ORPHA:820
Sneddon syndrome
Also known as: Ehrmann-Sneddon syndrome · Livedo racemosa-cerebrovascular accident syndrome · Livedo reticularis-cerebrovascular accident syndrome
Query health: suspect — Only one of 2 strategies returned hits (phrase).
Publications
452
75.9th percentile
Trials
0
Interventional, condition-specific
Researchers
1,042
Distinct authors in sample
Gene link
ADA2
Moderate
Readiness
2/6
Stages with a signal
Clinical definition (Orphanet)
Sneddon's syndrome (SS) is a rare non-inflammatory thrombotic vasculopathy characterized by the combination of cerebrovascular disease with livedo racemosa.
How rare: How common this is has not been clearly measured.
Cross-references
Joined from Mondo / Orphanet. MeSH labels may enter searches; UMLS / OMIM / NCIT are stored for reference.
- MONDO:0008436
- MeSH:D018860
- OMIM:182410
- UMLS:C0282492
Additional Mondo synonyms (2)
livedo racemosa-cerebrovascular accident syndrome · livedo reticularis-cerebrovascular accident syndrome
Research stages
Trial readiness signals
Where this condition sits on an open-data research pipeline — not how close a treatment is, and not medical advice. Empty stages often mean “not in these databases under this Mondo ID,” not “impossible.”
2/6 stages with a signal
No matched interventional trial; the gene is known and literature exists — preclinical or natural-history work may still be the practical next step.
- Gene identifiedPresent
Moderate — ADA2
- LiteraturePresent
452 matched papers (168 in last 10 years) Source
- Phenotype characterisedNot checked
Not yet enriched from Monarch / HPO
- Animal modelNot checked
Not yet enriched from Monarch / Alliance
- Orphan designationNot checked
FDA/EMA orphan-drug designation not enriched yet
- Interventional trialNot found
No matched interventional trial under our ClinicalTrials.gov rules
Biology
Genes and phenotypes
Gene–disease validity from GenCC, plus phenotypes and animal models joined from Monarch Initiative via Mondo ID — not a clinical diagnosis aid.
Do we know what causes it?
Probably — there is moderate evidence for ADA2.
GenCC classification: Moderate.
Phenotypes (Monarch / HPO)
Not enriched in this build — Monarch phenotype joins were not run for this record.
Animal models (Monarch / Alliance)
Not enriched in this build.
Literature
Is anyone studying this?
452
452 papers have ever been published on this condition (under this name). For scale, breast cancer has over 700,000. Median papers in the last 10 years for a rare disease in this dataset (publications denominator n=5449) is 41.
452 papers since the earliest indexed year in this search — median last-10-year count for a rare disease in this dataset is 41 (publications denominator n=5449).
168 in the last 10 years · medium confidence · 75.9th percentile (publications denominator)
Phrase hits: 452 · MeSH hits: 0
Who's working on it?
1,042
Distinct author names in 200 sampled papers — named people below.
Who's working on it?
No interventional trial matched this name; these authors publish on it in the sampled literature — a practical starting point for contact.
- 01Bersano A4 papers · 2026
Cerebrovascular Unit, IRCCS Foundation Neurological Institute "C. Besta", Via Celoria 11, Milan 20133, Italy. Electronic address: anna.bersano@gmail.com.
Papers in Europe PMC - 02Llamas-Velasco M4 papers · 2022
Department of Dermatology, Hospital Universitario de la Princesa, Madrid, Spain.
Papers in Europe PMC - 03Frijns CJM3 papers · 2024
Department of Neurology and Neurosurgery, University Medical Centre, Room G03.232, PO Box 85500, 3508 GA, Utrecht, The Netherlands. c.j.m.frijns@umcutrecht.nl.
Papers in Europe PMC - 04Kappelle LJ3 papers · 2024
Department of Neurology and Neurosurgery, University Medical Centre, Room G03.232, PO Box 85500, 3508 GA, Utrecht, The Netherlands.
Papers in Europe PMC - 05Kraemer M3 papers · 2021
Department of Neurology, Alfried Krupp Hospital, Alfried-Krupp-Strasse 21, 45130 Essen, Germany.
Papers in Europe PMC - 06Ni J3 papers · 2026
Department of Neurology, Peking Union Medical College Hospital, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing, China.
Papers in Europe PMC - 07Starmans NLP3 papers · 2024
Department of Neurology and Neurosurgery, University Medical Centre, Room G03.232, PO Box 85500, 3508 GA, Utrecht, The Netherlands.
Papers in Europe PMC - 08van Dijk MR3 papers · 2024
Department of Pathology, University Medical Centre Utrecht, Utrecht, The Netherlands.
Papers in Europe PMC - 09Yao M3 papers · 2026
Department of Neurology, Peking Union Medical College Hospital, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing, China.
Papers in Europe PMC - 10Zelger BG3 papers · 2022
Department of Pathology, Medical University Innsbruck, Innsbruck, Austria.
Papers in Europe PMC
Clinical research
Is a treatment being tested?
0
interventional trials for this specific condition
No interventional trial testing a treatment matched this specific condition name. 3 observational studies did — shown below because natural-history and cohort work can be an important step toward a trial.
Data as of 27 July 2026
No matched interventional trials. This is true for 73% of diseases in the trials denominator (5114 of 7003). Here are the researchers publishing on it.
medium confidence · 36.5th percentile (trials denominator)
Recruiting interventional trials
From the matched ClinicalTrials.gov set
No interventional trial testing a treatment was found for this specific condition name on ClinicalTrials.gov.
See who's working on it — people publishing on this disease are often the practical next contact when no trial is listed.
Observational and natural-history studies
3 observational studies match this condition. These do not test a treatment and are not counted in the interventional-trial headline, but they are genuine research: natural-history work often defines the endpoints needed for a future rare-disease trial, and families may be able to enroll.
Recruiting or not-yet-recruiting
- NCT06092346·RECRUITING·A Natural History Study Seeks to Understand the Clinical, Genomic, Pharmacological, Laboratory, and Dietary Determinates of Pyrimidine and Purine Metabolism Disorders
Conditions: AMPD3, OMIM*102772, AMP Deaminase Deficiency · AK1, OMIM *103000, Adenylate Kinase Deficiency · AMPD1, OMIM *102770, Myopathy Due to Myoadenylate Deaminase Deficiency · TPMT, OMIM *187680, Thoipurines, Poor Metabolism of·Matched via name phrase
- NCT06935578·RECRUITING·RAre, But Not aLone: a Large Italian Network to Empower the Impervious diaGNostic Pathway of Rare cerEbrovascular Diseases (ALIGNED)
Conditions: CADASIL · CADASIL (Diagnosis) · Moya Moya Disease · Moyamoya·Matched via name phrase
Where to find support
We do not yet link condition-specific patient organisations. These umbrella groups support undiagnosed and ultra-rare families:
India — NPRD
Last verified 2026-07-26This ORPHAcode is not on our curated NPRD list (direct or Mondo-parent match). That does not decide clinical eligibility; families in India should ask a notified Centre of Excellence about current coverage.
Hand-curated for this project. ORPHAcode mappings are best-effort and may be incomplete or imprecise for umbrella categories. Parent (Mondo) matches mean the policy lists a broader category — confirm eligibility with a Centre of Excellence. Financial entitlements summarised from public policy statements and may change. This is not official government guidance.
How we counted this
Europe PMC query (preferred label + any corrected label + Orphanet and Mondo exact synonyms, stoplisted; unioned with resolved MeSH labels when available). UMLS / OMIM / NCIT cross-references are stored on the overview but are not added to the query string.
"Sneddon syndrome" OR "Ehrmann-Sneddon syndrome" OR "Livedo racemosa-cerebrovascular accident syndrome" OR "Livedo reticularis-cerebrovascular accident syndrome"
ClinicalTrials.gov query (quoted phrases + MeSH via query.cond, plus recall-expansion terms when used):
"Sneddon syndrome" OR "Ehrmann-Sneddon syndrome" OR "Livedo racemosa-cerebrovascular accident syndrome" OR "Livedo reticularis-cerebrovascular accident syndrome" OR "ADA2"
Recall-expansion terms: ADA2
Study-type breakdown: 0 interventional · 3 observational · 0 expanded access. Only interventional studies enter the trial headline.
Query health: suspect — strategies attempted: phrase, recall-expansion; with hits: phrase
Run this search on ClinicalTrials.gov
Confidence reasoning
- Preferred label is short or not clearly distinctive
- No synonyms dropped by stoplist
- No label/synonym collisions with other diseases in this corpus
Ingested 2026-07-26T15:32:21.755Z