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ORPHA:101101

Charcot-Marie-Tooth disease type 2B2

low confidenceDisorder

Also known as: AR-CMT2B2 · Autosomal recessive axonal CMT4C3 · Autosomal recessive axonal Charcot-Marie-Tooth disease type 2B2

Publications

4,607

Trials

0

Interventional, condition-specific

Researchers

477

Distinct authors in sample

Gene link

MED25, PNKP

Strong

Readiness

4/6

Stages with a signal

Clinical definition (Orphanet)

Charcot-Marie-Tooth disease, type 2B2 (CMT2B2, also referred to as CMT4C3) is an axonal CMT peripheral sensorimotor polyneuropathy that has been described in a large consanguineous Costa Rican family of Spanish ancestry.

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 (5)

ARCMT2B · CMT2B2 · Charcot-Marie-Tooth disease, type 2B2 · autosomal recessive axonal CMT4C3 · autosomal recessive axonal Charcot-Marie-Tooth disease type 2B2

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.”

4/6 stages with a signal

No specific-condition interventional trial, but broader-category trials exist — discuss eligibility with a clinician.

  1. Gene identifiedPresent

    Strong — MED25, PNKP

  2. LiteraturePresent

    4,607 matched papers (2,646 in last 10 years) Source

  3. Phenotype characterisedPresent

    6 HPO annotations (e.g. Hyporeflexia; Decreased motor nerve conduction velocity; Distal amyotrophy) 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 trialPartial

    None under the specific name; 42 for broader category Charcot-Marie-Tooth disease

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 (MED25, PNKP).

GenCC classification: Strong.

Phenotypes (Monarch / HPO)

6

Associated phenotypes · MONDO:0011570

  • Hyporeflexia
  • Decreased motor nerve conduction velocity
  • Distal amyotrophy
  • Areflexia
  • Distal muscle weakness

Showing 5 of 6 — 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?

4,607

4,607 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.

4,607 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).

2,646 in the last 10 years · low confidence

Phrase hits: 56 · MeSH hits: 0

Open Europe PMC search

Who's working on it?

477

Distinct author names in 56 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
    Leal A9 papers · 2022

    Institute of Human Genetics, University of Erlangen-Nuremberg, Erlangen, Germany.

    Papers in Europe PMC
  2. 02
    Reis A6 papers · 2018

    Institute of Human Genetics, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany.

    Papers in Europe PMC
  3. 03
    Berghoff M5 papers · 2018

    Klinikum der Justus-Liebig-Universität, Gießen, Germany.

    Papers in Europe PMC
  4. 04
    Morera B5 papers · 2018

    School of Biological Sciences, Universidad Nacional, Heredia, Costa Rica.

    Papers in Europe PMC
  5. 05
    Rautenstrauss B5 papers · 2009
    Papers in Europe PMC
  6. 06
    Barrantes R4 papers · 2009
    Papers in Europe PMC
  7. 07
    Berghoff C4 papers · 2018

    Department of Neurology, University of Erlangen-Nuremberg, Erlangen, Germany.

    Papers in Europe PMC
  8. 08
    Heuss D4 papers · 2009
    Papers in Europe PMC
  9. 09
    Lupski JR4 papers · 2015

    Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA; Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX 77030, USA; Department of Pediatrics, Baylor College of Medicine, Houston, TX 77030, USA; Texas Children's Hospital, Houston, TX 77030, USA. Electronic address: jlupski@bcm.edu.

    Papers in Europe PMC
  10. 10
    Neundörfer B4 papers · 2009
    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. 1 observational study did — shown below because natural-history and cohort work can be an important step toward a trial. 42 trials are registered for Charcot-Marie-Tooth disease, the broader category — shown separately because they may or may not enrol this specific subtype.

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.

low 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.

42 interventional trials matched Charcot-Marie-Tooth disease, the broader category — listed below. Those studies are not counted in the condition-specific total.

Broader category: Charcot-Marie-Tooth disease

42

Interventional trials for the parent category, exclusive of NCT IDs already counted above. Eligibility for this subtype is not guaranteed.

Worth raising with a clinician. How we count trials.

Recruiting under the broader category

Observational and natural-history studies

1 observational study matches 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 2026-07-30

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 Charcot-Marie-Tooth disease type 2B2 — 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.

("Charcot-Marie-Tooth disease type 2B2" OR "AR-CMT2B2" OR "Autosomal recessive axonal CMT4C3" OR "Autosomal recessive axonal Charcot-Marie-Tooth disease type 2B2" OR "ARCMT2B" OR "CMT2B2" OR "Charcot-Marie-Tooth disease, type 2B2") OR (MESH:"Charcot-Marie-Tooth disease, Type 2B2") OR ("MED25" OR "MED25 syndrome" OR "MED25-related" OR "PNKP" OR "PNKP syndrome" OR "PNKP-related")

Run this search on Europe PMC

MeSH descriptor terms unioned into the query: Charcot-Marie-Tooth disease, Type 2B2

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

"Charcot-Marie-Tooth disease type 2B2" OR "AR-CMT2B2" OR "Autosomal recessive axonal CMT4C3" OR "Autosomal recessive axonal Charcot-Marie-Tooth disease type 2B2" OR "ARCMT2B" OR "CMT2B2" OR "Charcot-Marie-Tooth disease, type 2B2"

Study-type breakdown: 0 interventional · 1 observational · 0 expanded access. Only interventional studies enter the trial headline.

Parent-category trials query:

"Charcot-Marie-Tooth disease"

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 (4607) is implausibly high for prevalence class "<1 / 1 000 000" — treat as possible over-matching, not a measure of research intensity

Ingested 2026-07-27T07:19:05.416Z