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ORPHA:908

Fragile X syndrome

medium confidenceDisorder

Also known as: FRAXA syndrome · FXS · FraX syndrome · Martin-Bell syndrome

Publications

28,845

98th percentile

Trials

91

Interventional, condition-specific

Researchers

1,213

Distinct authors in sample

Gene link

FMR1

Definitive

Readiness

6/6

Stages with a signal

Clinical definition (Orphanet)

A rare genetic disease associated with mild to severe intellectual deficit that may be associated with behavioral disorders and characteristic physical features including a high forehead, prominent and large ears, hyperextensible finger joints, flat feet with pronation and, in adolescent and adult males, macroorchidism.

How rare: 1-5 / 10 000 — about one to five people per ten thousand (still uncommon, but less ultra-rare).

Orphanet entry

Cross-references

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

Additional Mondo synonyms (4)

Fragile X syndrome, X-linked dominant · fragile X intellectual disability syndrome · fragile X syndrome · marker X 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.”

6/6 stages with a signal

An interventional trial matched this condition name on ClinicalTrials.gov — see trials below.

  1. Gene identifiedPresent

    Definitive — FMR1

  2. LiteraturePresent

    28,845 matched papers (15,829 in last 10 years) Source

  3. Phenotype characterisedPresent

    57 HPO annotations (e.g. Joint hypermobility; Abnormal speech pattern; Moderate intellectual disability) Source

  4. Animal modelPresent

    23 genotype models (Danio rerio, Mus musculus, Rattus norvegicus) Source

  5. Orphan designationPresent

    15 FDA · 5 EMA designations (15 FDA orphan-indication approvals) — e.g. Balipodect Source

  6. Interventional trialPresent

    91 matched on ClinicalTrials.gov (18 recruiting in sample)

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 (FMR1).

GenCC classification: Definitive.

Phenotypes (Monarch / HPO)

57

Associated phenotypes · MONDO:0010383

  • Joint hypermobility
  • Abnormal speech pattern
  • Moderate intellectual disability
  • Mandibular prognathia
  • Delayed speech and language development

Showing 5 of 57 — open Monarch for the full list.

Animal models (Monarch / Alliance)

23

Model associations linked to this Mondo ID

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)

30

Designations · 15 with FDA orphan-indication approval

  • FDA BalipodectFragile X Syndrome · 2019-06-13 · Not FDA Approved for Orphan Indication
  • FDA GaboxadolFragile X Syndrome · 2017-10-03 · Not FDA Approved for Orphan Indication
  • FDA 5,5-dimethyl-3-[2-(7-methylspiro[2H-benzofuran-3,1'-cyclopropane]-4-yl)oxypyrimidin-5-yl]imidazolidine-2,4-dioneFragile X Syndrome · 2017-06-12 · Not FDA Approved for Orphan Indication
  • FDA CannabidivarinFragile X Syndrome · 2017-06-06 · Not FDA Approved for Orphan Indication
  • FDA ganaxoloneFragile X Syndrome · 2016-12-28 · Not FDA Approved for Orphan Indication
  • FDA cannabidiolFragile X Syndrome · 2016-02-23 · Not FDA Approved for Orphan Indication
  • FDA (3S)-(+)-(5-chloro-2-methoxyphenyl)-1,3-dihydro-3-fluoro-6-(trifluoromethyl)-2H-indol-2-oneFragile X Syndrome · 2015-12-09 · Not FDA Approved for Orphan Indication
  • FDA bryostatin 1Fragile X Syndrome · 2015-03-31 · Not FDA Approved for Orphan Indication

Sources: FDA OOPD · EMA orphan designations

Open Targets candidates

30

Drugs / clinical candidates · MONDO_0010383

CTD chemicals (MyDisease.info)

2 associated chemicals · 57 pathways. Therapeutic evidence is listed first when present — not a treatment recommendation.

  • Minocycline · therapeutic
  • Aluminum · marker/mechanism

Pathways: RNA transport; Serotonergic synapse; Alzheimer's disease; Hemostasis; Platelet degranulation; ZBP1(DAI) mediated induction of type I IFNs; Signal Transduction; Disease

MyDisease.info · MONDO:0010383

Literature

Is anyone studying this?

28,845

28,845 papers — among the better-studied rare conditions, though still a fraction of common-disease literature (breast cancer: over 700,000). Median papers in the last 10 years for a rare disease in this dataset (publications denominator n=3967) is 59.

28,845 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).

15,829 in the last 10 years · medium confidence · 98th percentile (publications denominator)

Phrase hits: 21,437 · MeSH hits: 0

Open Europe PMC search

Who's working on it?

1,213

Distinct author names in 200 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
    Erickson CA13 papers · 2026

    Division of Child and Adolescent Psychiatry, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA.

    Papers in Europe PMC
  2. 02
    Pedapati EV12 papers · 2026

    Division of Child and Adolescent Psychiatry, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, United States of America.

    Papers in Europe PMC
  3. 03
    Li R7 papers · 2026

    Center for Cognitive and Brain Sciences, Institute of Collaborative Innovation, University of Macau, Avenida da Universidade, Taipa, Macau, China.

    Papers in Europe PMC
  4. 04
    Liu Y7 papers · 2026

    Division of Child and Adolescent Psychiatry, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, United States of America.

    Papers in Europe PMC
  5. 05
    Miyakoshi M7 papers · 2026

    Division of Child and Adolescent Psychiatry, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, United States of America.

    Papers in Europe PMC
  6. 06
    Schmitt LM7 papers · 2026

    Phelan-McDermid Syndrome Foundation, Osprey, FL, USA.

    Papers in Europe PMC
  7. 07
    Cheng N6 papers · 2026

    Hotchkiss Brain Institute, University of Calgary, Calgary T2N 1N4, Canada; Faculty of Veterinary Medicine, University of Calgary, Calgary T2N 1N4, Canada; Alberta Children's Hospital Research Institute, University of Calgary, Calgary T2N 1N4, Canada; Owerko Centre, University of Calgary, Calgary T2N 1N4, Canada. Electronic address: ncheng@ucalgary.ca.

    Papers in Europe PMC
  8. 08
    Dominick KC6 papers · 2026

    Division of Child and Adolescent Psychiatry, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA.

    Papers in Europe PMC
  9. 09
    Horn PS6 papers · 2026

    Division of Neurology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, United States of America.

    Papers in Europe PMC
  10. 10
    Westerkamp G6 papers · 2026

    Division of Child and Adolescent Psychiatry, Cincinnati Children's Hospital Medical Center, 3333 Burnet Ave., Cincinnati, OH, 45229, USA.

    Papers in Europe PMC

Clinical research

Is a treatment being tested?

91

interventional trials for this specific condition

91 interventional trials matched this specific condition name; 18 currently recruiting in our sample.

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

91 interventional trials — more than 77.2% of diseases in the trials denominator have none at all (5501 of 7126; this disease is at the 98.4th percentile).

medium confidence · 98.4th percentile (trials denominator)

Recruiting interventional trials

From the matched ClinicalTrials.gov set

91 interventional trials matched after quoted-phrase search and title/condition post-filter.

Observational and natural-history studies

17 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

Open the complete matched search on ClinicalTrials.gov

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 22 · after dedupe 22 · already on CT.gov 0 · kept 0 · parent 0 · uncertain 22 · 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).

Uncertain / not reviewed (22)

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 Fragile X 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.

("Fragile X syndrome" OR "FRAXA syndrome" OR "FraX syndrome" OR "Martin-Bell syndrome" OR "Fragile X syndrome, X-linked dominant" OR "fragile X intellectual disability syndrome" OR "marker X syndrome") OR ("FMR1" OR "FMR1 syndrome" OR "FMR1-related")

Run this search on Europe PMC

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

"Fragile X syndrome" OR "FRAXA syndrome" OR "FraX syndrome" OR "Martin-Bell syndrome" OR "Fragile X syndrome, X-linked dominant" OR "fragile X intellectual disability syndrome" OR "marker X syndrome"

Interventional trials matched via: phrase (mesh = registered under a MeSH descriptor no name phrase would catch; recall-expansion = gene / selected parent terms used only for trials).

Study-type breakdown: 91 interventional · 17 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: FXS

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 2026-07-26T15:52:31.455Z