| Domain | Key facts | Identifiers / ontology suggestions | Quantitative / implementation notes | Evidence / caveats |
|---|---|---|---|---|
| Disease definition / spectrum | RYR1-related myopathy (RYR1-RM) is a genetically heterogeneous group of skeletal muscle disorders caused by pathogenic **RYR1** variants; it is described as the most common class of congenital myopathies. Reported histopathologic/clinical subtypes include **central core disease**, **multiminicore disease**, **core-rod myopathy**, **centronuclear myopathy**, **congenital fiber-type disproportion**, **King-Denborough syndrome**, **rhabdomyolysis-myalgia syndrome**, **atypical periodic paralysis**, **late-onset axial myopathy**, and malignant-hyperthermia-associated myopathic presentations. | **MONDO:** requires database verification. **OMIM / Orphanet / MeSH / ICD-10/11:** disease-group mapping requires database verification because “RYR1-related myopathy” spans multiple named entities. Suggested disease ontology links: congenital myopathy group, central core disease, malignant hyperthermia susceptibility. | Disease concept is **aggregated disease-level knowledge**, not EHR-derived. NGS expanded recognized spectrum beyond biopsy-led classification. | Spectrum and nomenclature are well supported in reviews, but exact identifier mapping should be verified in OMIM/Orphanet/MONDO because the umbrella term spans several entities (pqac-00000002, pqac-00000009). |
| Gene / protein | **RYR1** encodes **ryanodine receptor 1 (RyR1)**, the principal skeletal-muscle sarcoplasmic-reticulum Ca²⁺ release channel in excitation-contraction coupling; protein is a large homotetramer. Gene localizes to **19q13.2** and contains **106 exons**; protein length **5038 aa**, about **565 kDa**. | **Gene:** RYR1. **HGNC / NCBI Gene / UniProt IDs:** require database verification. Suggested GO terms: **calcium ion transmembrane transport**, **excitation-contraction coupling**, **sarcoplasmic reticulum calcium ion release channel activity**. Suggested GO cellular component: **sarcoplasmic reticulum membrane**, **terminal cisterna**, **calcium release unit**. | Functionally central to skeletal-muscle calcium release; associated proteins include FKBP12, calmodulin, DHPR/CACNA1S complex, triadin. | Core molecular facts are supported by review evidence; exact ontology IDs should be confirmed in HGNC/UniProt/GO databases (pqac-00000004, pqac-00000008). |
| Inheritance / genetics | Both **autosomal dominant** and **autosomal recessive** inheritance occur. Dominant disease is commonly linked to central core disease and malignant hyperthermia susceptibility; recessive disease is often associated with more severe congenital phenotypes such as multiminicore disease, centronuclear myopathy, and congenital fiber-type disproportion. | Suggested HPO / inheritance terms: **Autosomal dominant inheritance**, **Autosomal recessive inheritance**. Variant classes reported across the spectrum include missense and other pathogenic alleles; many cases are **germline**. | Reviews note approximately **400 RYR1 variants** identified by 2022. | Variant counts are review-level and likely underestimated relative to current ClinVar/literature; penetrance/expressivity are variable and should be verified per subtype/variant (pqac-00000006, pqac-00000009). |
| Hallmark phenotypes | Core manifestations: **muscle weakness**, **fatigue/fatigability**, exercise intolerance; additional features reported across the spectrum include hypotonia, facial weakness, ophthalmoparesis/ophthalmoplegia, contractures, scoliosis, respiratory involvement, myalgia, muscle cramps, rhabdomyolysis, and malignant hyperthermia susceptibility. | Suggested HPO terms: **Muscular hypotonia**, **Proximal muscle weakness**, **Exercise intolerance**, **Easy fatigability**, **Myalgia**, **Rhabdomyolysis**, **Scoliosis**, **Joint contracture**, **Respiratory insufficiency**, **Ophthalmoplegia**. | In a 6MWT cohort, disease was stable over **6 months** but fatigability was measurable during testing; speed declined between the first and last minute at 6 months (**p ≤ 0.0005**). In one adult MHS/RYR1 review, **48%** had elevated CK and **81%** showed muscle abnormalities. | Frequencies vary widely by subtype and cohort. Some statistics come from mixed RYR1/MHS populations rather than strictly biopsy/genotype-defined congenital myopathy cohorts (pqac-00000001, pqac-00000002). |
| Mechanism / pathophysiology | Three broad mechanisms are described: **(1) RyR1 hyperactivity with Ca²⁺ leak**, **(2) reduced channel activity / excitation-contraction uncoupling**, and **(3) reduced RyR1 protein abundance**. Downstream consequences include altered cytosolic Ca²⁺ homeostasis, sarcoplasmic-reticulum store abnormalities, mitochondrial dysfunction, and oxidative/nitrosative stress that can further damage RyR1 and muscle fibers. | Suggested GO terms: **regulation of release of sequestered calcium ion into cytosol**, **skeletal muscle contraction**, **response to oxidative stress**, **mitochondrial ATP synthesis coupled electron transport**. Suggested CL term: **skeletal muscle fiber cell**. Suggested UBERON: **skeletal muscle tissue**. | Patient/model data showed increased mitochondrial ROS: **26% ± 6.7%** increase in patient myotubes under basal conditions; zebrafish mutant myofibers **1369.0 ± 73.1 AU vs 920.6 ± 114.4 AU** in controls (**P = 0.001**). | Mechanistic evidence is strong but heterogeneous across human cells, zebrafish, mouse, and review synthesis; different variants can produce opposite primary channel effects (hyperactive vs hypomorphic) (pqac-00000004, pqac-00000011, pqac-00000012, pqac-00000014). |
| Diagnosis | Diagnostic workup typically integrates **clinical phenotype**, **family history**, **anesthesia/rhabdomyolysis history**, **serum CK**, **electromyography when indicated**, **muscle biopsy/histopathology**, **muscle imaging (MRI)**, and **genetic testing**. NGS has improved diagnosis because earlier approaches focused on hotspot regions and biopsy patterns. | Suggested diagnostic ontology links: congenital myopathy panel, **RYR1 single-gene testing**, **WES/WGS**, malignant hyperthermia evaluation. Suggested HPO/LOINC concepts: **Elevated serum creatine kinase**, muscle MRI abnormalities. | Muscle MRI may show selective patterns; review literature notes **relative rectus femoris sparing** among useful imaging clues. | No single universal diagnostic criterion for the umbrella term; biopsy findings and MRI patterns overlap with other congenital myopathies, so molecular confirmation is increasingly central (pqac-00000002, pqac-00000009). |
| Epidemiology / population | Pediatric point prevalence in the United States has been estimated at **~1:90,000** for RYR1-RM. Dominant **RYR1** variants also contribute to malignant hyperthermia susceptibility, broadening the clinically relevant population. | Disease-level prevalence identifier resources require verification in Orphanet/OMIM. Suggested population descriptors: pediatric congenital myopathy cohorts; anesthesia-triggered MHS cohorts. | Ongoing observational prevalence work: **NCT06791369** plans **~2000** participants using retrospective data from UK and Netherlands specialist centers. | The 1:90,000 estimate is frequently cited but comes from pediatric point-prevalence review synthesis; true prevalence is uncertain and likely underestimated due to underdiagnosis and expanded genotypic spectrum (pqac-00000002, pqac-00000007, pqac-00000008). |
| Management / current care | No FDA-approved disease-modifying therapy exists. Current care is mainly **supportive and rehabilitative** plus **risk avoidance**: physical therapy, respiratory monitoring, orthopedic management, management of fatigue, and avoidance of malignant-hyperthermia-triggering anesthetics where relevant. Off-label/experimental pharmacologic approaches discussed include **dantrolene**, **N-acetylcysteine (NAC)**, **salbutamol/albuterol**, **pyridostigmine**, and preclinical agents such as **AICAR** or rycals. | Suggested NCIT intervention terms: **Physical Therapy**, **Respiratory Support**, **Dantrolene**, **N-Acetylcysteine**, **Albuterol**, **Pyridostigmine**. Suggested CHEBI terms: calcium, reactive oxygen species, N-acetylcysteine. | NAC reduced oxidative stress in models; no approved standard pharmacotherapy yet. Personalized, genotype-aware strategies are emphasized because “one treatment fits all” is unlikely. | Evidence quality varies from case reports and small open-label studies to preclinical models; supportive care remains the clinical standard (pqac-00000003, pqac-00000006, pqac-00000011). |
| Trials / recent developments | Clinical development is active. **NCT04141670** evaluated **S 48168 / ARM210** (rycal) in adults with RYR1-RM; ClinicalTrials.gov notes a completed phase 1 study and links to a **2024** publication by Todd et al. (**PMID: 38318125**). **NCT07560020** is a recruiting **phase 2** placebo-controlled adult trial of **Surlorian (ARM210, S48168)** with planned enrollment **28**. Natural-history work includes **NCT06157268** (recruiting observational study, target **100**) and longstanding congenital-myopathy genetics studies such as **NCT00272883**. | Suggested NCIT terms: **Clinical Trial**, **Phase 1 Trial**, **Phase 2 Trial**, **Observational Study**, **Placebo**. | NCT04141670 enrolled **7** participants; NCT07560020 target **28**; NCT06157268 target **100**; NCT06791369 target **2000**. | Phase 1/2 studies are small and early; efficacy conclusions remain preliminary. Trial names and statuses should be rechecked at ClinicalTrials.gov at use time (pqac-00000010, pqac-00000007). |
| Models / comparative biology | Disease mechanisms and therapy testing use **zebrafish**, **mouse**, **patient-derived myotubes**, and emerging **iPSC / engineered skeletal muscle** systems. Natural disease relevance also extends to **pig** literature mainly through malignant hyperthermia/RYR1 biology rather than a full human-like congenital-myopathy spectrum. | Suggested model resources: zebrafish RYR1 mutants, knock-in mouse models, patient myotubes, iPSC-derived skeletal muscle. Suggested CL terms: **myoblast**, **myotube**, **skeletal muscle fiber cell**. | In zebrafish and patient myotubes, NAC improved oxidative-stress phenotypes; mouse models have been used for calcium-leak, heat sensitivity, and rycal/AICAR studies. | Model evidence is highly informative mechanistically but does not fully recapitulate human phenotypic heterogeneity. The iPSC evidence cited in current context is preprint/future-dated and should not be treated as established clinical evidence (pqac-00000011, pqac-00000012, pqac-00000013). |


*Table: This compact table summarizes the core knowledge-base elements for RYR1-related myopathy, including spectrum, mechanisms, diagnosis, epidemiology, management, trials, and models. It also flags where identifier mappings or quantitative estimates require external database verification.*