Autosomal Recessive Limb-Girdle Muscular Dystrophy

1. Disease Information

Overview

Autosomal recessive limb-girdle muscular dystrophies (AR-LGMDs) are a heterogeneous group of inherited muscular dystrophies characterized by progressive proximal muscle weakness predominantly affecting the shoulder and hip girdle muscles, leading to progressive disability (sun2025recentinsightsinto pages 1-5, sun2025recentinsightsinto pages 5-7). The classification of LGMDs has evolved substantially. At the 2017 European Neuromuscular Centre (ENMC) workshop, a revised nomenclature was established: autosomal dominant forms are designated LGMD D (type 1) and autosomal recessive forms LGMD R (type 2), with currently 31 recognized subtypes—26 of which are autosomal recessive (sun2025recentinsightsinto pages 5-7, sun2025recentinsightsinto pages 1-5). The autosomal recessive forms account for approximately 80–90% of all LGMD cases (sun2025recentinsightsinto pages 1-5, luglio2024hereditaryneuromusculardisorders pages 18-19).

Key Identifiers

• MONDO ID: MONDO:0016971 (limb-girdle muscular dystrophy) (OpenTargets Search: limb-girdle muscular dystrophy)
• OMIM: Multiple entries per subtype (e.g., LGMD2A/OMIM #253600; LGMD2B/OMIM #253601; LGMD2C/OMIM #253700; LGMD2D/OMIM #608099; LGMD2E/OMIM #604286; LGMD2I/OMIM #607155)
• Orphanet: ORPHA:263 (limb-girdle muscular dystrophy); specific subtypes have individual Orphanet entries
• ICD-10: G71.0 (Muscular dystrophy); ICD-11: 8C73 (Limb girdle muscular dystrophy)
• MeSH: D049288 (Muscular Dystrophies, Limb-Girdle)

Synonyms

Common synonyms include: Limb-girdle muscular dystrophy type 2 (LGMD2), Limb-girdle muscular dystrophy autosomal recessive, LGMD-R; subtype-specific names include calpainopathy (LGMDR1), dysferlinopathy (LGMDR2), sarcoglycanopathies (LGMDR3-R6), and dystroglycanopathies (LGMDR9, R11, R13-R15, R20).

2. Etiology

Disease Causal Factors

AR-LGMDs are exclusively genetic in origin, caused by biallelic (homozygous or compound heterozygous) pathogenic variants in genes encoding proteins essential for skeletal muscle structure, membrane integrity, and cellular signaling (bouchard2023limb–girdlemusculardystrophies pages 5-6, lin2023clinicalfeaturesimaging pages 1-2). No environmental, infectious, or acquired causes are recognized.

Genetic Risk Factors

The primary causal genes include CAPN3 (calpain 3), DYSF (dysferlin), SGCA/SGCB/SGCG/SGCD (sarcoglycans α/β/γ/δ), FKRP (fukutin-related protein), ANO5 (anoctamin 5), TCAP (telethonin), and numerous glycosyltransferase genes involved in α-dystroglycan modification (bouchard2023limb–girdlemusculardystrophies pages 5-6, bouchard2023limb–girdlemusculardystrophies pages 4-5, lin2023clinicalfeaturesimaging pages 1-2). Consanguinity substantially increases risk in populations with high rates of endogamy (lin2023clinicalfeaturesimaging pages 1-2).

Gene-Environment Interactions

While no classical gene-environment interactions have been established for AR-LGMD, physical exercise may influence disease expression. In calpainopathy models, zebrafish with capn3b inactivation showed increased susceptibility to muscle defects with elevated muscle activity (akyurek2025zebrafishasa pages 6-7). The role of exercise as a modifying factor in human AR-LGMD is being investigated.

3. Phenotypes

Core Phenotypes

Progressive proximal muscle weakness (HPO: HP:0003701 - Proximal muscle weakness): The hallmark feature across all AR-LGMD subtypes, affecting pelvic and shoulder girdle muscles with variable age of onset (sun2025recentinsightsinto pages 5-7).

Elevated serum creatine kinase (CK) (HPO: HP:0003236 - Elevated circulating creatine kinase concentration): Universally present across subtypes, ranging from 4,000 to over 40,000 U/L. In dysferlinopathy, CK levels reach 50–200 times normal values (anwar2024thedysferlinopathiesconundrum pages 2-3, anwar2024thedysferlinopathiesconundrum pages 3-4, sun2025recentinsightsinto pages 5-7).

Muscle atrophy and fatty replacement (HPO: HP:0003202 - Skeletal muscle atrophy): Progressive fibrofatty replacement of muscle tissue is characteristic, with distinct MRI patterns per subtype (bouchard2023limb–girdlemusculardystrophies pages 2-4, lin2023clinicalfeaturesimaging pages 1-2).

Subtype-Specific Features

• Calpainopathy (LGMDR1): Onset 2–53 years; early contractures and scoliosis; approximately 80% of patients become wheelchair-bound between the second and fourth decades of life (lin2023clinicalfeaturesimaging pages 1-2, sun2025recentinsightsinto pages 5-7).
• Dysferlinopathy (LGMDR2): Onset typically 13–40 years; characteristic "dysferlin gait" from quadriceps weakness; "diamond-shaped" quadriceps bulge; 15–50% lose ambulation; cardiac involvement is rare (3–10%) but respiratory impairment affects 20–30% (anwar2024thedysferlinopathiesconundrum pages 3-4, bouchard2023limb–girdlemusculardystrophies pages 2-4).
• Sarcoglycanopathies (LGMDR3–R6): Usually childhood onset (<10 years); account for 10–15% of LGMD cases; calf hypertrophy; CK 4–180× upper limit of normal; loss of ambulation typically ages 12–16 years; dilated/hypertrophic cardiomyopathy and respiratory failure are important complications (wicklund2025limbgirdlemusculardystrophy pages 2-3, lin2023clinicalfeaturesimaging pages 1-2).
• LGMDR9 (FKRP-related): Variable onset; progressive weakness with ~2% annual decline in respiratory function in adults; median loss of ambulation at age 43 for the common c.826C>A genotype (wicklund2025limbgirdlemusculardystrophy pages 2-3).

Quality of Life Impact

Overall, approximately 60.8% of LGMD patients experience loss of ambulation, with early childhood-onset forms showing higher rates (71.1% becoming non-ambulatory by mean age 17.7 years) (luglio2024hereditaryneuromusculardisorders pages 18-19). Quality of life is significantly impacted with substantial disability, psychosocial challenges, and the need for multidisciplinary care (anwar2024thedysferlinopathiesconundrum pages 3-4).

Suggested HPO Terms

• HP:0003701 (Proximal muscle weakness)
• HP:0003236 (Elevated circulating creatine kinase concentration)
• HP:0003202 (Skeletal muscle atrophy)
• HP:0003560 (Muscular dystrophy)
• HP:0001638 (Cardiomyopathy)
• HP:0002747 (Respiratory insufficiency due to muscle weakness)
• HP:0003551 (Difficulty climbing stairs)
• HP:0002359 (Frequent falls)
• HP:0008981 (Calf muscle hypertrophy)
• HP:0001371 (Flexion contracture)
• HP:0002650 (Scoliosis)
• HP:0003391 (Gowers sign)

4. Genetic/Molecular Information

Causal Genes and Pathogenic Variants

The following table summarizes the major AR-LGMD subtypes with their causal genes:

Table: This table summarizes the principal autosomal recessive limb-girdle muscular dystrophy subtypes, aligning old and new nomenclature with causal genes, proteins, loci, and hallmark clinical features. It is useful for rapid comparison across common sarcolemmal, sarcomeric, and dystroglycanopathy-associated forms.

Variant Types and Classification

Pathogenic variants across AR-LGMD genes include missense, nonsense, frameshift, splice-site, and structural variants. In calpainopathy, common mutations include c.2120A>G in Chinese populations and c.550del in European populations (lin2023clinicalfeaturesimaging pages 1-2). For dysferlinopathy, more than 600 mutations have been identified across the DYSF gene, with c.2997G>T frequent in Japanese patients and c.1375dup in Chinese patients (lin2023clinicalfeaturesimaging pages 1-2). The common FKRP founder mutation c.826C>A (p.Leu276Ile) is prevalent in European populations (wicklund2025limbgirdlemusculardystrophy pages 2-3). Variants are classified according to ACMG/AMP guidelines, with pathogenic and likely pathogenic variants deposited in ClinVar (OpenTargets Search: limb-girdle muscular dystrophy).

Founder Effects

Several population-specific founder mutations have been documented: α-sarcoglycan mutations in Acadian populations; FKRP mutations in Hutterite communities; γ-sarcoglycan mutations in Romani (Gypsy) populations; SGCG mutations in Puerto Rican Hispanics; and TCAP c.26_33dupAGGTGTCG in Southeast Chinese populations (83.3% of LGMDR7 cases) (kang2023geneticpatternsof pages 9-10, lin2023clinicalfeaturesimaging pages 1-2).

OpenTargets Disease-Target Associations

OpenTargets identifies 12 primary targets associated with LGMD (MONDO:0016971), with the highest association scores for CAPN3 (0.86), DYSF (0.86), LMNA (0.85), ANO5 (0.85), SGCA (0.85), SGCB (0.84), FKRP (0.84), GMPPB (0.83), SGCG (0.83), PLEC (0.82), TRAPPC11 (0.81), and DAG1 (0.81) (OpenTargets Search: limb-girdle muscular dystrophy).

5. Mechanism / Pathophysiology

Molecular Pathways

The pathophysiology of AR-LGMD involves multiple interconnected cascades initiated by protein dysfunction at the muscle cell membrane:

Dystrophin-Glycoprotein Complex (DGC) Disruption: In sarcoglycanopathies, mutations in sarcoglycan genes destabilize the entire sarcoglycan complex and the DGC, which normally links the intracellular cytoskeleton to the extracellular matrix. This compromises sarcolemmal integrity, leading to muscle weakness, atrophy, and potential cardiac/respiratory failure (bozzi2025misregulationofthe pages 17-19, lin2023clinicalfeaturesimaging pages 1-2).

Calcium Dysregulation: Muscle membrane damage causes intracellular Ca²⁺ concentration to increase from 100 nM to 1–10 µM, activating calpain 3 protease. This calcium dysregulation initiates a three-level cascade: immediate calpain hyperactivation and protein degradation, middle-term mitochondrial permeability transition pore opening with decreased ATP production, and long-term fiber type conversion from slow-twitch to fast-twitch fibers (sun2025recentinsightsinto pages 14-16).

Oxidative Stress: ROS/RNS imbalance occurs with increased NADPH oxidase activity, lipid peroxidation (MDA), and protein carbonylation. ROS damages cell membranes, reduces myosin heavy chain contraction efficiency, and triggers NF-κB-mediated inflammatory cycles (sun2025recentinsightsinto pages 11-14, sun2025recentinsightsinto pages 14-16).

Chronic Inflammation: Mutations prevent proper macrophage switching from pro-inflammatory M1 to anti-inflammatory M2 phenotypes, causing sustained pro-inflammatory signaling, excessive cytokine release, and impaired muscle regeneration (sun2025recentinsightsinto pages 11-14).

Autophagy and Ubiquitin-Proteasome System Dysregulation: In FKRP-related dystroglycanopathies, mTORC1 hyperactivation correlates with fibrosis and acute regeneration markers. Autophagic flux is dysregulated, with blockage occurring independently of Akt/mTOR signaling changes. ERK1/2 kinase activity is reduced in severe hypoglycosylation cases (bozzi2025misregulationofthe pages 17-19).

Mitochondrial Dysfunction: Mitochondrial impairment represents a critical pathogenic mechanism involving impaired biogenesis, dynamics, and autophagy, with decreased ATP production (sun2025recentinsightsinto pages 14-16).

Subtype-Specific Mechanisms

• Calpainopathy (CAPN3): Loss-of-function mutations inactivate the proteolytic function of calpain 3, disrupting Ca²⁺ release, sarcomere remodeling, muscle contraction, and NF-κB signaling (lin2023clinicalfeaturesimaging pages 1-2, bouchard2023limb–girdlemusculardystrophies pages 2-4).
• Dysferlinopathy (DYSF): Dysferlin deficiency disrupts Ca²⁺ homeostasis, vesicle trafficking, sarcolemmal resealing, and T-tubule system shaping (lin2023clinicalfeaturesimaging pages 1-2).
• Dystroglycanopathies (FKRP, POMT1, POMT2, etc.): Abnormal O-glycosylation of α-dystroglycan leads to impaired ECM binding and sarcolemmal instability (bouchard2023limb–girdlemusculardystrophies pages 5-6).

Suggested GO Terms

• GO:0043034 (costamere)
• GO:0016529 (sarcoglycan complex)
• GO:0016010 (dystrophin-associated glycoprotein complex)
• GO:0042383 (sarcolemma)
• GO:0006816 (calcium ion transport)
• GO:0006954 (inflammatory response)
• GO:0006979 (response to oxidative stress)
• GO:0006914 (autophagy)

Suggested Cell Ontology Terms

• CL:0000187 (muscle cell)
• CL:0000188 (cell of skeletal muscle)
• CL:0008002 (skeletal muscle fiber)
• CL:0000235 (macrophage)
• CL:0000057 (fibroblast)

6. Anatomical Structures Affected

Primary Organs

• Skeletal muscle (UBERON:0001134): Proximal limb-girdle muscles are primary targets, including pelvic girdle (gluteus maximus, quadriceps, hip flexors) and shoulder girdle muscles (sun2025recentinsightsinto pages 5-7, anwar2024thedysferlinopathiesconundrum pages 2-3).
• Heart (UBERON:0000948): Cardiomyopathy (dilated or hypertrophic) occurs in sarcoglycanopathies and FKRP-related LGMD; cardiac abnormalities detected in 22% of one Chinese cohort (wicklund2025limbgirdlemusculardystrophy pages 2-3, lin2023clinicalfeaturesimaging pages 1-2).
• Respiratory system (UBERON:0001004): Progressive respiratory muscle weakness with restrictive insufficiency (15.4% in one cohort); adults with LGMDR9 show ~2% annual decline in respiratory function (wicklund2025limbgirdlemusculardystrophy pages 2-3, lin2023clinicalfeaturesimaging pages 1-2).

Tissue and Cell Level

• Skeletal muscle fibers (type I and type II)
• Sarcolemma and associated protein complexes
• Connective tissue (fibrotic replacement)
• Adipose tissue (fatty infiltration)

Subcellular Level

• Sarcolemma (GO:0042383)
• Dystrophin-glycoprotein complex (GO:0016010)
• Sarcoplasmic reticulum (calcium handling)
• Mitochondria (GO:0005739)
• Lysosomes/autophagosomes (autophagy pathway)

7. Temporal Development

Onset

Age of onset varies substantially by subtype: sarcoglycanopathies typically present in childhood (<10 years); calpainopathy has a wide range (2–53 years, commonly childhood/adolescence); dysferlinopathy presents in the late teens to thirties (13–40 years); LGMDR12 (ANO5) and LGMDR9 often present in adulthood (wicklund2025limbgirdlemusculardystrophy pages 2-3, anwar2024thedysferlinopathiesconundrum pages 3-4, sun2025recentinsightsinto pages 5-7).

Progression

Disease progression is universally progressive but with variable rates. Sarcoglycanopathies tend toward rapid progression with loss of ambulation in adolescence. Dysferlinopathy shows slow progressive decline, with 15–50% losing ambulation (anwar2024thedysferlinopathiesconundrum pages 3-4). LGMDR9 (FKRP) with the common c.826C>A mutation has a later median age of ambulation loss (43 years) (wicklund2025limbgirdlemusculardystrophy pages 2-3). Calpainopathy results in wheelchair dependence typically in the second to fourth decade (lin2023clinicalfeaturesimaging pages 1-2).

Patterns

The disease course is chronic, progressive, and lifelong with no spontaneous remission. There are no well-defined disease stages analogous to cancer staging, but clinical milestones include loss of independent ambulation, onset of respiratory support requirement, and cardiac involvement.

8. Inheritance and Population

Epidemiology

LGMD prevalence estimates range from 1 in 14,500 to 1 in 123,000 individuals, varying by studied population (luglio2024hereditaryneuromusculardisorders pages 18-19). Calpainopathy (LGMDR1) specifically has an estimated prevalence of 6.8–10.2 per million worldwide and represents 30–40% of all LGMD cases (lin2023clinicalfeaturesimaging pages 1-2). Sarcoglycanopathy prevalence ranges from 0.31–0.58 per 100,000 depending on ethnicity and region (lin2023clinicalfeaturesimaging pages 1-2). The global carrier frequency for all autosomal recessive neuromuscular diseases is approximately 32.9% (OpenTargets Search: limb-girdle muscular dystrophy).

Inheritance Pattern

All AR-LGMD subtypes follow autosomal recessive inheritance. Both parents must be carriers (heterozygous) for an affected child to be born (25% recurrence risk). Penetrance is generally high (complete or near-complete) for biallelic pathogenic variants, though expressivity is variable—even siblings with identical mutations can show different severity (luglio2024hereditaryneuromusculardisorders pages 18-19, bouchard2023limb–girdlemusculardystrophies pages 2-4).

Population Demographics

In a Southeast Chinese cohort, LGMDR2 (36.6%) and LGMDR1 (29.3%) were the most common subtypes (lin2023clinicalfeaturesimaging pages 1-2). In the US MD STARnet surveillance network, the most common associated genes were FKRP, CAPN3, ANO5, and DYSF (kang2023geneticpatternsof pages 9-10). In Iranian populations, CAPN3 was the most frequently mutated gene (20%), followed by POMGNT1 and TTN (OpenTargets Search: limb-girdle muscular dystrophy). Geographic and ethnic variation is substantial (kang2023geneticpatternsof pages 9-10, kang2023geneticpatternsof pages 10-10).

9. Diagnostics

Clinical Tests

Serum Creatine Kinase (CK): Markedly elevated in all subtypes; ranges from 4× to 200× upper limit of normal depending on subtype and stage. Dysferlinopathy characteristically shows CK levels 50–200× normal (anwar2024thedysferlinopathiesconundrum pages 2-3, sun2025recentinsightsinto pages 5-7).

Muscle Biopsy: Findings include dystrophic changes (varied fiber sizes, increased internal nuclei, necrosis, regeneration), inflammatory cell infiltration, fibrotic replacement, and fatty deposits. Immunohistochemistry reveals specific protein deficiencies (absent/reduced dysferlin, sarcoglycans, α-dystroglycan hypoglycosylation) (anwar2024thedysferlinopathiesconundrum pages 2-3, sun2025recentinsightsinto pages 5-7).

Muscle MRI: Reveals characteristic fatty infiltration patterns that differ by subtype. LGMDR1 shows more severe fatty infiltration of posterior thigh muscles, while LGMDR2 shows edema in lower leg muscles. "Target signs" in rectus femoris and "sandwich signs" in vastus lateralis have high diagnostic value. A "diamond on quadriceps" sign is characteristic of dysferlinopathy (bouchard2023limb–girdlemusculardystrophies pages 2-4, bouchard2023limb–girdlemusculardystrophies pages 11-12, lin2023clinicalfeaturesimaging pages 1-2).

Electrophysiology: EMG shows myopathic changes. Nerve conduction studies are typically normal.

Cardiac monitoring: Echocardiography and ECG for cardiomyopathy and rhythm disturbances, particularly in sarcoglycanopathies and FKRP-related LGMD (wicklund2025limbgirdlemusculardystrophy pages 2-3).

Pulmonary function tests: Forced vital capacity (FVC) monitoring for respiratory decline (wicklund2025limbgirdlemusculardystrophy pages 2-3).

Genetic Testing

Next-generation sequencing (NGS) is the primary diagnostic approach, including targeted neuromuscular gene panels, whole exome sequencing (WES), and whole genome sequencing (WGS) (bouchard2023limb–girdlemusculardystrophies pages 11-12, lin2023clinicalfeaturesimaging pages 17-18). The diagnostic criteria established by the 2017 ENMC workshop require: (i) proximal or non-proximal muscle dystrophy; (ii) muscle fiber degeneration and necrosis; (iii) elevated serum CK levels; and (iv) muscle degenerative changes with fibrofatty infiltration (sun2025recentinsightsinto pages 5-7). A diagnostic approach typically progresses from clinical assessment and CK measurement, through muscle biopsy with immunohistochemistry, to genetic confirmation via NGS (wicklund2025limbgirdlemusculardystrophy pages 12-12).

Differential Diagnosis

• Duchenne/Becker muscular dystrophy (X-linked)
• Facioscapulohumeral muscular dystrophy (FSHD)
• Emery-Dreifuss muscular dystrophy
• Metabolic myopathies (Pompe disease/GAA deficiency)
• Inflammatory myopathies (polymyositis, dermatomyositis)
• Congenital muscular dystrophies

Biomarkers

miR-1, miR-133a, and miR-206 are differentially expressed in serum and muscle of LGMD animal models and change according to the degree of inflammation, fibrosis, muscle regeneration, and disease progression (OpenTargets Search: limb-girdle muscular dystrophy). Glycosylated α-dystroglycan is being evaluated as a biomarker for LGMDR9 severity.

10. Outcome/Prognosis

Survival and Morbidity

Life expectancy varies by subtype. Severe sarcoglycanopathies and some dystroglycanopathies may lead to early mortality from cardiac and respiratory complications. Dysferlinopathy and milder forms of calpainopathy have near-normal life expectancy with appropriate cardiac and respiratory management (wicklund2025limbgirdlemusculardystrophy pages 2-3, anwar2024thedysferlinopathiesconundrum pages 3-4). In one Chinese cohort, a patient with LMNA-related muscular dystrophy experienced sudden cardiac death at age 37, highlighting the cardiac risks in certain subtypes (lin2023clinicalfeaturesimaging pages 1-2).

Complications

• Loss of ambulation (60.8% overall; 71.1% for early childhood-onset forms by mean age 17.7 years) (luglio2024hereditaryneuromusculardisorders pages 18-19)
• Dilated or hypertrophic cardiomyopathy and rhythm disturbances (wicklund2025limbgirdlemusculardystrophy pages 2-3)
• Restrictive respiratory insufficiency (lin2023clinicalfeaturesimaging pages 1-2)
• Scoliosis and joint contractures (sun2025recentinsightsinto pages 5-7)
• Secondary metabolic complications (fatty liver, diabetes reported in rare cases) (lin2023clinicalfeaturesimaging pages 1-2)

11. Treatment

Current Symptomatic Management

No curative treatments are currently approved. Management is primarily supportive, including corticosteroids (with limited evidence specific to LGMD), physical therapy, occupational therapy, orthopedic interventions, respiratory support (non-invasive ventilation), and cardiac management (ACE inhibitors, beta-blockers, pacemakers/ICDs as needed) (akyurek2025zebrafishasa pages 6-7, kaur2025towardsacure pages 12-14). MAXO terms: MAXO:0001298 (physical therapy), MAXO:0000016 (respiratory support), MAXO:0001001 (gene therapy).

Gene Therapy (Experimental)

Gene therapy is the most actively pursued therapeutic modality for AR-LGMD:

SRP-9003 (bidridistrogene xeboparvovec) for LGMDR4/LGMD2E: Uses AAVrh74 vector with MHCK7 promoter to deliver full-length β-sarcoglycan gene. Phase 1/2 interim data showed dose-dependent SGCB expression (36.2–62.1% at 60 days) and significant CK reductions (−92.4 to −94.9%), maintained through 2 years with preliminary motor function improvements. Currently in Phase 3 trial (NCT06246513) (kaur2025towardsacure pages 14-16).

ATA-200 for LGMDR5/LGMD2C: AAV8-based γ-sarcoglycan gene therapy in Phase 1b pediatric trials (NCT05973630) (kaur2025towardsacure pages 12-14).

SRP-9004 (patidistrogene bexoparvovec) for LGMDR3/LGMD2D: Completed Phase 1/2 (NCT01976091) with sustained α-sarcoglycan expression at 6 months post-treatment (bouchard2023limb–girdlemusculardystrophies pages 8-9).

CRISPR/Cas9 approaches for LGMDR1: Direct correction of CAPN3 mutations through double-strand breaks and wild-type allele insertion, with recent advances in non-viral delivery systems (kaur2025towardsacure pages 14-16).

Exon skipping: Antisense oligonucleotides have shown effectiveness in skipping exon 32 in dysferlin in vitro; multi-exon skipping cocktails have successfully corrected SGCG mutations in LGMDR5 patient-derived cell lines, though human clinical trials have not yet been conducted (bouchard2023limb–girdlemusculardystrophies pages 8-9, sun2025recentinsightsinto pages 18-21).

The following table summarizes key clinical trials:

Table: This table summarizes key current and recent gene therapy trials for autosomal recessive LGMD subtypes, including sarcoglycanopathies and dysferlinopathy. It is useful for quickly comparing study phase, status, intervention, and sponsor across the most relevant programs.

12. Prevention

Primary Prevention

No primary prevention exists for AR-LGMD as it is a genetic disorder. Genetic counseling is essential for carrier identification, family planning, and recurrence risk assessment (luglio2024hereditaryneuromusculardisorders pages 18-19).

Genetic Screening

• Carrier screening: Recommended for at-risk family members and populations with high consanguinity rates
• Prenatal diagnosis: Available through chorionic villus sampling or amniocentesis when family mutations are known
• Preimplantation genetic testing (PGT): Available for families with identified pathogenic variants (luglio2024hereditaryneuromusculardisorders pages 18-19)
• Cascade screening: Family members of affected individuals should be offered genetic testing

Tertiary Prevention

Regular cardiac monitoring, respiratory function assessment, and physical rehabilitation to prevent complications and optimize function (wicklund2025limbgirdlemusculardystrophy pages 2-3).

13. Model Organisms

Mouse Models

Multiple mouse models have been developed for AR-LGMD subtypes:

• Dysferlinopathy: BLA/J mice (A/J × C57BL/6 hybrid, retrotransposon in Dysf intron 4), extensively used for therapeutic studies; A/J mice (inbred, retrotransposon insertion); SJL/J mice (splice-site mutation with 15% residual dysferlin expression); and 129 and MMex38 strains. These models exhibit varying disease onset and progression patterns (anwar2024thedysferlinopathiesconundrum pages 15-16).
• Sarcoglycanopathy: Naturally occurring and genetically modified Sgca, Sgcb, and Sgcg knockout mice recapitulate human disease phenotypes. Sarcospan overexpression in Sgcg-null mice has been shown to protect against LGMDR5 by enabling substitution of γ-sarcoglycan by ζ-sarcoglycan (akyurek2025zebrafishasa pages 7-8).

Zebrafish Models

Zebrafish (Danio rerio) have become increasingly important for LGMD research:

• Calpainopathy: capn3b-inactivated zebrafish generated using CRISPR/Cas9 show muscle damage under challenging conditions (akyurek2025zebrafishasa pages 6-7).
• Dysferlinopathy: Morpholino knockdown models used to understand dysferlin's role in muscle structure stabilization and sarcolemma repair (akyurek2025zebrafishasa pages 6-7, akyurek2025zebrafishasa pages 4-6).
• Sarcoglycanopathies: CRISPR/Cas9 knockout lines for β-SG and δ-SG showing progressive dystrophic phenotypes mirroring human disease (akyurek2025zebrafishasa pages 7-8, akyurek2025zebrafishasa pages 4-6).
• Additional models: TALEN-based exon skipping for collagen VI-related myopathies; morpholino depletion of telethonin/Tcap affecting sarcomere-membrane interaction (akyurek2025zebrafishasa pages 14-16, akyurek2025zebrafishasa pages 8-10).

These models are extensively used for drug screening, gene therapy testing, and understanding pathogenetic mechanisms (akyurek2025zebrafishasa pages 7-8, akyurek2025zebrafishasa pages 14-16).

14. Environmental Information and Lifestyle Factors

No specific environmental toxins, infectious agents, or lifestyle factors are known to cause AR-LGMD. However, physical exercise and activity patterns may influence disease expression and progression. Aerobic exercise at moderate intensity is generally recommended for maintaining function, while excessive strenuous activity may exacerbate muscle damage. Nutritional optimization and weight management are important supportive measures.

15. Summary

Autosomal recessive limb-girdle muscular dystrophies represent a complex group of at least 26 genetically distinct conditions unified by progressive proximal muscle weakness. The field has advanced substantially in recent years with the revised ENMC nomenclature system, improved genetic diagnostic capabilities through NGS, and—most promisingly—the emergence of AAV-based gene therapy clinical trials for sarcoglycanopathies and other subtypes. SRP-9003 for LGMDR4 has shown encouraging Phase 1/2 data with significant protein restoration and CK reduction, and has progressed to Phase 3 trials (kaur2025towardsacure pages 14-16). The heterogeneity across and within LGMD subtypes continues to present significant challenges for drug development, necessitating natural history studies and validated clinical outcome assessments to support future therapeutic trials (wicklund2025limbgirdlemusculardystrophy pages 2-3). Multidisciplinary management remains essential, combining cardiac and respiratory surveillance with physical rehabilitation, while gene therapy and other molecular approaches offer hope for disease-modifying treatments in the coming years.

References

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5. (bouchard2023limb–girdlemusculardystrophies pages 5-6): Camille Bouchard and Jacques P. Tremblay. Limb–girdle muscular dystrophies classification and therapies. Journal of Clinical Medicine, 12:4769, Jul 2023. URL: https://doi.org/10.3390/jcm12144769, doi:10.3390/jcm12144769. This article has 73 citations.

6. (lin2023clinicalfeaturesimaging pages 1-2): Feng Lin, Kang Yang, Xin Lin, Ming Jin, Long Chen, Fu-ze Zheng, Liang-liang Qiu, Zhi-xian Ye, Hai-zhu Chen, Min-ting Lin, Ning Wang, and Zhi-qiang Wang. Clinical features, imaging findings and molecular data of limb-girdle muscular dystrophies in a cohort of chinese patients. Orphanet Journal of Rare Diseases, Nov 2023. URL: https://doi.org/10.1186/s13023-023-02897-x, doi:10.1186/s13023-023-02897-x. This article has 17 citations and is from a peer-reviewed journal.

7. (bouchard2023limb–girdlemusculardystrophies pages 4-5): Camille Bouchard and Jacques P. Tremblay. Limb–girdle muscular dystrophies classification and therapies. Journal of Clinical Medicine, 12:4769, Jul 2023. URL: https://doi.org/10.3390/jcm12144769, doi:10.3390/jcm12144769. This article has 73 citations.

8. (akyurek2025zebrafishasa pages 6-7): Eylem Emek Akyürek, Martina Erba, Francesco Dalla Barba, Dorianna Sandonà, and Roberta Sacchetto. Zebrafish as a model organism for research in rare genetic neuromuscular diseases. International Journal of Molecular Sciences, 26:8832, Sep 2025. URL: https://doi.org/10.3390/ijms26188832, doi:10.3390/ijms26188832. This article has 5 citations.

9. (anwar2024thedysferlinopathiesconundrum pages 2-3): Saeed Anwar and Toshifumi Yokota. The dysferlinopathies conundrum: clinical spectra, disease mechanism and genetic approaches for treatments. Biomolecules, 14:256, Feb 2024. URL: https://doi.org/10.3390/biom14030256, doi:10.3390/biom14030256. This article has 15 citations.

10. (anwar2024thedysferlinopathiesconundrum pages 3-4): Saeed Anwar and Toshifumi Yokota. The dysferlinopathies conundrum: clinical spectra, disease mechanism and genetic approaches for treatments. Biomolecules, 14:256, Feb 2024. URL: https://doi.org/10.3390/biom14030256, doi:10.3390/biom14030256. This article has 15 citations.

11. (bouchard2023limb–girdlemusculardystrophies pages 2-4): Camille Bouchard and Jacques P. Tremblay. Limb–girdle muscular dystrophies classification and therapies. Journal of Clinical Medicine, 12:4769, Jul 2023. URL: https://doi.org/10.3390/jcm12144769, doi:10.3390/jcm12144769. This article has 73 citations.

12. (wicklund2025limbgirdlemusculardystrophy pages 2-3): Matthew P. Wicklund, Lindsay N. Alfano, Nicholas E. Johnson, Peter B. Kang, Peter Marks, Katherine D. Mathews, Jerry R. Mendell, Louise Rodino-Klapac, Douglas Sproule, Nicole Verdun, and Kathryn Bryant. Limb-girdle muscular dystrophy scientific workshop: a multistakeholder discussion focused on charting the path forward for drug development. Neurology. Clinical practice, 15 5:e200496, Oct 2025. URL: https://doi.org/10.1212/cpj.0000000000200496, doi:10.1212/cpj.0000000000200496. This article has 1 citations.

13. (kang2023geneticpatternsof pages 9-10): Peter B. Kang, Magali Jorand-Fletcher, Wanfang Zhang, Suzanne W. McDermott, Reba Berry, Chelsea Chambers, Kristen N. Wong, Yara Mohamed, Shiny Thomas, Y Swamy Venkatesh, Christina Westfield, Nedra Whitehead, and Nicholas E. Johnson. Genetic patterns of selected muscular dystrophies in the muscular dystrophy surveillance, tracking, and research network. Neurology Genetics, Dec 2023. URL: https://doi.org/10.1212/nxg.0000000000200113, doi:10.1212/nxg.0000000000200113. This article has 7 citations.

14. (bozzi2025misregulationofthe pages 17-19): Manuela Bozzi, Francesca Sciandra, Maria Giulia Bigotti, and Andrea Brancaccio. Misregulation of the ubiquitin–proteasome system and autophagy in muscular dystrophies associated with the dystrophin–glycoprotein complex. Cells, 14:721, May 2025. URL: https://doi.org/10.3390/cells14100721, doi:10.3390/cells14100721. This article has 2 citations.

15. (sun2025recentinsightsinto pages 14-16): Chen-Chen Sun, Jiang-Ling Xiao, Zhe Zhao, Heng-Yuan Liu, and Chang-Fa Tang. Recent insights into limb-girdle muscular dystrophy: impacts, therapy, and challenges. Histology and histopathology, pages 18929, Apr 2025. URL: https://doi.org/10.14670/hh-18-929, doi:10.14670/hh-18-929. This article has 3 citations and is from a peer-reviewed journal.

16. (sun2025recentinsightsinto pages 11-14): Chen-Chen Sun, Jiang-Ling Xiao, Zhe Zhao, Heng-Yuan Liu, and Chang-Fa Tang. Recent insights into limb-girdle muscular dystrophy: impacts, therapy, and challenges. Histology and histopathology, pages 18929, Apr 2025. URL: https://doi.org/10.14670/hh-18-929, doi:10.14670/hh-18-929. This article has 3 citations and is from a peer-reviewed journal.

17. (kang2023geneticpatternsof pages 10-10): Peter B. Kang, Magali Jorand-Fletcher, Wanfang Zhang, Suzanne W. McDermott, Reba Berry, Chelsea Chambers, Kristen N. Wong, Yara Mohamed, Shiny Thomas, Y Swamy Venkatesh, Christina Westfield, Nedra Whitehead, and Nicholas E. Johnson. Genetic patterns of selected muscular dystrophies in the muscular dystrophy surveillance, tracking, and research network. Neurology Genetics, Dec 2023. URL: https://doi.org/10.1212/nxg.0000000000200113, doi:10.1212/nxg.0000000000200113. This article has 7 citations.

18. (bouchard2023limb–girdlemusculardystrophies pages 11-12): Camille Bouchard and Jacques P. Tremblay. Limb–girdle muscular dystrophies classification and therapies. Journal of Clinical Medicine, 12:4769, Jul 2023. URL: https://doi.org/10.3390/jcm12144769, doi:10.3390/jcm12144769. This article has 73 citations.

19. (lin2023clinicalfeaturesimaging pages 17-18): Feng Lin, Kang Yang, Xin Lin, Ming Jin, Long Chen, Fu-ze Zheng, Liang-liang Qiu, Zhi-xian Ye, Hai-zhu Chen, Min-ting Lin, Ning Wang, and Zhi-qiang Wang. Clinical features, imaging findings and molecular data of limb-girdle muscular dystrophies in a cohort of chinese patients. Orphanet Journal of Rare Diseases, Nov 2023. URL: https://doi.org/10.1186/s13023-023-02897-x, doi:10.1186/s13023-023-02897-x. This article has 17 citations and is from a peer-reviewed journal.

20. (wicklund2025limbgirdlemusculardystrophy pages 12-12): Matthew P. Wicklund, Lindsay N. Alfano, Nicholas E. Johnson, Peter B. Kang, Peter Marks, Katherine D. Mathews, Jerry R. Mendell, Louise Rodino-Klapac, Douglas Sproule, Nicole Verdun, and Kathryn Bryant. Limb-girdle muscular dystrophy scientific workshop: a multistakeholder discussion focused on charting the path forward for drug development. Neurology. Clinical practice, 15 5:e200496, Oct 2025. URL: https://doi.org/10.1212/cpj.0000000000200496, doi:10.1212/cpj.0000000000200496. This article has 1 citations.

21. (kaur2025towardsacure pages 12-14): Devinder Kaur and Akash Ajay. Towards a cure: emerging therapeutic advances for dmd, lgmd, and gnem- insights from pre-clinical and clinical research. Unknown journal, Dec 2025. URL: https://doi.org/10.20944/preprints202512.1267.v1, doi:10.20944/preprints202512.1267.v1.

22. (kaur2025towardsacure pages 14-16): Devinder Kaur and Akash Ajay. Towards a cure: emerging therapeutic advances for dmd, lgmd, and gnem- insights from pre-clinical and clinical research. Unknown journal, Dec 2025. URL: https://doi.org/10.20944/preprints202512.1267.v1, doi:10.20944/preprints202512.1267.v1.

23. (bouchard2023limb–girdlemusculardystrophies pages 8-9): Camille Bouchard and Jacques P. Tremblay. Limb–girdle muscular dystrophies classification and therapies. Journal of Clinical Medicine, 12:4769, Jul 2023. URL: https://doi.org/10.3390/jcm12144769, doi:10.3390/jcm12144769. This article has 73 citations.

24. (sun2025recentinsightsinto pages 18-21): Chen-Chen Sun, Jiang-Ling Xiao, Zhe Zhao, Heng-Yuan Liu, and Chang-Fa Tang. Recent insights into limb-girdle muscular dystrophy: impacts, therapy, and challenges. Histology and histopathology, pages 18929, Apr 2025. URL: https://doi.org/10.14670/hh-18-929, doi:10.14670/hh-18-929. This article has 3 citations and is from a peer-reviewed journal.

25. (anwar2024thedysferlinopathiesconundrum pages 15-16): Saeed Anwar and Toshifumi Yokota. The dysferlinopathies conundrum: clinical spectra, disease mechanism and genetic approaches for treatments. Biomolecules, 14:256, Feb 2024. URL: https://doi.org/10.3390/biom14030256, doi:10.3390/biom14030256. This article has 15 citations.

26. (akyurek2025zebrafishasa pages 7-8): Eylem Emek Akyürek, Martina Erba, Francesco Dalla Barba, Dorianna Sandonà, and Roberta Sacchetto. Zebrafish as a model organism for research in rare genetic neuromuscular diseases. International Journal of Molecular Sciences, 26:8832, Sep 2025. URL: https://doi.org/10.3390/ijms26188832, doi:10.3390/ijms26188832. This article has 5 citations.

27. (akyurek2025zebrafishasa pages 4-6): Eylem Emek Akyürek, Martina Erba, Francesco Dalla Barba, Dorianna Sandonà, and Roberta Sacchetto. Zebrafish as a model organism for research in rare genetic neuromuscular diseases. International Journal of Molecular Sciences, 26:8832, Sep 2025. URL: https://doi.org/10.3390/ijms26188832, doi:10.3390/ijms26188832. This article has 5 citations.

28. (akyurek2025zebrafishasa pages 14-16): Eylem Emek Akyürek, Martina Erba, Francesco Dalla Barba, Dorianna Sandonà, and Roberta Sacchetto. Zebrafish as a model organism for research in rare genetic neuromuscular diseases. International Journal of Molecular Sciences, 26:8832, Sep 2025. URL: https://doi.org/10.3390/ijms26188832, doi:10.3390/ijms26188832. This article has 5 citations.

29. (akyurek2025zebrafishasa pages 8-10): Eylem Emek Akyürek, Martina Erba, Francesco Dalla Barba, Dorianna Sandonà, and Roberta Sacchetto. Zebrafish as a model organism for research in rare genetic neuromuscular diseases. International Journal of Molecular Sciences, 26:8832, Sep 2025. URL: https://doi.org/10.3390/ijms26188832, doi:10.3390/ijms26188832. This article has 5 citations.

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