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This syndrome is characterized by the association of multiple capillary malformations (CM) with an arteriovenous malformation (AVM) and arteriovenous fistulas.
No HPO annotations are available for this condition.
The clinical manifestations of RASA1-capillary malformation-arteriovenous malformation (RASA1-CM-AVM) syndrome have been described in many individuals with large cohorts by (n=39), (n=101), and (n=138), with insights from a number of other case series and case reports [, , , , , , , , , , , , ]. The clinical manifestations of EPHB4 capillary malformation-arteriovenous malformation (EPHB4-CM-AVM) syndrome have been described in two studies by (n=102), and (n=10). Significant intra- and interfamilial variability in the existence and location of vascular malformations has been described.
Diagnostic criteria for capillary malformation-arteriovenous malformation (CM-AVM) syndrome have been proposed but not systematically evaluated .
CM-AVM syndrome should be suspected in probands who have any of the following:
Source: GeneReviews — "Capillary Malformation-Arteriovenous Malformation Syndrome"
No approved treatments are currently available for capillary malformation-arteriovenous malformation syndrome. The disease remains an area of unmet medical need.
Evaluations Following Initial Diagnosis To establish the extent of disease and needs of an individual diagnosed with capillary malformation-arteriovenous malformation (CM-AVM) syndrome, the following evaluations (if not performed as part of the evaluation that led to the diagnosis) are recommended: • Medical history and physical examination with a focus on symptoms and findings secondary to arteriovenous malformations/arteriovenous fistulas (AVMs/AVFs) • Brain imaging – if not already performed – to identify AVMs/AVFs (e.g., vein of Galen aneurysms and other intracranial AVMs) to allow early identification of macrofistulas that can be treated prior to the development of symptoms • Consideration of spine imaging to identify and characterize AVMs/AVFs. Currently no consensus protocols for radiographic evaluation of individuals with CM-AVM syndrome have been developed; therefore, discussion with a radiologist is recommended in order to develop an appropriate plan for imaging based on the patient's age and the capabilities and experience of the imaging facility. • Consideration of further imaging in individuals with evidence of cardiac overload, to look for causative AVMs/AVFs • Evaluation for evidence of epistaxis (nosebleeds), and if present, referral to otolaryngologist as appropriate. If epistaxis is present, consider complete blood count for evaluation of anemia. • Consultation with a clinical geneticist and/or genetic counselor Treatment of Manifestations Table 4. Treatment of Manifestations in Individuals with CM-AVM Syndrome
The clinician should have a low threshold to repeat imaging studies if clinical signs/symptoms of AVMs/AVFs become evident over time.
Source: GeneReviews — "Capillary Malformation-Arteriovenous Malformation Syndrome"
Estimated prevalence: Unknown (Unknown prevalence).
No clinical trials have been registered for capillary malformation-arteriovenous malformation syndrome.
28 publications have been identified in PubMed for capillary malformation-arteriovenous malformation syndrome. Research spans Case Report / Case Series (57%), Review / Meta-Analysis (25%), and Epidemiology / Natural History (7%).
Research Type | Count | % of Total |
|---|---|---|
Patient case studies | 16 | 57% |
Data assembled from 4 of 12 sources · Last updated Sep 19, 2026, 3:01 PM UTC
European rare disease database
Genetic and Rare Diseases Info Center
Table 2.
Features of Capillary Malformation-Arteriovenous Malformation
Feature | % of Persons w/Feature by Associated Gene
RASA1-CM-AVM1 | EPHB4-CM-AVM2
| ~97% | 100%
Arteriovenous
Source: GeneReviews — "Capillary Malformation-Arteriovenous Malformation Syndrome"
Table 3. Other Genes of Interest in the Differential Diagnosis of Capillary Malformation-Arteriovenous Malformation (CV-AVM) Syndrome
Gene(s) | Differential Disorder | MOI | Clinical Features of Differential Disorder |
|---|---|---|---|
Hereditary hemorrhagic telangiectasia | AD | Multiple AVMs that lack intervening capillaries result in direct connections between arteries veins | Spontaneous recurrent nosebleeds (epistaxis) are more common.; Telangiectases generally only on lips, nose, hands; ~25% may have GI bleeding later in life.; Large capillary malformations are not typical. |
GNAQ | Sturge-Weber syndrome (SWS) (OMIM 185300) | Seefootnote 2. | Intracranial vascular anomaly3 |
PIK3CA | Klippel-Trenaunay-Weber syndrome5 | Seefootnote 6. | CMs hypertrophy of the related bones soft tissues |
PTEN | PTEN hamartoma tumor syndromes8 | AD | Overgrowth fast-flow lesions |
Multiple cutaneous and mucosal venous malformations | AD | Cutaneous VMs can be mistaken for CMs. | Small, multifocal bluish cutaneous /or mucosal VMs, usually present at birth. New lesions appear w/time.; Small lesions are usually asymptomatic; larger lesions can invade subcutaneous muscle cause pain. |
GLMN | Hereditary glomuvenous malformations (GVMs) (OMIM 138000) | AD | Cutaneous VMs can be mistaken for CMs. |
Source: GeneReviews — "Capillary Malformation-Arteriovenous Malformation Syndrome"
Manifestation/Concern | Treatment | Considerations/Other |
|---|---|---|
CMs telangiectases | Referral to dermatologist | To evaluate CMs of cosmetic concern discuss risks benefits of intervention |
AVMs/AVFs | Multidisciplinary team incl specialists in interventional radiology, neurosurgery, surgery, cardiology, dermatology depending on location symptoms | To determine treatment (e.g., embolization vs surgery); Risks benefits of intervention for AVMs AVFs must be considered. |
Cardiac overload | Referral to cardiologist | — |
Hemihyperplasia /or leg length discrepancy | Referral to orthopedist | Consider:; Lymphangiography to evaluate for lymphatic malformations;; Compression stockings for those w/evidence of lymphedema. |
Epistaxis (nosebleeds) | Humidification nasal lubricants; referral to otolaryngologist | If epistaxis, perform complete blood count for eval of anemia. The clinician should have a low threshold to repeat imaging studies if clinical signs/symptoms of AVMs/AVFs become evident over time. |
Source: GeneReviews — "Capillary Malformation-Arteriovenous Malformation Syndrome"
View trials for capillary malformation-arteriovenous malformation syndrome
Research summaries |
7 |
25% |
Disease patterns and progression | 2 | 7% |
Other research | 1 | 4% |
Clinical study results | 1 | 4% |
Laboratory research | 1 | 4% |
Demir M (2026). [PMID: 41592542](https://pubmed.ncbi.nlm.nih.gov/41592542/). *Allergy Asthma Immunol Res*. [Epidemiology / Natural History]
Kenaston MW (2026). [PMID: 41052613](https://pubmed.ncbi.nlm.nih.gov/41052613/). *J Pain Symptom Manage*. [Case Report / Case Series]
Borthakur K (2026). [PMID: 41763666](https://pubmed.ncbi.nlm.nih.gov/41763666/). *BMJ Case Rep*. [Case Report / Case Series]
Wu L (2026). [PMID: 42215316](https://pubmed.ncbi.nlm.nih.gov/42215316/). *Am J Med Genet A*. [Case Report / Case Series]
Lin Y (2026). [PMID: 41970387](https://pubmed.ncbi.nlm.nih.gov/41970387/). *Front Med (Lausanne)*. [Case Report / Case Series]
Sanri A (2025). [PMID: 41409310](https://pubmed.ncbi.nlm.nih.gov/41409310/). *Mol Syndromol*. [Case Report / Case Series]
Tanaka M (2025). [PMID: 40018280](https://pubmed.ncbi.nlm.nih.gov/40018280/). *J Neuroendovasc Ther*. [Review / Meta-Analysis]
Echols TC (2025). [PMID: 40047120](https://pubmed.ncbi.nlm.nih.gov/40047120/). *Am J Med Genet A*. [Case Report / Case Series]
Espinosa A (2025). [PMID: 41203499](https://pubmed.ncbi.nlm.nih.gov/41203499/). *An Pediatr (Engl Ed)*. [Case Report / Case Series]
Jaeger ZJ (2025). [PMID: 40518121](https://pubmed.ncbi.nlm.nih.gov/40518121/). *J Am Acad Dermatol*. [Review / Meta-Analysis]