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ORPHA:368

Glycogen storage disease due to muscle glycogen phosphorylase deficiency

low confidenceDisorder

Also known as: GSD due to muscle glycogen phosphorylase deficiency · GSD type 5 · GSD type V · Glycogen storage disease type 5 · Glycogen storage disease type V · Glycogenosis due to muscle glycogen phosphorylase deficiency · Glycogenosis type 5 · Glycogenosis type V · McArdle disease · Myophosphorylase deficiency

Publications

3,085

Trials

9

Interventional, condition-specific

Researchers

997

Distinct authors in sample

Gene link

PYGM

Definitive

Readiness

5/6

Stages with a signal

Clinical definition (Orphanet)

A form of glycogen storage disease (GSD) characterized by exercise intolerance and rhabdomyolysis episodes, due to a deficiency of the muscle isoform of glycogen phosphorylase.

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 (10)

Mcardle disease · PYGM glycogen storage disease · glycogen storage disease V · glycogen storage disease caused by mutation in PYGM · glycogen storage disease type 5 · glycogen storage disease type V · glycogenosis due to muscle glycogen phosphorylase deficiency · glycogenosis type 5 · glycogenosis type V · myophosphorylase 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.”

5/6 stages with a signal

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

  1. Gene identifiedPresent

    Definitive — PYGM

  2. LiteraturePresent

    3,085 matched papers (1,657 in last 10 years) Source

  3. Phenotype characterisedPresent

    37 HPO annotations (e.g. Elevated circulating creatine kinase activity; Exercise-induced rhabdomyolysis; Myoglobinuria) Source

  4. Animal modelPresent

    2 genotype models (Mus musculus) Source

  5. Orphan designationNot found

    No FDA or EMA orphan-drug designation matched this disease via UMLS or preferred name Source

  6. Interventional trialPresent

    9 matched on ClinicalTrials.gov

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 (PYGM).

GenCC classification: Definitive.

Phenotypes (Monarch / HPO)

37

Associated phenotypes · MONDO:0009293

  • Elevated circulating creatine kinase activity
  • Exercise-induced rhabdomyolysis
  • Myoglobinuria
  • Hyperuricemia
  • Rhabdomyolysis

Showing 5 of 37 — open Monarch for the full list.

Animal models (Monarch / Alliance)

2

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)

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

3

Drugs / clinical candidates · MONDO_0009293

CTD chemicals (MyDisease.info)

1 associated chemical · 16 pathways. Therapeutic evidence is listed first when present — not a treatment recommendation.

  • Adrenocorticotropic Hormone · therapeutic

Pathways: Starch and sucrose metabolism; Metabolic pathways; Renin-angiotensin system; Insulin signaling pathway; Glucagon signaling pathway; Renin secretion; Insulin resistance; Chagas disease (American trypanosomiasis)

MyDisease.info · MONDO:0009293

Literature

Is anyone studying this?

3,085

3,085 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.

3,085 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).

1,657 in the last 10 years · low confidence

Phrase hits: 1,431 · MeSH hits: 0

Open Europe PMC search

Who's working on it?

997

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
    Lucia A28 papers · 2025

    Faculty of Sport Sciences, Universidad Europea de Madrid, Madrid, Spain.

    Papers in Europe PMC
  2. 02
    Pinós T23 papers · 2025

    Biomedical Network Research Centre on Rare Diseases (CIBERER), Instituto de Salud Carlos III, and Research Group on Neuromuscular and Mitochondrial Diseases, Vall d'Hebron Research Institute, Universitat Autònoma de Barcelona, Barcelona, Catalonia, Spain.

    Papers in Europe PMC
  3. 03
    Quinlivan R20 papers · 2025

    MRC Centre for Neuromuscular Disease, National Hospital for Neurology and Neurosurgery, London, UK.

    Papers in Europe PMC
  4. 04
    Santalla A18 papers · 2024

    Instituto de Investigación Hospital, 12 de Octubre (imas12), Madrid, Spain.

    Papers in Europe PMC
  5. 05
    Vissing J18 papers · 2024

    Copenhagen Neuromuscular Center, Section 6921, Rigshospitalet, University of Copenhagen, 2100, Copenhagen, Denmark. john.vissing@regionh.dk.

    Papers in Europe PMC
  6. 06
    Arenas J16 papers · 2025

    Laboratorio de Enfermedades Mitocondriales y Neuromusculares, Hospital 12 de Octubre, Madrid, Spain.

    Papers in Europe PMC
  7. 07
    Martín MA14 papers · 2025

    Centre for Biomedical Network Research on Rare Diseases (CIBERER), Instituto de Salud Carlos III, Madrid, Spain.

    Papers in Europe PMC
  8. 08
    Nogales-Gadea G14 papers · 2022

    Department of Neurosciences, Institut d'Investigació en Ciències de la Salut Germans Trias i Pujol I Campus Can Ruti, Universitat Autònoma de Barcelona, Badalona, Spain.

    Papers in Europe PMC
  9. 09
    Andreu AL13 papers · 2023

    Biomedical Network Research Centre on Rare Diseases (CIBERER), Instituto de Salud Carlos III, and Research Group on Neuromuscular and Mitochondrial Diseases, Vall d'Hebron Research Institute, Universitat Autònoma de Barcelona, Barcelona, Catalonia, Spain.

    Papers in Europe PMC
  10. 10
    Løkken N11 papers · 2024

    Copenhagen Neuromuscular Center, Department of Neurology, Rigshospitalet, University of Copenhagen, Denmark.

    Papers in Europe PMC

Clinical research

Is a treatment being tested?

9

interventional trials for this specific condition

9 interventional trials matched this specific condition name; none in our sample are currently recruiting.

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

9 interventional trials — more than 77.2% of diseases in the trials denominator have none at all (5501 of 7126; this disease is at the 92th percentile).

low confidence · 92th percentile (trials denominator)

Recruiting interventional trials

From the matched ClinicalTrials.gov set

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

No currently recruiting studies in the matched set. Open the same search on ClinicalTrials.gov.

Observational and natural-history studies

7 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.

None of the matched observational studies is currently listed as 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 5 · after dedupe 5 · already on CT.gov 0 · kept 0 · parent 0 · uncertain 5 · 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 (5)

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 Glycogen storage disease due to muscle glycogen phosphorylase 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.

("Glycogen storage disease due to muscle glycogen phosphorylase deficiency" OR "GSD due to muscle glycogen phosphorylase deficiency" OR "GSD type 5" OR "GSD type V" OR "Glycogen storage disease type 5" OR "Glycogen storage disease type V" OR "Glycogenosis due to muscle glycogen phosphorylase deficiency" OR "Glycogenosis type 5" OR "Glycogenosis type V" OR "McArdle disease" OR "Myophosphorylase deficiency" OR "PYGM glycogen storage disease" OR "glycogen storage disease V") OR ("PYGM" OR "PYGM syndrome" OR "PYGM-related")

Run this search on Europe PMC

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

"Glycogen storage disease due to muscle glycogen phosphorylase deficiency" OR "GSD due to muscle glycogen phosphorylase deficiency" OR "GSD type 5" OR "GSD type V" OR "Glycogen storage disease type 5" OR "Glycogen storage disease type V" OR "Glycogenosis due to muscle glycogen phosphorylase deficiency" OR "Glycogenosis type 5" OR "Glycogenosis type V" OR "McArdle disease" OR "Myophosphorylase deficiency" OR "PYGM glycogen storage disease" OR "glycogen storage disease V"

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: 9 interventional · 7 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: glycogen storage disease caused by mutation in PYGM

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 (3085) is extremely high with unknown/missing prevalence — treat as possible over-matching, not proven research intensity

Ingested 2026-07-26T13:35:32.164Z