| Topic | Current evidence status for MONDO:0957270 |
|---|---|
| Identity | **Muscular dystrophy, limb-girdle, autosomal recessive 28**; MONDO identifier surfaced in disease-target resources as **MONDO_0957270**. The entity appears to be a **newly catalogued ultra-rare autosomal-recessive LGMD** rather than a well-established legacy subtype with extensive literature. (pqac-00000000, pqac-00000001) |
| Causal gene | **HMGCR** is the **primary implicated gene** based on current retrieved disease-target evidence and a cited 2023 neuromuscular conference abstract titled *“Bi-allelic variants in HMGCR cause limb girdle muscular dystrophy and further implicate the mevalonate pathway in muscle disease”* (DOI: https://doi.org/10.1016/j.nmd.2023.07.195). **CERT1** also appears in aggregated association outputs, but retrieved evidence does **not** establish CERT1 as an independent confirmed cause of this LGMD entity. (pqac-00000000, pqac-00000001) |
| Inheritance | Reported/curated as **autosomal recessive**, with evidence summaries indicating **biallelic** variant interpretation for the HMGCR-associated disease signal. (pqac-00000000, pqac-00000001) |
| Evidence date/source | Most disease-specific signal identified here is **recent (2023 onward)** and largely derives from **aggregated database evidence** plus the **2023 conference abstract** rather than a full-length, richly phenotyped primary paper retrievable in this search set. Open Targets lists supporting literature including **PMIDs 36745799 and 37167966**, but the retrieved context does not provide disease-specific full-text extraction sufficient for detailed phenotype/variant curation. (pqac-00000000, pqac-00000001) |
| Phenotype | Disease label indicates a **limb-girdle muscular dystrophy phenotype**, implying predominant **proximal shoulder/pelvic girdle weakness**. However, **disease-specific quantitative phenotype data**—for example exact onset ages, CK ranges, MRI pattern, biopsy findings, cardiopulmonary involvement, cognition, or wheelchair-loss rates—were **not available** in retrieved disease-specific sources and should not be inferred from other LGMD subtypes. (pqac-00000000, pqac-00000001) |
| Mechanism | Current best-supported mechanistic interpretation is **HMGCR dysfunction affecting the mevalonate pathway**, thereby implicating defective production/regulation of sterol and nonsterol isoprenoid metabolites important for muscle biology. Any more granular chain linking HMGCR deficiency to fiber degeneration, membrane instability, autophagy, or inflammation remains **plausible but incompletely demonstrated** for this exact disease in the retrieved evidence. **CERT1-related sphingolipid transport involvement remains ambiguous** for MONDO:0957270. (pqac-00000000, pqac-00000001) |
| Diagnostics | At present, the most defensible disease-specific diagnostic approach is **genomic testing** in patients with unexplained LGMD/proximal myopathy, especially **exome or genome sequencing** or curated neuromuscular gene panels that include **HMGCR**. There is **no retrieved disease-specific validated biomarker set, pathology signature, or formal diagnostic criteria** unique to LGMD autosomal recessive 28. (pqac-00000000, pqac-00000001) |
| Treatment / trials | **No disease-specific approved therapy or interventional clinical trial** for MONDO:0957270 was identified in retrieved sources. Results involving **statins** or **anti-HMGCR immune-mediated necrotizing myopathy** should **not** be transferred to this genetic LGMD, because those represent a distinct acquired autoimmune/statin-associated disorder rather than inherited biallelic HMGCR-related muscular dystrophy. (pqac-00000000, pqac-00000001) |
| Epidemiology | **No disease-specific prevalence, incidence, carrier frequency, sex ratio, or founder-effect estimates** were identified in the retrieved evidence. The condition should currently be treated as **extremely rare/ultra-rare** with insufficient published epidemiologic quantification. (pqac-00000000, pqac-00000001) |
| Major caveats | Major limitations are: **(1)** likely dependence on **very recent and sparse evidence**, **(2)** absence of a retrievable full disease-defining article in the search set, **(3)** **no invented variant-level curation should be made**, **(4)** **CERT1 association may reflect neighboring/overlapping submitted evidence rather than proven dual causality**, and **(5)** broad LGMD, statin-myopathy, or anti-HMGCR autoimmune literature must be kept separate from this Mendelian disease entry. (pqac-00000000, pqac-00000001) |


*Table: This table summarizes what can currently be stated with confidence about muscular dystrophy, limb-girdle, autosomal recessive 28 from the retrieved evidence. It highlights HMGCR as the primary implicated gene, the unresolved CERT1 signal, and the major quantitative data gaps that should constrain downstream curation.*