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1
Inheritance
3
Pathophys.
6
Phenotypes
3
Pathograph
2
Genes
2
Treatments
2
Subtypes
3
Trials
1
Deep Research
👪

Inheritance

1
Autosomal dominant inheritance HP:0000006
CM-AVM is usually inherited as an autosomal dominant disorder caused by heterozygous pathogenic variants in RASA1 or EPHB4, with variable expression.
Autosomal dominant inheritance
Show evidence (1 reference)
PMID:24038909 SUPPORT Human Clinical
"Capillary malformation-arteriovenous malformation (CM-AVM) is an autosomal-dominant disorder, caused by heterozygous RASA1 mutations, and manifesting multifocal CMs and high risk for fast-flow lesions."
This directly supports autosomal dominant RASA1-related CM-AVM.

Subtypes

2
CM-AVM Type 1 (RASA1) MONDO:0020783
RASA1-related subtype with multifocal capillary malformations and risk of fast-flow lesions.
CM-AVM Type 2 (EPHB4) MONDO:0020785
EPHB4-related subtype with capillary malformations, telangiectasia, Bier spots, and fast-flow lesion risk.

Pathophysiology

3
Germline RASA1 and EPHB4 loss of vascular Ras suppression
Heterozygous pathogenic variants in RASA1 or EPHB4 reduce signaling control of endothelial vascular development, including negative regulation of Ras signaling, creating systemic susceptibility to CM-AVM fast-flow lesions.
endothelial cell link
negative regulation of Ras protein signal transduction link ↓ DECREASED blood vessel morphogenesis link ⚠ ABNORMAL
Show evidence (2 references)
PMID:24038909 SUPPORT Human Clinical
"Capillary malformation-arteriovenous malformation (CM-AVM) is an autosomal-dominant disorder, caused by heterozygous RASA1 mutations, and manifesting multifocal CMs and high risk for fast-flow lesions."
This supports heterozygous RASA1 variants as a systemic susceptibility mechanism for CM-AVM.
PMID:37978175 SUPPORT Human Clinical
"Rare, damaging transmitted variants were enriched in Ephrin receptor-B4 (EPHB4) (17.5-fold, p = 1.22 x 10-5), which cooperates with p120 RasGAP to regulate vascular development."
This supports EPHB4 cooperation with p120 RasGAP/RASA1 in human cerebrovascular development.
Somatic second-hit allele loss in focal lesions
Lesion tissue can lose the remaining wild-type RASA1 allele, supporting a two-hit model in which inherited susceptibility is followed by focal allele loss in malformation tissue.
endothelial cell link
negative regulation of Ras protein signal transduction link ↓ DECREASED
Show evidence (1 reference)
PMID:24038909 SUPPORT Human Clinical
"The analysis of the tissue showed loss of the wild-type RASA1 allele."
Loss of the wild-type allele in lesion tissue supports a focal second-hit mechanism.
RAS-MAPK/ERK-driven arteriovenous malformation formation
Impaired Ras suppression and EPHB4-RASA1 vascular developmental signaling converge on abnormal ERK/MAPK signaling and blood vessel morphogenesis, promoting arteriovenous malformation and fistula formation.
endothelial cell link
ERK1 and ERK2 cascade link ↑ INCREASED blood vessel morphogenesis link ⚠ ABNORMAL
Show evidence (1 reference)
PMID:37978175 SUPPORT Model Organism
"Mice expressing a VOGM-specific EPHB4 kinase-domain missense variant (Phe867Leu) exhibited disrupted developmental angiogenesis and impaired hierarchical development of arterial-capillary-venous networks, but only in the presence of a "second-hit" allele."
This mixed human/genetic and model-organism study supports abnormal arteriovenous network morphogenesis downstream of EPHB4/RASA1 pathway disruption.

Pathograph

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

6
Cardiovascular 2
Arteriovenous malformation or fistula FREQUENT Arteriovenous malformation (HP:0100026)
Show evidence (1 reference)
PMID:29891884 SUPPORT Human Clinical
"Most (75.4%) individuals with a RASA1 variant had CMs, and 44.9% had an AVM/AVF."
This clinical series quantifies capillary and fast-flow lesion prevalence in RASA1-positive individuals.
Telangiectasia Telangiectasia (HP:0001009)
Show evidence (1 reference)
PMID:35088870 SUPPORT Human Clinical
"Telangiectasias were reported in 28 (22%) patients, and Bier spots were described in 20 (15.7%) patients."
The EPHB4-focused review reports telangiectasias in a subset of CM-AVM2 patients.
Integument 2
Multifocal capillary malformations VERY_FREQUENT Capillary malformation (HP:0025104)
Show evidence (1 reference)
PMID:24038909 SUPPORT Human Clinical
"Capillary malformation-arteriovenous malformation (CM-AVM) is an autosomal-dominant disorder, caused by heterozygous RASA1 mutations, and manifesting multifocal CMs and high risk for fast-flow lesions."
This establishes multifocal capillary malformations as part of the defining RASA1-related phenotype.
Bier spots OCCASIONAL Hypopigmentation of the skin (HP:0001010)
Show evidence (1 reference)
PMID:35088870 SUPPORT Human Clinical
"Telangiectasias were reported in 28 (22%) patients, and Bier spots were described in 20 (15.7%) patients."
The EPHB4-focused review reports Bier spots in 15.7% of CM-AVM2 patients.
Other 2
Cerebral arteriovenous malformation Cerebral arteriovenous malformation (HP:0002408)
Show evidence (1 reference)
PMID:37978175 SUPPORT Human Clinical
"To elucidate the pathogenesis of vein of Galen malformations (VOGMs), the most common and most severe of congenital brain arteriovenous malformations, we performed an integrated analysis of 310 VOGM proband-family exomes and 336,326 human cerebrovasculature single-cell transcriptomes."
This supports cerebral arteriovenous malformations as a relevant fast-flow lesion context for RASA1/EPHB4 pathway disruption.
Parkes Weber syndrome or limb arteriovenous shunting Arteriovenous fistula (HP:0004947)
Show evidence (1 reference)
PMID:29891884 SUPPORT Human Clinical
"RASA1-related disorders are vascular malformation syndromes characterized by hereditary capillary malformations (CM) with or without arteriovenous malformations (AVM), arteriovenous fistulas (AVF), or Parkes Weber syndrome."
This directly supports Parkes Weber syndrome within the RASA1-related CM-AVM spectrum.
🧬

Genetic Associations

2
RASA1 (Causative)
Autosomal dominant inheritance
Show evidence (1 reference)
PMID:24038909 SUPPORT Human Clinical
"Fifty-eight distinct RASA1 mutations (43 novel) were identified in 68 index patients with CM-AVM and none in patients with other phenotypes."
This cohort establishes RASA1 variants as specific to the CM-AVM phenotype among tested groups.
EPHB4 (Causative)
Autosomal dominant inheritance
Show evidence (1 reference)
PMID:35088870 SUPPORT Human Clinical
"We describe here a four-generation family with a novel heterozygous pathogenic variant in the EPHB4 gene (NM_004444.5 (EPHB4): c.2224G>C, p.(Ala742Pro))."
This report supports heterozygous pathogenic EPHB4 variants as causative for CM-AVM2.
💊

Treatments

2
Endovascular or surgical treatment of fast-flow lesions
Action: therapeutic procedure Ontology label: Therapeutic Procedure NCIT:C49236
Management is lesion-specific and can include embolization or surgery for clinically significant arteriovenous malformations or fistulas.
Show evidence (1 reference)
PMID:35547535 PARTIAL Human Clinical
"The genetic data helps to classify these malformations and to guide treatment toward lowest risk of post-operative cerebral ischemic-hemorrhagic complications."
This supports genotype-informed procedural planning for cerebral high-flow shunts but does not specify a single intervention for all CM-AVM lesions.
Trametinib for Ras/MAPK-driven vascular anomalies
Action: Pharmacotherapy NCIT:C15986
Agent: trametinib
Trametinib is an investigational MEK inhibitor approach for complicated Ras/MAPK-driven vascular anomalies, including arteriovenous malformations.
Show evidence (1 reference)
clinicaltrials:NCT04258046 SUPPORT Human Clinical
"The purpose of this study is to assess the safety and efficacy of Trametinib in children and adults with Extracranial Arteriovenous Malformation (AVM)."
This trial supports trametinib as an investigational MEK-inhibitor therapy for complicated AVM.
🔬

Clinical Trials

3
NCT04258046 PHASE_II COMPLETED
Phase II trametinib study for complicated extracranial arteriovenous malformation.
Target Phenotypes: Arteriovenous malformation
Show evidence (1 reference)
clinicaltrials:NCT04258046 SUPPORT Human Clinical
"The purpose of this study is to assess the safety and efficacy of Trametinib in children and adults with Extracranial Arteriovenous Malformation (AVM)."
This supports a trametinib clinical trial relevant to CM-AVM fast-flow lesions.
NCT07549646 PHASE_II ACTIVE_NOT_RECRUITING
Phase II trametinib study for Ras/MAPK pathway-driven vascular anomalies.
Target Phenotypes: Arteriovenous malformation
Show evidence (1 reference)
clinicaltrials:NCT07549646 SUPPORT Human Clinical
"The purpose of this study is to assess the effectiveness and safety of Trametinib (the "Study Drug") in patients with Ras/MAPK pathway driven vascular anomalies (VA)."
This supports a pathway-directed trametinib trial for vascular anomalies relevant to CM-AVM biology.
NCT07072403 PHASE_I ACTIVE_NOT_RECRUITING
Prospective systemic trametinib study for complicated vascular anomalies.
Target Phenotypes: Arteriovenous malformation
Show evidence (1 reference)
clinicaltrials:NCT07072403 SUPPORT Human Clinical
"This study aims to evaluate the safety and efficacy of systemic trametinib therapy in patients with complicated vascular anomalies."
This supports an additional prospective trametinib trial for complicated vascular anomalies.
{ }

Source YAML

click to show
name: Capillary Malformation-Arteriovenous Malformation Syndrome
creation_date: "2026-05-04T22:23:50Z"
updated_date: "2026-05-05T01:00:46Z"
description: >-
  Capillary malformation-arteriovenous malformation syndrome is an autosomal
  dominant vascular malformation disorder characterized by multifocal cutaneous
  capillary malformations and increased risk of fast-flow arteriovenous
  malformations or fistulas. Major molecular subtypes are RASA1-related CM-AVM1
  and EPHB4-related CM-AVM2.
category: Mendelian
disease_term:
  preferred_term: capillary malformation-arteriovenous malformation syndrome
  term:
    id: MONDO:0012016
    label: capillary malformation-arteriovenous malformation syndrome
synonyms:
- CM-AVM
- CMAVM
- CM-AVM1
- CM-AVM2
parents:
- Vascular disorder
has_subtypes:
- name: CM-AVM1
  display_name: CM-AVM Type 1 (RASA1)
  subtype_term:
    preferred_term: capillary malformation-arteriovenous malformation 1
    term:
      id: MONDO:0020783
      label: capillary malformation-arteriovenous malformation 1
  review_notes: MONDO:0020783 carries OMIM:608354 as a cross-reference.
  description: RASA1-related subtype with multifocal capillary malformations and risk of fast-flow lesions.
- name: CM-AVM2
  display_name: CM-AVM Type 2 (EPHB4)
  subtype_term:
    preferred_term: capillary malformation-arteriovenous malformation 2
    term:
      id: MONDO:0020785
      label: capillary malformation-arteriovenous malformation 2
  review_notes: MONDO:0020785 carries OMIM:618196 as a cross-reference.
  description: EPHB4-related subtype with capillary malformations, telangiectasia, Bier spots, and fast-flow lesion risk.
inheritance:
- name: Autosomal dominant inheritance
  inheritance_term:
    preferred_term: Autosomal dominant inheritance
    term:
      id: HP:0000006
      label: Autosomal dominant inheritance
  description: >-
    CM-AVM is usually inherited as an autosomal dominant disorder caused by
    heterozygous pathogenic variants in RASA1 or EPHB4, with variable expression.
  evidence:
  - reference: PMID:24038909
    reference_title: RASA1 mutations and associated phenotypes in 68 families with capillary malformation-arteriovenous malformation.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Capillary malformation-arteriovenous malformation (CM-AVM) is an autosomal-dominant disorder, caused by heterozygous RASA1 mutations, and manifesting multifocal CMs and high risk for fast-flow lesions.
    explanation: This directly supports autosomal dominant RASA1-related CM-AVM.
pathophysiology:
- name: Germline RASA1 and EPHB4 loss of vascular Ras suppression
  description: >-
    Heterozygous pathogenic variants in RASA1 or EPHB4 reduce signaling control
    of endothelial vascular development, including negative regulation of Ras
    signaling, creating systemic susceptibility to CM-AVM fast-flow lesions.
  cell_types:
  - preferred_term: endothelial cell
    term:
      id: CL:0000115
      label: endothelial cell
  biological_processes:
  - preferred_term: negative regulation of Ras protein signal transduction
    modifier: DECREASED
    term:
      id: GO:0046580
      label: negative regulation of Ras protein signal transduction
  - preferred_term: blood vessel morphogenesis
    modifier: ABNORMAL
    term:
      id: GO:0048514
      label: blood vessel morphogenesis
  evidence:
  - reference: PMID:24038909
    reference_title: RASA1 mutations and associated phenotypes in 68 families with capillary malformation-arteriovenous malformation.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Capillary malformation-arteriovenous malformation (CM-AVM) is an autosomal-dominant disorder, caused by heterozygous RASA1 mutations, and manifesting multifocal CMs and high risk for fast-flow lesions.
    explanation: This supports heterozygous RASA1 variants as a systemic susceptibility mechanism for CM-AVM.
  - reference: PMID:37978175
    reference_title: Mutation of key signaling regulators of cerebrovascular development in vein of Galen malformations.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Rare, damaging transmitted variants were enriched in Ephrin receptor-B4 (EPHB4) (17.5-fold, p = 1.22 x 10-5), which cooperates with p120 RasGAP to regulate vascular development.
    explanation: This supports EPHB4 cooperation with p120 RasGAP/RASA1 in human cerebrovascular development.
  downstream:
  - target: Somatic second-hit allele loss in focal lesions
    description: Germline susceptibility can be followed by focal allele loss in vascular lesion tissue.
- name: Somatic second-hit allele loss in focal lesions
  description: >-
    Lesion tissue can lose the remaining wild-type RASA1 allele, supporting a
    two-hit model in which inherited susceptibility is followed by focal allele
    loss in malformation tissue.
  cell_types:
  - preferred_term: endothelial cell
    term:
      id: CL:0000115
      label: endothelial cell
  biological_processes:
  - preferred_term: negative regulation of Ras protein signal transduction
    modifier: DECREASED
    term:
      id: GO:0046580
      label: negative regulation of Ras protein signal transduction
  evidence:
  - reference: PMID:24038909
    reference_title: RASA1 mutations and associated phenotypes in 68 families with capillary malformation-arteriovenous malformation.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      The analysis of the tissue showed loss of the wild-type RASA1 allele.
    explanation: Loss of the wild-type allele in lesion tissue supports a focal second-hit mechanism.
  downstream:
  - target: RAS-MAPK/ERK-driven arteriovenous malformation formation
    description: Focal loss of residual pathway control promotes abnormal ERK/MAPK-driven vascular morphogenesis.
- name: RAS-MAPK/ERK-driven arteriovenous malformation formation
  description: >-
    Impaired Ras suppression and EPHB4-RASA1 vascular developmental signaling
    converge on abnormal ERK/MAPK signaling and blood vessel morphogenesis,
    promoting arteriovenous malformation and fistula formation.
  cell_types:
  - preferred_term: endothelial cell
    term:
      id: CL:0000115
      label: endothelial cell
  biological_processes:
  - preferred_term: ERK1 and ERK2 cascade
    modifier: INCREASED
    term:
      id: GO:0070371
      label: ERK1 and ERK2 cascade
  - preferred_term: blood vessel morphogenesis
    modifier: ABNORMAL
    term:
      id: GO:0048514
      label: blood vessel morphogenesis
  evidence:
  - reference: PMID:37978175
    reference_title: Mutation of key signaling regulators of cerebrovascular development in vein of Galen malformations.
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: >-
      Mice expressing a VOGM-specific EPHB4 kinase-domain missense variant (Phe867Leu) exhibited disrupted developmental angiogenesis and impaired hierarchical development of arterial-capillary-venous networks, but only in the presence of a "second-hit" allele.
    explanation: This mixed human/genetic and model-organism study supports abnormal arteriovenous network morphogenesis downstream of EPHB4/RASA1 pathway disruption.
phenotypes:
- category: Dermatologic
  name: Multifocal capillary malformations
  frequency: VERY_FREQUENT
  diagnostic: true
  description: >-
    Multiple small capillary malformations are the most characteristic cutaneous
    finding and often prompt molecular testing.
  phenotype_term:
    preferred_term: Capillary malformation
    term:
      id: HP:0025104
      label: Capillary malformation
  evidence:
  - reference: PMID:24038909
    reference_title: RASA1 mutations and associated phenotypes in 68 families with capillary malformation-arteriovenous malformation.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Capillary malformation-arteriovenous malformation (CM-AVM) is an autosomal-dominant disorder, caused by heterozygous RASA1 mutations, and manifesting multifocal CMs and high risk for fast-flow lesions.
    explanation: This establishes multifocal capillary malformations as part of the defining RASA1-related phenotype.
- category: Cardiovascular
  name: Arteriovenous malformation or fistula
  frequency: FREQUENT
  description: >-
    Fast-flow arteriovenous malformations and fistulas can involve skin, soft
    tissue, brain, spine, and other vascular beds.
  phenotype_term:
    preferred_term: Arteriovenous malformation
    term:
      id: HP:0100026
      label: Arteriovenous malformation
  evidence:
  - reference: PMID:29891884
    reference_title: Expanding the clinical and molecular findings in RASA1 capillary malformation-arteriovenous malformation.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Most (75.4%) individuals with a RASA1 variant had CMs, and 44.9% had an AVM/AVF.
    explanation: This clinical series quantifies capillary and fast-flow lesion prevalence in RASA1-positive individuals.
- category: Neurological
  name: Cerebral arteriovenous malformation
  description: Cerebral arteriovenous malformations and vein of Galen malformations occur within the CM-AVM fast-flow lesion spectrum.
  phenotype_term:
    preferred_term: Cerebral arteriovenous malformation
    term:
      id: HP:0002408
      label: Cerebral arteriovenous malformation
  evidence:
  - reference: PMID:37978175
    reference_title: Mutation of key signaling regulators of cerebrovascular development in vein of Galen malformations.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      To elucidate the pathogenesis of vein of Galen malformations (VOGMs), the most common and most severe of congenital brain arteriovenous malformations, we performed an integrated analysis of 310 VOGM proband-family exomes and 336,326 human cerebrovasculature single-cell transcriptomes.
    explanation: This supports cerebral arteriovenous malformations as a relevant fast-flow lesion context for RASA1/EPHB4 pathway disruption.
- category: Cardiovascular
  name: Parkes Weber syndrome or limb arteriovenous shunting
  description: RASA1-related disease can include Parkes Weber syndrome with limb overgrowth and high-flow arteriovenous shunting.
  phenotype_term:
    preferred_term: Parkes Weber syndrome or limb arteriovenous shunting
    term:
      id: HP:0004947
      label: Arteriovenous fistula
  review_notes: >-
    No exact local HPO term for Parkes Weber syndrome was available; HP:0004947
    captures the arteriovenous shunting component supported by the evidence.
  evidence:
  - reference: PMID:29891884
    reference_title: Expanding the clinical and molecular findings in RASA1 capillary malformation-arteriovenous malformation.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      RASA1-related disorders are vascular malformation syndromes characterized by hereditary capillary malformations (CM) with or without arteriovenous malformations (AVM), arteriovenous fistulas (AVF), or Parkes Weber syndrome.
    explanation: This directly supports Parkes Weber syndrome within the RASA1-related CM-AVM spectrum.
- category: Dermatologic
  name: Bier spots
  subtype: CM-AVM2
  frequency: OCCASIONAL
  description: Bier spots are reported as a distinct cutaneous finding in EPHB4-related CM-AVM2.
  phenotype_term:
    preferred_term: Bier spots
    term:
      id: HP:0001010
      label: Hypopigmentation of the skin
  review_notes: >-
    No exact local HPO term for Bier spots was available; HP:0025548 resolves
    locally to Increased mean corpuscular hemoglobin concentration, so the
    broader hypopigmentation term is used.
  evidence:
  - reference: PMID:35088870
    reference_title: "Capillary Malformation-arteriovenous Malformation Type 2: A Case Report and Review."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Telangiectasias were reported in 28 (22%) patients, and Bier spots were described in 20 (15.7%) patients.
    explanation: The EPHB4-focused review reports Bier spots in 15.7% of CM-AVM2 patients.
- category: Dermatologic
  name: Telangiectasia
  description: Telangiectasias occur particularly in EPHB4-related CM-AVM2 and can overlap clinically with HHT.
  phenotype_term:
    preferred_term: Telangiectasia
    term:
      id: HP:0001009
      label: Telangiectasia
  evidence:
  - reference: PMID:35088870
    reference_title: "Capillary Malformation-arteriovenous Malformation Type 2: A Case Report and Review."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Telangiectasias were reported in 28 (22%) patients, and Bier spots were described in 20 (15.7%) patients.
    explanation: The EPHB4-focused review reports telangiectasias in a subset of CM-AVM2 patients.
genetic:
- name: RASA1
  association: Causative
  presence: Positive
  subtype: CM-AVM1
  gene_term:
    preferred_term: RASA1
    term:
      id: hgnc:9871
      label: RASA1
  inheritance:
  - name: Autosomal dominant inheritance
    inheritance_term:
      preferred_term: Autosomal dominant inheritance
      term:
        id: HP:0000006
        label: Autosomal dominant inheritance
  notes: >-
    RASA1 encodes p120 RasGAP. Heterozygous pathogenic variants cause CM-AVM1;
    loss of the wild-type allele in lesion tissue supports a second-hit model.
    Clinical expression is highly penetrant but variable, and mosaicism can
    modify the observed lesion burden.
  evidence:
  - reference: PMID:24038909
    reference_title: RASA1 mutations and associated phenotypes in 68 families with capillary malformation-arteriovenous malformation.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Fifty-eight distinct RASA1 mutations (43 novel) were identified in 68 index patients with CM-AVM and none in patients with other phenotypes.
    explanation: This cohort establishes RASA1 variants as specific to the CM-AVM phenotype among tested groups.
- name: EPHB4
  association: Causative
  presence: Positive
  subtype: CM-AVM2
  gene_term:
    preferred_term: EPHB4
    term:
      id: hgnc:3395
      label: EPHB4
  inheritance:
  - name: Autosomal dominant inheritance
    inheritance_term:
      preferred_term: Autosomal dominant inheritance
      term:
        id: HP:0000006
        label: Autosomal dominant inheritance
  notes: >-
    EPHB4 pathogenic variants cause CM-AVM2 and are linked to capillary
    malformations, telangiectasia, Bier spots, and cerebrovascular high-flow
    lesions.
  evidence:
  - reference: PMID:35088870
    reference_title: "Capillary Malformation-arteriovenous Malformation Type 2: A Case Report and Review."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      We describe here a four-generation family with a novel heterozygous pathogenic variant in the EPHB4 gene (NM_004444.5 (EPHB4): c.2224G>C, p.(Ala742Pro)).
    explanation: This report supports heterozygous pathogenic EPHB4 variants as causative for CM-AVM2.
diagnosis:
- name: Molecular testing for RASA1 and EPHB4
  description: >-
    Molecular diagnosis uses sequencing and copy-number analysis of RASA1 and
    EPHB4, especially for patients with multifocal capillary malformations or
    fast-flow lesions.
  diagnosis_term:
    preferred_term: genetic testing
    term:
      id: MAXO:0000127
      label: genetic testing
  results: A pathogenic variant in RASA1 or EPHB4 supports a molecular diagnosis.
  evidence:
  - reference: PMID:29891884
    reference_title: Expanding the clinical and molecular findings in RASA1 capillary malformation-arteriovenous malformation.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Our data suggest that screening for large RASA1 deletions and duplications in this disorder is important and suggest that NGS multi-gene panel testing is beneficial for the molecular diagnosis of cases with complex vascular phenotypes.
    explanation: This supports molecular testing, including deletion/duplication and panel approaches.
treatments:
- name: Endovascular or surgical treatment of fast-flow lesions
  description: >-
    Management is lesion-specific and can include embolization or surgery for
    clinically significant arteriovenous malformations or fistulas.
  treatment_term:
    preferred_term: therapeutic procedure
    term:
      id: NCIT:C49236
      label: Therapeutic Procedure
  evidence:
  - reference: PMID:35547535
    reference_title: "Arteriovenous Cerebral High Flow Shunts in Children: From Genotype to Phenotype."
    supports: PARTIAL
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      The genetic data helps to classify these malformations and to guide treatment toward lowest risk of post-operative cerebral ischemic-hemorrhagic complications.
    explanation: This supports genotype-informed procedural planning for cerebral high-flow shunts but does not specify a single intervention for all CM-AVM lesions.
- name: Trametinib for Ras/MAPK-driven vascular anomalies
  description: >-
    Trametinib is an investigational MEK inhibitor approach for complicated
    Ras/MAPK-driven vascular anomalies, including arteriovenous malformations.
  treatment_term:
    preferred_term: Pharmacotherapy
    term:
      id: NCIT:C15986
      label: Pharmacotherapy
    therapeutic_agent:
    - preferred_term: trametinib
      term:
        id: CHEBI:75998
        label: trametinib
  evidence:
  - reference: clinicaltrials:NCT04258046
    reference_title: Phase II Clinical Trial of MEK Inhibitor Trametinib in the Treatment of Complicated Extracranial Arterial Venous Malformation (VM)
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      The purpose of this study is to assess the safety and efficacy of Trametinib in children and adults with Extracranial Arteriovenous Malformation (AVM).
    explanation: This trial supports trametinib as an investigational MEK-inhibitor therapy for complicated AVM.
clinical_trials:
- name: NCT04258046
  phase: PHASE_II
  status: COMPLETED
  description: Phase II trametinib study for complicated extracranial arteriovenous malformation.
  target_phenotypes:
  - preferred_term: Arteriovenous malformation
    term:
      id: HP:0100026
      label: Arteriovenous malformation
  evidence:
  - reference: clinicaltrials:NCT04258046
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      The purpose of this study is to assess the safety and efficacy of Trametinib in children and adults with Extracranial Arteriovenous Malformation (AVM).
    explanation: This supports a trametinib clinical trial relevant to CM-AVM fast-flow lesions.
- name: NCT07549646
  phase: PHASE_II
  status: ACTIVE_NOT_RECRUITING
  description: Phase II trametinib study for Ras/MAPK pathway-driven vascular anomalies.
  target_phenotypes:
  - preferred_term: Arteriovenous malformation
    term:
      id: HP:0100026
      label: Arteriovenous malformation
  evidence:
  - reference: clinicaltrials:NCT07549646
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      The purpose of this study is to assess the effectiveness and safety of Trametinib (the "Study Drug") in patients with Ras/MAPK pathway driven vascular anomalies (VA).
    explanation: This supports a pathway-directed trametinib trial for vascular anomalies relevant to CM-AVM biology.
- name: NCT07072403
  phase: PHASE_I
  status: ACTIVE_NOT_RECRUITING
  description: Prospective systemic trametinib study for complicated vascular anomalies.
  target_phenotypes:
  - preferred_term: Arteriovenous malformation
    term:
      id: HP:0100026
      label: Arteriovenous malformation
  evidence:
  - reference: clinicaltrials:NCT07072403
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      This study aims to evaluate the safety and efficacy of systemic trametinib therapy in patients with complicated vascular anomalies.
    explanation: This supports an additional prospective trametinib trial for complicated vascular anomalies.
📚

References & Deep Research

Deep Research

1
Falcon
Capillary Malformation–Arteriovenous Malformation (CM‑AVM) Syndrome — Disease Characteristics Research Report
Edison Scientific Literature 72 citations 2026-05-04T18:43:30.449232

Capillary Malformation–Arteriovenous Malformation (CM‑AVM) Syndrome — Disease Characteristics Research Report

1. Disease Information

Concise overview (current understanding)

Capillary malformation–arteriovenous malformation (CM‑AVM) syndrome is a rare, autosomal dominant vascular malformation disorder characterized by multifocal cutaneous capillary malformations (CMs) and an increased risk of fast‑flow vascular lesions, especially arteriovenous malformations (AVMs) and arteriovenous fistulas (AVFs). (palermo2025capillarymalformation–arteriovenousmalformation pages 1-2, brix2022capillarymalformationarteriovenousmalformation pages 1-2)

A recent systematic review abstract summarizes the canonical definition: CM‑AVM is “characterized by cutaneous capillary malformations and fast‑flow vascular lesions, including arteriovenous malformations (AVMs) and arteriovenous fistulas (AVFs).” (Palermo et al., 2025‑12; https://doi.org/10.1007/s00381-025-07089-5) (palermo2025capillarymalformation–arteriovenousmalformation pages 1-2)

Key identifiers (retrieved in this run)

Identifier type Value Notes Source URL
MONDO ID MONDO_0012016 Open Targets disease association lists capillary malformation-arteriovenous malformation syndrome as MONDO_0012016; associated targets include RASA1 and EPHB4 (palermo2025capillarymalformation–arteriovenousmalformation pages 1-2) https://platform.opentargets.org
OMIM 608354 CM-AVM / CMAVM / capillary malformation-arteriovenous malformation syndrome; cited as OMIM #608354 in RASA1-focused CM-AVM literature (wooderchakdonahue2018expandingtheclinical pages 1-2, revencu2020rasa1mosaicmutations pages 1-2) https://doi.org/10.1038/s41431-018-0196-1
OMIM 618196 CM-AVM2; EPHB4-related form explicitly noted as OMIM #618196 in EPHB4/VOGM literature (zhao2023geneticdysregulationof pages 12-14, zhao2023mutationofkey pages 1-2) https://doi.org/10.1038/s41467-023-43062-z
Orphanet 137667 Open Targets evidence includes Orphanet_137667 for “Capillary malformation - arteriovenous malformation”; direct Orphanet page URL not retrieved in provided evidence (palermo2025capillarymalformation–arteriovenousmalformation pages 1-2) https://www.orpha.net
Synonym CM-AVM Standard abbreviation used across cohort/review papers for the syndrome (palermo2025capillarymalformation–arteriovenousmalformation pages 1-2, wooderchakdonahue2018expandingtheclinical pages 1-2) https://doi.org/10.1007/s00381-025-07089-5
Synonym CMAVM Variant abbreviation used in clinical genetics/neurovascular literature (le2025arteriovenousmalformations(avms) pages 1-3) https://doi.org/10.3389/fped.2022.871565
Synonym capillary malformation-arteriovenous malformation syndrome Full disease name used in reviews and case series (palermo2025capillarymalformation–arteriovenousmalformation pages 1-2, coccia2023prenatalclinicalfindings pages 9-11) https://doi.org/10.3390/genes14030549
Synonym capillary malformation–AVM syndrome Punctuation variant used in recent reviews (morin2025vascularmalformationsfrom pages 5-6) https://doi.org/10.1038/s44321-025-00344-x
Synonym CM-AVM1 RASA1-related subtype; papers distinguish CM-AVM1 from CM-AVM2 (lin2026chinesecapillarymalformationarteriovenous pages 7-9, zhao2023geneticdysregulationof pages 12-14) https://doi.org/10.1038/s41467-023-43062-z
Synonym CM-AVM2 EPHB4-related subtype; recognized in EPHB4 case review and cerebrovascular genetics literature (brix2022capillarymalformationarteriovenousmalformation pages 1-2, zhao2023geneticdysregulationof pages 12-14) https://doi.org/10.2340/actadv.v102.1126

Table: This table compiles key disease identifiers and commonly used synonyms for capillary malformation-arteriovenous malformation syndrome from the available evidence. It is useful for harmonizing nomenclature across knowledge base entries and linked resources.

Notes on missing identifiers: ICD‑10/ICD‑11 and MeSH terms were not retrieved from the available full texts in this tool run; MONDO and OMIM/Orphanet identifiers were recovered (artifact above). (palermo2025capillarymalformation–arteriovenousmalformation pages 1-2, wooderchakdonahue2018expandingtheclinical pages 1-2, revencu2020rasa1mosaicmutations pages 1-2)

Synonyms and alternative names

Commonly used synonyms include CM‑AVM, CMAVM, capillary malformation–AVM syndrome, and genetic subtypes CM‑AVM1 (RASA1) and CM‑AVM2 (EPHB4). (brix2022capillarymalformationarteriovenousmalformation pages 1-2, wooderchakdonahue2018expandingtheclinical pages 1-2, zhao2023mutationofkey pages 1-2)

Evidence source type

Most knowledge about CM‑AVM comes from aggregated disease‑level resources (systematic reviews and cohorts) plus case series and family studies; some mechanistic understanding derives from mouse and zebrafish models and endothelial cell studies. (palermo2025capillarymalformation–arteriovenousmalformation pages 2-4, zhao2023mutationofkey pages 1-2, zhao2023geneticdysregulationof pages 35-39)


2. Etiology

Disease causal factors

CM‑AVM is primarily a Mendelian genetic disorder caused by pathogenic variants in RASA1 (CM‑AVM1) and EPHB4 (CM‑AVM2), which disrupt endothelial signaling that normally restrains RAS‑MAPK/ERK activity. (palermo2025capillarymalformation–arteriovenousmalformation pages 1-2, chen2023ephb4rasa1mediatednegativeregulation pages 2-4, morin2025vascularmalformationsfrom pages 5-6)

Risk factors

  • Genetic: Heterozygous pathogenic variants in RASA1 or EPHB4; de novo variants occur (e.g., ~26.5% likely de novo in a large RASA1 cohort). (revencu2013rasa1mutationsand pages 7-9)
  • Somatic/mosaic contributions: Low‑level post‑zygotic mosaic RASA1 variants can cause classical CM‑AVM; mosaic allele fractions as low as a few percent were detected, and gonosomal mosaicism can confer recurrence risk. (revencu2020rasa1mosaicmutations pages 1-2)

Protective factors

No disease‑specific protective genetic or environmental factors were identified in the retrieved sources.

Gene–environment interactions

No specific gene–environment interactions were identified in the retrieved sources.


3. Phenotypes

Core phenotype spectrum with HPO suggestions

Clinical feature Description Typical onset/course Frequency/quant data Suggested HPO term(s)
Multifocal capillary malformations (CMs) Small round-to-oval pink-red to violaceous capillary malformations, often multifocal and sometimes with surrounding pale halo/white halo; hallmark cutaneous finding of CM-AVM Usually congenital or early childhood; chronic, often stable in number/appearance but variable expressivity RASA1 cohort: 306/314 (97%) had CMs; EPHB4 review: multiple CMs in 114/127 (89.8%), solitary CM in 12/127 (9.4%); ARUP RASA1 series: 75.4% had CMs (revencu2013rasa1mutationsand pages 1-2, wooderchakdonahue2018expandingtheclinical pages 1-2, brix2022capillarymalformationarteriovenousmalformation pages 1-2, revencu2013rasa1mutationsand pages 7-9) Capillary malformation [HP:0001052]; Multiple capillary malformations [HP:0200049]
Pale halo / white halo around skin lesions Perilesional pale halo or white halo surrounding CMs; may reflect microshunting and is diagnostically suggestive Present from infancy/childhood; usually persistent Reported as characteristic in RASA1- and EPHB4-related disease; proposed as diagnostic clue though precise pooled prevalence not established in the provided evidence (brix2022capillarymalformationarteriovenousmalformation pages 1-2, wooderchakdonahue2018expandingtheclinical pages 1-2, revencu2020rasa1mosaicmutations pages 1-2, brix2022capillarymalformationarteriovenousmalformation pages 4-5) Halo nevus-like lesion / Perilesional pallor [suggested HPO mapping: Abnormality of skin color around lesion, no exact term confirmed]
Fast-flow vascular malformation (AVM/AVF spectrum) Arteriovenous malformations and arteriovenous fistulas affecting skin, muscle, bone, brain, spine, and other sites; major source of morbidity Congenital/developmental; may present in childhood or later when symptomatic; can progress or decompensate hemodynamically Revencu 2013: 75/314 (23%) had AVM/AVF; Wooderchak-Donahue 2018: ~30% historically, 44.9% in the ARUP referred series; EPHB4 review: 23/127 (18.1%) had AVM/AVF (revencu2013rasa1mutationsand pages 1-2, wooderchakdonahue2018expandingtheclinical pages 1-2, brix2022capillarymalformationarteriovenousmalformation pages 1-2, revencu2013rasa1mutationsand pages 7-9) Arteriovenous malformation [HP:0100026]; Arteriovenous fistula [HP:0012404]
Intracranial / cerebrovascular fast-flow lesions Brain vascular lesions including pial AVFs, parenchymal AVMs, and vein-of-Galen malformations; important screening target Often congenital or pediatric onset; may be asymptomatic or present acutely with neurologic/hemodynamic complications Palermo 2025 pooled 148 genetically confirmed patients: pial AVF 63/148 (43.3%), AVM 54/148 (36.0%), vein-of-Galen malformation 26/148 (17.3%); Revencu 2013: 32/314 (10%) had intracranial lesions (palermo2025capillarymalformation–arteriovenousmalformation pages 1-2, palermo2025capillarymalformation–arteriovenousmalformation pages 2-4, revencu2013rasa1mutationsand pages 1-2) Cerebral arteriovenous malformation [HP:0002409]; Intracranial arteriovenous fistula [suggested HPO mapping]; Vein of Galen malformation [suggested HPO mapping]
Spinal arteriovenous lesions Intraspinal AVM/AVF causing neurologic risk Congenital/developmental; may present in childhood with neurologic deficits or pain Revencu 2013 included intraspinal AVM/AVF within fast-flow spectrum; Brix 2022 review noted 2/127 (1.6%) spinal AVMs among EPHB4 cases (revencu2013rasa1mutationsand pages 7-9, brix2022capillarymalformationarteriovenousmalformation pages 4-5) Spinal arteriovenous malformation [suggested HPO mapping]; Abnormality of the spinal vasculature [suggested HPO mapping]
Vein of Galen aneurysmal malformation (VGAM/VGaM) Distinct high-flow cerebral shunt phenotype particularly enriched in EPHB4-related disease Prenatal, neonatal, or infancy presentation common; may cause heart failure/hydrocephalus Palermo 2025: 26/148 (17.3%) overall; Tas 2022: among VGAM (n=64), 9 EPHB4 and 2 RASA1 cases; Brix 2022 EPHB4 review: 3/127 (2.4%) VGaM (palermo2025capillarymalformation–arteriovenousmalformation pages 2-4, tas2022arteriovenouscerebralhigh pages 3-4, brix2022capillarymalformationarteriovenousmalformation pages 4-5) Vein of Galen malformation [suggested HPO mapping]; Cerebral arteriovenous malformation [HP:0002409]
Parkes Weber syndrome / limb overgrowth with AV shunting Combined capillary malformation, soft-tissue/bony hypertrophy, and AV microfistulas/high-flow shunting in an extremity Usually congenital/childhood; may progress with growth and hemodynamic burden Revencu 2013: 26/314 (8%) had Parkes Weber syndrome; characteristic within RASA1 spectrum (revencu2013rasa1mutationsand pages 1-2, revencu2020rasa1mosaicmutations pages 1-2, revencu2013rasa1mutationsand pages 7-9) Hemihyperplasia [HP:0003074]; Limb overgrowth [HP:0001537]; Arteriovenous fistula [HP:0012404]
Telangiectasia Punctate or macular telangiectatic lesions, often contributing to HHT-like appearance Childhood to adulthood; persistent EPHB4 literature review: 28/127 (22.0%) had telangiectasia; Wooderchak-Donahue reported telangiectatic dermal lesions in 11 individuals with pathogenic RASA1 variants (brix2022capillarymalformationarteriovenousmalformation pages 1-2, brix2022capillarymalformationarteriovenousmalformation pages 2-4, wooderchakdonahue2018expandingtheclinical pages 10-11) Telangiectasia [HP:0001009]
Bier spots Irregular pale macules/spots, especially reported in EPHB4-related CM-AVM2 Often childhood/adolescence; may persist EPHB4 literature review: 20/127 (15.7%) with Bier spots (brix2022capillarymalformationarteriovenousmalformation pages 1-2, brix2022capillarymalformationarteriovenousmalformation pages 4-5) Bier spots [HP:0025548]
Epistaxis / recurrent nosebleeds Recurrent epistaxis can occur, particularly in EPHB4-related disease, creating overlap with HHT Variable onset, often later childhood/adulthood; episodic Reported in at least 9 CM-AVM2 cases in Brix review; frequency incompletely reported across studies (brix2022capillarymalformationarteriovenousmalformation pages 1-2, brix2022capillarymalformationarteriovenousmalformation pages 2-4, brix2022capillarymalformationarteriovenousmalformation pages 4-5, palermo2025capillarymalformation–arteriovenousmalformation pages 11-13) Epistaxis [HP:0000421]
Heart failure from high-flow shunt Congestive heart failure due to significant AV shunting, especially neonatal cerebral or thoracoabdominal lesions Prenatal/neonatal or infantile in severe cases; potentially life-threatening Highlighted in prenatal RASA1 series and AVM literature as major complication; prenatal-onset cases included congestive heart failure among key warning signs (coccia2023prenatalclinicalfindings pages 9-11, wooderchakdonahue2018expandingtheclinical pages 1-2, palermo2025capillarymalformation–arteriovenousmalformation pages 11-13) Congestive heart failure [HP:0001635]
Neurologic complications Hemorrhage, seizures, hydrocephalus, neurologic injury, or brain/spinal dysfunction from CNS vascular malformations Childhood to adulthood; may be acute if hemorrhage occurs Wooderchak-Donahue notes AVMs/AVFs can cause hemorrhage and neurologic injury; Palermo review emphasizes severe neurologic complications if lesions are undetected (wooderchakdonahue2018expandingtheclinical pages 1-2, palermo2025capillarymalformation–arteriovenousmalformation pages 1-2, palermo2025capillarymalformation–arteriovenousmalformation pages 11-13) Seizure [HP:0001250]; Intracranial hemorrhage [HP:0002170]; Hydrocephalus [HP:0000238]; Abnormal nervous system physiology [suggested HPO mapping]
Prenatal hydrops / non-immune hydrops fetalis Severe prenatal manifestation of RASA1-related CM-AVM, likely reflecting occult high-flow lesions or lymphatic/hemodynamic compromise Prenatal onset; severe, sometimes fatal Coccia 2023 notes only 21 prenatal-onset cases had been reported; death occurred in 6/21 (30%); key prenatal signs include non-immune hydrops fetalis and polyhydramnios (coccia2023prenatalclinicalfindings pages 9-11) Nonimmune hydrops fetalis [HP:0001790]; Fetal hydrops [HP:0001789]
Polyhydramnios Excess amniotic fluid in prenatal-onset CM-AVM Prenatal onset; may signal severe fetal disease Reported among prenatal warning signs in RASA1-related CM-AVM; included among 21 published prenatal-onset cases reviewed by Coccia et al. (coccia2023prenatalclinicalfindings pages 9-11) Polyhydramnios [HP:0001561]
Pleural effusion / chylothorax Prenatal or neonatal thoracic fluid accumulation reported in severe prenatal cases Prenatal or neonatal onset; can contribute to respiratory compromise Coccia 2023 specifically lists pleural effusion and chylothorax among prenatal manifestations (coccia2023prenatalclinicalfindings pages 9-11) Pleural effusion [HP:0002202]; Chylothorax [HP:0010310]
Multifocal neurovascular malformations in children with syndromic clue lesions In pediatric neurovascular cohorts, the presence of multiple cutaneous capillary malformations increases suspicion for CM-AVM Usually recognized in childhood; supports syndromic diagnosis and surveillance Engel 2023 found having ≥2 capillary malformations strongly associated with definite CM-AVM; genetic diagnoses included RASA1 and EPHB4 variants (engel2023prevalenceandpredictors pages 13-17) Multiple capillary malformations [HP:0200049]; Vascular malformation [HP:0005297]

Table: This table summarizes the core clinical phenotype spectrum of capillary malformation–arteriovenous malformation syndrome, including quantitative frequencies where available and suggested HPO mappings. It is useful for disease knowledge-base curation, phenotype annotation, and genotype-phenotype interpretation.

High‑value quantitative phenotype statistics (recent aggregated sources)

  • In a 2025 systematic review of 148 genetically confirmed CM‑AVM patients with cerebrovascular manifestations, pooled lesion frequencies were: pial AVF 43.3% (63/148), AVM 36.0% (54/148), vein of Galen malformation 17.3% (26/148); nearly 24.7% underwent endovascular embolization and 5.3% underwent surgery. (Palermo et al., 2025‑12; https://doi.org/10.1007/s00381-025-07089-5) (palermo2025capillarymalformation–arteriovenousmalformation pages 2-4, palermo2025capillarymalformation–arteriovenousmalformation pages 7-9)
  • For CM‑AVM2 (EPHB4) across a 2022 literature review of 127 EPHB4‑confirmed patients: multiple CMs 89.8%, AVM/AVF 18.1%, telangiectasia 22%, Bier spots 15.7%, and CNS fast‑flow lesions 3.9% (including vein‑of‑Galen malformations and spinal AVMs). (Brix et al., 2022‑03; https://doi.org/10.2340/actadv.v102.1126) (brix2022capillarymalformationarteriovenousmalformation pages 1-2, brix2022capillarymalformationarteriovenousmalformation pages 4-5)
  • For RASA1 CM‑AVM across combined cohorts: capillary malformations in 97%, AVM/AVF in 23%, intracranial lesions in 10%, and Parkes Weber syndrome in 8%. (Revencu et al., 2013‑12; https://doi.org/10.1002/humu.22431) (revencu2013rasa1mutationsand pages 1-2)

Prenatal/neonatal manifestations (recent, 2023)

Coccia et al. (Genes, 2023‑02; https://doi.org/10.3390/genes14030549) emphasize that prenatal presentations exist and can be severe. Their abstract states: “Pathogenic variants in RASA1 are typically associated with a clinical condition called ‘capillary malformation‑arteriovenous malformation’ (CM‑AVM) syndrome, an autosomal dominant genetic disease characterized by a broad phenotypic variability, even within families.” (coccia2023prenatalclinicalfindings pages 9-11)

In the same abstract: “Although CM‑AVM syndrome has been widely described in the literature, only 21 cases with prenatal onset of clinical features have been reported thus far.” and prenatal warning signs include hydrops‑type presentations; mortality among reported prenatal‑onset cases was ~30% (6/21). (coccia2023prenatalclinicalfindings pages 9-11)


4. Genetic / Molecular Information

Causal genes

  • RASA1 (RAS p21 protein activator 1) — CM‑AVM1 (OMIM 608354). (wooderchakdonahue2018expandingtheclinical pages 1-2, revencu2020rasa1mosaicmutations pages 1-2)
  • EPHB4 (EPH receptor B4) — CM‑AVM2 (OMIM 618196). (zhao2023mutationofkey pages 1-2)

Variant types, mosaicism, and “second hit” concept

Subtype Causal gene Variant class (typical) Inheritance Key pathway/mechanism Evidence highlights (include at least one quantitative/stat statement where available) Key citations (PMID if available in text; otherwise DOI)
CM-AVM1 RASA1 Predominantly loss-of-function; truncating/nonsense, frameshift, splice-site; multi-exon deletions also reported; mosaic variants can occur Autosomal dominant with high penetrance and variable expressivity; de novo and mosaic cases documented RASA1 encodes p120 RasGAP, a negative regulator of RAS-MAPK/ERK signaling in endothelial cells; lesion formation is supported by a second-hit model in at least some vascular beds In a 68-family cohort, 306/314 (97%) had capillary malformations, 75/314 (23%) had AVM/AVF, 32/314 (10%) had intracranial lesions, and 26/314 (8%) had Parkes Weber syndrome; penetrance reported as 98.5% and ~26.5% of mutations were likely de novo (revencu2013rasa1mutationsand pages 1-2, revencu2013rasa1mutationsand pages 7-9) Revencu 2013, Human Mutation, DOI: https://doi.org/10.1002/humu.22431
CM-AVM1 with mosaicism RASA1 Low-level postzygotic mosaic loss-of-function variants, including nonsense/truncating alleles; occasional lesion-specific second hits Mosaic; can include gonosomal/germline transmission risk Mosaic loss of endothelial RASA1 can produce classical CM-AVM; supports germline-or-mosaic susceptibility plus local second-hit pathogenesis Four distinct mosaic RASA1 variants were detected with allele fractions ranging from 3% to 25% overall; one patient also had a somatic second hit, and one mosaic proband had 3 affected children, showing reproductive risk (revencu2020rasa1mosaicmutations pages 1-2) Revencu 2020, Journal of Medical Genetics, DOI: https://doi.org/10.1136/jmedgenet-2019-106024
RASA1-related CM-AVM spectrum RASA1 Function-affecting variants of diverse classes, including nonsense/frameshift/splice and large deletions/duplications Autosomal dominant; familial and sporadic cases Loss of RASA1 activity disrupts endothelial Ras restraint and promotes fast-flow malformations; somatic second-hit events in lesions further support focal disease biology In an ARUP series of 69 unrelated cases, 60 had deleterious RASA1 variants, 29 of them novel; 5 large deletions gave a deletion/duplication rate of 8.3%; 75.4% had capillary malformations and 44.9% had AVM/AVF (wooderchakdonahue2018expandingtheclinical pages 1-2, wooderchakdonahue2018expandingtheclinical pages 10-11) Wooderchak-Donahue 2018, Eur J Hum Genet, DOI: https://doi.org/10.1038/s41431-018-0196-1
CM-AVM2 EPHB4 Germline loss-of-function variants are typical; kinase-domain damaging variants also implicated in cerebrovascular disease Autosomal dominant with incomplete/variable expressivity EPHB4 acts upstream of RASA1 to suppress endothelial RAS-MAPK signaling and regulate venous identity, endothelial sorting, and arteriovenous patterning Recent pooled cerebrovascular review found 21/148 (14.0%) genetically confirmed CM-AVM cases carried EPHB4 variants; compared with RASA1, EPHB4 cases showed a narrower cerebrovascular phenotype and were more often linked to vein-of-Galen malformations (palermo2025capillarymalformation–arteriovenousmalformation pages 1-2, palermo2025capillarymalformation–arteriovenousmalformation pages 2-4) Palermo 2025, Child's Nervous System, DOI: https://doi.org/10.1007/s00381-025-07089-5
CM-AVM1/2 shared mechanism RASA1 / EPHB4 Germline loss-of-function; mosaic/postzygotic events also reported in vascular malformations Usually autosomal dominant for syndromic disease EPHB4→RASA1→RAS inactivation: EPHB4 signaling restrains endothelial Ras-MAPK activity via RASA1-dependent mechanisms; failure perturbs angiogenic remodeling and AV specification Morin summarizes CM-AVM as caused by germline RASA1 or EPHB4 loss-of-function and places both genes in the endothelial RAS regulatory module; the review also notes that such variants can occur as mosaic events in sporadic vascular malformations (morin2025vascularmalformationsfrom pages 5-6) Morin 2025, EMBO Mol Med, DOI: https://doi.org/10.1038/s44321-025-00344-x
Endothelial signaling module underlying CM-AVM EPHB4-RASA1 axis Functional disruption of receptor-effector signaling; disease-causing missense or loss-of-function changes can converge on failed Ras suppression Mechanism relevant to inherited and mosaic disease EPHB4 normally recruits/activates RASA1-linked Ras suppression in endothelial cells; loss causes excess ERK/MAPK activity, impaired collagen IV export, abnormal angiogenesis, and defective arterial-capillary-venous remodeling Mechanistic review states RASA1 mutations account for ~70% of CM-AVM and EPHB4 ~30%; constitutive mouse deficiency of either gene causes embryonic lethality around E10.5 with failure of primitive plexus remodeling into hierarchical arterial-capillary-venous networks (chen2023ephb4rasa1mediatednegativeregulation pages 2-4, chen2023ephb4rasa1mediatednegativeregulation pages 7-9, chen2023ephb4rasa1mediatednegativeregulation pages 6-7) Chen/van der Ent/King 2023 mechanistic review, DOI: 10.1101/2023.03.18.532837 (preprint-related mechanistic source as available in context)
Cerebrovascular/high-flow subtype enrichment RASA1 predominantly; EPHB4 enriched in VGAM Heterozygous damaging germline variants Autosomal dominant susceptibility for syndromic cases Developing endothelial cells are the likely spatiotemporal locus; genotype influences shunt subtype In children with cerebral high-flow shunts, RASA1 variants were found in 25% overall and across all shunt types, whereas EPHB4 variants were found in 8% overall and were specific to true VGAM in that cohort; among VGAM (n=64) there were 9 EPHB4 vs 2 RASA1 cases (tas2022arteriovenouscerebralhigh pages 3-4) Tas 2022, Front Pediatr, DOI: https://doi.org/10.3389/fped.2022.871565
Human genetics plus animal-model evidence for cerebrovascular CM-AVM biology RASA1 / EPHB4 De novo RASA1 loss-of-function; damaging transmitted EPHB4 variants; EPHB4 kinase-domain variant model Germline susceptibility with evidence for additional-hit requirement in some models Integrated human genetics and model systems support an endothelial RAS signaling network controlling developmental angiogenesis and AV network hierarchy Nature Communications 2023 identified a genome-wide significant burden of de novo RASA1 loss-of-function variants (2042.5-fold, p=4.79×10⁻⁷) and 17.5-fold enrichment of damaging transmitted EPHB4 variants (p=1.22×10⁻⁵); an EPHB4 Phe867Leu mouse model showed disrupted angiogenesis only with a second-hit allele (zhao2023mutationofkey pages 1-2, zhao2023geneticdysregulationof pages 12-14) Zhao 2023, Nature Communications, DOI: https://doi.org/10.1038/s41467-023-43062-z
Arteriovenous specification relevance to EPHB4 disease EPHB4 Endothelial Ephb4 loss in model systems Experimental conditional endothelial loss Eph/ephrin signaling couples endothelial cell sorting, arterial specification, and AV patterning; provides mechanistic rationale for EPHB4-related vascular malformations In inducible mouse retina models, postnatal Ephb4 inactivation increased incorporation of mutant endothelial cells into arteries and produced more arterial branches and increased arterial extension, linking EPHB4 deficiency to abnormal AV patterning (stewen2024ephephrinsignalingcouples pages 1-2) Stewen 2024, Nature Communications, DOI: https://doi.org/10.1038/s41467-024-46300-0
Aggregate cerebrovascular CM-AVM phenotype across genes RASA1 / EPHB4 Genetically confirmed pathogenic variants Mostly autosomal dominant syndromic disease Shared fast-flow predisposition, but genotype influences lesion spectrum; screening is justified because lesions are clinically important and often treatable In a systematic review of 148 genetically confirmed CM-AVM patients, cerebrovascular lesions included pial AVF 43.3% (63/148), AVM 36.0% (54/148), and vein-of-Galen malformation 17.3% (26/148); 24.7% underwent endovascular embolization and 5.3% surgery (palermo2025capillarymalformation–arteriovenousmalformation pages 1-2, palermo2025capillarymalformation–arteriovenousmalformation pages 2-4) Palermo 2025, Child's Nervous System, DOI: https://doi.org/10.1007/s00381-025-07089-5

Table: This table summarizes the main genetic subtypes and mechanisms underlying capillary malformation–arteriovenous malformation syndrome, focusing on RASA1 and EPHB4. It integrates cohort data, mosaic/second-hit evidence, and recent mechanistic studies to support genotype-to-pathway interpretation.

Key primary‑literature findings: * High penetrance and de novo events: Revencu et al. report penetrance ~98.5% and ~26.5% de novo RASA1 variants in their cohort; they also report strong variability and support for second‑hit biology. (revencu2013rasa1mutationsand pages 7-9) * Mosaicism: Revencu et al. (J Med Genet, 2020‑07) report mosaic RASA1 allele fractions in blood/tissue and conclude: “This study shows that RASA1 mosaic mutations can cause capillary malformation‑arteriovenous malformation.” (https://doi.org/10.1136/jmedgenet-2019-106024) (revencu2020rasa1mosaicmutations pages 1-2) * Human genetics + systems biology (2023): Zhao et al. (Nat Commun, 2023‑11; https://doi.org/10.1038/s41467-023-43062-z) found a genome‑wide significant burden of de novo loss‑of‑function RASA1 and enrichment of damaging EPHB4 variants in vein‑of‑Galen malformations, and used endothelial‑focused analyses and animal models to localize mechanism to developing endothelial cells. (zhao2023mutationofkey pages 1-2)

Allele frequency in population databases

Specific gnomAD allele frequencies for CM‑AVM pathogenic variants were not available in the retrieved excerpts.

Modifier genes / epigenetics / chromosomal abnormalities

No definitive modifier genes, epigenetic signatures specific to CM‑AVM, or recurrent chromosomal abnormalities were identified in the retrieved CM‑AVM‑focused evidence.


5. Environmental Information

No specific non‑genetic environmental, lifestyle, or infectious causal contributors were identified in the retrieved sources; CM‑AVM is predominantly a genetic developmental vascular disorder in the available literature. (palermo2025capillarymalformation–arteriovenousmalformation pages 1-2, revencu2013rasa1mutationsand pages 1-2)


6. Mechanism / Pathophysiology

Upstream → downstream causal chain (current model)

  1. Germline heterozygous loss‑of‑function in RASA1 or EPHB4 establishes a susceptibility state in endothelial development. (morin2025vascularmalformationsfrom pages 5-6)
  2. In some lesions, additional mosaic/second‑hit events or focal endothelial dysfunction further reduce pathway restraint, resulting in localized malformations (multifocality). (revencu2020rasa1mosaicmutations pages 1-2, revencu2013rasa1mutationsand pages 7-9)
  3. Loss of EPHB4–RASA1 negative regulation increases RAS‑MAPK/ERK signaling, altering angiogenic remodeling, endothelial survival/ECM handling, and arteriovenous specification, producing fast‑flow shunts (AVMs/AVFs) and related lesions. (chen2023ephb4rasa1mediatednegativeregulation pages 2-4, zhao2023geneticdysregulationof pages 12-14)

Key pathways

  • RAS‑MAPK/ERK signaling: CM‑AVM is described as resulting from RASA1/EPHB4 mutations “leading to aberrant Ras‑MAPK signaling.” (Palermo et al., 2025‑12) (palermo2025capillarymalformation–arteriovenousmalformation pages 1-2)
  • EPHB4–RASA1 axis as Ras restraint in endothelium: experimental work reviewed in 2023 indicates EPHB4 inhibits endothelial Ras‑MAPK via a RASA1‑dependent mechanism and that disruption affects vascular remodeling and extracellular matrix handling (collagen IV export). (chen2023ephb4rasa1mediatednegativeregulation pages 2-4, chen2023ephb4rasa1mediatednegativeregulation pages 7-9)

Cell types (CL term suggestions)

  • Endothelial cell (CL:0000115) — primary implicated cell type; single‑cell integration in Zhao et al. localizes disease to developing endothelial cells. (zhao2023mutationofkey pages 1-2, zhao2023geneticdysregulationof pages 12-14)
  • Venous endothelial cell (suggested; EphB4 is a venous EC marker) and tip cell progeny in retinal angiogenesis models. (stewen2024ephephrinsignalingcouples pages 1-2)

GO biological process term suggestions

  • angiogenesis (GO:0001525)
  • blood vessel morphogenesis (GO:0048514)
  • artery development / arteriovenous specification (suggested mapping; supported by EphB4/ephrin signaling models) (stewen2024ephephrinsignalingcouples pages 1-2)
  • negative regulation of Ras protein signal transduction (GO:0046579) (supported conceptually by RASA1 function) (chen2023ephb4rasa1mediatednegativeregulation pages 2-4)

Anatomical loci and tissue damage mechanisms

Mechanistic and clinical data highlight cerebrovascular and cutaneous vascular beds; severe lesions can cause heart failure, hemorrhage, and neurologic injury. (palermo2025capillarymalformation–arteriovenousmalformation pages 11-13, wooderchakdonahue2018expandingtheclinical pages 1-2)


7. Anatomical Structures Affected

Organ/system level (UBERON suggestions)

  • Skin (UBERON:0002097): multifocal capillary malformations. (brix2022capillarymalformationarteriovenousmalformation pages 1-2, revencu2013rasa1mutationsand pages 1-2)
  • Brain / intracranial vasculature (UBERON:0000955; cerebrovasculature): pial AVF, AVM, vein‑of‑Galen malformations. (palermo2025capillarymalformation–arteriovenousmalformation pages 2-4)
  • Spinal cord / spinal vasculature (UBERON:0002240): spinal AVMs reported. (brix2022capillarymalformationarteriovenousmalformation pages 4-5)
  • Extremities (limb) (UBERON:0002101): Parkes Weber syndrome (overgrowth + AV shunting). (revencu2013rasa1mutationsand pages 1-2)

Subcellular/localization notes

No CM‑AVM‑specific subcellular compartment pathology was explicitly described in the retrieved excerpts.


8. Temporal Development

Onset

  • Cutaneous lesions are often present at birth or in early childhood. (palermo2025capillarymalformation–arteriovenousmalformation pages 1-2, brix2022capillarymalformationarteriovenousmalformation pages 1-2)
  • Severe prenatal presentations exist (hydrops‑type findings, polyhydramnios). (coccia2023prenatalclinicalfindings pages 9-11)

Progression/course

Course is variable; morbidity is driven by high‑flow lesion location and hemodynamic effects. There is no uniform staging system described in the retrieved sources.


9. Inheritance and Population

Inheritance pattern

CM‑AVM is autosomal dominant with high but not necessarily complete penetrance and variable expressivity. (palermo2025capillarymalformation–arteriovenousmalformation pages 1-2, brix2022capillarymalformationarteriovenousmalformation pages 1-2, revencu2013rasa1mutationsand pages 7-9)

Penetrance/expressivity

  • RASA1 cohort penetrance reported as 98.5% with substantial intra‑ and interfamilial variability. (revencu2013rasa1mutationsand pages 7-9)
  • Mosaic cases can transmit to offspring (germline involvement). (revencu2020rasa1mosaicmutations pages 1-2)

Epidemiology

Reliable prevalence/incidence estimates were not present in the retrieved excerpts; the condition is consistently described as rare. (palermo2025capillarymalformation–arteriovenousmalformation pages 1-2)


10. Diagnostics

Clinical suspicion

Suspicion is raised by multiple small capillary malformations, especially with pale halos, and by personal/family history of fast‑flow lesions. (brix2022capillarymalformationarteriovenousmalformation pages 1-2, wooderchakdonahue2018expandingtheclinical pages 1-2)

Genetic testing (real‑world implementation)

  • RASA1 and EPHB4 are central diagnostic genes and are commonly included in NGS vascular anomaly panels. (palermo2025capillarymalformation–arteriovenousmalformation pages 11-13, revencu2020rasa1mosaicmutations pages 1-2)
  • High‑depth sequencing may be needed when blood testing is negative, as mosaicism can explain apparently sporadic presentations; Revencu et al. recommend highly sensitive sequencing approaches in such settings. (revencu2020rasa1mosaicmutations pages 1-2)
  • Copy‑number analysis matters for RASA1: a clinical series found multi‑exon deletions (8.3%) among function‑affecting RASA1 variants, supporting deletion/duplication testing in workflows. (wooderchakdonahue2018expandingtheclinical pages 10-11)

Imaging and screening/surveillance

  • CM‑AVM can be confused with HHT; genetic testing and cerebrovascular screening are emphasized to prevent missed intracranial lesions. (palermo2025capillarymalformation–arteriovenousmalformation pages 1-2, palermo2025capillarymalformation–arteriovenousmalformation pages 13-14)
  • Palermo et al. stress that “regular imaging and clinical evaluation” are key for early lesion detection and to prevent severe neurologic complications. (palermo2025capillarymalformation–arteriovenousmalformation pages 1-2)
  • A pediatric neurovascular cohort noted lack of consensus on intervals; their clinical approach was brain and spine imaging at diagnosis, with repeat imaging before puberty and after puberty depending on circumstances. (engel2023prevalenceandpredictors pages 13-17)

Differential diagnosis

Important differentials include: * Hereditary hemorrhagic telangiectasia (HHT) (ENG/ACVRL1/SMAD4/GDF2), because epistaxis/telangiectasia can occur in CM‑AVM2 and some RASA1 cases, causing misclassification. (brix2022capillarymalformationarteriovenousmalformation pages 2-4, palermo2025capillarymalformation–arteriovenousmalformation pages 11-13) * Sturge–Weber syndrome and Klippel–Trenaunay syndrome in the dermatologic differential of capillary malformations. (brix2022capillarymalformationarteriovenousmalformation pages 2-4)


11. Outcome / Prognosis

Morbidity

Morbidity is driven by fast‑flow shunts (CNS/spine/face/extremity) with risks including hemorrhage, seizures, and high‑output cardiac failure. (wooderchakdonahue2018expandingtheclinical pages 1-2, palermo2025capillarymalformation–arteriovenousmalformation pages 11-13)

Outcome statistics

  • In prenatal‑onset RASA1 CM‑AVM cases reviewed by Coccia et al., death occurred in 30% (6/21); however, they note “generally a good long‑term prognosis” overall while warning that unrecognized deep malformations can be fatal. (coccia2023prenatalclinicalfindings pages 9-11)
  • In the cerebrovascular systematic review cohort, ~25% required embolization and ~5% surgery, indicating clinically significant lesion burden in screened/ascertained cases. (palermo2025capillarymalformation–arteriovenousmalformation pages 7-9)

12. Treatment

Standard and interventional management (current practice)

CM‑AVM management is typically multidisciplinary and focused on detection and treatment of treatable high‑flow lesions (endovascular embolization and sometimes surgery). (palermo2025capillarymalformation–arteriovenousmalformation pages 11-13, palermo2025capillarymalformation–arteriovenousmalformation pages 7-9)

MAXO suggestions (non‑exhaustive): * Endovascular embolization (MAXO term suggestion: endovascular embolization procedure) * Surgical resection of vascular malformation (MAXO suggestion: surgical excision) * Genetic counseling (MAXO suggestion: genetic counseling) * Surveillance imaging (MAXO suggestion: diagnostic imaging procedure)

Targeted/medical therapies (emerging; 2024+ reviews)

Recent vascular anomalies reviews emphasize the shift toward theragnostic targeted therapy, repurposing oncology/transplant drugs: * Seront et al. (ASH Hematology, 2024‑12; https://doi.org/10.1182/hematology.2024000598) highlight MEK inhibition and mTOR inhibition as precision approaches in vascular malformations; they describe clinical benefit signals with trametinib in AVM cohorts and symptom control with sirolimus in some vascular anomalies contexts. (seront2024molecularlandscapeand pages 6-7) * Morin et al. (EMBO Mol Med, 2025‑11; https://doi.org/10.1038/s44321-025-00344-x) explicitly lists CM‑AVM (RASA1/EPHB4) among syndromes and notes that MAPK inhibitors (e.g., trametinib) and mTOR/PI3K inhibitors (e.g., sirolimus, alpelisib) are being applied across vascular malformations with genotype–phenotype logic. (morin2025vascularmalformationsfrom pages 3-5, morin2025vascularmalformationsfrom pages 12-13)

Clinical trials (real‑world implementations; ClinicalTrials.gov)

  • Trametinib for complicated extracranial AVM: NCT04258046 (Stanford; Phase 2; status COMPLETED; start 2020‑12‑01; primary completion 2026‑02‑02). Inclusion requires complicated extracranial AVM; genetic testing for RAS/MAPK variants is preferred. Primary endpoint is disease response at month 6 using composite radiographic/clinical/functional/QoL criteria. https://clinicaltrials.gov/study/NCT04258046 (NCT04258046 chunk 1)
  • Trametinib for Ras/MAPK pathway vascular anomalies (VATCH): NCT07549646 (CHOP; Phase 2; ACTIVE_NOT_RECRUITING; ages 2 months–30 years). Primary endpoint uses an individualized composite response after 6 cycles (radiology + PROMIS PRO + clinical benefit). https://clinicaltrials.gov/study/NCT07549646 (NCT07549646 chunk 1)
  • Trametinib for complicated vascular anomalies (pediatric): NCT07072403 (West China Hospital; Phase 1/2; ACTIVE_NOT_RECRUITING; ages 1–18). Objective response defined as ≥20% lesion volume reduction at month 12. https://clinicaltrials.gov/study/NCT07072403 (NCT07072403 chunk 1)
  • Sirolimus for severe AVMs: NCT02042326 (Amiens; Phase 2; prospective evaluation of efficacy/safety in severe arteriovenous malformations). https://clinicaltrials.gov/study/NCT02042326 (morin2025vascularmalformationsfrom pages 6-7)

Relevance to CM‑AVM specifically: These trials generally enroll AVMs/vascular anomalies rather than CM‑AVM genetically defined cohorts; however, CM‑AVM lesions are mechanistically linked to RAS/MAPK dysregulation and therefore overlap with eligibility in Ras/MAPK‑targeted vascular anomaly trials. (palermo2025capillarymalformation–arteriovenousmalformation pages 1-2, NCT04258046 chunk 1)


13. Prevention

Primary prevention

No known primary prevention exists for inherited CM‑AVM aside from reproductive options.

Secondary/tertiary prevention

  • Cascade testing and early detection: Because of autosomal dominant inheritance and clinically significant occult lesions, genetic confirmation plus appropriate imaging surveillance is emphasized to prevent complications. (palermo2025capillarymalformation–arteriovenousmalformation pages 11-13, engel2023prevalenceandpredictors pages 13-17)
  • Prenatal considerations: Coccia et al. stress careful interpretation of prenatal ultrasound signs and recommend genetic counseling and family evaluation because undiagnosed deep malformations can be fatal in newborns and relatives with the same variant. (coccia2023prenatalclinicalfindings pages 9-11)

14. Other Species / Natural Disease

No naturally occurring CM‑AVM syndrome in non‑human species was identified in the retrieved sources.


15. Model Organisms

Animal and experimental systems support causal biology: * Mouse (EPHB4 kinase-domain variant; two-hit requirement): Zhao et al. report that mice expressing an EPHB4 missense variant (Phe867Leu) show disrupted angiogenesis and impaired arterial–capillary–venous network development, with severe phenotypes requiring an additional “second‑hit” allele. (zhao2023geneticdysregulationof pages 12-14, zhao2023mutationofkey pages 1-2) * Mouse retinal angiogenesis (conditional Ephb4 inactivation): Eph/ephrin signaling experiments in retina show EphB4 influences endothelial sorting and arterial specification, supporting relevance to EPHB4‑related vascular malformations. (stewen2024ephephrinsignalingcouples pages 1-2) * Zebrafish ephb4 depletion: zebrafish models show supernumerary arteriovenous connections and altered venous structures with ephb4 perturbation, consistent with disturbed arteriovenous patterning. (zhao2023geneticdysregulationof pages 35-39)

Model limitations: Most models address developmental angiogenesis and may not perfectly recapitulate focal post‑zygotic mosaic lesions typical of human CM‑AVM; mechanistic reviews explicitly note the need for models that more closely mimic somatic second hits. (chen2023ephb4rasa1mediatednegativeregulation pages 7-9)


Recent Developments (2023–2024 prioritization)

  1. Integrated genetics + single‑cell approaches in cerebrovascular malformations (2023): Zhao et al. (Nature Communications, 2023‑11) combined large-scale human exome analysis with cerebrovascular single-cell transcriptomics, implicating RASA1 and EPHB4 in a developing endothelial Ras signaling network relevant to vein-of-Galen malformations and, by extension, CM‑AVM biology. https://doi.org/10.1038/s41467-023-43062-z (zhao2023mutationofkey pages 1-2)
  2. Prenatal CM‑AVM characterization (2023): Coccia et al. (Genes, 2023‑02) consolidate prenatal warning signs and stress the risk of fatal neonatal complications if deep malformations are missed. https://doi.org/10.3390/genes14030549 (coccia2023prenatalclinicalfindings pages 9-11)
  3. Precision medicine framing in vascular anomalies (2024): Seront et al. (ASH Hematology, 2024‑12) emphasize genomic testing for vascular malformations and discuss targeted inhibitors (MEK, mTOR/PI3K) as an emerging management paradigm. https://doi.org/10.1182/hematology.2024000598 (seront2024molecularlandscapeand pages 1-3, seront2024molecularlandscapeand pages 6-7)
  4. Mechanistic arteriovenous specification biology (2024): Stewen et al. (Nat Commun, 2024‑04) provide in vivo evidence that EphB4/ephrin signaling couples endothelial cell sorting and arterial specification, relevant to EPHB4‑driven CM‑AVM2. https://doi.org/10.1038/s41467-024-46300-0 (stewen2024ephephrinsignalingcouples pages 1-2)

Key Gaps / Not Available in Retrieved Evidence

  • ICD‑10/ICD‑11 codes and MeSH terms were not captured in the retrieved full texts in this run.
  • Population prevalence/incidence estimates were not available from the retrieved sources.
  • Variant‑level population allele frequencies (gnomAD) and ClinVar aggregation were not retrieved in the excerpts.

References

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