Rare & Orphan Lab · DeCure for X

DeCure for Autosomal recessive limb-girdle muscular dystrophy type 2C

DeCure's autonomous Rare AI scientist is researching a drug-repurposing hypothesis for autosomal recessive limb-girdle muscular dystrophy type 2C — screening already-approved drugs against its 2-gene Open Targets disease module to publish open-access research. Research is fast; the path to publication is funded in milestone stages.

Disease module2 genesLead labRare & Orphan
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Rare & OrphanDOID:0110277$DeCureRare

The disease map

Disease moduleAutosomal recessive limb-girdle muscular dystrophy type 2C maps to a 2-gene Open Targets module — the target space DeCure's AI scientist screens approved drugs against.
DeCure.ai methodSignature reversal (LINCS) plus network proximity (STRING) rank already-approved drugs likely to perturb this module — the same engine that produces DeCure.ai's repurposing hypotheses.
Repurposing thesisScreening approved medicines against this disease module, then publishing the evidence for the strongest candidate. Known pharmacology and human exposure data make the first question sharper — they do not establish safety or efficacy in a new indication.

Research record

01
ResearchComing soon
Candidate research + dossier — target rationale, drug-repurposing thesis and evidence pack.proof: Published dossier + on-chain hash
02
ValidationComing soon
In-vitro biological validation at a contract research org (CRO).proof: CRO contract + in-vitro report
03
Peer review & paperComing soon
Peer-reviewed paper published open-access (preprint + journal).proof: DOI + open-access link + on-chain hash

Current lead

No approved-drug candidate for autosomal recessive limb-girdle muscular dystrophy type 2c is corroborated in the literature DeepSearch retrieved. Some conditions are managed with non-pharmacological care — a device, surgery or physical therapy — rather than a medicine; that may be the case here, or the literature we found may simply be too sparse yet to support a drug-repurposing angle.

Molecular view

sacsin molecular chaperone (SACS)SACS is one of the genes genetically linked to this disease in Open Targets — shown as context, not as a drug target we're pursuing: no approved-drug candidate for this disease is yet corroborated in the literature we found.

Loading structure…
helix sheet apo structuredrag to rotate · scroll to zoom

RCSB Protein Data Bank · entry 5V44 · 1.56 Å · ligand none (apo structure). Experimental structure, not a prediction.

What the evidence adds up to

In a Japanese cohort of 324 patients initially suspected of having Duchenne muscular dystrophy, only two were found to have limb-girdle muscular dystrophy type 2C after genetic testing. One carried a homozygous deletion of exon 6 in the SGCG gene, the other a novel single nucleotide insertion in exon 7 combined with a deletion of exon 6 on the other allele; both mutations created a stop codon and caused gamma-sarcoglycan deficiency. The relative incidence of LGMD2C among Japanese DMD-like patients was 0.6% (2 of 324), and the estimated population incidence was 1 per 560,000 males, or 1.8 per million. This is the first study to demonstrate a low incidence of LGMD2C in Japan.

A 2018 case report from Saudi Arabia describes a patient with limb-girdle muscular dystrophy type 2B, a different subtype caused by dysferlin gene mutations, not LGMD2C. That report notes there is no curative treatment for dysferlinopathy and that steroids and immunosuppressive medications are not effective and may have side effects. It does not provide data on any therapeutic intervention.

A 2023 review of limb-girdle muscular dystrophies states that 31 subtypes are now described, five autosomal dominant and 26 autosomal recessive. It mentions evolving targeted treatment options but gives no specific efficacy data for any drug in any LGMD subtype. No drug therapy is tested or reported in any of these three papers for LGMD2C or any other limb-girdle muscular dystrophy.

What is still missing for LGMD2C is any clinical trial data on drug treatments, any patient stratification by specific SGCG mutation, and the funding needed to move from genetic diagnosis to therapeutic development. The Japanese incidence data are from a single centre and may not generalise to other populations.

Evidence

Retrieved by DeepSearch across 234,678,978 indexed works and resolved on OpenAlex — ranked by citations, including the results that did not work.

Archives of Neurology · 2007 · 265 citations

Phenotypic Study in 40 Patients With Dysferlin Gene Mutations

AbstractOBJECTIVE: To describe the phenotypic spectrum of dysferlin (DYSF) gene mutations (which cause dysferlinopathies, autosomal recessive muscular dystrophies) in patients with a dysferlin protein deficiency. DESIGN: Clinical, biological, and pathological data from 40 patients were reviewed. The diagnosis of dysferlinopathy was based on the absence or strong reduction of dysferlin in muscle, and confirmed by mutational screening of the DYSF gene. SETTING: Two French neuromuscular diseases centers (in Paris and Marseilles). RESULTS: Two main dysferlinopathy phenotypes are well recognized: Miyoshi myopathy and limb-girdle muscular dystrophy type 2B. Typical Miyoshi myopathy and limb-girdle muscular dystrophy type 2B were found in 20 (50%) patients only. Unusual phenotypes included a mixed phenotype, referred to as "proximodistal," combining distal and proximal onset in 14 (35%) patients, pseudometabolic myopathy in 4 (10%), and asymptomatic hyperCKemia (an increased serum creatine kinase level) in 2 (5%). The disease may worsen rapidly, and 10 (25%) patients were initially misdiagnosed as having polymyositis. We suggest a relationship between proximodistal phenotype, inflammation, and severity. CONCLUSION: In addition to typical Miyoshi myopathy and limb-girdle muscular dystrophy type 2B, dysferlinopathies are a clinically heterogeneous group of disorders ranging from asymptomatism to severe functional disability.

https://doi.org/10.1001/archneur.64.8.1176
BMC Medical Genetics · 2010 · 11 citations · open access

Low incidence of limb-girdle muscular dystrophy type 2C revealed by a mutation study in Japanese patients clinically diagnosed with DMD

AbstractBACKGROUND: Limb-girdle muscular dystrophy type 2C (LGMD2C) is an autosomal recessive muscle dystrophy that resembles Duchenne muscular dystrophy (DMD). Although DMD is known to affect one in every 3500 males regardless of race, a widespread founder mutation causing LGMD2C has been described in North Africa. However, the incidence of LGMD2C in Japanese has been unknown because the genetic background remains uncharacterized in many patients clinically diagnosed with DMD. METHODS: We enrolled 324 patients referred to the Kobe University Hospital with suspected DMD. Mutations in the dystrophin or the SGCG genes were analyzed using not only genomic DNA but also cDNA. RESULTS: In 322 of the 324 patients, responsible mutations in the dystrophin were successfully revealed, confirming DMD diagnosis. The remaining two patients had normal dystrophin expression but absence of gamma-sarcoglycan in skeletal muscle. Mutation analysis of the SGCG gene revealed homozygous deletion of exon 6 in one patient, while the other had a novel single nucleotide insertion in exon 7 in one allele and deletion of exon 6 in the other allele. These mutations created a stop codon that led to a gamma-sarcoglycan deficiency, and we therefore diagnosed these two patients as having LGMD2C. Thus, the relative incidence of LGMD2C among Japanese DMD-like patients can be calculated as 1 in 161 patients suspected to have DMD (2 of 324 patients = 0.6%). Taking into consideration the DMD incidence for the overall population (1/3,500 males), the incidence of LGMD2C can be estimated as 1 per 560,000 or 1.8 per million. CONCLUSIONS: To the best of our knowledge, this is the first study to demonstrate a low incidence of LGMD2C in the Japanese population.

https://doi.org/10.1186/1471-2350-11-49
Journal of Back and Musculoskeletal Rehabilitation · 2018 · 9 citations

Limb-girdle muscular dystrophy type 2B: An unusual cause of proximal muscular weakness in Saudi Arabia

AbstractDysferlinopathies encompass a group of neuromuscular diseases characterized by the absence of dysferlin in skeletal muscle. It is a genetic disorder caused by a mutation in the dysferlin gene (DYSF) with an autosomal recessive mode of inheritance. In this article, we report a case of Limb-girdle muscular dystrophy type 2B with a rare homozygous duplication c.164dupA, p.(Ile57Hisfs*8) (rs863225020) in DYSF in a Saudi patient. To the best of our knowledge, this is the first case from Saudi Arabia with complete clinical data, pathology findings, radiology findings, and genetic analysis. Although there is no curative treatment for this disease, an accurate diagnosis is important to avoid using steroids and immunosuppressive medications, which are not effective and may have several side effects. Further studies are needed to explore potential therapies for this rare condition.

https://doi.org/10.3233/bmr-181129
Sri Lanka Journal of Neurology · 2023 · 0 citations · open access

Limb-girdle muscular dystrophies: An update

AbstractLimb-girdle muscular dystrophies (LGMDs) are a heterogenous group of genetically driven muscle disorders, which share the two common features of progressive, predominantly proximal girdle skeletal muscle involvement and dystrophic changes on pathology. This is a rapidly expanding landscape in neurology both in relation to diagnosis as well as evolving targeted treatment options. Thirty-one LGMD subtypes are described to date; five of autosomal dominant inheritance and 26 of autosomal recessive transmission. This article describes their pathogenesis, clinical presentation, diagnosis and recent therapeutic advances.

https://doi.org/10.4038/sljon.v10i2.154

Disease module: DeepOracle (Open Targets). Structures: RDKit from PubChem SMILES. Literature: retrieved by DeepSearch across 234,678,978 indexed works (targeted per-candidate search), resolved on OpenAlex.

DeCure is a research and publication project, not medical advice and not a treatment. "DeCure for X" describes a research goal, not a claim that a cure exists. Backing a cure is a contribution to fund the research — it is not an investment, and confers no yield, royalty, equity or IP ownership. Papers are published open-access by the DeCure.ai DAO.