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ORPHA:52503

X-linked creatine transporter deficiency

low confidenceDisorder

Also known as: Creatine transporter deficiency · SLC6A8 deficiency

Publications

1,844

Trials

3

Interventional, condition-specific

Researchers

1,182

Distinct authors in sample

Gene link

SLC6A8

Definitive

Readiness

6/6

Stages with a signal

Clinical definition (Orphanet)

X-linked creatine transporter deficiency (CRTR-D) is a creatine deficiency syndrome characterized clinically by global / (DD/ID) with prominent speech/language delay, autistic behavior and .

How rare: How common this is has not been clearly measured.

Orphanet entry

Cross-references

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

Additional Mondo synonyms (4)

cerebral creatine deficiency syndrome 1 · cerebral creatine deficiency syndrome 1, X-linked recessive · cerebral creatine deficiency syndrome type 1 · creatine transporter deficiency

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 — SLC6A8

  2. LiteraturePresent

    1,844 matched papers (1,275 in last 10 years) Source

  3. Phenotype characterisedPresent

    73 HPO annotations (e.g. Ptosis; Self-mutilation; Intellectual disability) Source

  4. Animal modelPresent

    5 genotype models (Mus musculus) Source

  5. Orphan designationPresent

    1 FDA designation (1 FDA orphan-indication approval) — e.g. cyclocreatine Source

  6. Interventional trialPresent

    3 matched on ClinicalTrials.gov (2 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 (SLC6A8).

GenCC classification: Definitive.

Phenotypes (Monarch / HPO)

73

Associated phenotypes · MONDO:0010305

  • Ptosis
  • Self-mutilation
  • Intellectual disability
  • Seizure
  • Hypertonia

Showing 5 of 73 — open Monarch for the full list.

Animal models (Monarch / Alliance)

5

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)

1

Designation · 1 with FDA orphan-indication approval

  • FDA cyclocreatineCreatine transporter deficiency · 2012-06-18 · Not FDA Approved for Orphan Indication

Sources: FDA OOPD · EMA orphan designations

Open Targets candidates

No drugs or clinical candidates returned for this Mondo ID on Open Targets.

CTD chemicals (MyDisease.info)

1 associated chemical · 4 pathways. Therapeutic evidence is listed first when present — not a treatment recommendation.

  • Creatine · marker/mechanism

Pathways: Metabolism; Metabolism of polyamines; Creatine metabolism; Metabolism of amino acids and derivatives

MyDisease.info · MONDO:0010305

Literature

Is anyone studying this?

1,844

1,844 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.

1,844 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).

1,275 in the last 10 years · low confidence

Phrase hits: 593 · MeSH hits: 0

Open Europe PMC search

Who's working on it?

1,182

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
    Salomons GS14 papers · 2025

    Metabolic Unit, Department of Clinical Chemistry, VU University Medical Center, Amsterdam Neuroscience, Amsterdam, The Netherlands.

    Papers in Europe PMC
  2. 02
    Baroncelli L13 papers · 2026

    Department of Developmental Neuroscience, IRCCS Stella Maris Foundation, I-56128 Pisa, Italy.

    Papers in Europe PMC
  3. 03
    Putignano E12 papers · 2026

    Institute of Neuroscience, National Research Council (CNR), Via Moruzzi 1, 56124, Pisa, Italy.

    Papers in Europe PMC
  4. 04
    Porter FD11 papers · 2026

    Section on Molecular Dysmorphology, Division of Translational Medicine, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA. Electronic address: fdporter@mail.nih.gov.

    Papers in Europe PMC
  5. 05
    Mabondzo A10 papers · 2025

    Service de Pharmacologie et d'Immunoanalyse, CEA, Université Paris-Saclay, F-91191 Gif-sur-Yvette, France.

    Papers in Europe PMC
  6. 06
    Skelton MR10 papers · 2026

    Department of Pediatrics, University of Cincinnati College of Medicine & Division of Neurology, Cincinnati Children's Research Foundation, Cincinnati, OH, USA.

    Papers in Europe PMC
  7. 07
    Alessandrì MG9 papers · 2026

    Department of Developmental Neuroscience, IRCCS Stella Maris Foundation, 56128, Pisa, Italy.

    Papers in Europe PMC
  8. 08
    Schulze A9 papers · 2026

    Research Institute, The Hospital for Sick Children, University of Toronto, Toronto, ON, M5G 1X8, Canada.

    Papers in Europe PMC
  9. 09
    Thurm A9 papers · 2026

    National Institute of Mental Health, National Institutes of Health, Bethesda, MD.

    Papers in Europe PMC
  10. 10
    Longo N8 papers · 2026

    Department of Pathology, University of Utah, ARUP Laboratories, Salt Lake City, UT, USA; Division of Medical Genetics, Department of Pediatrics, University of Utah, Salt Lake City, UT, USA.

    Papers in Europe PMC

Clinical research

Is a treatment being tested?

3

interventional trials for this specific condition

3 interventional trials matched this specific condition name; 2 currently recruiting in our sample.

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

3 interventional trials — more than 77.2% of diseases in the trials denominator have none at all (5501 of 7126; this disease is at the 86.7th percentile).

low confidence · 86.7th percentile (trials denominator)

Recruiting interventional trials

From the matched ClinicalTrials.gov set

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

Observational and natural-history studies

5 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 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 creatine transporter deficiency — 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 creatine transporter deficiency" OR "Creatine transporter deficiency" OR "SLC6A8 deficiency" OR "cerebral creatine deficiency syndrome 1" OR "cerebral creatine deficiency syndrome 1, X-linked recessive" OR "cerebral creatine deficiency syndrome type 1") OR (MESH:"Creatine deficiency, X-linked") OR ("SLC6A8" OR "SLC6A8 syndrome" OR "SLC6A8-related")

Run this search on Europe PMC

MeSH descriptor terms unioned into the query: Creatine deficiency, X-linked

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

"X-linked creatine transporter deficiency" OR "Creatine transporter deficiency" OR "SLC6A8 deficiency" OR "cerebral creatine deficiency syndrome 1" OR "cerebral creatine deficiency syndrome 1, X-linked recessive" OR "cerebral creatine deficiency syndrome type 1" OR "Creatine deficiency, X-linked"

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

Study-type breakdown: 3 interventional · 5 observational · 0 expanded access. Only interventional studies enter the trial headline.

Query health: ok — strategies attempted: phrase, mesh; with hits: phrase, mesh

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
  • Publication count (1844) is extremely high with unknown/missing prevalence — treat as possible over-matching, not proven research intensity

Ingested 2026-07-27T00:50:11.587Z