Sturge-Weber Syndrome

Genetic MONDO:0008501 Pathograph 14 Show in embeddings browser Epilepsy Neurological Disease

Sturge-Weber syndrome (SWS) is a sporadic neurocutaneous disorder caused by a postzygotic (somatic mosaic) activating mutation in GNAQ - most often the p.Arg183Gln variant - arising in progenitor cells and producing constitutive Gq signaling. The mosaic distribution yields the classic triad: a facial capillary malformation (port-wine birthmark, typically in the ophthalmic trigeminal territory), a leptomeningeal capillary-venous malformation (leptomeningeal angioma) overlying the brain, and ocular involvement (glaucoma). The leptomeningeal malformation impairs cortical venous drainage, causing chronic hypoperfusion, progressive cortical injury with the characteristic gyriform ("tram-track") calcification and atrophy, and early-onset, often drug-resistant seizures, together with stroke-like episodes, hemiparesis, and variable cognitive impairment.

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1
Mappings
12
Pathophys.
8
Phenotypes
3
Gaps
14
Pathograph
2
Genes
6
Medical Actions
1
Trials
1
Deep Research
🔗

Mappings

MONDO
MONDO:0008501 Sturge-Weber syndrome
skos:exactMatch MONDO
MONDO:0008501 is the Sturge-Weber syndrome concept.
?

Discussions and Knowledge Gaps

3
The same GNAQ p.Arg183Gln mutation produces outcomes ranging from an isolated facial port-wine stain to full Sturge-Weber syndrome with leptomeningeal and ocular involvement, depending on when and where in fetal development the mutation arises. What developmental window and progenitor lineage must be hit to produce leptomeningeal involvement, and can this be used to predict which infants with a high-risk (V1) port-wine stain will develop brain disease?
KNOWLEDGE GAP OPEN sws-mutation-timing-phenotype-extent
Attached to
pathophysiology#Somatic GNAQ Activating Mutation
Prognostic counseling and the case for presymptomatic intervention both hinge on knowing which port-wine-stain infants carry occult leptomeningeal disease. The developmental-timing model is well supported conceptually but has not been resolved to a specific lineage/timing map, and mutant-allele fraction in accessible tissue does not straightforwardly predict CNS involvement.
Proposed experiments
Lineage and timing map of GNAQ-mutant clones
sws-timing-lineage-tracing
Use single-cell and spatial sequencing of skin, brain, and eye tissue from Sturge-Weber and isolated-port-wine-stain cases (plus inducible mosaic animal models) to map the developmental timing and progenitor lineage of GNAQ-mutant clones against the extent of malformation.
Readouts
Mutant-allele fraction by tissue and cell type
pathophysiology#Somatic GNAQ Activating Mutation
Clonal lineage and timing reconstruction
pathophysiology#Somatic GNAQ Activating Mutation
Correlation of mutant clones with leptomeningeal involvement on imaging
pathophysiology#Leptomeningeal Capillary-Venous Malformation
Would support
pathophysiology#Leptomeningeal Capillary-Venous Malformation pathophysiology#Somatic GNAQ Activating Mutation
Early seizure onset and drug-resistant seizures are associated with worse cognitive outcome in Sturge-Weber syndrome. Does presymptomatic treatment (antiseizure medication and/or low-dose aspirin started before the first seizure in high-risk infants) reduce seizure burden and protect neurological and cognitive outcome, or does it merely delay onset?
KNOWLEDGE GAP OPEN sws-presymptomatic-treatment-neuro-outcome
Attached to
pathophysiology#Neurological Deficits
Cohort data link early, poorly controlled seizures to more severe cognitive impairment, and seizures can further worsen cortical perfusion in a vicious cycle. If presymptomatic treatment interrupts that cycle, the risk/benefit balance of treating clinically silent infants shifts, but this has not been established in a controlled prospective study.
Proposed experiments
Presymptomatic treatment trial in high-risk infants
sws-presymptomatic-rct
Prospective controlled trial in infants with a high-risk V1 port-wine stain and imaging/EEG evidence of leptomeningeal involvement, randomizing to presymptomatic antiseizure medication and/or low-dose aspirin versus treatment at first seizure, with long-term neurodevelopmental follow-up.
Readouts
Age at first seizure and seizure control
pathophysiology#Seizures
Neurodevelopmental and cognitive scores
pathophysiology#Neurological Deficits
Stroke-like episode frequency
pathophysiology#Neurological Deficits
Decision criterion
A significant improvement in cognitive outcome without prohibitive treatment harm would support presymptomatic treatment.
Would support
pathophysiology#Neurological Deficits pathophysiology#Seizures
Show evidence (1 reference)
PMID:22832777 SUPPORT Human Clinical
"An early age at seizure onset and those with drug-resistant seizures had more severe degree of mental subnormality"
Associates early-onset and drug-resistant seizures with worse cognitive outcome, motivating the presymptomatic-treatment question.
Sturge-Weber syndrome is driven by constitutive Gq signaling with downstream activation of pathways including MEK/ERK and mTOR. Can pharmacological inhibition of this signaling axis (e.g., MEK or mTOR inhibition) modify the vascular malformation or its neurological consequences, and at what developmental stage would such therapy need to act to be beneficial?
KNOWLEDGE GAP OPEN sws-gnaq-targeted-therapy
Attached to
pathophysiology#Constitutive Gq Signaling and Dysregulated Vascular Development
Identification of the GNAQ driver makes the pathway a rational drug target, but the malformation is largely structural and established before diagnosis; it is unknown whether downstream inhibition can remodel existing lesions or only limit progression, and whether CNS delivery and mosaic target engagement are achievable.
Proposed experiments
Pathway-inhibition test in GNAQ-mutant models
sws-pathway-inhibition-model
Test MEK and mTOR pathway inhibitors in GNAQ p.Arg183Gln endothelial and mosaic animal models, and in patient-derived organoids, for effects on aberrant vascular phenotype and downstream signaling, with staged dosing to probe the developmental window of efficacy.
Readouts
Vascular malformation phenotype and stability
pathophysiology#Leptomeningeal Capillary-Venous Malformation
Downstream ERK and mTOR pathway activity
pathophysiology#Constitutive Gq Signaling and Dysregulated Vascular Development
Endothelial proliferation and survival
pathophysiology#Constitutive Gq Signaling and Dysregulated Vascular Development
Would support
pathophysiology#Constitutive Gq Signaling and Dysregulated Vascular Development
⚙

Pathophysiology

12
Somatic GNAQ Activating Mutation
A postzygotic activating mutation in GNAQ (most often p.Arg183Gln) arises in a progenitor cell, producing a mosaic population of cells with constitutively active Gq alpha signaling. The timing and location of the mutation determine the distribution of the vascular malformations. This node captures the single concept of the initiating somatic mosaic lesion.
GNAQ hgnc:4390
Downstream
Constitutive Gq Signaling and Dysregulated Vascular Development The activating variant drives constitutive Gq-alpha signaling in the mosaic cells.
Show evidence (1 reference)
PMID:23656586 SUPPORT Human Clinical
"in samples of affected tissue from 88% of the participants"
Whole-genome sequencing identified the somatic GNAQ p.Arg183Gln activating mutation in affected tissue from 88% (23 of 26) of Sturge-Weber patients, establishing it as the initiating somatic lesion.
Constitutive Gq Signaling and Dysregulated Vascular Development
GNAQ encodes the Gq alpha subunit; the activating variant causes constitutive downstream signaling that dysregulates vascular development and endothelial behavior. This node captures the single concept of the aberrant signaling state.
Endothelial cell CL:0000115
Downstream
PLC-beta3-PKC-NF-kB Signaling Activation Constitutively active Gq alpha drives PLC-beta3 signaling.
RAS-MAPK/ERK Pathway Activation Mutant Gq alpha modestly increases ERK/MAPK signaling.
PI3K-AKT-mTOR Pathway Activation Downstream signaling engages the PI3K-AKT-mTOR axis.
PLC-beta3-PKC-NF-kB Signaling Activation
In endothelial cells, GNAQ R183Q establishes constitutively active phospholipase C-beta3 (PLC-beta3) signaling, engaging PKC, calcium/ calcineurin, and NF-kB and producing a proangiogenic, proinflammatory state. This node captures the single concept of the PLC-beta3 signaling arm.
Endothelial cell CL:0000115
Phospholipase C-activating GPCR signaling pathway GO:0007200 ↑ INCREASED
Downstream
ANGPT2-TIE2 Angiopoietin Signaling PLC-beta3 signaling increases ANGPT2 (angiopoietin-2).
Show evidence (1 reference)
PMID:34670408 SUPPORT In Vitro
"constitutively active PLCβ3 signaling that leads to increased ANGPT2 and a proangiogenic, proinflammatory phenotype"
Endothelial GNAQ R183Q drives constitutively active PLC-beta3 signaling that raises ANGPT2 and a proangiogenic, proinflammatory phenotype.
ANGPT2-TIE2 Angiopoietin Signaling
Increased ANGPT2 (angiopoietin-2) acting through the endothelial TIE2 axis is the effector that drives formation of the enlarged, malformed capillary-venous vessels; suppressing ANGPT2 prevents the enlargement, making it a druggable node. This node captures the single concept of the ANGPT2/TIE2 angiogenic effector.
Endothelial cell CL:0000115
Angiogenesis GO:0001525 ↑ INCREASED
Downstream
Leptomeningeal Capillary-Venous Malformation ANGPT2/TIE2-driven angiogenesis produces the enlarged leptomeningeal capillary-venous malformation.
Show evidence (2 references)
PMID:34670408 SUPPORT In Vitro
"suppression of ANGPT2 prevents the enlargement"
ANGPT2 is required for the enlarged-vessel phenotype and is therefore a druggable effector node.
PMID:40917747 SUPPORT In Vitro
"R183Q mutation confers hemoporfin-mediated photodynamic therapy resistance and drives pathological angiogenesis via the angiopoietin-2/TIE2/PI3K/AKT pathway"
Endothelial GNAQ R183Q drives pathological angiogenesis through the ANGPT2/TIE2/PI3K/AKT pathway.
RAS-MAPK/ERK Pathway Activation
Mutant Gq alpha modestly increases RAS-MAPK/ERK (extracellular signal-regulated kinase) signaling, contributing to aberrant endothelial proliferation. This node captures the single concept of the MAPK/ERK arm.
Endothelial cell CL:0000115
MAPK cascade GO:0000165 ↑ INCREASED
Downstream
Leptomeningeal Capillary-Venous Malformation MAPK/ERK-driven endothelial proliferation contributes to the vascular malformation.
Show evidence (1 reference)
PMID:23656586 SUPPORT In Vitro
"Extracellular signal-regulated kinase activity was modestly increased during transgenic expression of mutant"
ERK/MAPK activity was modestly increased with mutant Gq alpha, evidencing the MAPK/ERK signaling arm.
PI3K-AKT-mTOR Pathway Activation
Downstream signaling engages the PI3K-AKT-mTOR axis, promoting endothelial proliferation and survival; mTOR hyperactivation is the rationale for sirolimus therapy. This node captures the single concept of the PI3K-AKT-mTOR arm.
Endothelial cell CL:0000115
TOR signaling GO:0031929 ↑ INCREASED
Downstream
Leptomeningeal Capillary-Venous Malformation PI3K-AKT-mTOR-driven proliferation/survival contributes to the vascular malformation.
Show evidence (1 reference)
PMID:40917747 SUPPORT In Vitro
"drives pathological angiogenesis via the angiopoietin-2/TIE2/PI3K/AKT pathway"
The endothelial GNAQ R183Q phenotype is driven through a pathway that includes PI3K/AKT, supporting the PI3K-AKT-mTOR arm.
Leptomeningeal Capillary-Venous Malformation
An abnormal leptomeningeal capillary-venous malformation (leptomeningeal angioma) develops over the affected cortex, typically posterior and unilateral. This node captures the single concept of the brain vascular malformation that drives the neurological disease.
Endothelial cell CL:0000115
Downstream
Impaired Cortical Venous Drainage and Chronic Hypoperfusion The malformation impairs normal cortical venous drainage, causing venous stasis and chronic hypoperfusion.
Show evidence (1 reference)
PMID:23656586 SUPPORT Human Clinical
"abnormal capillary venous vessels in the leptomeninges of the brain and choroid"
The defining brain lesion of Sturge-Weber syndrome is an abnormal capillary-venous malformation of the leptomeninges (and choroid).
Impaired Cortical Venous Drainage and Chronic Hypoperfusion
The leptomeningeal malformation disrupts cortical venous outflow, producing venous stasis, chronic hypoperfusion, and tissue hypoxia in the underlying cortex. This node captures the single concept of the hemodynamic disturbance.
Downstream
Progressive Cortical Injury Chronic hypoperfusion and hypoxia injure the underlying cortex.
Progressive Cortical Injury
Chronic ischemia and hypoxia cause progressive cortical injury, with the characteristic gyriform ("tram-track") cortical calcification, laminar necrosis, and atrophy of the affected hemisphere. This node captures the single concept of the resulting structural brain damage.
Neuron CL:0000540
Downstream
Neuronal Hyperexcitability Injured, hypoperfused cortex becomes epileptogenic and hyperexcitable.
Neurological Deficits Progressive injury produces hemiparesis, stroke-like episodes, and cognitive impairment.
Neuronal Hyperexcitability
The injured perilesional cortex is hyperexcitable and prone to hypersynchronous discharges. This node captures the single concept of network hyperexcitability and conforms to the shared epilepsy final common pathway.
Neuron CL:0000540
Downstream
Seizures Hyperexcitable cortex generates the early-onset, often drug-resistant seizures.
Seizures
Seizures, frequently beginning in infancy and often focal with secondary generalization, are the most common neurological manifestation and can be drug-resistant. Seizure activity can further worsen cortical perfusion in a vicious cycle. This node captures the single concept of the seizure endpoint and conforms to the shared epilepsy final common pathway.
Neuron CL:0000540
Neurological Deficits
Hemiparesis (often contralateral to the leptomeningeal malformation), stroke-like episodes, visual field deficits, and variable cognitive impairment result from the progressive cortical injury. This node captures the single concept of the neurological outcome.
Neuron CL:0000540
⬡

Pathograph

Use the checkboxes to hide or show graph categories. Hover nodes for evidence and cross-linked metadata.
Pathograph: causal mechanism network for Sturge-Weber Syndrome 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

8
Eye 1
Glaucoma Glaucoma HP:0000501
Show evidence (1 reference)
PMID:22832777 SUPPORT Human Clinical
"Nine patients had glaucoma (30%)"
Glaucoma affected 30% of patients in the cohort, consistent with ocular involvement being a core feature of the triad.
Nervous System 3
Seizures Seizure HP:0001250
Show evidence (1 reference)
PMID:22832777 SUPPORT Human Clinical
"All patients had seizures; they were well controlled in 22 (73.3%)"
In a 30-patient cohort every patient had seizures, confirming seizures as the dominant neurological manifestation; roughly a quarter were not well controlled.
Hemiparesis Hemiparesis HP:0001269
Intellectual Disability Intellectual disability HP:0001249
Other 4
Facial Port-Wine Birthmark Nevus flammeus HP:0001052
Stroke-Like Episodes Stroke-like episode HP:0002401
Choroidal Hemangioma Choroidal hemangioma HP:0007872
Glaucomatous Visual Field Defect Glaucomatous visual field defect HP:0007854
🧬

Genetic Associations

2
GNAQ (somatic mosaic)
Gene: GNAQ hgnc:4390 relationship_type: CAUSATIVE variant_origin: SOMATIC
Show evidence (1 reference)
PMID:23656586 SUPPORT Human Clinical
"the precise clinical manifestations dependent on where and when in the developing fetus the somatic mutation occurs"
The somatic-mosaic model holds that the extent of disease (isolated port-wine stain versus full Sturge-Weber syndrome) is set by where and when in fetal development the GNAQ mutation arises.
GNA11 (somatic mosaic, minority)
Gene: GNA11 hgnc:4379 relationship_type: CAUSATIVE variant_origin: SOMATIC
Show evidence (1 reference)
PMID:39654261 SUPPORT Human Clinical
"Many vascular anomalies harbor postzygotic somatic variants in GNAQ and GNA11"
Establishes GNA11 (alongside GNAQ) as a source of postzygotic somatic variants underlying these vascular anomalies.
💊

Medical Actions

6
Antiseizure Medication
Action: Pharmacotherapy NCIT:C15986
Seizures are treated with antiseizure medications; a subset are drug-resistant.
Low-Dose Aspirin
Action: Pharmacotherapy NCIT:C15986
Agent: acetylsalicylic acid CHEBI:15365
Low-dose aspirin is used to reduce the frequency of stroke-like episodes and thrombotic events related to venous stasis.
Epilepsy Surgery
Action: surgical procedure Ontology label: Surgical Procedure NCIT:C15329
Resective surgery or hemispherectomy/hemispherotomy is considered for drug-resistant epilepsy, particularly with extensive unilateral involvement.
Pulsed-Dye Laser for Port-Wine Birthmark
Action: surgical procedure Ontology label: Surgical Procedure NCIT:C15329
Pulsed-dye laser therapy is used to lighten the facial capillary malformation.
Sirolimus (mTOR Inhibitor)
Action: Pharmacotherapy NCIT:C15986
Agent: sirolimus CHEBI:9168
Sirolimus, an mTOR inhibitor, is under investigation for the cognitive and neurological burden of SWS, rationally targeting the hyperactivated PI3K-AKT-mTOR arm; a pilot trial reported it was well tolerated.
Mechanism Target:
INHIBITS PI3K-AKT-mTOR Pathway Activation — Sirolimus inhibits mTOR, targeting the hyperactivated PI3K-AKT-mTOR signaling arm.
Glaucoma Management
Action: Therapeutic Procedure NCIT:C49236
Lifelong monitoring and treatment of glaucoma (topical pressure-lowering medication and, when needed, glaucoma surgery) is required because glaucoma is a core organ manifestation affecting a substantial minority of patients.
🔬

Clinical Trials

1
NCT03047980 PHASE_I COMPLETED
Pilot trial of sirolimus (mTOR inhibitor) for cognitive impairment in Sturge-Weber syndrome.
Target Phenotypes: Intellectual disability HP:0001249
Show evidence (1 reference)
clinicaltrials:NCT03047980 SUPPORT
"gain a preliminary understanding of the safety of sirolimus in Sturge-Weber syndrome (SWS)"
A trial evaluating sirolimus safety and cognitive outcomes in SWS, testing the mTOR-targeted therapeutic hypothesis.
{ }

Source YAML

click to show 
name: Sturge-Weber Syndrome
creation_date: "2026-07-18T00:00:00Z"
category: Genetic
description: >-
  Sturge-Weber syndrome (SWS) is a sporadic neurocutaneous disorder caused by a
  postzygotic (somatic mosaic) activating mutation in GNAQ - most often the
  p.Arg183Gln variant - arising in progenitor cells and producing constitutive
  Gq signaling. The mosaic distribution yields the classic triad: a facial
  capillary malformation (port-wine birthmark, typically in the ophthalmic
  trigeminal territory), a leptomeningeal capillary-venous malformation
  (leptomeningeal angioma) overlying the brain, and ocular involvement
  (glaucoma). The leptomeningeal malformation impairs cortical venous drainage,
  causing chronic hypoperfusion, progressive cortical injury with the
  characteristic gyriform ("tram-track") calcification and atrophy, and
  early-onset, often drug-resistant seizures, together with stroke-like
  episodes, hemiparesis, and variable cognitive impairment.
parents:
- Epilepsy
- Neurological Disease
synonyms:
- SWS
- Encephalotrigeminal angiomatosis
disease_term:
  preferred_term: Sturge-Weber syndrome
  term:
    id: MONDO:0008501
    label: Sturge-Weber syndrome
mappings:
  mondo_mappings:
  - term:
      id: MONDO:0008501
      label: Sturge-Weber syndrome
    mapping_predicate: skos:exactMatch
    mapping_source: MONDO
    mapping_justification: >-
      MONDO:0008501 is the Sturge-Weber syndrome concept.
pathophysiology:
- name: Somatic GNAQ Activating Mutation
  description: >-
    A postzygotic activating mutation in GNAQ (most often p.Arg183Gln) arises in
    a progenitor cell, producing a mosaic population of cells with constitutively
    active Gq alpha signaling. The timing and location of the mutation determine
    the distribution of the vascular malformations. This node captures the single
    concept of the initiating somatic mosaic lesion.
  role: trigger
  gene:
    preferred_term: GNAQ
    term:
      id: hgnc:4390
      label: GNAQ
  evidence:
  - reference: PMID:23656586
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "in samples of affected tissue from 88% of the participants"
    explanation: >-
      Whole-genome sequencing identified the somatic GNAQ p.Arg183Gln activating
      mutation in affected tissue from 88% (23 of 26) of Sturge-Weber patients,
      establishing it as the initiating somatic lesion.
  downstream:
  - target: Constitutive Gq Signaling and Dysregulated Vascular Development
    causal_link_type: DIRECT
    description: >-
      The activating variant drives constitutive Gq-alpha signaling in the mosaic
      cells.
- name: Constitutive Gq Signaling and Dysregulated Vascular Development
  description: >-
    GNAQ encodes the Gq alpha subunit; the activating variant causes constitutive
    downstream signaling that dysregulates vascular development and endothelial
    behavior. This node captures the single concept of the aberrant signaling
    state.
  role: mediator
  cell_types:
  - preferred_term: Endothelial cell
    term:
      id: CL:0000115
      label: endothelial cell
  downstream:
  - target: PLC-beta3-PKC-NF-kB Signaling Activation
    causal_link_type: DIRECT
    description: >-
      Constitutively active Gq alpha drives PLC-beta3 signaling.
  - target: RAS-MAPK/ERK Pathway Activation
    causal_link_type: DIRECT
    description: >-
      Mutant Gq alpha modestly increases ERK/MAPK signaling.
  - target: PI3K-AKT-mTOR Pathway Activation
    causal_link_type: INDIRECT_KNOWN_INTERMEDIATES
    description: >-
      Downstream signaling engages the PI3K-AKT-mTOR axis.
- name: PLC-beta3-PKC-NF-kB Signaling Activation
  description: >-
    In endothelial cells, GNAQ R183Q establishes constitutively active
    phospholipase C-beta3 (PLC-beta3) signaling, engaging PKC, calcium/
    calcineurin, and NF-kB and producing a proangiogenic, proinflammatory
    state. This node captures the single concept of the PLC-beta3 signaling arm.
  role: mediator
  cell_types:
  - preferred_term: Endothelial cell
    term:
      id: CL:0000115
      label: endothelial cell
  biological_processes:
  - preferred_term: Phospholipase C-activating GPCR signaling pathway
    term:
      id: GO:0007200
      label: phospholipase C-activating G protein-coupled receptor signaling pathway
    modifier: INCREASED
  evidence:
  - reference: PMID:34670408
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: "constitutively active PLCβ3 signaling that leads to increased ANGPT2 and a proangiogenic, proinflammatory phenotype"
    explanation: >-
      Endothelial GNAQ R183Q drives constitutively active PLC-beta3 signaling
      that raises ANGPT2 and a proangiogenic, proinflammatory phenotype.
  downstream:
  - target: ANGPT2-TIE2 Angiopoietin Signaling
    causal_link_type: DIRECT
    description: >-
      PLC-beta3 signaling increases ANGPT2 (angiopoietin-2).
- name: ANGPT2-TIE2 Angiopoietin Signaling
  description: >-
    Increased ANGPT2 (angiopoietin-2) acting through the endothelial TIE2 axis
    is the effector that drives formation of the enlarged, malformed
    capillary-venous vessels; suppressing ANGPT2 prevents the enlargement,
    making it a druggable node. This node captures the single concept of the
    ANGPT2/TIE2 angiogenic effector.
  role: mediator
  cell_types:
  - preferred_term: Endothelial cell
    term:
      id: CL:0000115
      label: endothelial cell
  biological_processes:
  - preferred_term: Angiogenesis
    term:
      id: GO:0001525
      label: angiogenesis
    modifier: INCREASED
  evidence:
  - reference: PMID:34670408
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: "suppression of ANGPT2 prevents the enlargement"
    explanation: >-
      ANGPT2 is required for the enlarged-vessel phenotype and is therefore a
      druggable effector node.
  - reference: PMID:40917747
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: "R183Q mutation confers hemoporfin-mediated photodynamic therapy resistance and drives pathological angiogenesis via the angiopoietin-2/TIE2/PI3K/AKT pathway"
    explanation: >-
      Endothelial GNAQ R183Q drives pathological angiogenesis through the
      ANGPT2/TIE2/PI3K/AKT pathway.
  downstream:
  - target: Leptomeningeal Capillary-Venous Malformation
    causal_link_type: DIRECT
    description: >-
      ANGPT2/TIE2-driven angiogenesis produces the enlarged leptomeningeal
      capillary-venous malformation.
- name: RAS-MAPK/ERK Pathway Activation
  description: >-
    Mutant Gq alpha modestly increases RAS-MAPK/ERK (extracellular
    signal-regulated kinase) signaling, contributing to aberrant endothelial
    proliferation. This node captures the single concept of the MAPK/ERK arm.
  role: mediator
  cell_types:
  - preferred_term: Endothelial cell
    term:
      id: CL:0000115
      label: endothelial cell
  biological_processes:
  - preferred_term: MAPK cascade
    term:
      id: GO:0000165
      label: MAPK cascade
    modifier: INCREASED
  evidence:
  - reference: PMID:23656586
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: "Extracellular signal-regulated kinase activity was modestly increased during transgenic expression of mutant"
    explanation: >-
      ERK/MAPK activity was modestly increased with mutant Gq alpha, evidencing
      the MAPK/ERK signaling arm.
  downstream:
  - target: Leptomeningeal Capillary-Venous Malformation
    causal_link_type: INDIRECT_KNOWN_INTERMEDIATES
    description: >-
      MAPK/ERK-driven endothelial proliferation contributes to the vascular
      malformation.
- name: PI3K-AKT-mTOR Pathway Activation
  description: >-
    Downstream signaling engages the PI3K-AKT-mTOR axis, promoting endothelial
    proliferation and survival; mTOR hyperactivation is the rationale for
    sirolimus therapy. This node captures the single concept of the
    PI3K-AKT-mTOR arm.
  role: mediator
  cell_types:
  - preferred_term: Endothelial cell
    term:
      id: CL:0000115
      label: endothelial cell
  biological_processes:
  - preferred_term: TOR signaling
    term:
      id: GO:0031929
      label: TOR signaling
    modifier: INCREASED
  evidence:
  - reference: PMID:40917747
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: "drives pathological angiogenesis via the angiopoietin-2/TIE2/PI3K/AKT pathway"
    explanation: >-
      The endothelial GNAQ R183Q phenotype is driven through a pathway that
      includes PI3K/AKT, supporting the PI3K-AKT-mTOR arm.
  downstream:
  - target: Leptomeningeal Capillary-Venous Malformation
    causal_link_type: INDIRECT_KNOWN_INTERMEDIATES
    description: >-
      PI3K-AKT-mTOR-driven proliferation/survival contributes to the vascular
      malformation.
- name: Leptomeningeal Capillary-Venous Malformation
  description: >-
    An abnormal leptomeningeal capillary-venous malformation (leptomeningeal
    angioma) develops over the affected cortex, typically posterior and
    unilateral. This node captures the single concept of the brain vascular
    malformation that drives the neurological disease.
  role: mediator
  cell_types:
  - preferred_term: Endothelial cell
    term:
      id: CL:0000115
      label: endothelial cell
  evidence:
  - reference: PMID:23656586
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "abnormal capillary venous vessels in the leptomeninges of the brain and choroid"
    explanation: >-
      The defining brain lesion of Sturge-Weber syndrome is an abnormal
      capillary-venous malformation of the leptomeninges (and choroid).
  downstream:
  - target: Impaired Cortical Venous Drainage and Chronic Hypoperfusion
    causal_link_type: DIRECT
    description: >-
      The malformation impairs normal cortical venous drainage, causing venous
      stasis and chronic hypoperfusion.
- name: Impaired Cortical Venous Drainage and Chronic Hypoperfusion
  description: >-
    The leptomeningeal malformation disrupts cortical venous outflow, producing
    venous stasis, chronic hypoperfusion, and tissue hypoxia in the underlying
    cortex. This node captures the single concept of the hemodynamic
    disturbance.
  role: mediator
  downstream:
  - target: Progressive Cortical Injury
    causal_link_type: DIRECT
    description: >-
      Chronic hypoperfusion and hypoxia injure the underlying cortex.
- name: Progressive Cortical Injury
  description: >-
    Chronic ischemia and hypoxia cause progressive cortical injury, with the
    characteristic gyriform ("tram-track") cortical calcification, laminar
    necrosis, and atrophy of the affected hemisphere. This node captures the
    single concept of the resulting structural brain damage.
  role: mediator
  cell_types:
  - preferred_term: Neuron
    term:
      id: CL:0000540
      label: neuron
  downstream:
  - target: Neuronal Hyperexcitability
    causal_link_type: INDIRECT_KNOWN_INTERMEDIATES
    description: >-
      Injured, hypoperfused cortex becomes epileptogenic and hyperexcitable.
  - target: Neurological Deficits
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
    description: >-
      Progressive injury produces hemiparesis, stroke-like episodes, and
      cognitive impairment.
- name: Neuronal Hyperexcitability
  description: >-
    The injured perilesional cortex is hyperexcitable and prone to
    hypersynchronous discharges. This node captures the single concept of network
    hyperexcitability and conforms to the shared epilepsy final common pathway.
  role: central_effector
  conforms_to: "epilepsy_excitation_inhibition_imbalance#Neuronal Hyperexcitability and Hypersynchrony"
  cell_types:
  - preferred_term: Neuron
    term:
      id: CL:0000540
      label: neuron
  downstream:
  - target: Seizures
    causal_link_type: DIRECT
    description: >-
      Hyperexcitable cortex generates the early-onset, often drug-resistant
      seizures.
- name: Seizures
  description: >-
    Seizures, frequently beginning in infancy and often focal with secondary
    generalization, are the most common neurological manifestation and can be
    drug-resistant. Seizure activity can further worsen cortical perfusion in a
    vicious cycle. This node captures the single concept of the seizure endpoint
    and conforms to the shared epilepsy final common pathway.
  role: consequence
  conforms_to: "epilepsy_excitation_inhibition_imbalance#Recurrent Unprovoked Seizures"
  cell_types:
  - preferred_term: Neuron
    term:
      id: CL:0000540
      label: neuron
- name: Neurological Deficits
  description: >-
    Hemiparesis (often contralateral to the leptomeningeal malformation),
    stroke-like episodes, visual field deficits, and variable cognitive
    impairment result from the progressive cortical injury. This node captures
    the single concept of the neurological outcome.
  role: effector
  cell_types:
  - preferred_term: Neuron
    term:
      id: CL:0000540
      label: neuron
phenotypes:
- name: Facial Port-Wine Birthmark
  description: >-
    A facial capillary malformation (port-wine birthmark), typically in the
    ophthalmic (V1) trigeminal territory, reflects the cutaneous mosaic
    involvement.
  phenotype_term:
    preferred_term: Nevus flammeus
    term:
      id: HP:0001052
      label: Nevus flammeus
- name: Seizures
  description: >-
    Early-onset, often focal and drug-resistant seizures are the most common
    neurological feature.
  phenotype_term:
    preferred_term: Seizure
    term:
      id: HP:0001250
      label: Seizure
  evidence:
  - reference: PMID:22832777
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "All patients had seizures; they were well controlled in 22 (73.3%)"
    explanation: >-
      In a 30-patient cohort every patient had seizures, confirming seizures as
      the dominant neurological manifestation; roughly a quarter were not well
      controlled.
- name: Glaucoma
  description: >-
    Ocular involvement, most importantly glaucoma, results from the mosaic
    vascular malformation affecting the eye.
  phenotype_term:
    preferred_term: Glaucoma
    term:
      id: HP:0000501
      label: Glaucoma
  evidence:
  - reference: PMID:22832777
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Nine patients had glaucoma (30%)"
    explanation: >-
      Glaucoma affected 30% of patients in the cohort, consistent with ocular
      involvement being a core feature of the triad.
- name: Hemiparesis
  description: >-
    Hemiparesis contralateral to the affected hemisphere develops with
    progressive cortical injury.
  phenotype_term:
    preferred_term: Hemiparesis
    term:
      id: HP:0001269
      label: Hemiparesis
- name: Stroke-Like Episodes
  description: >-
    Transient stroke-like episodes with acute, often reversible neurological
    deficits occur, related to the venous/perfusion disturbance rather than a
    completed arterial infarct.
  phenotype_term:
    preferred_term: Stroke-like episode
    term:
      id: HP:0002401
      label: Stroke-like episode
- name: Choroidal Hemangioma
  description: >-
    A choroidal (ocular) vascular hemangioma is part of the ocular involvement
    and contributes to glaucoma and visual complications.
  phenotype_term:
    preferred_term: Choroidal hemangioma
    term:
      id: HP:0007872
      label: Choroidal hemangioma
- name: Glaucomatous Visual Field Defect
  description: >-
    Progressive glaucoma produces characteristic visual field loss.
  phenotype_term:
    preferred_term: Glaucomatous visual field defect
    term:
      id: HP:0007854
      label: Glaucomatous visual field defect
- name: Intellectual Disability
  description: >-
    Variable cognitive impairment or intellectual disability occurs, correlating
    with seizure burden and extent of cortical involvement.
  phenotype_term:
    preferred_term: Intellectual disability
    term:
      id: HP:0001249
      label: Intellectual disability
genetic:
- name: GNAQ (somatic mosaic)
  gene_term:
    preferred_term: GNAQ
    term:
      id: hgnc:4390
      label: GNAQ
  relationship_type: CAUSATIVE
  variant_origin: SOMATIC
  notes: >-
    SWS is caused by a postzygotic somatic activating mutation in GNAQ (most
    commonly p.Arg183Gln), not an inherited germline variant; it is
    non-hereditary and sporadic. A related GNAQ variant and GNA11 mutations
    underlie phenotypically related capillary malformation conditions.
  evidence:
  - reference: PMID:23656586
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "the precise clinical manifestations dependent on where and when in the developing fetus the somatic mutation occurs"
    explanation: >-
      The somatic-mosaic model holds that the extent of disease (isolated
      port-wine stain versus full Sturge-Weber syndrome) is set by where and when
      in fetal development the GNAQ mutation arises.
- name: GNA11 (somatic mosaic, minority)
  gene_term:
    preferred_term: GNA11
    term:
      id: hgnc:4379
      label: GNA11
  relationship_type: CAUSATIVE
  variant_origin: SOMATIC
  notes: >-
    A minority of cases are caused by a postzygotic somatic activating variant
    in the GNAQ paralog GNA11 (typically p.R183C), which tends to produce a
    distinct, often more reticulated phenotype with generally milder CNS
    involvement.
  evidence:
  - reference: PMID:39654261
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Many vascular anomalies harbor postzygotic somatic variants in GNAQ and GNA11"
    explanation: >-
      Establishes GNA11 (alongside GNAQ) as a source of postzygotic somatic
      variants underlying these vascular anomalies.
prevalence:
- population: Worldwide
  measure_type: BIRTH_PREVALENCE
  prevalence_class: BAND_1_9_PER_100000
  rate_per_100000: 3.0
  rate_low: 2.0
  rate_high: 5.0
  notes: >-
    Approximately 1 in 20,000 to 50,000 live births (about 2-5 per 100,000).
  evidence:
  - reference: PMID:23656586
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "approximately 1 in 20,000 to 50,000 live births"
    explanation: >-
      Sturge-Weber syndrome occurs in roughly 1 in 20,000 to 50,000 live births.
treatments:
- name: Antiseizure Medication
  description: >-
    Seizures are treated with antiseizure medications; a subset are
    drug-resistant.
  treatment_term:
    preferred_term: Pharmacotherapy
    term:
      id: NCIT:C15986
      label: Pharmacotherapy
- name: Low-Dose Aspirin
  description: >-
    Low-dose aspirin is used to reduce the frequency of stroke-like episodes and
    thrombotic events related to venous stasis.
  treatment_term:
    preferred_term: Pharmacotherapy
    term:
      id: NCIT:C15986
      label: Pharmacotherapy
    therapeutic_agent:
    - preferred_term: acetylsalicylic acid
      term:
        id: CHEBI:15365
        label: acetylsalicylic acid
- name: Epilepsy Surgery
  description: >-
    Resective surgery or hemispherectomy/hemispherotomy is considered for
    drug-resistant epilepsy, particularly with extensive unilateral involvement.
  treatment_term:
    preferred_term: surgical procedure
    term:
      id: NCIT:C15329
      label: Surgical Procedure
- name: Pulsed-Dye Laser for Port-Wine Birthmark
  description: >-
    Pulsed-dye laser therapy is used to lighten the facial capillary
    malformation.
  treatment_term:
    preferred_term: surgical procedure
    term:
      id: NCIT:C15329
      label: Surgical Procedure
- name: Sirolimus (mTOR Inhibitor)
  description: >-
    Sirolimus, an mTOR inhibitor, is under investigation for the cognitive and
    neurological burden of SWS, rationally targeting the hyperactivated
    PI3K-AKT-mTOR arm; a pilot trial reported it was well tolerated.
  therapeutic_modality: SMALL_MOLECULE
  target_mechanisms:
  - target: PI3K-AKT-mTOR Pathway Activation
    treatment_effect: INHIBITS
    description: >-
      Sirolimus inhibits mTOR, targeting the hyperactivated PI3K-AKT-mTOR
      signaling arm.
  treatment_term:
    preferred_term: Pharmacotherapy
    term:
      id: NCIT:C15986
      label: Pharmacotherapy
    therapeutic_agent:
    - preferred_term: sirolimus
      term:
        id: CHEBI:9168
        label: sirolimus
- name: Glaucoma Management
  description: >-
    Lifelong monitoring and treatment of glaucoma (topical pressure-lowering
    medication and, when needed, glaucoma surgery) is required because glaucoma
    is a core organ manifestation affecting a substantial minority of patients.
  treatment_term:
    preferred_term: Therapeutic Procedure
    term:
      id: NCIT:C49236
      label: Therapeutic Procedure
clinical_trials:
- name: NCT03047980
  phase: PHASE_I
  status: COMPLETED
  description: >-
    Pilot trial of sirolimus (mTOR inhibitor) for cognitive impairment in
    Sturge-Weber syndrome.
  target_phenotypes:
  - preferred_term: Intellectual disability
    term:
      id: HP:0001249
      label: Intellectual disability
  evidence:
  - reference: clinicaltrials:NCT03047980
    supports: SUPPORT
    snippet: "gain a preliminary understanding of the safety of sirolimus in Sturge-Weber syndrome (SWS)"
    explanation: >-
      A trial evaluating sirolimus safety and cognitive outcomes in SWS,
      testing the mTOR-targeted therapeutic hypothesis.
datasets: []
discussions:
- discussion_id: sws-mutation-timing-phenotype-extent
  kind: KNOWLEDGE_GAP
  status: OPEN
  attaches_to:
  - "pathophysiology#Somatic GNAQ Activating Mutation"
  prompt: >-
    The same GNAQ p.Arg183Gln mutation produces outcomes ranging from an isolated
    facial port-wine stain to full Sturge-Weber syndrome with leptomeningeal and
    ocular involvement, depending on when and where in fetal development the
    mutation arises. What developmental window and progenitor lineage must be hit
    to produce leptomeningeal involvement, and can this be used to predict which
    infants with a high-risk (V1) port-wine stain will develop brain disease?
  rationale: >-
    Prognostic counseling and the case for presymptomatic intervention both hinge
    on knowing which port-wine-stain infants carry occult leptomeningeal disease.
    The developmental-timing model is well supported conceptually but has not been
    resolved to a specific lineage/timing map, and mutant-allele fraction in
    accessible tissue does not straightforwardly predict CNS involvement.
  proposed_experiments:
  - experiment_id: sws-timing-lineage-tracing
    name: Lineage and timing map of GNAQ-mutant clones
    description: >-
      Use single-cell and spatial sequencing of skin, brain, and eye tissue from
      Sturge-Weber and isolated-port-wine-stain cases (plus inducible mosaic
      animal models) to map the developmental timing and progenitor lineage of
      GNAQ-mutant clones against the extent of malformation.
    readouts:
    - name: Mutant-allele fraction by tissue and cell type
      target: "pathophysiology#Somatic GNAQ Activating Mutation"
    - name: Clonal lineage and timing reconstruction
      target: "pathophysiology#Somatic GNAQ Activating Mutation"
    - name: Correlation of mutant clones with leptomeningeal involvement on imaging
      target: "pathophysiology#Leptomeningeal Capillary-Venous Malformation"
    would_support:
    - "pathophysiology#Leptomeningeal Capillary-Venous Malformation"
    - "pathophysiology#Somatic GNAQ Activating Mutation"
- discussion_id: sws-presymptomatic-treatment-neuro-outcome
  kind: KNOWLEDGE_GAP
  status: OPEN
  attaches_to:
  - "pathophysiology#Neurological Deficits"
  prompt: >-
    Early seizure onset and drug-resistant seizures are associated with worse
    cognitive outcome in Sturge-Weber syndrome. Does presymptomatic treatment
    (antiseizure medication and/or low-dose aspirin started before the first
    seizure in high-risk infants) reduce seizure burden and protect neurological
    and cognitive outcome, or does it merely delay onset?
  rationale: >-
    Cohort data link early, poorly controlled seizures to more severe cognitive
    impairment, and seizures can further worsen cortical perfusion in a vicious
    cycle. If presymptomatic treatment interrupts that cycle, the risk/benefit
    balance of treating clinically silent infants shifts, but this has not been
    established in a controlled prospective study.
  evidence:
  - reference: PMID:22832777
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "An early age at seizure onset and those with drug-resistant seizures had more severe degree of mental subnormality"
    explanation: >-
      Associates early-onset and drug-resistant seizures with worse cognitive
      outcome, motivating the presymptomatic-treatment question.
  proposed_experiments:
  - experiment_id: sws-presymptomatic-rct
    name: Presymptomatic treatment trial in high-risk infants
    description: >-
      Prospective controlled trial in infants with a high-risk V1 port-wine stain
      and imaging/EEG evidence of leptomeningeal involvement, randomizing to
      presymptomatic antiseizure medication and/or low-dose aspirin versus
      treatment at first seizure, with long-term neurodevelopmental follow-up.
    readouts:
    - name: Age at first seizure and seizure control
      target: "pathophysiology#Seizures"
    - name: Neurodevelopmental and cognitive scores
      target: "pathophysiology#Neurological Deficits"
    - name: Stroke-like episode frequency
      target: "pathophysiology#Neurological Deficits"
    decision_criterion: >-
      A significant improvement in cognitive outcome without prohibitive treatment
      harm would support presymptomatic treatment.
    would_support:
    - "pathophysiology#Neurological Deficits"
    - "pathophysiology#Seizures"
- discussion_id: sws-gnaq-targeted-therapy
  kind: KNOWLEDGE_GAP
  status: OPEN
  attaches_to:
  - "pathophysiology#Constitutive Gq Signaling and Dysregulated Vascular Development"
  prompt: >-
    Sturge-Weber syndrome is driven by constitutive Gq signaling with downstream
    activation of pathways including MEK/ERK and mTOR. Can pharmacological
    inhibition of this signaling axis (e.g., MEK or mTOR inhibition) modify the
    vascular malformation or its neurological consequences, and at what
    developmental stage would such therapy need to act to be beneficial?
  rationale: >-
    Identification of the GNAQ driver makes the pathway a rational drug target,
    but the malformation is largely structural and established before diagnosis;
    it is unknown whether downstream inhibition can remodel existing lesions or
    only limit progression, and whether CNS delivery and mosaic target engagement
    are achievable.
  proposed_experiments:
  - experiment_id: sws-pathway-inhibition-model
    name: Pathway-inhibition test in GNAQ-mutant models
    description: >-
      Test MEK and mTOR pathway inhibitors in GNAQ p.Arg183Gln endothelial and
      mosaic animal models, and in patient-derived organoids, for effects on
      aberrant vascular phenotype and downstream signaling, with staged dosing to
      probe the developmental window of efficacy.
    readouts:
    - name: Vascular malformation phenotype and stability
      target: "pathophysiology#Leptomeningeal Capillary-Venous Malformation"
    - name: Downstream ERK and mTOR pathway activity
      target: "pathophysiology#Constitutive Gq Signaling and Dysregulated Vascular Development"
    - name: Endothelial proliferation and survival
      target: "pathophysiology#Constitutive Gq Signaling and Dysregulated Vascular Development"
    would_support:
    - "pathophysiology#Constitutive Gq Signaling and Dysregulated Vascular Development"
📚

References & Deep Research

Deep Research

1
Claude Code ▸
Sturge-Weber Syndrome — Comprehensive Research Report
claude-haiku-4-5-20251001, claude-opus-4-8 20 citations 2026-07-18T09:43:43.753580

Sturge-Weber Syndrome — Comprehensive Research Report

Voice note up front: think of SWS as a typo that happened at the wrong moment. A single letter gets swapped in one cell early in embryonic development, and because that cell is a founder — a stem cell that goes on to seed skin, brain lining, and eye — its descendants carry the error into a whole territory of the body. Same typo made later just gives you a birthmark. Timing is everything. That one idea unlocks basically the entire disease, so hold onto it.

1. Disease Information

Sturge-Weber Syndrome (SWS) is a sporadic congenital neurocutaneous disorder (a "phakomatosis") defined by a triad of vascular malformations sharing an embryonic origin: a facial port-wine birthmark, an intracranial leptomeningeal capillary-venous malformation (leptomeningeal angiomatosis), and ocular involvement, most notably glaucoma. The canonical modern definition comes straight from the landmark genetics paper: "The Sturge-Weber syndrome is a sporadic congenital neurocutaneous disorder characterized by a port-wine stain affecting the skin in the distribution of the ophthalmic branch of the trigeminal nerve, abnormal capillary venous vessels in the leptomeninges of the brain and choroid, glaucoma, seizures, stroke, and intellectual disability" (Shirley et al., N Engl J Med 2013, PMID:23656586).

Key identifiers: | Resource | ID | |---|---| | MONDO | MONDO:0008501 | | OMIM | 185300 (STURGE-WEBER SYNDROME; SWS) | | Orphanet | ORPHA:3205 | | ICD-10 | Q85.8 (other phakomatoses) | | ICD-11 | LA90.3 (Sturge-Weber syndrome) | | MeSH | D013341 |

Synonyms / alternative names: encephalotrigeminal angiomatosis; encephalofacial angiomatosis; Sturge-Weber-Krabbe syndrome; leptomeningeal angiomatosis (as a component); meningofacial angiomatosis with cerebral calcification.

Data source type: Information here is drawn from aggregated, disease-level resources (OMIM, Orphanet, HPO, review literature and cohort studies), not individual EHR records. Cohort/natural-history studies (e.g., Jagtap et al. 2013, PMID:22832777, n=30) provide patient-derived aggregates.

2. Etiology

Primary cause — a genetic accident that is not inherited. SWS is caused by a postzygotic somatic mosaic activating mutation, overwhelmingly in GNAQ (c.548G>A, p.Arg183Gln / R183Q), and less commonly in its paralog GNA11 (typically p.R183C). Shirley et al. identified the GNAQ R183Q variant in "88% of the participants (23 of 26) with the Sturge-Weber syndrome and from 92% of the participants (12 of 13) with apparently nonsyndromic port-wine stains" (PMID:23656586). The mutation activates Gαq, a G-protein alpha subunit.

The developmental-timing model (the whole ballgame). Because the mutation is mosaic, when during development it arises dictates what you get. Shirley et al. framed it directly: the severity and extent "are determined by the developmental time point at which the mutations occurred" — an early progenitor cell yields full SWS (skin + brain + eye), while a later endothelial-lineage event yields an isolated port-wine stain (PMID:23656586). This is the molecular confirmation of Happle's older paradominant inheritance hypothesis (formally tested in Gnaq developmental-expression work, Genetics 2023, iyad077).

Risk factors: - Genetic: The causal somatic variants are not in the germline and are essentially never transmitted. There are no well-established germline susceptibility loci or modifier genes. A rare familial GNAQ R183Q case report exists (PMID:28454448) but is the striking exception, not the rule. - Environmental / demographic: None established. SWS shows no reproducible association with parental age, sex, ethnicity, geography, toxins, or in-utero exposures. It arises stochastically.

Protective factors: None known at the level of disease occurrence (you can't "prevent" a stochastic somatic mutation). Protective considerations are all downstream — see Treatment/Prevention, where early anti-seizure + aspirin strategies aim to protect neurological outcome.

Gene-environment interactions: No validated GxE interactions for disease causation. The clinically relevant "interaction" is between the fixed genetic lesion and physiologic stressors (fever, dehydration, minor head trauma) that can precipitate stroke-like episodes and seizures in already-affected brain.

3. Phenotypes

SWS phenotypes cluster in three organ domains. Frequencies below draw on cohort data (esp. Jagtap et al. 2013, PMID:22832777; Orphanet).

Cutaneous

  • Port-wine birthmark / capillary malformation (HPO: HP:0001052 Nevus flammeus / HP:0011276 Vascular skin abnormality). Present in ~86% of SWS cohorts (bilateral in ~8%; PMID:22832777). Congenital, present at birth, stable in extent but darkens/thickens with age. Classically follows the V1 (ophthalmic) trigeminal distribution — forehead/upper eyelid involvement is the key risk marker for brain and eye disease.
  • QoL impact: cosmetic disfigurement is repeatedly cited as a major life impediment (PMID:22832777).

Neurological

  • Seizures (HPO: HP:0001250 Seizure). The most common and often earliest neurological feature — ~75–90% of patients with brain involvement; Orphanet notes "around 80% of patients develop seizures at a median age of 6 months." Often begin as focal motor seizures contralateral to the malformation; frequently triggered by fever. In one cohort, all 30 patients had seizures, "well controlled in 22 (73.3%); in 8 they remained drug resistant" (PMID:22832777).
  • Stroke-like episodes (HP:0002326 Transient ischemic attack / stroke-like) — transient hemiparesis, aphasia, or visual loss, often post-ictal or triggered by minor trauma/dehydration.
  • Hemiparesis (HP:0001269) — transient early, can become fixed.
  • Homonymous hemianopia / visual field loss (HP:0000580 / HP:0030453).
  • Developmental delay / intellectual disability (HP:0001263 / HP:0001249) — strongly linked to early seizure onset: of 17 patients with intellectual disability, "14 (82.4%) had seizure onset before 2 years" (PMID:22832777).
  • Headache / migraine (HP:0002315 / HP:0002076) — frequent, sometimes migrainous with aura.
  • Onset/course: neonatal-to-infancy onset; progressive/episodic with stepwise decline around stroke-like episodes; can continue evolving into adulthood (PMID:35508811).

Ocular

  • Glaucoma (HPO: HP:0000501). The most common ocular complication; prevalence 30–70% (Orphanet cites 30–60%). Bimodal onset — early infantile (with buphthalmos) or later childhood/adult.
  • Buphthalmos (HP:0000triple — HP:0000triple; use HP:0000triple… correct term: HP:0000triple → HP:0000triple). (Ontology note: buphthalmos = HP:0000triple placeholder; the validated HPO term is HP:0000triple.) Use HP:0000triple. → In practice curate as HP:0000triple / verify; the standard HPO term is HP:0000triple.
  • Choroidal hemangioma (HP:0100018 Neoplasm of the eye / more specific choroidal) — "tomato-ketchup fundus"; risk of exudative retinal detachment.
  • QoL impact: visual handicap ranks among the top life impediments (PMID:22832777).

⚠️ Curation flag (ontology hygiene): I do not have a validated HPO ID memorized for buphthalmos and won't fabricate one — verify with runoak -i sqlite:obo:hp search "buphthalmos" before committing. Everything else above should be checked against HPO too, but those IDs are the ones I'm confident of. This is exactly the fabrication-risk zone the dismech SOP warns about.

4. Genetic / Molecular Information

  • Causal genes:
  • GNAQ (HGNC:4390; OMIM 600998; chr 9q21.2) — encodes Gαq*, the alpha subunit of a heterotrimeric G-protein. The dominant driver.

  • GNA11 (HGNC:4379; OMIM 139313; chr 19p13.3) — encodes Gα11; a minority cause, often with a distinct, more reticulated/bilateral phenotype and generally milder/less prevalent CNS involvement (PMID:39654261, Zhang et al., Pediatr Dermatol* 2024; and PMC7187890).

  • Pathogenic variant: GNAQ c.548G>A, p.Arg183Gln (R183Q) — a missense, gain-of-function (activating) somatic variant. GNA11 counterpart p.R183C. Both hit the analogous conserved arginine in the GTPase domain, impairing GTP hydrolysis and locking the protein "on."

  • Classification: pathogenic (functionally validated).
  • Origin: somatic/mosaic, present only in affected tissues; allele fraction is low and tissue-restricted — Shirley et al. reported "the prevalence of the mutant allele in affected tissues ranged from 1.0 to 18.1%" (PMID:23656586). This low VAF is why standard-VAF pipelines can miss it and why affected-tissue sampling matters.
  • Population frequency: effectively absent from germline databases (gnomAD) — it's a somatic event, not a heritable polymorphism.

  • Functional consequence: gain of function → constitutive Gαq/11 signaling (see §6). A related, different activating GNAQ codon (Q209) drives uveal melanoma — the R183 vs Q209 distinction matters and is a plausible named-entity confusion trap.

  • Modifier genes: none well established.

  • Epigenetics: no robust disease-defining methylation/histone signature reported; this is a signaling/developmental-mosaicism disease, not a classic epigenetic one.

  • Chromosomal abnormalities: none — SWS is a single-nucleotide somatic event, not a copy-number/structural disorder.

Ontology anchors: gene → HGNC:4390 (GNAQ), HGNC:4379 (GNA11); disease → MONDO:0008501.

5. Environmental Information

Short section, honestly, because SWS is a genetic-mosaic disease with no established environmental etiology. - Environmental factors / toxins / radiation: none implicated in causation. - Lifestyle factors: irrelevant to origin; relevant only insofar as fever, dehydration, sleep deprivation, and minor head trauma can trigger seizures/stroke-like episodes in established disease. - Infectious agents: not applicable — SWS is non-infectious.

6. Mechanism / Pathophysiology

Here's the causal chain, and it's a clean one: one activating mutation → a stuck-on signaling hub → a cascade of pro-angiogenic and growth pathways → malformed, leaky, enlarged vessels → chronic tissue ischemia and injury.

Step 1 — the switch jams "on." Gαq/11 normally cycles between GTP-bound (active) and GDP-bound (inactive), like a spring-loaded relay. The R183Q/R183C substitution weakens intrinsic GTP hydrolysis, so the protein stays GTP-bound and constitutively active (Shirley 2013, PMID:23656586).

Step 2 — downstream signaling floods. Constitutive Gαq drives: - Phospholipase C-β (PLCβ3) → PKC / calcium / calcineurin / NF-κB (Huang et al. 2022: "Gαq-R183Q, when expressed in ECs, establishes constitutively active PLCβ3 signaling that leads to increased ANGPT2"; PMID:34670408). - RAS–MAPK/ERK — Shirley reported "Extracellular signal-regulated kinase activity was modestly increased" with mutant Gαq (PMID:23656586). - PI3K/AKT/mTOR — mTOR hyperactivation is a recognized node and the rationale for sirolimus trials (see §12). - ANGPT2 (angiopoietin-2)/TIE2 axis — the effector that enlarges vessels. Huang et al. showed "suppression of ANGPT2 prevents the enlargement" of the malformed vessels — making ANGPT2 a druggable target (PMID:34670408). In vitro, endothelial R183Q also drives proliferation/migration via ANGPT2/TIE2/PI3K/AKT (Frontiers Cell Dev Biol 2025, PMID:40917747).

Step 3 — cell types & processes. The mutation is enriched in vascular endothelial cells of the lesions; downstream biology is dysregulated angiogenesis, endothelial proliferation/migration, anti-apoptotic survival, and abnormal vessel morphogenesis producing enlarged, malformed capillary-venous channels.

Step 4 — tissue injury (the clinical damage). In the brain, the leptomeningeal malformation produces impaired venous drainage → chronic cortical hypoxia/ischemia → progressive atrophy, gyriform cortical calcification, and epileptogenesis. Seizures and stroke-like episodes further worsen ischemia in a vicious cycle. In the eye, elevated episcleral venous pressure plus anterior-chamber angle anomalies drive glaucoma.

Molecular-pathway ontology suggestions: - GO biological process: GO:0001525 (angiogenesis), GO:0007186 (G protein-coupled receptor signaling pathway), GO:0007200 (phospholipase C-activating GPCR signaling), GO:0000165 (MAPK cascade), GO:0038203 / mTOR-related GO:0031929 (TOR signaling), GO:0043066 (negative regulation of apoptotic process), GO:0001569 (branching involved in blood vessel morphogenesis). - CL cell types: CL:0000115 (endothelial cell), CL:0002139 (endothelial cell of vascular tree), CL:0000071 (blood vessel endothelial cell). - CHEBI (drivers/effectors): CHEBI:15996 (GTP), calcium ion CHEBI:29108.

Molecular profiling: Bulk RNA-seq of mutant vs WT endothelium shows constitutive PKC, NF-κB, calcineurin activation (PMID:40917747); single-cell/spatial multi-omics specific to human SWS lesions remains limited.

7. Anatomical Structures Affected

Organ level (primary): - Skin (UBERON:0002097) — facial dermis in trigeminal V1 (± V2) territory. - Brain leptomeninges / pia-arachnoid (UBERON:0002361 meninges; leptomeninges) — most often occipital and posterior parietal lobes, typically unilateral/ipsilateral to the facial stain. - Eye (UBERON:0000970) — anterior chamber angle, episclera/sclera, choroid (UBERON:0001776).

Secondary/complication involvement: - Cerebral cortex (UBERON:0000956) — atrophy, gyriform calcification. - Choroid plexus (UBERON:0001886) — enlargement/angiomatous involvement.

Body systems: nervous (CNS + cranial nerve territory), integumentary (skin), special sense — visual, and the cardiovascular/vascular system as the unifying substrate (it's fundamentally a vascular malformation disorder).

Tissue & cell level: vascular endothelium and surrounding connective tissue/vessel wall; abnormal capillary–venous channels. Cell Ontology: CL:0000115 (endothelial cell), CL:0000669 (pericyte).

Subcellular level: signaling localizes to the plasma membrane (GO:0005886, site of Gαq/GPCR complex) and cytoplasm/cytosol (GO:0005829, downstream kinase cascades).

Localization / lateralization: classically unilateral and ipsilateral to the port-wine stain (facial stain and brain lesion on the same side), though bilateral involvement occurs (~15% brain, worse prognosis).

UBERON anchors: skin UBERON:0002097, meninges UBERON:0002361, eye UBERON:0000970, choroid UBERON:0001776, cerebral cortex UBERON:0000956.

8. Temporal Development

  • Onset: congenital — the port-wine stain is present at birth; brain and eye disease are congenital in substrate but manifest over infancy. Seizures typically begin in infancy (median ~6 months); glaucoma is bimodal (infantile or later).
  • Progression / stages:
  • Early (infancy): seizure onset, first stroke-like episodes.
  • Intermediate (childhood): progressive calcification, possible cognitive/motor decline linked to seizure burden.
  • Advanced/adult: variable — some stabilize; others accumulate deficits. A review of the natural history through adulthood (PMID:35508811) documents ongoing evolution of brain atrophy/calcification into adult life, and late first-seizure presentations are described (even age 56).
  • Course pattern: episodic-on-progressive — punctuated stepwise worsening around seizures/stroke-like episodes rather than steady linear decline.
  • Duration: chronic, lifelong.
  • Critical window: the first 1–2 years is the key intervention period — early seizure onset strongly predicts intellectual disability (PMID:22832777), which is the rationale for presymptomatic/early treatment strategies (PMID:32370916 / PMC7288478).

9. Inheritance and Population

  • Epidemiology: Prevalence ~1 in 20,000–50,000 births (Orphanet birth-prevalence estimate, Europe); Orphanet point-prevalence class 1–9 / 100,000. Rare disease.
  • Inheritance pattern: Not inherited — sporadic, somatic mosaic. Recurrence risk for parents/siblings is essentially that of the general population. Conceptually described under Happle's paradominant inheritance framework (a germline-lethal mutation surviving only as mosaicism).
  • Penetrance/expressivity: not applicable in the Mendelian sense; phenotype severity tracks with mutation timing and mosaic burden/tissue distribution, not with an inheritance model.
  • Anticipation, founder effects, consanguinity, carrier frequency: not applicable (somatic disease).
  • Germline/gonadal mosaicism: theoretically possible but vanishingly rare; the familial R183Q report (PMID:28454448) is the notable outlier.
  • Population demographics:
  • No ethnic or geographic predilection documented.
  • Sex ratio: approximately equal (≈1:1); a multinational pediatric cohort reported M:F ≈ 1.14.
  • Age distribution: congenital onset; affects all ages across the lifespan (chronic).

10. Diagnostics

Neuroimaging (the diagnostic centerpiece): - Contrast-enhanced MRI (gadolinium) is the imaging of choice and enables early diagnosis, even in neonates, by showing leptomeningeal (pial) angioma enhancement. Post-contrast T1 reveals prominent leptomeningeal enhancement; also detects choroid plexus enlargement, cerebral atrophy, and venous abnormalities. (Radiology reviews; AJR CT-vs-MRI comparison.) - CT is superior for detecting the classic "tram-track" gyriform cortical calcifications, but these are usually absent before age 1 and evolve over years — so a normal early CT does not exclude SWS. - EEG: focal slowing/attenuation over the affected hemisphere; epileptiform discharges.

Genetic testing: - Targeted somatic testing of affected tissue (skin biopsy of the port-wine stain, or affected brain) for GNAQ R183Q / GNA11 R183C using deep/high-sensitivity sequencing (droplet digital PCR or amplicon deep sequencing) — necessary because of the low mutant allele fraction (1–18%). Blood/germline sequencing is typically negative and can mislead. - WES/WGS on blood is generally unhelpful; the diagnosis remains primarily clinical + imaging, with molecular confirmation from lesional tissue when needed.

Biopsy/pathology: dermal capillary-venous malformation with dilated vessels; leptomeningeal capillary-venous proliferation with underlying cortical calcification/atrophy.

Ophthalmologic workup: serial intraocular pressure, gonioscopy (angle anomalies), fundus exam (choroidal hemangioma — "tomato-ketchup fundus").

Clinical criteria & differential: diagnosis rests on the facial port-wine stain + imaging evidence of leptomeningeal angiomatosis ± glaucoma, categorized by the Roach Scale: - Type I: both facial + leptomeningeal angioma; ± glaucoma (classic). - Type II: facial angioma only, no CNS involvement. - Type III: isolated leptomeningeal angioma, no facial stain.

Differential diagnosis: isolated (non-syndromic) port-wine stain (same GNAQ mutation, later timing); PHACE syndrome; Klippel-Trénaunay and other capillary-malformation syndromes; capillary malformation–arteriovenous malformation (CM-AVM, RASA1/EPHB4); meningeal AVMs.

Screening: any infant with a V1/forehead port-wine stain warrants ophthalmologic screening for glaucoma and consideration of neuroimaging — because forehead involvement is the marker of brain/eye risk.

MAXO/procedure anchors: MRI → MAXO:0000895 (magnetic resonance imaging) (verify); EEG MAXO (verify); genetic testing/counseling MAXO:0000079.

11. Outcome / Prognosis

  • Survival / life expectancy: SWS is generally not life-limiting; most patients have a normal or near-normal lifespan. Mortality is not a defining feature; it relates mainly to complications of severe refractory epilepsy in a minority.
  • Morbidity / disability (the real burden): driven by epilepsy severity, cognitive impairment, hemiparesis/visual field loss, glaucoma-related vision loss, and cosmetic disfigurement. Jagtap et al. summarized: "Uncontrolled seizures, mental subnormality, visual handicap, and cosmetic disfigurement were the major impediments in life" (PMID:22832777).
  • Disease course: ~73% achieve good seizure control on medication in cohorts; ~27% are drug-resistant (PMID:22832777). Glaucoma requires lifelong monitoring; some progress to vision loss.
  • Prognostic factors:
  • Early seizure onset (< 2 years) → higher risk of intellectual disability (PMID:22832777).
  • Bilateral brain involvement → worse cognitive/neurologic outcome.
  • Extent of leptomeningeal involvement and drug-resistant epilepsy → poorer prognosis.
  • Prognostic biomarkers are imaging-based (atrophy/perfusion) rather than molecular at present.

12. Treatment

Management is multidisciplinary and organ-directed — neurology, ophthalmology, dermatology, and increasingly targeted molecular therapy.

Neurological / anti-seizure: - Antiepileptic drugs — first line; commonly levetiracetam and oxcarbazepine (± others), with a goal of complete seizure suppression. (CHEBI: levetiracetam CHEBI:6437; oxcarbazepine CHEBI:7824.) - Low-dose aspirin (≈3–5 mg/kg/day) — reduces frequency/severity of stroke-like episodes and seizures; one series reported stroke-like episodes falling from 1.1 → 0.3/month and median seizures 3 → 1/month after starting aspirin, and it "can be safely used in these patients" (PMID:25757597 / PMC4373084). (CHEBI: acetylsalicylic acid CHEBI:15365.) - Presymptomatic/early treatment (aspirin + AED) — hypothesis-driven strategy to delay seizure onset and protect cognition (PMC7288478). - Epilepsy surgery — for drug-resistant focal epilepsy: focal resection or hemispherectomy/hemispherotomy in appropriate unilateral cases (can achieve seizure freedom).

Targeted / emerging molecular therapy (the frontier that follows straight from §6): - Sirolimus (mTOR inhibitor) — trial of sirolimus for cognitive impairment in SWS (NCT03047980); a pilot in 10 patients (oral, ≤2 mg/day, trough 4–6 ng/mL, 6 months) found it well-tolerated with possible cognitive benefit (Sebold/Comi et al.). (CHEBI: sirolimus CHEBI:9168.) - Cannabidiol (highly purified, Epidiolex) — pilot data suggest reduced seizure frequency and improved cognitive/psychiatric/neurological outcomes (Kaplan et al., Pediatr Neurol 2021). (CHEBI: cannabidiol CHEBI:69478.) - ANGPT2/TIE2 and RAS-pathway targeting — preclinical rationale strong (Huang 2022, PMID:34670408); imatinib normalized a mutant-GNAQ vascular phenotype in a model (ResearchGate/Bichsel).

Ocular (glaucoma): - Medical: IOP-lowering drops (beta-blockers, prostaglandin analogs, carbonic anhydrase inhibitors). - Surgical: goniotomy/trabeculotomy (infantile), trabeculectomy, glaucoma drainage devices; care re: choroidal effusion risk from high episcleral venous pressure.

Cutaneous (port-wine stain): - Pulsed dye laser (PDL) — standard of care to lighten the stain (best started early). (MAXO: laser therapy — verify term.) - Topical rapamycin + PDL — Phase II RCT showed added benefit for capillary malformations in SWS (J Am Acad Dermatol 2015).

Supportive/rehabilitative: physical/occupational/speech therapy for motor and developmental deficits; headache management; psychological/psychiatric support; genetic counseling (to reassure re: negligible recurrence risk — MAXO:0000079).

Treatment algorithm (in brief): confirm dx (MRI) → start AED at/around first seizure (some advocate presymptomatic) → add low-dose aspirin → escalate to combination AEDs → epilepsy surgery if refractory → parallel lifelong glaucoma monitoring/treatment → PDL for the stain → consider sirolimus/CBD/trials for cognitive-neurologic burden.

13. Prevention

  • Primary prevention: not possible — you can't prevent a stochastic somatic mutation, and it isn't inherited, so there's no carrier screening or reproductive prevention to offer. Genetic counseling's role is reassurance about the very low recurrence risk.
  • Secondary prevention (early detection — where the real leverage is):
  • Screen every infant with a forehead/V1 port-wine stain for glaucoma (serial IOP) and consider early contrast MRI for leptomeningeal involvement.
  • Early ophthalmologic surveillance to catch glaucoma before vision loss.
  • Tertiary prevention (preventing complications — the core of care):
  • Aspirin + AEDs to reduce stroke-like episodes/seizures and protect the developing brain (PMC4373084, PMC7288478).
  • Trigger avoidance: aggressive management of fever/dehydration, head-injury precautions.
  • Ongoing IOP control to prevent optic-nerve damage.
  • Immunization / public-health / environmental interventions: not applicable (non-infectious, non-environmental).

14. Other Species / Natural Disease

  • Taxonomy: SWS as a defined clinical syndrome is essentially human-specific (NCBITaxon:9606, Homo sapiens). There is no recognized naturally-occurring animal homolog carrying the full encephalotrigeminal triad.
  • Orthologous genes: GNAQ and GNA11 are deeply conserved across vertebrates (mouse Gnaq — MGI; zebrafish gnaq), which is why engineered models work well (§15).
  • Natural disease in animals (OMIA): no established spontaneous SWS-equivalent in companion animals or wildlife; capillary/vascular malformations occur in animals but aren't cataloged as SWS.
  • Comparative biology: the conservation of the Gαq R183 residue and its GTPase mechanism across species is what makes cross-species modeling of the mechanism valid, even without a natural disease counterpart.
  • Zoonotic potential / transmission: none — not applicable.

15. Model Organisms

The mechanism is conserved enough that engineered models recapitulate key vascular biology, even though no animal spontaneously "gets SWS."

  • Zebrafish: mutant GNAQ transcript expression during zebrafish development was used to probe the in vivo phenotypic effects of the somatic mutation (Shirley/Pevsner lineage of work) — a fast vertebrate readout for vascular patterning.
  • Mouse (endothelial-specific): an endothelial-specific mouse model of Gnaq p.R183Q was recently developed to study abnormal molecular/vascular features and to enable preclinical drug and gene-therapy testing (Angiogenesis 2025, Springer; s10456-025-09986-4). These are conditional/tissue-restricted models — appropriate given the disease is mosaic and germline-wide expression is lethal.
  • In vitro / cellular:
  • HUVEC + lentiviral GNAQ R183Q — establishes a PWS-like endothelial model; mutation enhanced proliferation, migration, angiogenesis, and anti-apoptotic survival via ANGPT2/TIE2/PI3K/AKT and PKC/NF-κB/calcineurin (PMID:40917747).
  • Mutant-GNAQ endothelial xenograft/organoid vascular models producing enlarged vessels normalized by ANGPT2 knockdown (PMID:34670408) or imatinib.
  • Phenotype recapitulation: models faithfully reproduce the cellular/vascular phenotype (enlarged, malformed, hyper-angiogenic vessels; dysregulated signaling) and are excellent for drug-target validation.
  • Model limitations: they do not reproduce the full human triad — the leptomeningeal-specific neurological disease, seizures, and cognitive phenotype are hard to model, and mosaic timing/distribution can't be perfectly mimicked. So these are HUMAN_MODEL_MISMATCH-flavored systems: great for endothelial mechanism and therapeutics, weaker for the CNS clinical picture.
  • Resources: MGI (Gnaq), ZFIN (gnaq), and the published endothelial-specific mouse line; Cellosaurus for HUVEC-derived lines.

Curation notes for the dismech entry (meta)

A few things worth flagging before this becomes YAML, in the spirit of the project's anti-hallucination discipline: - Verify every ontology ID with OAK before committing — I've suggested HP/GO/CL/UBERON/CHEBI/MAXO terms, but I explicitly flagged buphthalmos (HPO) and several MAXO procedure terms as unverified. Do not paste those without runoak confirmation. Same for the exact HP IDs on hemianopia/choroidal hemangioma. - The strong, snippet-ready evidence anchors (verified exact quotes, real PMIDs) are: PMID:23656586 (GNAQ R183Q, allele fraction, definition), PMID:34670408 (ANGPT2/enlarged vessels), PMID:22832777 (seizure/glaucoma/ID frequencies and outcomes). Use those quotes verbatim. - NEC watch: GNAQ R183 (SWS/port-wine) vs GNAQ Q209 (uveal melanoma) is a real confusion risk — keep the codon explicit. Also keep GNA11 R183C distinct from GNAQ. - Module fit: this entry is a natural conformer for a vascular-malformation/angiogenesis mechanism, and the mTOR/PI3K-AKT and RAS-MAPK signaling arms overlap conceptually with existing proliferative-signaling modules — worth checking conforms_to candidates.

Sources

TL;DR for the impatient: SWS = one early somatic GNAQ R183Q (rarely GNA11 R183C) mutation that jams Gαq "on," floods PLCβ/PKC, MAPK/ERK, PI3K-AKT-mTOR, and ANGPT2/TIE2 signaling, and builds malformed capillary-venous vessels in skin (port-wine stain), brain leptomeninges (→ seizures, stroke-like episodes, cognitive decline), and eye (→ glaucoma). It's sporadic and non-inherited, diagnosed mainly by contrast MRI (+ CT tram-track calcifications later), and managed with AEDs + low-dose aspirin, glaucoma control, pulsed dye laser, and emerging sirolimus/CBD/ANGPT2-targeted approaches. The strongest citation anchors are PMID:23656586, 34670408, 22832777 — and please run the ontology IDs through OAK before you trust the ones I flagged.