants” or environmental protective factors specific to EDARADD‑related HED were identified in the retrieved evidence.

2.4 Gene–environment interactions

No direct gene–environment interaction studies specific to EDARADD‑related HED were identified in the retrieved evidence. Downstream, inability to sweat (genetic) interacts with heat exposure (environment) to increase risk for hyperthermia. (callea2022extendedoverviewof pages 2-4)

3. Phenotypes

3.1 Core phenotypes (symptoms/signs) with suggested HPO terms

The classic HED triad is consistently emphasized: * Hypohidrosis/anhidrosis (reduced/absent sweating) (asano2021characterizationofedaradd pages 1-3, callea2022extendedoverviewof pages 2-4) * Suggested HPO: HP:0000972 (Anhidrosis) / HP:0000966 (Hypohidrosis) * Hypodontia/anodontia (missing teeth) and/or abnormal tooth shape (kablan2024novelhomozygousframeshift pages 1-2, callea2022extendedoverviewof pages 2-4) * Suggested HPO: HP:0000668 (Hypodontia), HP:0000674 (Anodontia), HP:0000692 (Abnormality of tooth shape), HP:0000689 (Dental crowding) where present * Hypotrichosis / sparse hair (kablan2024novelhomozygousframeshift pages 1-2, callea2022extendedoverviewof pages 2-4) * Suggested HPO: HP:0001006 (Hypotrichosis), HP:0002209 (Sparse scalp hair)

Additional manifestations described in an EDARADD case report include dry skin and craniofacial features: * Dry skin (kablan2024novelhomozygousframeshift pages 1-2) * Suggested HPO: HP:0000958 (Dry skin) * Facial dysmorphism (mildly prominent forehead; periorbital wrinkles; sparse eyebrows/eyelashes) (kablan2024novelhomozygousframeshift pages 1-2) * Suggested HPO: HP:0000337 (Broad forehead) / HP:0011220 (Prominent forehead), HP:0000534 (Sparse eyelashes), HP:0002223 (Sparse eyebrow)

3.2 Phenotype characteristics

  • Age of onset: Congenital/early childhood presentation is typical; in the EDARADD case report, features were present in early childhood (ages 2 and 5). (kablan2024novelhomozygousframeshift pages 1-2)
  • Severity/variability: Variable expressivity is implied; in siblings with the same homozygous EDARADD frameshift, the younger sibling had “less severe” features. (kablan2024novelhomozygousframeshift pages 1-2)

3.3 Quality of life impact

HED is associated with clinically significant morbidity from thermoregulation issues and downstream complications. A review notes that affected individuals are “at risk for life-threatening hyperthermia” and may experience “chronic developmental, respiratory, cutaneous, ocular, and psychosocial disorders.” (callea2022extendedoverviewof pages 2-4)

4. Genetic / molecular information

4.1 Causal gene

  • EDARADD (EDAR‑associated death domain), OMIM/MIM606603, chromosomal locus 1q42‑q43 / 1q42.3* as reported in review and cohort literature. (callea2022extendedoverviewof pages 2-4, martinezromero2019edaedaredaradd pages 1-2)

4.2 Pathogenic variants and functional consequences

4.2.1 Dominant‑negative EDARADD missense variants (functional study)

Asano et al. (2021; J Dermatol; DOI 10.1111/1346-8138.16044) performed in vitro characterization of three dominantly inherited and one recessively inherited EDARADD missense variants:

Verbatim abstract quotes: * “we performed detailed in vitro analyses in order to characterize three dominantly inherited missense mutations, p.D120Y, p.L122R, and p.D123N, and one recessively inherited missense mutation, p.E152K, in the EDARADD gene.” (asano2021characterizationofedaradd pages 1-3) * “Nuclear factor (NF)-κB reporter assays demonstrated that all the mutant EDARADD showed reduction in activation of NF-κB.” (asano2021characterizationofedaradd pages 1-3) * “Importantly, p.D120Y-, p.L122R-, and p.D123N-mutant EDARADD slightly reduced the NF-κB activity induced by wild-type EDARADD in a dominant negative manner.” (asano2021characterizationofedaradd pages 1-3) * “Finally, we found that p.D120Y-, p.L122R-, and p.D123N-mutant EDARADD completely lost the ability to bind with TRAF6, while p.E152K-mutant EDARADD showed a mild reduction in the affinity.” (asano2021characterizationofedaradd pages 1-3)

Mechanistic details from results/discussion text: * Dominant mutants reduced EDAR–WT‑EDARADD interaction: the amount of EDAR intracellular domain co‑immunoprecipitated with WT EDARADD was “markedly reduced” when p.D120Y/p.L122R/p.D123N were overexpressed, supporting interference with EDAR–EDARADD complex formation. (asano2021characterizationofedaradd pages 5-7) * TRAF6 binding: p.D120Y/p.L122R/p.D123N “completely failed to bind with TRAF6,” while p.E152K retained binding with only a “slight” reduction (~20% as reported in text). (asano2021characterizationofedaradd pages 5-7)

Interpretation (current expert consensus based on evidence above): * p.D120Y, p.L122R, p.D123N behave as dominant‑negative variants that disrupt the EDAR signalosome and abolish TRAF6 recruitment, resulting in strongly decreased NF‑κB signaling. (asano2021characterizationofedaradd pages 1-3, asano2021characterizationofedaradd pages 5-7) * p.E152K appears hypomorphic/partial loss‑of‑function in the same assays. (asano2021characterizationofedaradd pages 1-3, asano2021characterizationofedaradd pages 5-7)

4.2.2 Recessive truncating variant (human case report)

Kablan & Tasdelen (2024; Italian Journal of Pediatrics; DOI 10.1186/s13052-024-01681-2) reported a novel homozygous frameshift: * EDARADD c.322_323insCGGGC, p.(Arg108ProfsTer7) identified in two affected brothers. (kablan2024novelhomozygousframeshift pages 1-2)

Verbatim abstract quote: * “targeted next-generation sequencing analysis yielded the novel homozygous insertion variant c.322_323insCGGGC p.(Arg108ProfsTer7) in EDARADD.” (kablan2024novelhomozygousframeshift pages 1-2)

The authors explicitly link the pathway to NF‑κB: * “Proper function of these three genes and their products is crucial for downstream activation of the nuclear factor (NF‑κB) … involved in ectodermal development.” (kablan2024novelhomozygousframeshift pages 1-2)

4.3 Modifier genes

No EDARADD‑specific modifier gene evidence was identified in the retrieved texts. Broader ED genetics includes other genes that can produce ED/HED‑like phenotypes (e.g., TRAF6, NF‑κB pathway genes), but modifier roles for EDARADD phenotypic severity were not established in the available evidence. (kim2024geneticprofilingand pages 2-4)

4.4 Epigenetics

No EDARADD‑specific epigenetic mechanisms were identified in the retrieved evidence.

4.5 Chromosomal abnormalities

No EDARADD‑related structural chromosomal abnormalities were identified in the retrieved evidence.

5. Environmental information

No specific environmental toxins/lifestyle/infectious triggers as causal factors were identified; HED is primarily genetic. Clinically, fever/infections and heat exposure are important exacerbating contexts for hyperthermia risk due to hypohidrosis. (kablan2024novelhomozygousframeshift pages 1-2, callea2022extendedoverviewof pages 2-4)

6. Mechanism / pathophysiology

6.1 Molecular pathway (EDA‑EDAR‑EDARADD‑TRAF6‑NF‑κB)

As described in Asano et al. 2021: * “EDARADD is an adaptor protein of EDAR… EDARADD also binds to key proteins for the signal transduction, such as… TRAF6, which finally leads to the downstream activation of… NF‑κB.” (asano2021characterizationofedaradd pages 1-3)

Causal chain to phenotype (integrated): 1. Upstream trigger: Germline EDARADD pathogenic variant (loss‑of‑function or dominant negative). (kablan2024novelhomozygousframeshift pages 1-2, asano2021characterizationofedaradd pages 1-3) 2. Signalosome defect: Impaired EDAR–EDARADD interactions and/or impaired EDARADD–TRAF6 binding. (asano2021characterizationofedaradd pages 5-7) 3. Pathway output: Reduced downstream NF‑κB activation (reporter assay reductions; abolished TRAF6 binding for dominant variants). (asano2021characterizationofedaradd pages 1-3, asano2021characterizationofedaradd pages 5-7) 4. Developmental consequence: NF‑κB‑dependent transcriptional programs for ectodermal appendage development are disrupted, resulting in hypoplasia/absence of sweat glands, abnormal dentition, and hypotrichosis. (asano2021characterizationofedaradd pages 1-3, callea2022extendedoverviewof pages 2-4)

6.2 Suggested ontology terms

GO Biological Process (suggestions): * NF‑κB signaling (e.g., “I‑kappaB kinase/NF‑kappaB signaling”) * Ectodermal appendage development (hair follicle development; tooth development; sweat gland development)

Cell types (CL suggestions): * Epidermal keratinocyte * Epithelial cell of eccrine sweat gland * Odontogenic epithelial cell / dental epithelium

Because ontology identifiers were not retrieved by tools in this session, the above are suggestions for curation rather than evidence‑linked claims.

7. Anatomical structures affected

HED affects ectoderm‑derived structures. In EDARADD‑related disease, the most prominently affected include: * Hair follicles / scalp hair (hypotrichosis) (kablan2024novelhomozygousframeshift pages 1-2, callea2022extendedoverviewof pages 2-4) * Teeth / dentition (hypodontia; conical teeth; spacing) (kablan2024novelhomozygousframeshift pages 1-2, callea2022extendedoverviewof pages 2-4) * Eccrine sweat glands (hypohidrosis/anhidrosis) (callea2022extendedoverviewof pages 2-4)

Suggested UBERON terms (for curation): * Eccrine sweat gland; hair follicle; tooth; epidermis.

8. Temporal development

  • Onset: Congenital/developmental; recognized in infancy/childhood due to tooth eruption abnormalities, sparse hair, and heat intolerance/anhidrosis. (kablan2024novelhomozygousframeshift pages 1-2, callea2022extendedoverviewof pages 2-4)
  • Course: Lifelong developmental disorder; complications (hyperthermia risk; ocular/respiratory/skin issues) persist and require ongoing management. (callea2022extendedoverviewof pages 2-4)

9. Inheritance and population

9.1 Inheritance

  • EDARADD‑related HED can be autosomal recessive (e.g., homozygous frameshift c.322_323insCGGGC) (kablan2024novelhomozygousframeshift pages 1-2)
  • Specific EDARADD missense variants can be autosomal dominant via dominant‑negative mechanisms (p.D120Y/p.L122R/p.D123N). (asano2021characterizationofedaradd pages 1-3)

9.2 Epidemiology (recent/authoritative statistics)

Reported estimates vary by source and by whether the estimate refers to all HED, XLHED specifically, or broader ED.

  • HED affects “at least 1 in 17,000 people worldwide” (review). (callea2022extendedoverviewof pages 2-4)
  • XLHED incidence: “1/50,000–100,000 males” (Spanish cohort background statement). (martinezromero2019edaedaredaradd pages 1-2)
  • One review reports HED “occurs in ~7 per 10,000 live births” (interpretation caution: this may reflect broader ED ascertainment or mixed definitions across sources). (higashino2017advancesinthe pages 1-7)

Population-level ED diagnostic yield (implementation statistic): In a 2024 Korean ED cohort (n=27), 74.1% (20/27) were mutation-positive; among positives, EDA/EDAR comprised 80% (16/20). The authors also report WES virtual panel yield 56.5% (13/23), and expanded OMIM analysis adding 4 more diagnoses (~17% increase). (kim2024geneticprofilingand pages 1-2)

10. Diagnostics

10.1 Clinical diagnosis

Clinical suspicion is typically triggered by the triad of hair/sweating/dental anomalies. (callea2022extendedoverviewof pages 2-4)

10.2 Genetic testing (real-world implementation)

Testing approaches supported by 2024 evidence: * For “classical symptoms,” targeted sequencing of core genes (e.g., EDA/EDAR; in broader practice this often includes EDARADD and WNT10A panels) can be prioritized; when classic features are absent or phenotype is atypical, WES can improve yield. (kim2024geneticprofilingand pages 1-2, kim2024geneticprofilingand pages 2-4)

Verbatim abstract quote (Kim et al. 2024): * “When conducting molecular diagnostics for ED, opting for targeted sequencing of EDA/EDAR mutations is advisable for cases with classical symptoms, while WES is deemed an effective strategy for cases in which these symptoms are absent.” (kim2024geneticprofilingand pages 1-2)

10.3 Prenatal diagnosis (expert discussion)

A review describes ultrasound assessment of tooth germs/maxilla/mandible in at‑risk fetuses as a prenatal diagnostic tool in families with ED history. (callea2022extendedoverviewof pages 2-4)

10.4 Differential diagnosis

Other ED/HED‑like disorders arise from mutations in EDA, EDAR, WNT10A and additional ED genes (including NF‑κB pathway–related genes), which can overlap clinically. (higashino2017advancesinthe pages 1-7, kim2024geneticprofilingand pages 2-4)

11. Outcome / prognosis

HED can involve substantial morbidity. A review notes risk for “life‑threatening hyperthermia” and chronic multi‑system burdens (respiratory, cutaneous, ocular, psychosocial). (callea2022extendedoverviewof pages 2-4)

Specific survival/life‑expectancy statistics for EDARADD‑related HED were not identified in the retrieved evidence.

12. Treatment

12.1 Standard of care (current applications)

For HED generally, management is largely supportive and preventive, focusing on avoiding/mitigating hyperthermia and addressing dental/dermatologic/ocular complications. (higashino2017advancesinthe pages 1-7)

Suggested MAXO terms (for curation): * Cooling therapy / thermoregulation support * Dental prosthodontic rehabilitation * Artificial tears / ocular surface lubrication

12.2 Targeted/experimental therapies (latest research and real-world implementations)

Although EDARADD‑related disease itself does not yet have an EDARADD‑specific molecular therapy, targeted replacement therapy has advanced for XLHED (EDA mutations) and is mechanistically relevant as pathway restoration.

12.2.1 Postnatal EDA‑A1 replacement protein (EDI200) — clinical trial

ClinicalTrials.gov NCT01775462 (Edimer Pharmaceuticals), Phase 2, male neonates with genetically confirmed XLHED: * Dosing initiated “between day‑of‑life 2 and 14,” 2 doses/week for 5 total doses; cohorts at 3 mg/kg/dose and 10 mg/kg/dose. (NCT01775462 chunk 1)

12.2.2 Prenatal intra‑amniotic EDA replacement — clinical trial and prior compassionate-use evidence

A 2022 review summarizes intra‑amniotic recombinant EDA (Fc‑EDA) administration in three pregnancies (26 weeks; and for twins, 26 and 31 weeks), reporting normal sweating and absence of XLHED symptoms at 14 and 22 months follow‑up. (callea2022extendedoverviewof pages 2-4)

ClinicalTrials.gov NCT04980638 (EDELIFE) — prenatal ER004: * Phase 2, open‑label, multicenter trial of intra‑amniotic ER004, described as “a first‑in‑class signaling protein replacement molecule designed for specific, high affinity binding to the endogenous EDA1 receptor (EDAR).” (NCT04980638 chunk 1) * Dosing: “Intra‑amniotic route 100 mg/kg of estimated fetal weight per injection. 3 injections, approximately 3 weeks apart starting from gestational week 26.” (NCT04980638 chunk 1) * Primary endpoint includes pilocarpine‑induced sweat volume at 6 months. (NCT04980638 chunk 1)

Relevance to EDARADD: EDARADD lies downstream of EDAR; thus, EDARADD loss‑of‑function would not be expected to be corrected by EDA ligand replacement, whereas EDARADD dominant‑negative or partial function could hypothetically influence pathway responsiveness. No EDARADD‑targeted clinical trials were identified in the retrieved ClinicalTrials.gov evidence.

13. Prevention

Primary prevention is not currently feasible for a Mendelian developmental disorder; however, genetic counseling, carrier testing, and prenatal/preimplantation genetic diagnosis are key preventive strategies for at‑risk families. Reviews highlight that identification of causative genes enables “DNA‑based prenatal diagnosis.” (higashino2017advancesinthe pages 1-7)

Secondary/tertiary prevention includes anticipatory guidance to prevent hyperthermia and prompt management of complications. (higashino2017advancesinthe pages 1-7, callea2022extendedoverviewof pages 2-4)

14. Other species / natural disease

No EDARADD‑specific natural disease in non‑human species was retrieved in the evidence available for citation in this run.

15. Model organisms

No EDARADD‑specific model organism papers were available for citation within the collected evidence set in this run (despite known existence in the broader literature). As such, this section cannot be completed with citable primary sources here.

Key references (with publication dates and URLs)

  • Kablan A, Tasdelen E. 2024-06. Italian Journal of Pediatrics. “Novel homozygous frameshift insertion variant… EDARADD…” https://doi.org/10.1186/s13052-024-01681-2 (kablan2024novelhomozygousframeshift pages 1-2)
  • Asano N, et al. 2021 (accepted 2021-06-08). The Journal of Dermatology. “Characterization of EDARADD gene mutations…” https://doi.org/10.1111/1346-8138.16044 (asano2021characterizationofedaradd pages 1-3, asano2021characterizationofedaradd pages 5-7)
  • Kim MJ, et al. 2024-09. Orphanet Journal of Rare Diseases. “Genetic profiling and diagnostic strategies…” https://doi.org/10.1186/s13023-024-03331-6 (kim2024geneticprofilingand pages 1-2)
  • Martínez‑Romero MC, et al. 2019-12. Orphanet Journal of Rare Diseases. “EDA, EDAR, EDARADD and WNT10A…” https://doi.org/10.1186/s13023-019-1251-x (martinezromero2019edaedaredaradd pages 1-2)
  • Callea M, et al. 2022-09. Children. “Extended overview of ocular phenotype…” https://doi.org/10.3390/children9091357 (callea2022extendedoverviewof pages 2-4)
  • ClinicalTrials.gov. NCT01775462 (posted 2013-01-25; last update posted 2016-01-20). EDI200 neonate Phase 2. (NCT01775462 chunk 1)
  • ClinicalTrials.gov. NCT04980638 (first posted 2021-07-28; last update posted 2025-04-30). EDELIFE ER004 prenatal Phase 2. (NCT04980638 chunk 1)

References

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  10. (NCT01775462 chunk 1): Phase 2 Study to Evaluate Safety, Pharmacokinetics, Immunogenicity and Pharmacodynamics/Efficacy of EDI200 in Male Infants With X-Linked Hypohidrotic Ectodermal Dysplasia (XLHED). Edimer Pharmaceuticals. 2013. ClinicalTrials.gov Identifier: NCT01775462

  11. (NCT04980638 chunk 1): Intraamniotic Administrations of ER004 to Male Subjects With X-linked Hypohidrotic Ectodermal Dysplasia. EspeRare Foundation. 2022. ClinicalTrials.gov Identifier: NCT04980638