ORPHA:908
Fragile X syndrome
Also known as: FRAXA syndrome · FXS · FraX syndrome · Martin-Bell syndrome
Publications
21,437
98.6th percentile
Trials
92
Interventional, condition-specific
Researchers
1,213
Distinct authors in sample
Gene link
FMR1
Definitive
Readiness
3/6
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).
Cross-references
Joined from Mondo / Orphanet. MeSH labels may enter searches; UMLS / OMIM / NCIT are stored for reference.
- MONDO:0010383
- MeSH:D005600
- OMIM:300624
- UMLS:C0016667
- NCIT:C84717
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.”
3/6 stages with a signal
An interventional trial matched this condition name on ClinicalTrials.gov — see trials below.
- Gene identifiedPresent
Definitive — FMR1
- LiteraturePresent
21,437 matched papers (10,577 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 trialPresent
92 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)
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?
21,437
21,437 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=5449) is 41.
21,437 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).
10,577 in the last 10 years · medium confidence · 98.6th percentile (publications denominator)
Phrase hits: 21,437 · MeSH hits: 0
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.
- 01Erickson CA13 papers · 2026
Division of Child and Adolescent Psychiatry, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA.
Papers in Europe PMC - 02Pedapati 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 - 03Li 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 - 04Liu 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 - 05Miyakoshi 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 - 06
- 07Cheng 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 - 08Dominick KC6 papers · 2026
Division of Child and Adolescent Psychiatry, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA.
Papers in Europe PMC - 09Horn PS6 papers · 2026
Division of Neurology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, United States of America.
Papers in Europe PMC - 10Westerkamp 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?
92
interventional trials for this specific condition
92 interventional trials matched this specific condition name; 18 currently recruiting in our sample.
Data as of 27 July 2026
92 interventional trials — more than 73% of diseases in the trials denominator have none at all (5114 of 7003; this disease is at the 98.3th percentile).
medium confidence · 98.3th percentile (trials denominator)
Recruiting interventional trials
From the matched ClinicalTrials.gov set
92 interventional trials matched after quoted-phrase search and title/condition post-filter.
- NCT06088589·RECRUITING·Speech-in-noise Perception in Autism and Fragile X
Conditions: Autism Spectrum Disorder · Fragile X Syndrome·Matched via name phrase
- NCT06261450·NOT YET RECRUITING·Effect of CBD on the Brain
Conditions: Fragile X Syndrome·Matched via name phrase
- NCT06081348·RECRUITING·Sertraline vs. Placebo in the Treatment of Anxiety in Children and AdoLescents With NeurodevelopMental Disorders
Conditions: Neurodevelopmental Disorders · Autism · Autism Spectrum Disorder · Fragile X Syndrome·Matched via name phrase
- NCT00768820·RECRUITING·The Psychiatric and Cognitive Phenotypes in Velocardiofacial Syndrome
Conditions: Velocardiofacial Syndrome · Williams Syndrome · Fragile X Syndrome·Matched via name phrase
- NCT06261502·NOT YET RECRUITING·Effect of CANnabidiol on Anxiety and GABAergic Function in Individuals with Fragile-X Syndrome
Conditions: Fragile X Syndrome·Matched via name phrase
- NCT03836300·ENROLLING BY INVITATION·Parent and Infant Inter(X)Action Intervention (PIXI)
Conditions: Fragile X Syndrome · Angelman Syndrome · Prader-Willi Syndrome · Dup15Q Syndrome·Matched via name phrase
- NCT06868979·RECRUITING·Optical Imaging in X-linked Disorders.
Conditions: Fragile X Syndrome (FXS) · Creatine Transporter Deficiency·Matched via name phrase
- NCT06560242·RECRUITING·Tracking Early Emergence of Sound Perception Impairments in FXS With Multimodal fNIRS/EEG- Infant
Conditions: Fragile X Syndrome·Matched via name phrase
- NCT05120505·RECRUITING·Metformin in Children With Fragile X Syndrome
Conditions: Fragile X Syndrome · Metformin·Matched via name phrase
- NCT05957549·RECRUITING·Tracking Early Emergence of Sound Perception Impairments in FXS With Multimodal fNIRS/EEG-Preschool Age
Conditions: Fragile X Syndrome·Matched via name phrase
- NCT07654114·RECRUITING·Safety, Tolerability, and Preliminary Effectiveness of CTH120 in Fragile X Syndrome
Conditions: Fragile X Syndrome (FXS) · Fragile X Syndrome·Matched via name phrase
- NCT06677866·RECRUITING·Group CBT in Adolescents With Fragile X Syndrome and in Adolescents With Autism Spectrum Disorder
Conditions: Fragile X Syndrome (FXS) · Autism Spectrum Disorder·Matched via name phrase
- NCT07439510·NOT YET RECRUITING·A Study to Investigate the Effects and Safety of SPG601 for the Treatment of Fragile X Syndrome in Male Participants
Conditions: Fragile X Syndrome (FXS)·Matched via name phrase
- NCT06740162·RECRUITING·Physical Activity and Community EmPOWERment Project
Conditions: Intellectual Disability · Neurodevelopmental Disorders · Autism Spectrum Disorder · Down Syndrome·Matched via name phrase
- NCT05301361·ENROLLING BY INVITATION·Sensitivity of the NIH Toolbox to Stimulant Treatment in Intellectual Disabilities
Conditions: Intellectual Disability · Fragile X Syndrome · Down Syndrome · Attention Deficit Hyperactivity Disorder·Matched via name phrase
Observational and natural-history studies
18 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
- NCT07434037·NOT YET RECRUITING·The Neurocognitive Bases of Trust in Intellectual Disability
Conditions: Down Syndrome (Trisomy 21) · Fragile X Syndrome (FXS)·Matched via name phrase
- NCT07493096·RECRUITING·Intensive Multimodal Neurorehabilitation Targeting Neuroplasticity in Pediatric Neurodevelopmental and Chromosomal Disorders
Conditions: Neurodevelopmental Disorders · Neurodevelopmental Disorders (NDD) · Neurodevelopmental Disorders and Developmental Abnormalities · Developmental Delay (Disorder)·Matched via name phrase
- NCT06147414·RECRUITING·Development of Non-Invasive Prenatal Diagnosis for Single Gene Disorders
Conditions: Invasive PreNatal Diagnosis in a Context of Family History of Single-gene Disorders, Including · Sickle Cell Disease · Cystic Fibrosis · Fragile X Syndrome·Matched via name phrase
- NCT07039734·RECRUITING·Assessment of Ovarian Reserve in Patients With Fragile X Premutation
Conditions: FMR1 Gene Premutation·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.
"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"
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" OR "FMR1"
Recall-expansion terms: FMR1
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: 92 interventional · 18 observational · 0 expanded access. Only interventional studies enter the trial headline.
Query health: ok — strategies attempted: phrase, recall-expansion; with hits: phrase, recall-expansion
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