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.
Ask a research question about Capillary Malformation-Arteriovenous Malformation Syndrome. OpenScientist will conduct autonomous deep research using the Disorder Mechanisms Knowledge Base and PubMed literature (typically 10-30 minutes).
Do not include personal health information in your question. Questions and results are cached in your browser's local storage.
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.
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)
| 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)
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)
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)
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)
No disease‑specific protective genetic or environmental factors were identified in the retrieved sources.
No specific gene–environment interactions were identified in the retrieved sources.
| 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.
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)
| 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)
Specific gnomAD allele frequencies for CM‑AVM pathogenic variants were not available in the retrieved excerpts.
No definitive modifier genes, epigenetic signatures specific to CM‑AVM, or recurrent chromosomal abnormalities were identified in the retrieved CM‑AVM‑focused evidence.
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)
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)
No CM‑AVM‑specific subcellular compartment pathology was explicitly described in the retrieved excerpts.
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.
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)
Reliable prevalence/incidence estimates were not present in the retrieved excerpts; the condition is consistently described as rare. (palermo2025capillarymalformation–arteriovenousmalformation pages 1-2)
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)
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)
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)
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)
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)
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)
No known primary prevention exists for inherited CM‑AVM aside from reproductive options.
No naturally occurring CM‑AVM syndrome in non‑human species was identified in the retrieved sources.
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)
References
(palermo2025capillarymalformation–arteriovenousmalformation pages 1-2): Matteo Palermo, Alessandro Olivi, and Carmelo Lucio Sturiale. Capillary malformation–arteriovenous malformation syndrome (cm-avm): a systematic review of cerebrovascular manifestations. Child's Nervous System, Dec 2025. URL: https://doi.org/10.1007/s00381-025-07089-5, doi:10.1007/s00381-025-07089-5. This article has 0 citations.
(brix2022capillarymalformationarteriovenousmalformation pages 1-2): Anna Trier Heiberg Brix, Pernille Mathiesen Tørring, and Anette Bygum. Capillary malformation-arteriovenous malformation type 2: a case report and review. Acta Dermato-Venereologica, 102:adv00662, Mar 2022. URL: https://doi.org/10.2340/actadv.v102.1126, doi:10.2340/actadv.v102.1126. This article has 15 citations and is from a domain leading peer-reviewed journal.
(wooderchakdonahue2018expandingtheclinical pages 1-2): Whitney L. Wooderchak-Donahue, Peter Johnson, Jamie McDonald, Francine Blei, Alejandro Berenstein, Michelle Sorscher, Jennifer Mayer, Angela E. Scheuerle, Tracey Lewis, J. Fredrik Grimmer, Gresham T. Richter, Marcie A. Steeves, Angela E. Lin, David A. Stevenson, and Pinar Bayrak-Toydemir. Expanding the clinical and molecular findings in rasa1 capillary malformation-arteriovenous malformation. European Journal of Human Genetics, 26:1521-1536, Jun 2018. URL: https://doi.org/10.1038/s41431-018-0196-1, doi:10.1038/s41431-018-0196-1. This article has 79 citations and is from a domain leading peer-reviewed journal.
(revencu2020rasa1mosaicmutations pages 1-2): Nicole Revencu, Elodie Fastre, Marie Ravoet, Raphaël Helaers, Pascal Brouillard, Annouk Bisdorff-Bresson, Clara W T Chung, Marion Gerard, Veronika Dvorakova, Alan D Irvine, Laurence M Boon, and Miikka Vikkula. Rasa1 mosaic mutations in patients with capillary malformation-arteriovenous malformation. Journal of Medical Genetics, 57:48-52, Jul 2020. URL: https://doi.org/10.1136/jmedgenet-2019-106024, doi:10.1136/jmedgenet-2019-106024. This article has 79 citations and is from a domain leading peer-reviewed journal.
(zhao2023geneticdysregulationof pages 12-14): Shujuan Zhao, Kedous Y. Mekbib, Martijn A. van der Ent, Garrett Allington, Andrew Prendergast, Jocelyn E. Chau, Hannah Smith, John Shohfi, Jack Ocken, Daniel Duran, Charuta G. Furey, Hao Thi Le, Phan Q. Duy, Benjamin C. Reeves, Junhui Zhang, Carol Nelson-Williams, Di Chen, Boyang Li, Timothy Nottoli, Suxia Bai, Myron Rolle, Xue Zeng, Weilai Dong, Po-Ying Fu, Yung-Chun Wang, Shrikant Mane, Paulina Piwowarczyk, Katie Pricola Fehnel, Alfred Pokmeng See, Bermans J. Iskandar, Beverly Aagaard-Kienitz, Adam J. Kundishora, Tyrone DeSpenza, Ana B.W. Greenberg, Seblewengel M. Kidanemariam, Andrew T. Hale, James M. Johnston, Eric M. Jackson, Phillip B. Storm, Shih-Shan Lang, William E. Butler, Bob S. Carter, Paul Chapman, Christopher J. Stapleton, Aman B. Patel, Georges Rodesch, Stanislas Smajda, Alejandro Berenstein, Tanyeri Barak, E. Zeynep Erson-Omay, Hongyu Zhao, Andres Moreno-De-Luca, Mark R. Proctor, Edward R. Smith, Darren B. Orbach, Seth L. Alper, Stefania Nicoli, Titus J. Boggon, Richard P. Lifton, Murat Gunel, Philip D. King, Sheng Chih Jin, and Kristopher T. Kahle. Genetic dysregulation of an endothelial ras signaling network in vein of galen malformations. BioRxiv, Mar 2023. URL: https://doi.org/10.1101/2023.03.18.532837, doi:10.1101/2023.03.18.532837. This article has 3 citations.
(zhao2023mutationofkey pages 1-2): Shujuan Zhao, Kedous Y. Mekbib, Martijn A. van der Ent, Garrett Allington, Andrew Prendergast, Jocelyn E. Chau, Hannah Smith, John Shohfi, Jack Ocken, Daniel Duran, Charuta G. Furey, Le Thi Hao, Phan Q. Duy, Benjamin C. Reeves, Junhui Zhang, Carol Nelson-Williams, Di Chen, Boyang Li, Timothy Nottoli, Suxia Bai, Myron Rolle, Xue Zeng, Weilai Dong, Po-Ying Fu, Yung-Chun Wang, Shrikant Mane, Paulina Piwowarczyk, Katie Pricola Fehnel, Alfred Pokmeng See, Bermans J. Iskandar, Beverly Aagaard-Kienitz, Quentin J. Moyer, Evan Dennis, Emre Kiziltug, Adam J. Kundishora, Tyrone DeSpenza, Ana B. W. Greenberg, Seblewengel M. Kidanemariam, Andrew T. Hale, James M. Johnston, Eric M. Jackson, Phillip B. Storm, Shih-Shan Lang, William E. Butler, Bob S. Carter, Paul Chapman, Christopher J. Stapleton, Aman B. Patel, Georges Rodesch, Stanislas Smajda, Alejandro Berenstein, Tanyeri Barak, E. Zeynep Erson-Omay, Hongyu Zhao, Andres Moreno-De-Luca, Mark R. Proctor, Edward R. Smith, Darren B. Orbach, Seth L. Alper, Stefania Nicoli, Titus J. Boggon, Richard P. Lifton, Murat Gunel, Philip D. King, Sheng Chih Jin, and Kristopher T. Kahle. Mutation of key signaling regulators of cerebrovascular development in vein of galen malformations. Nature Communications, Nov 2023. URL: https://doi.org/10.1038/s41467-023-43062-z, doi:10.1038/s41467-023-43062-z. This article has 25 citations and is from a highest quality peer-reviewed journal.
(le2025arteriovenousmalformations(avms) pages 1-3): Nga Le, Yan Li, Gianni Walker, Bao-Ngoc Nguyen, Arash Bornak, Sapna Deo, Omaida Velazquez, and Zhao-Jun Liu. Arteriovenous malformations (avms): molecular pathogenesis, clinical features, and emerging therapeutic strategies. Biomolecules, Nov 2025. URL: https://doi.org/10.3390/biom15121661, doi:10.3390/biom15121661. This article has 4 citations.
(coccia2023prenatalclinicalfindings pages 9-11): Emanuele Coccia, Lara Valeri, Roberta Zuntini, Stefano Giuseppe Caraffi, Francesca Peluso, Luca Pagliai, Antonietta Vezzani, Zaira Pietrangiolillo, Francesco Leo, Nives Melli, Valentina Fiorini, Andrea Greco, Francesca Romana Lepri, Elisa Pisaneschi, Annabella Marozza, Diana Carli, Alessandro Mussa, Francesca Clementina Radio, Beatrice Conti, Maria Iascone, Giancarlo Gargano, Antonio Novelli, Marco Tartaglia, Orsetta Zuffardi, Maria Francesca Bedeschi, and Livia Garavelli. Prenatal clinical findings in rasa1-related capillary malformation-arteriovenous malformation syndrome. Genes, 14:549, Feb 2023. URL: https://doi.org/10.3390/genes14030549, doi:10.3390/genes14030549. This article has 14 citations.
(morin2025vascularmalformationsfrom pages 5-6): Gabriel Morin, Ilaria Galasso, and Guillaume Canaud. Vascular malformations: from genetics to therapeutics. EMBO Molecular Medicine, 18:1-21, Nov 2025. URL: https://doi.org/10.1038/s44321-025-00344-x, doi:10.1038/s44321-025-00344-x. This article has 4 citations and is from a highest quality peer-reviewed journal.
(lin2026chinesecapillarymalformationarteriovenous pages 7-9): Yan-yan Lin, Shuyan Dong, Changhua Zhu, Linxin Dong, Lihang Lin, and Xuemin Xiao. Chinese capillary malformation-arteriovenous malformation: clinical and genetic analysis of eight cases. Frontiers in Medicine, Mar 2026. URL: https://doi.org/10.3389/fmed.2026.1774495, doi:10.3389/fmed.2026.1774495. This article has 0 citations.
(palermo2025capillarymalformation–arteriovenousmalformation pages 2-4): Matteo Palermo, Alessandro Olivi, and Carmelo Lucio Sturiale. Capillary malformation–arteriovenous malformation syndrome (cm-avm): a systematic review of cerebrovascular manifestations. Child's Nervous System, Dec 2025. URL: https://doi.org/10.1007/s00381-025-07089-5, doi:10.1007/s00381-025-07089-5. This article has 0 citations.
(zhao2023geneticdysregulationof pages 35-39): Shujuan Zhao, Kedous Y. Mekbib, Martijn A. van der Ent, Garrett Allington, Andrew Prendergast, Jocelyn E. Chau, Hannah Smith, John Shohfi, Jack Ocken, Daniel Duran, Charuta G. Furey, Hao Thi Le, Phan Q. Duy, Benjamin C. Reeves, Junhui Zhang, Carol Nelson-Williams, Di Chen, Boyang Li, Timothy Nottoli, Suxia Bai, Myron Rolle, Xue Zeng, Weilai Dong, Po-Ying Fu, Yung-Chun Wang, Shrikant Mane, Paulina Piwowarczyk, Katie Pricola Fehnel, Alfred Pokmeng See, Bermans J. Iskandar, Beverly Aagaard-Kienitz, Adam J. Kundishora, Tyrone DeSpenza, Ana B.W. Greenberg, Seblewengel M. Kidanemariam, Andrew T. Hale, James M. Johnston, Eric M. Jackson, Phillip B. Storm, Shih-Shan Lang, William E. Butler, Bob S. Carter, Paul Chapman, Christopher J. Stapleton, Aman B. Patel, Georges Rodesch, Stanislas Smajda, Alejandro Berenstein, Tanyeri Barak, E. Zeynep Erson-Omay, Hongyu Zhao, Andres Moreno-De-Luca, Mark R. Proctor, Edward R. Smith, Darren B. Orbach, Seth L. Alper, Stefania Nicoli, Titus J. Boggon, Richard P. Lifton, Murat Gunel, Philip D. King, Sheng Chih Jin, and Kristopher T. Kahle. Genetic dysregulation of an endothelial ras signaling network in vein of galen malformations. BioRxiv, Mar 2023. URL: https://doi.org/10.1101/2023.03.18.532837, doi:10.1101/2023.03.18.532837. This article has 3 citations.
(chen2023ephb4rasa1mediatednegativeregulation pages 2-4): D Chen, MA Van der Ent, NL Lartey, and PD King. Ephb4-rasa1-mediated negative regulation of ras-mapk signaling in the vasculature: implications for the treatment of ephb4-and rasa1-related vascular …. Unknown journal, 2023.
(revencu2013rasa1mutationsand pages 7-9): Nicole Revencu, Laurence M. Boon, Antonella Mendola, Maria Rosa Cordisco, Josée Dubois, Philippe Clapuyt, Frank Hammer, David J. Amor, Alan D. Irvine, Eulalia Baselga, Anne Dompmartin, Samira Syed, Ana Martin-Santiago, Lesley Ades, Felicity Collins, Janine Smith, Sarah Sandaradura, Victoria R. Barrio, Patricia E. Burrows, Francine Blei, Mariarosaria Cozzolino, Nicola Brunetti-Pierri, Asuncion Vicente, Marc Abramowicz, Julie Désir, Catheline Vilain, Wendy K. Chung, Ashley Wilson, Carol A. Gardiner, Yim Dwight, David J.E. Lord, Leona Fishman, Cheryl Cytrynbaum, Sarah Chamlin, Fred Ghali, Yolanda Gilaberte, Shelagh Joss, Maria del C. Boente, Christine Léauté-Labrèze, Marie-Ange Delrue, Susan Bayliss, Loreto Martorell, Maria-Antonia González-Enseñat, Juliette Mazereeuw-Hautier, Brid O'Donnell, Didier Bessis, Reed E. Pyeritz, Aicha Salhi, Oon T. Tan, Orli Wargon, John B. Mulliken, and Miikka Vikkula. Rasa1 mutations and associated phenotypes in 68 families with capillary malformation–arteriovenous malformation. Human Mutation, 34:1632-1641, Dec 2013. URL: https://doi.org/10.1002/humu.22431, doi:10.1002/humu.22431. This article has 353 citations and is from a domain leading peer-reviewed journal.
(revencu2013rasa1mutationsand pages 1-2): Nicole Revencu, Laurence M. Boon, Antonella Mendola, Maria Rosa Cordisco, Josée Dubois, Philippe Clapuyt, Frank Hammer, David J. Amor, Alan D. Irvine, Eulalia Baselga, Anne Dompmartin, Samira Syed, Ana Martin-Santiago, Lesley Ades, Felicity Collins, Janine Smith, Sarah Sandaradura, Victoria R. Barrio, Patricia E. Burrows, Francine Blei, Mariarosaria Cozzolino, Nicola Brunetti-Pierri, Asuncion Vicente, Marc Abramowicz, Julie Désir, Catheline Vilain, Wendy K. Chung, Ashley Wilson, Carol A. Gardiner, Yim Dwight, David J.E. Lord, Leona Fishman, Cheryl Cytrynbaum, Sarah Chamlin, Fred Ghali, Yolanda Gilaberte, Shelagh Joss, Maria del C. Boente, Christine Léauté-Labrèze, Marie-Ange Delrue, Susan Bayliss, Loreto Martorell, Maria-Antonia González-Enseñat, Juliette Mazereeuw-Hautier, Brid O'Donnell, Didier Bessis, Reed E. Pyeritz, Aicha Salhi, Oon T. Tan, Orli Wargon, John B. Mulliken, and Miikka Vikkula. Rasa1 mutations and associated phenotypes in 68 families with capillary malformation–arteriovenous malformation. Human Mutation, 34:1632-1641, Dec 2013. URL: https://doi.org/10.1002/humu.22431, doi:10.1002/humu.22431. This article has 353 citations and is from a domain leading peer-reviewed journal.
(brix2022capillarymalformationarteriovenousmalformation pages 4-5): Anna Trier Heiberg Brix, Pernille Mathiesen Tørring, and Anette Bygum. Capillary malformation-arteriovenous malformation type 2: a case report and review. Acta Dermato-Venereologica, 102:adv00662, Mar 2022. URL: https://doi.org/10.2340/actadv.v102.1126, doi:10.2340/actadv.v102.1126. This article has 15 citations and is from a domain leading peer-reviewed journal.
(tas2022arteriovenouscerebralhigh pages 3-4): Berivan Tas, Daniele Starnoni, Stanislas Smajda, Alexandre J. Vivanti, Catherine Adamsbaum, Mélanie Eyries, Judith Melki, Marcel Tawk, Augustin Ozanne, Nicole Revencu, Florent Soubrier, Selima Siala, Miikka Vikkula, Kumaran Deiva, and Guillaume Saliou. Arteriovenous cerebral high flow shunts in children: from genotype to phenotype. Frontiers in Pediatrics, Apr 2022. URL: https://doi.org/10.3389/fped.2022.871565, doi:10.3389/fped.2022.871565. This article has 10 citations.
(brix2022capillarymalformationarteriovenousmalformation pages 2-4): Anna Trier Heiberg Brix, Pernille Mathiesen Tørring, and Anette Bygum. Capillary malformation-arteriovenous malformation type 2: a case report and review. Acta Dermato-Venereologica, 102:adv00662, Mar 2022. URL: https://doi.org/10.2340/actadv.v102.1126, doi:10.2340/actadv.v102.1126. This article has 15 citations and is from a domain leading peer-reviewed journal.
(wooderchakdonahue2018expandingtheclinical pages 10-11): Whitney L. Wooderchak-Donahue, Peter Johnson, Jamie McDonald, Francine Blei, Alejandro Berenstein, Michelle Sorscher, Jennifer Mayer, Angela E. Scheuerle, Tracey Lewis, J. Fredrik Grimmer, Gresham T. Richter, Marcie A. Steeves, Angela E. Lin, David A. Stevenson, and Pinar Bayrak-Toydemir. Expanding the clinical and molecular findings in rasa1 capillary malformation-arteriovenous malformation. European Journal of Human Genetics, 26:1521-1536, Jun 2018. URL: https://doi.org/10.1038/s41431-018-0196-1, doi:10.1038/s41431-018-0196-1. This article has 79 citations and is from a domain leading peer-reviewed journal.
(palermo2025capillarymalformation–arteriovenousmalformation pages 11-13): Matteo Palermo, Alessandro Olivi, and Carmelo Lucio Sturiale. Capillary malformation–arteriovenous malformation syndrome (cm-avm): a systematic review of cerebrovascular manifestations. Child's Nervous System, Dec 2025. URL: https://doi.org/10.1007/s00381-025-07089-5, doi:10.1007/s00381-025-07089-5. This article has 0 citations.
(engel2023prevalenceandpredictors pages 13-17): ER Engel. Prevalence and predictors of hht and cm-avm syndrome among children with neurovascular malformations. Unknown journal, 2023.
(palermo2025capillarymalformation–arteriovenousmalformation pages 7-9): Matteo Palermo, Alessandro Olivi, and Carmelo Lucio Sturiale. Capillary malformation–arteriovenous malformation syndrome (cm-avm): a systematic review of cerebrovascular manifestations. Child's Nervous System, Dec 2025. URL: https://doi.org/10.1007/s00381-025-07089-5, doi:10.1007/s00381-025-07089-5. This article has 0 citations.
(chen2023ephb4rasa1mediatednegativeregulation pages 7-9): D Chen, MA Van der Ent, NL Lartey, and PD King. Ephb4-rasa1-mediated negative regulation of ras-mapk signaling in the vasculature: implications for the treatment of ephb4-and rasa1-related vascular …. Unknown journal, 2023.
(chen2023ephb4rasa1mediatednegativeregulation pages 6-7): D Chen, MA Van der Ent, NL Lartey, and PD King. Ephb4-rasa1-mediated negative regulation of ras-mapk signaling in the vasculature: implications for the treatment of ephb4-and rasa1-related vascular …. Unknown journal, 2023.
(stewen2024ephephrinsignalingcouples pages 1-2): Jonas Stewen, Kai Kruse, Anca T. Godoi-Filip, Zenia, Hyun-Woo Jeong, Susanne Adams, Frank Berkenfeld, Martin Stehling, Kristy Red-Horse, Ralf H. Adams, and Mara E. Pitulescu. Eph-ephrin signaling couples endothelial cell sorting and arterial specification. Nature Communications, Apr 2024. URL: https://doi.org/10.1038/s41467-024-46300-0, doi:10.1038/s41467-024-46300-0. This article has 37 citations and is from a highest quality peer-reviewed journal.
(palermo2025capillarymalformation–arteriovenousmalformation pages 13-14): Matteo Palermo, Alessandro Olivi, and Carmelo Lucio Sturiale. Capillary malformation–arteriovenous malformation syndrome (cm-avm): a systematic review of cerebrovascular manifestations. Child's Nervous System, Dec 2025. URL: https://doi.org/10.1007/s00381-025-07089-5, doi:10.1007/s00381-025-07089-5. This article has 0 citations.
(seront2024molecularlandscapeand pages 6-7): Emmanuel Seront, Angela Queisser, Laurence M. Boon, and Miikka Vikkula. Molecular landscape and classification of vascular anomalies. Hematology, 2024:700-708, Dec 2024. URL: https://doi.org/10.1182/hematology.2024000598, doi:10.1182/hematology.2024000598. This article has 8 citations and is from a peer-reviewed journal.
(morin2025vascularmalformationsfrom pages 3-5): Gabriel Morin, Ilaria Galasso, and Guillaume Canaud. Vascular malformations: from genetics to therapeutics. EMBO Molecular Medicine, 18:1-21, Nov 2025. URL: https://doi.org/10.1038/s44321-025-00344-x, doi:10.1038/s44321-025-00344-x. This article has 4 citations and is from a highest quality peer-reviewed journal.
(morin2025vascularmalformationsfrom pages 12-13): Gabriel Morin, Ilaria Galasso, and Guillaume Canaud. Vascular malformations: from genetics to therapeutics. EMBO Molecular Medicine, 18:1-21, Nov 2025. URL: https://doi.org/10.1038/s44321-025-00344-x, doi:10.1038/s44321-025-00344-x. This article has 4 citations and is from a highest quality peer-reviewed journal.
(NCT04258046 chunk 1): Joyce Teng. Trametinib in the Treatment of Complicated Extracranial Arterial Venous Malformation. Stanford University. 2020. ClinicalTrials.gov Identifier: NCT04258046
(NCT07549646 chunk 1): 24VA021; VATCH Trametinib for Ras/MAPK Pathway VAs. Children's Hospital of Philadelphia. 2025. ClinicalTrials.gov Identifier: NCT07549646
(NCT07072403 chunk 1): Yi Ji. Trametinib Treatment for Complicated Vascular Anomalies. West China Hospital. 2025. ClinicalTrials.gov Identifier: NCT07072403
(morin2025vascularmalformationsfrom pages 6-7): Gabriel Morin, Ilaria Galasso, and Guillaume Canaud. Vascular malformations: from genetics to therapeutics. EMBO Molecular Medicine, 18:1-21, Nov 2025. URL: https://doi.org/10.1038/s44321-025-00344-x, doi:10.1038/s44321-025-00344-x. This article has 4 citations and is from a highest quality peer-reviewed journal.
(seront2024molecularlandscapeand pages 1-3): Emmanuel Seront, Angela Queisser, Laurence M. Boon, and Miikka Vikkula. Molecular landscape and classification of vascular anomalies. Hematology, 2024:700-708, Dec 2024. URL: https://doi.org/10.1182/hematology.2024000598, doi:10.1182/hematology.2024000598. This article has 8 citations and is from a peer-reviewed journal.