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ORPHA:3063

X-linked intellectual disability, Snyder type

medium confidenceDisorder

Also known as: Snyder-Robinson syndrome

Publications

397

75th percentile

Trials

0

Interventional, condition-specific

Researchers

1,115

Distinct authors in sample

Gene link

SMS

Definitive

Readiness

3/6

Stages with a signal

Clinical definition (Orphanet)

X-linked , Snyder type is a rare X-linked syndrome characterized by , asthenic build with diminished muscle mass, severe generalized psychomotor delay, unsteady gait and moderate to severe , as well as a long, thin, asymmetrical face with prominent lower lip, long fingers and toes and nasal, dysarthric or absent speech. Bone abnormalities (e.g., osteoporosis, kyphoscoliosis, fractures, joint contractures) are also characteristic. Myoclonic, or myoclonic-like, and renal abnormalities have been associated in some patients.

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)

SRS · Snyder-Robinson Syndrome · Snyder-Robinson intellectual disability syndrome · Snyder-Robinson mental retardation syndrome · intellectual developmental disorder, X-linked syndromic, Snyder-Robinson type, X-linked recessive · intellectual disability, X-linked, Snyder-Robinson type · syndromic X-linked intellectual disability Snyder type

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

No matched interventional trial; the gene is known and literature exists — preclinical or natural-history work may still be the practical next step.

  1. Gene identifiedPresent

    Definitive — SMS

  2. LiteraturePresent

    397 matched papers (292 in last 10 years) Source

  3. Phenotype characterisedPresent

    117 HPO annotations (e.g. Narrow face; Facial asymmetry; Osteoporosis) 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 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?

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

GenCC classification: Definitive.

Phenotypes (Monarch / HPO)

117

Associated phenotypes · MONDO:0010664

  • Narrow face
  • Facial asymmetry
  • Osteoporosis
  • Hypernasal speech
  • Unsteady gait

Showing 5 of 117 — 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?

397

397 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.

397 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).

292 in the last 10 years · medium confidence · 75th percentile (publications denominator)

Phrase hits: 198 · MeSH hits: 0

Open Europe PMC search

Who's working on it?

1,115

Distinct author names in 198 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.

  1. 01
    Pegg AE20 papers · 2026

    College of Medicine, Milton S. Hershey Medical Center, Pennsylvania State University, Hershey, PA, USA.

    Papers in Europe PMC
  2. 02
    Schwartz CE20 papers · 2026

    JC Self Research Institute of Human Genetics, Greenwood Genetic Center, Greenwood, SC 29646, USA.

    Papers in Europe PMC
  3. 03
    Casero RA Jr16 papers · 2026

    Department of Oncology, Johns Hopkins University School of Medicine and the Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins, Baltimore, MD 21231, USA. rcasero@jhmi.edu

    Papers in Europe PMC
  4. 04
    Alexov E15 papers · 2025

    Computational Biophysics and Bioinformatics, Physics Department, Clemson University, Clemson, SC 29634, USA. ealexov@clemson.edu.

    Papers in Europe PMC
  5. 05
    Foley JR11 papers · 2024

    Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins School of Medicine; Baltimore, MD 21287, USA.

    Papers in Europe PMC
  6. 06
    Wang X9 papers · 2025

    Department of Cellular and Molecular Physiology, Milton S. Hershey Medical Center, Pennsylvania State University College of Medicine, Hershey, Pennsylvania 17033, USA.

    Papers in Europe PMC
  7. 07
    Zhai RG9 papers · 2026

    Department of Molecular and Cellular Pharmacology, University of Miami Miller School of Medicine, Miami, FL, 33136, USA. gzhai@med.miami.edu.

    Papers in Europe PMC
  8. 08
    Zhang Z9 papers · 2026

    Computational Biophysics and Bioinformatics, Department of Physics and Astronomy, Clemson University, SC 29634, USA.

    Papers in Europe PMC
  9. 09
    Bachmann AS8 papers · 2026

    Department of Pediatrics and Human Development, College of Human Medicine, Michigan State University, Grand Rapids, MI 49503, USA.

    Papers in Europe PMC
  10. 10
    Ikeguchi Y7 papers · 2014

    Department of Biochemistry, Faculty of Pharmaceutical Sciences, Josai University, Sakado, Saitama 350-0295.

    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 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.

medium 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 2026-07-29

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, Snyder type — 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, Snyder type" OR "Snyder-Robinson syndrome" OR "Snyder-Robinson intellectual disability syndrome" OR "Snyder-Robinson mental retardation syndrome" OR "intellectual developmental disorder, X-linked syndromic, Snyder-Robinson type, X-linked recessive" OR "intellectual disability, X-linked, Snyder-Robinson type" OR "syndromic X-linked intellectual disability Snyder type") OR ("SMS syndrome" OR "SMS-related")

Run this search on Europe PMC

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

"X-linked intellectual disability, Snyder type" OR "Snyder-Robinson syndrome" OR "Snyder-Robinson intellectual disability syndrome" OR "Snyder-Robinson mental retardation syndrome" OR "intellectual developmental disorder, X-linked syndromic, Snyder-Robinson type, X-linked recessive" OR "intellectual disability, X-linked, Snyder-Robinson type" OR "syndromic X-linked intellectual disability Snyder type"

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

Synonyms dropped by stoplist: SRS

Confidence reasoning

  • Preferred label is multi-word and distinctive
  • 1 synonym(s) dropped by stoplist (may under-count)
  • No label/synonym collisions with other diseases in this corpus

Ingested 2026-07-26T22:07:35.983Z