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ORPHA:480907

X-linked intellectual disability-global development delay-facial dysmorphism-sacral caudal remnant syndrome

low confidenceDisorder

Query health: suspect — Only one of 2 strategies returned hits (phrase). Source fetch failed for trials.

Publications

3,460

Trials

—

Interventional, condition-specific

Researchers

224

Distinct authors in sample

Gene link

TAF1

Definitive

Readiness

3/6

Stages with a signal

Clinical definition (Orphanet)

A rare multiple anomalies/ syndrome characterized by global , , growth retardation, hearing impairment, characteristic facial dysmorphology (including prominent supraorbital ridges, downslanting palpebral fissures, deep-set eyes, long face, sagging cheeks, anteverted nares, and pointed chin), generalized , joint hypermobility, gluteal crease with sacral caudal remnant and sacral dimple, and variable neurological features. Various ophthalmic, cutaneous, musculoskeletal, gastrointestinal, and cardiovascular anomalies have also been described.

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.

Orphanet entry

Cross-references

Joined from Mondo / Orphanet. MeSH labels may enter searches; UMLS / OMIM / NCIT are stored for reference.

Additional Mondo synonyms (7)

MRXS33 · TAF1 X-linked syndromic intellectual disability · X-linked syndromic intellectual disability caused by mutation in TAF1 · intellectual developmental disorder, X-linked syndromic 33, X-linked recessive · intellectual disability, X-linked, syndromic type 33 · mental retardation, X-linked, syndromic 33 · mental retardation, X-linked, syndromic type 33

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.”

3/6 stages with a signal

Research-stage checklist from open sources (GenCC, literature, Monarch when enriched, ClinicalTrials.gov). Not a prognosis or care recommendation.

  1. Gene identifiedPresent

    Definitive — TAF1

  2. LiteraturePresent

    3,460 matched papers (2,128 in last 10 years) Source

  3. Phenotype characterisedPresent

    124 HPO annotations (e.g. Low-set ears; Protruding ear; Delayed speech and language development) Source

  4. Animal modelNot found

    No Alliance genotype “model of” associations via Monarch for these Mondo IDs

  5. Orphan designationNot found

    No FDA or EMA orphan-drug designation matched this disease via UMLS or preferred name Source

  6. Interventional trialNot checked

    Trial fetch failed or incomplete

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?

Yes — we know a specific gene responsible (TAF1).

GenCC classification: Definitive.

Phenotypes (Monarch / HPO)

124

Associated phenotypes · MONDO:0018823

  • Low-set ears
  • Protruding ear
  • Delayed speech and language development
  • Intellectual disability
  • Global developmental delay

Showing 5 of 124 — open Monarch for the full list.

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?

3,460

3,460 papers have been published on this condition. That is a real research literature — still far smaller than common diseases (breast cancer: over 700,000 papers). Median papers in the last 10 years for a rare disease in this dataset (publications denominator n=3967) is 59.

3,460 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).

2,128 in the last 10 years · low confidence

Phrase hits: 20 · MeSH hits: 0

Open Europe PMC search

Who's working on it?

224

Distinct author names in 20 sampled papers — named people below.

Who's working on it?

People publishing on this condition (sampled Europe PMC records). Affiliation is the most recent found in that sample.

  1. 01
    Chen C3 papers · 2026

    Laboratory of Medical Genetics, School of Life Sciences, Central South University, Changsha, China.

    Papers in Europe PMC
  2. 02
    Cleverley K3 papers · 2025

    Department of Neuromuscular Diseases, UCL Institute of Neurology, University College London, London WC1N 3BG, UK.

    Papers in Europe PMC
  3. 03
    Crombie EM3 papers · 2025

    Department of Neuromuscular Diseases, UCL Institute of Neurology, University College London, London WC1N 3BG, UK.

    Papers in Europe PMC
  4. 04
    Boinon L2 papers · 2020

    Department of Pharmacology, University of Arizona College of Medicine and College of Pharmacy, Tucson, AZ, USA.

    Papers in Europe PMC
  5. 05
    Fisher EMC2 papers · 2024

    Department of Neuromuscular Diseases, UCL Institute of Neurology, University College London, London WC1N 3BG, UK.

    Papers in Europe PMC
  6. 06
    Janakiraman U2 papers · 2020

    Department of Pathology, University of Arizona College of Medicine and College of Pharmacy, Tucson, AZ, USA.

    Papers in Europe PMC
  7. 07
    Khanna R2 papers · 2020

    Department of Pathology, University of Arizona College of Medicine and College of Pharmacy, Tucson, AZ, USA; Department of Pharmacology, University of Arizona College of Medicine and College of Pharmacy, Tucson, AZ, USA; The Center for Innovation in Brain Sciences, The University of Arizona Health Sciences, Tucson, AZ, United States of America; The BIO5 Institute, University of Arizona, United States of America.

    Papers in Europe PMC
  8. 08
    Lupski JR2 papers · 2022

    Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, USA.

    Papers in Europe PMC
  9. 09
    Moutal A2 papers · 2020

    Department of Pharmacology, University of Arizona College of Medicine and College of Pharmacy, Tucson, AZ, USA.

    Papers in Europe PMC
  10. 10
    Nelson MA2 papers · 2020

    Department of Pathology, University of Arizona College of Medicine and College of Pharmacy, Tucson, AZ, USA. Electronic address: mnelson@pathology.arizona.edu.

    Papers in Europe PMC

Clinical research

Is a treatment being tested?

—

interventional trials for this specific condition

We could not load trial data for this condition right now.

Data as of 11 September 2026 · last trial check 28 July 2026

low confidence

Recruiting interventional trials

From the matched ClinicalTrials.gov set

Trial data could not be loaded for this build. This is not the same as finding zero interventional trials.

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 intellectual disability-global development delay-facial dysmorphism-sacral caudal remnant syndrome — check Associations / patient organisations on that page.

India — NPRD

Last verified 2026-07-26

This 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 intellectual disability-global development delay-facial dysmorphism-sacral caudal remnant syndrome" OR "MRXS33" OR "TAF1 X-linked syndromic intellectual disability" OR "X-linked syndromic intellectual disability caused by mutation in TAF1" OR "intellectual developmental disorder, X-linked syndromic 33, X-linked recessive" OR "intellectual disability, X-linked, syndromic type 33" OR "mental retardation, X-linked, syndromic 33" OR "mental retardation, X-linked, syndromic type 33") OR ("TAF1" OR "TAF1 syndrome" OR "TAF1-related")

Run this search on Europe PMC

ClinicalTrials.gov query (quoted phrases + MeSH via query.cond, plus recall-expansion terms when used):

(empty)

Query health: suspect — strategies attempted: phrase, recall-expansion; with hits: phrase

Source errors: trials: Error: HTTP 400 for https://clinicaltrials.gov/api/v2/studies?query.cond=%22X-linked%20intellectual%20disability-global%20development%20delay-facial%20dysmorphism-sacral%20caudal%20remnant%20syndrome%22&format=json&pageSize=100&countTotal=true

Confidence reasoning

  • Preferred label is multi-word and distinctive
  • No synonyms dropped by stoplist
  • No label/synonym collisions with other diseases in this corpus
  • Publication count (3460) is implausibly high for prevalence class "<1 / 1 000 000" — treat as possible over-matching, not a measure of research intensity

Ingested 2026-07-27T17:15:42.190Z