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ORPHA:544602

Congenital myopathy with reduced type 2 muscle fibers

low confidenceDisorder

Also known as: Congenital myopathy with fast-twitch fiber atrophy · Congenital myopathy with reduced type II muscle fibers · Congenital myopathy with type 2 muscle fiber atrophy · Congenital myopathy with type II fiber atrophy

Publications

2,538

Trials

0

Interventional, condition-specific

Researchers

0

Distinct authors in sample

Gene link

MYL1

Moderate

Readiness

4/6

Stages with a signal

Clinical definition (Orphanet)

A rare characterized by onset of severe muscle weakness with selective atrophy/hypotrophy or absence of type II myofibers. Patients present at birth with and respiratory failure, as well as mild facial and severe axial and proximal upper and lower limb weakness with areflexia and mild contractures. Eye movements and cardiac function are normal.

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 (2)

myopathy, congenital, with fast-twitch (type II) fiber atrophy · myopathy, congenital, with fast-twitch (type II) fibre atrophy

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

    Moderate — MYL1

  2. LiteraturePresent

    2,538 matched papers (1,405 in last 10 years) Source

  3. Phenotype characterisedPresent

    27 HPO annotations (e.g. Hip contracture; Motor delay; Weakness of facial musculature) 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; 6 for broader category congenital myopathy

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?

Probably — there is moderate evidence for MYL1.

GenCC classification: Moderate.

Phenotypes (Monarch / HPO)

27

Associated phenotypes · MONDO:0034109

  • Hip contracture
  • Motor delay
  • Weakness of facial musculature
  • Respiratory failure
  • Type 1 muscle fiber predominance

Showing 5 of 27 — 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?

2,538

2,538 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.

2,538 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).

1,405 in the last 10 years · low confidence

Phrase hits: 0 · MeSH hits: 0

Open Europe PMC search

Who's working on it?

0

Distinct author names in 0 sampled papers.

Who's working on it?

No author names could be extracted from the sampled publications. Try the Europe PMC query in “How we counted this,” or contact an umbrella rare-disease organisation for researcher referrals.

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). 6 trials are registered for congenital myopathy, 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.

6 interventional trials matched congenital myopathy, the broader category — listed below. Those studies are not counted in the condition-specific total.

Broader category: congenital myopathy

6

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

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 Congenital myopathy with reduced type 2 muscle fibers — 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.

("Congenital myopathy with reduced type 2 muscle fibers" OR "Congenital myopathy with fast-twitch fiber atrophy" OR "Congenital myopathy with reduced type II muscle fibers" OR "Congenital myopathy with type 2 muscle fiber atrophy" OR "Congenital myopathy with type II fiber atrophy" OR "myopathy, congenital, with fast-twitch (type II) fiber atrophy" OR "myopathy, congenital, with fast-twitch (type II) fibre atrophy") OR ("MYL1" OR "MYL1 syndrome" OR "MYL1-related")

Run this search on Europe PMC

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

"Congenital myopathy with reduced type 2 muscle fibers" OR "Congenital myopathy with fast-twitch fiber atrophy" OR "Congenital myopathy with reduced type II muscle fibers" OR "Congenital myopathy with type 2 muscle fiber atrophy" OR "Congenital myopathy with type II fiber atrophy" OR "myopathy, congenital, with fast-twitch (type II) fiber atrophy" OR "myopathy, congenital, with fast-twitch (type II) fibre atrophy"

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

Parent-category trials query:

"congenital myopathy"

Query health: ok — strategies attempted: phrase; with hits: none

Parent literature probe: autosomal recessive disease (MONDO:0006025) — 11924 hits

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 (2538) is implausibly high for prevalence class "<1 / 1 000 000" — treat as possible over-matching, not a measure of research intensity

Ingested 2026-07-27T18:17:50.190Z