ORPHA:622925
X-linked severe syndromic thoracic aortic aneurysm and dissection
Also known as: Meester-Loeys syndrome · X-linked severe syndromic TAAD
Publications
50
47.6th percentile
Trials
0
Interventional, condition-specific
Researchers
347
Distinct authors in sample
Gene link
—
Readiness
1/6
Stages with a signal
Clinical definition (Orphanet)
A rare genetic systemic syndrome characterized by early-onset aortic aneurysm (involving the aortic root/ more distal ascending aorta) and dissection. Mild mitral or aortic insufficiency may also be present. Majority of the patients present with variable facial dysmorphism including frontal bossing, hypertelorism, downslanting palpebral fissures, proptosis and malar hypoplasia. Additional clinical features may include joint hypermobility, contractures, and mild skeletal .
How rare: <1 / 1 000 000 — fewer than one in a million. In a city the size of Kolkata, that might mean on the order of fifteen people.
Cross-references
Joined from Mondo / Orphanet. MeSH labels may enter searches; UMLS / OMIM / NCIT are stored for reference.
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.”
1/6 stages with a signal
Research-stage checklist from open sources (GenCC, literature, Monarch when enriched, ClinicalTrials.gov). Not a prognosis or care recommendation.
- Gene identifiedNot found
No GenCC disease–gene assertion in this build
- LiteraturePresent
50 matched papers (50 in last 10 years) Source
- Phenotype characterisedNot found
No HPO disease–phenotype associations via Monarch for these Mondo IDs
- Animal modelNot found
No Alliance genotype “model of” associations via Monarch for these Mondo IDs
- Orphan designationNot found
No FDA or EMA orphan-drug designation matched this disease via UMLS or preferred name Source
- 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?
Not yet — the cause hasn't been pinned down in GenCC.
No strong gene–disease assertion joined for this Orphanet entity.
Phenotypes (Monarch / HPO)
None returned for this Mondo ID. That often means “not linked under this ID,” not “no clinical features.”
Animal models (Monarch / Alliance)
None returned for this Mondo ID. Empty here is not proof that no model organism work exists under another name or gene.
Monarch fetch 2026-07-29
Therapies
Designations, candidates, and chemicals
FDA OOPD and EMA orphan designations, Open Targets clinical candidates, and CTD chemical associations via MyDisease.info. These never change the interventional-trial headline.
Orphan designation (FDA · EMA)
No designation matched this disease via UMLS or preferred name on the FDA OOPD mirror or EMA orphan register. Absence here is not proof that none exists under another wording.
Open Targets candidates
No drugs or clinical candidates returned for this Mondo ID on Open Targets.
CTD chemicals (MyDisease.info)
No CTD chemical associations returned for this Mondo ID.
Literature
Is anyone studying this?
50
50 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=3967) is 59.
50 papers since the earliest indexed year in this search — median last-10-year count for a rare disease in this dataset is 59 (publications denominator n=3967).
50 in the last 10 years · high confidence · 47.6th percentile (publications denominator)
Phrase hits: 50 · MeSH hits: 0
Who's working on it?
347
Distinct author names in 50 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.
- 01Meester JAN7 papers · 2024
Center of Medical Genetics, University of Antwerp and Antwerp University Hospital, Antwerp, Belgium.
Papers in Europe PMC - 02Elefteriades JA6 papers · 2023
Aortic Institute at Yale-New Haven Hospital, Yale University School of Medicine, New Haven, Connecticut, USA.
Papers in Europe PMC - 03Ziganshin BA6 papers · 2023
Aortic Institute at Yale-New Haven Hospital, Yale University School of Medicine, New Haven, Connecticut, USA.
Papers in Europe PMC - 04Brownstein AJ4 papers · 2019
Aortic Institute at Yale-New Haven Hospital, Yale University School of Medicine, New Haven, Connecticut, USA.
Papers in Europe PMC - 05De Kinderen P4 papers · 2023
Center of Medical Genetics, University of Antwerp and Antwerp University Hospital, Antwerp Belgium.
Papers in Europe PMC - 06Loeys B4 papers · 2024
European Reference Network for Rare Multisystemic Vascular Disease (VASCERN), HTAD and MSA Rare Disease, Working Group, Paris, France.
Papers in Europe PMC - 07Milewicz DM4 papers · 2023
McGovern Medical School, Division of Medical Genetics, Department of Internal Medicine, University of Texas Health Science Center, Houston, TX, USA - dianna.m.milewicz@uth.tmc.edu.
Papers in Europe PMC - 08Verstraeten A4 papers · 2024
Center of Medical Genetics, University of Antwerp and Antwerp University Hospital, Antwerp Belgium.
Papers in Europe PMC - 09Woo YJ4 papers · 2023
AHA/ACC Joint Committee on Clinical Practice Guidelines liaison.
Papers in Europe PMC - 10
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 on ClinicalTrials.gov (observational studies and pan-disease registries are listed separately when present).
Data as of 11 September 2026 · last trial check 11 September 2026
No matched interventional trials. This is true for 77.2% of diseases in the trials denominator (5501 of 7126). Here are the researchers publishing on it.
high confidence · 38.6th 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.
Other registries (secondary)
Broader net from EU CTIS, ISRCTN, and ICTRP when available — deduped against ClinicalTrials.gov IDs already counted above. Dual-model LLM relevance gates what we keep. These rows are not added to the interventional headline.
raw 0 · after dedupe 0 · already on CT.gov 0 · kept 0 · parent 0 · uncertain 0 · dropped 0 · fetched 2026-07-30
Source notes: ictrp: Error: ICTRP public search unavailable (WHO portal is SPA-only; SOAP needs partnership). Tried: https://apps.who.int/tri
No secondary-registry studies passed dual-model relevance for this condition name (after dedupe).
Where to find support
Condition-specific patient organisations, when Orphanet lists them, are on the disease’s Orphanet page. We also link umbrella groups that support undiagnosed and ultra-rare families.
Orphanet entry for X-linked severe syndromic thoracic aortic aneurysm and dissection — check Associations / patient organisations on that page.
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.
"X-linked severe syndromic thoracic aortic aneurysm and dissection" OR "Meester-Loeys syndrome" OR "X-linked severe syndromic TAAD"
ClinicalTrials.gov query (quoted phrases + MeSH via query.cond, plus recall-expansion terms when used):
"X-linked severe syndromic thoracic aortic aneurysm and dissection" OR "Meester-Loeys syndrome" OR "X-linked severe syndromic TAAD"
Study-type breakdown: 0 interventional · 0 observational · 0 expanded access. Only interventional studies enter the trial headline.
Query health: ok — strategies attempted: phrase; with hits: phrase
Run this search on ClinicalTrials.gov
Confidence reasoning
- Preferred label is multi-word and distinctive
- No synonyms dropped by stoplist
- No label/synonym collisions with other diseases in this corpus
Ingested 2026-07-27T19:10:54.834Z