RARE DISEASE
Laminin subunit alpha 2-related congenital muscular dystrophy
Laminin subunit alpha 2-related congenital muscular dystrophy
Laminin subunit alpha 2-related congenital muscular dystrophy
Synonyms: CMD1A, Congenital muscular dystrophy due to laminin alpha2 deficiency, Congenital muscular dystrophy type 1A, MDC1A, Merosin-negative congenital muscular dystrophy
Synonyms: CMD1A, Congenital muscular dystrophy due to laminin alpha2 deficiency, Congenital muscular dystrophy type 1A, MDC1A, Merosin-negative congenital muscular dystrophy
Synonyms: CMD1A, Congenital muscular dystrophy due to laminin alpha2 deficiency, Congenital muscular dystrophy type 1A, MDC1A, Merosin-negative congenital muscular dystrophy
Drug discovery
3
drugs
With orphan designations
Overview
Laminin subunit alpha 2-related congenital muscular dystrophy (LAMA2-CMD) is an autosomal recessive disorder caused by mutations in the LAMA2 gene, leading to partial or complete deficiency of laminin-α2 (merosin). Clinical features range from severe congenital hypotonia, joint contractures, and respiratory insufficiency (MDC1A) to milder limb-girdle muscular dystrophy with late-onset proximal weakness. Central nervous system involvement includes white matter abnormalities on MRI, while serum creatine kinase (CK) levels typically exceed 1,000 IU/L [1][9][14].
Burden
Severe forms: 30% mortality in the first decade due to respiratory failure [14][17].
Progressive disability: Contractures, scoliosis, cardiac involvement (dilated cardiomyopathy), and epilepsy in 30% of cases [4][14][15].
High caregiving demands: Multidisciplinary management and lifelong assistance required [17][18].
Therapies
Supportive care: Respiratory support, physiotherapy, and scoliosis management [1][17].
Experimental approaches: Gene therapy, laminin-111 protein replacement, and anti-apoptotic small molecules (e.g., omigapil in phase 1 trials) [3][7][19].
Preclinical research: CRISPR/Cas9-mediated exon skipping and artificial linker proteins to stabilize muscle membranes [7][20].
Categories: rare genetic diseases, rare neurological diseases
Research Papers
192 drug discovery papers about Laminin subunit alpha 2-related congenital muscular dystrophy, with 3 first-in-class and 3 next-in-class emerging drug candidates forecasted to outperform the average preclinical success rate. Recent publications:
192 drug discovery papers about Laminin subunit alpha 2-related congenital muscular dystrophy, with 3 first-in-class and 3 next-in-class emerging drug candidates forecasted to outperform the average preclinical success rate. Recent publications:
2026-05-26 | Unexplained multiorgan fat embolism syndrome in a 10-year-old child with LAMA2-related congenital muscular dystrophy
A 10-year-old cachectic boy who was delivered at 29 weeks' gestation following an uneventful first pregnancy was diagnosed with laminin subunit alpha-2 (LAMA2)-related (merosin deficient) congenital muscular dystrophy at the age of 5 years. A week before his last hospitalization, he was treated with antibiotics for respiratory infection. A day before his death, he vomited and was visibly irritable. He collapsed during rehabilitation treatment and became unresponsive. He did not sustain any injuries. The patient presented to the hospital with tachycardia, elevated cardiac enzymes, and respiratory insufficiency. Computed tomography of the brain revealed irregular hypodense areas in the supratentorial region and the lungs showed ground glass opacity. He required mechanical ventilation and high doses of vasopressors. The patient died 12 h after admission due to circulatory collapse. Postmortem histologic examination revealed skeletal muscle and myocardial degeneration, and multiorgan fat embolism involving the lungs, heart, kidneys and brain. Death was attributed to cardiovascular collapse due to heart failure associated with a genetically determined muscle disease with unexplained fat embolism syndrome.
2026-05-13 | Anti-Receptor Activator of Nuclear Factor-κB Ligand Improves Muscle Dysfunction and Strengthens Bone in Laminin-α2-Deficient dy2J/dy2J Dystrophic Mice.
Congenital muscular dystrophy type 1A (CMD1A) is a severe genetic neuromuscular disorder caused by mutations in the LAMA2 gene, which encodes the laminin-α2 subunit, an essential structural protein for maintaining muscle integrity during contraction. Affected children experience progressive muscle damage, hypotonia, delayed motor development, and respiratory tract insufficiency. CMD1A muscles undergo repeated cycles of degeneration and regeneration accompanied by chronic inflammation. Beyond its established role in bone remodeling, the receptor activator of nuclear factor-κB/receptor activator of nuclear factor-κB ligand (RANKL)/osteoprotegerin signaling axis has also been implicated in muscle pathophysiology. A 10-day treatment with full-length osteoprotegerin fused to an Fc fragment was previously shown to restore muscle function in a Duchenne muscular dystrophy mouse model. In this study, anti-RANKL therapy was evaluated in a more severe mouse model, specifically 4-week-old male dy2J/dy2J mice, which recapitulate key CMD1A features. A 1-month anti-RANKL treatment significantly improved specific muscle strength, increased myofiber cross-sectional area, and reduced edema and immune cell infiltration. It also enhanced bone strength and microarchitecture. However, absolute muscle force and global motor performance remained unchanged. Overall, anti-RANKL treatment improved muscle intrinsic properties and bone parameters in dy2J/dy2J dystrophic mice, but these improvements were insufficient to enhance absolute muscle force or global motor performance.
2026-03-02 | Expanding the phenotypic spectrum of LAMA2-related disorders: Axonal neuropathy in the absence of muscular dystrophy.
The LAMA2 gene encodes the alpha-2 chain of laminin-2, a key component of the basement membrane that maintains muscle fiber stability and integrity. Mutations in this gene are linked with LAMA2-related muscular dystrophies, which includes congenital muscular dystrophy type 1 A (MDC1A) and limb-girdle muscular dystrophy autosomal recessive 23 (LGMDR23). Here, we present two siblings from one of 200 unrelated Iranian Charcot-Marie-Tooth (CMT) families, exhibiting axonal sensorimotor polyneuropathy, without any clinical signs of muscular dystrophy, carrying a homozygous variant in the LAMA2 gene. Following clinical and paraclinical assessments of the patients, genomic DNA was extracted from peripheral blood samples. Whole-exome sequencing (WES) was employed to identify potential genetic variants, and Sanger sequencing was subsequently used to confirm the detected variant. In silico prediction tools were further applied to evaluate the potential pathogenicity and functional impact of the identified variant. A homozygous missense variant in the LAMA2 gene, c.2916 T > G; p.Phe972Leu, was identified and co-segregated with the disease status within the family, whose neurological assessments confirmed axonal sensorimotor polyneuropathy. So far, only two studies have reported LAMA2 variants in patients only manifesting a neuropathy phenotype. None of these studies reported the detailed clinical data of their cases. However, our study provides further evidence of the association between LAMA2 mutations and neuropathy, and includes comprehensive clinical and paraclinical characterization of the affected individuals. Our findings underscore the importance of comprehensive genomic testing in diagnosing neuromuscular disorders and expand the phenotypic spectrum associated with LAMA2 mutations.
2026-02-04 | Dual AAV gene therapy using laminin-linking proteins ameliorates muscle and nerve defects in LAMA2-related muscular dystrophy.
Adeno-associated virus (AAV)-mediated gene replacement holds promise for treating genetic diseases but faces challenges due to the limited packaging capacity and potential immune responses to transgene products, especially in patients lacking endogenous protein. LAMA2-related muscular dystrophy (LAMA2 MD), a severe congenital disorder caused by loss of laminin-α2, presents both hurdles: the LAMA2 gene exceeds AAV capacity, and severely affected patients do not produce the native protein. Here, we developed an AAV-based therapy using two engineered linker proteins derived from endogenously expressed components. These linker proteins restore laminin receptor binding and polymerization, enabling reassembly of a functional basement membrane. Dual AAV delivery of the linkers in a severe LAMA2 MD mouse model resulted in robust expression and significant improvements in muscle histology and function. Employing myotropic capsids enabled therapeutic efficacy at lower vector doses. However, muscle-specific targeting unmasked a LAMA2-related peripheral neuropathy. To address this, we expressed one linker under a muscle-specific promoter and the other under a ubiquitous promoter, delivered via AAV9 or AAV8. This approach achieved near-complete phenotypic restoration when administered neonatally and provided significant benefit when given at progressed disease stages. Our strategy offers a mutation-independent, size-compatible, and potentially immune-tolerable treatment for LAMA2 MD with broad clinical potential.
2026-01-22 | LAMA2 variants associated with muscular dystrophy, brain structural abnormalities, and epilepsy: a genotype-phenotype study.
LAMA2-related congenital muscular dystrophy (LAMA2-MD) is a genetically heterogeneous disorder defined by progressive muscle weakness, brain structural abnormalities, epilepsy, and multisystem involvement. The primary goal of this study was to characterize the clinical features, temporal progression, and genotype-phenotype correlations of LAMA2-MD. Medical records of patients with genetically confirmed LAMA2-MD were extracted from a clinical data repository and analyzed retrospectively. Clinical manifestations, laboratory findings, and neuroimaging features were systematically reviewed and compared across different age groups. Variant data were retrieved from public databases to perform comprehensive genetic analyses. A total of five patients (two males and three females) were enrolled, delayed motor milestones and varying degrees of ankle contractures and persistent motor impairment in all patients were the initial presenting symptom at diagnosis in all cases, and two patients also exhibited cognitive delays. Laboratory analysis of muscle enzymes showed varying degrees of abnormalities, with creatine kinase (CK) levels displaying the most significant elevation. Cranial magnetic resonance imaging (MRI) revealed symmetrical white matter abnormalities in four patients. Seizures were documented in three school-aged patients. All patients carried compound heterozygous variants in the LAMA2 gene. A literature review indicated that the most common variant types were stop-gain and missense variants: stop-gain variants were predominantly associated with complete merosin deficiency (MDC1A), whereas missense variants typically correlated with late-onset limb-girdle muscular dystrophy. LAMA2-MD exhibits a broad phenotypic spectrum and a progressive disease course. Early manifestations include muscle weakness, delayed achievement of developmental milestones, joint contractures, seizures and characteristic intracranial abnormalities.
2026-05-26 | Unexplained multiorgan fat embolism syndrome in a 10-year-old child with LAMA2-related congenital muscular dystrophy
A 10-year-old cachectic boy who was delivered at 29 weeks' gestation following an uneventful first pregnancy was diagnosed with laminin subunit alpha-2 (LAMA2)-related (merosin deficient) congenital muscular dystrophy at the age of 5 years. A week before his last hospitalization, he was treated with antibiotics for respiratory infection. A day before his death, he vomited and was visibly irritable. He collapsed during rehabilitation treatment and became unresponsive. He did not sustain any injuries. The patient presented to the hospital with tachycardia, elevated cardiac enzymes, and respiratory insufficiency. Computed tomography of the brain revealed irregular hypodense areas in the supratentorial region and the lungs showed ground glass opacity. He required mechanical ventilation and high doses of vasopressors. The patient died 12 h after admission due to circulatory collapse. Postmortem histologic examination revealed skeletal muscle and myocardial degeneration, and multiorgan fat embolism involving the lungs, heart, kidneys and brain. Death was attributed to cardiovascular collapse due to heart failure associated with a genetically determined muscle disease with unexplained fat embolism syndrome.
2026-05-13 | Anti-Receptor Activator of Nuclear Factor-κB Ligand Improves Muscle Dysfunction and Strengthens Bone in Laminin-α2-Deficient dy2J/dy2J Dystrophic Mice.
Congenital muscular dystrophy type 1A (CMD1A) is a severe genetic neuromuscular disorder caused by mutations in the LAMA2 gene, which encodes the laminin-α2 subunit, an essential structural protein for maintaining muscle integrity during contraction. Affected children experience progressive muscle damage, hypotonia, delayed motor development, and respiratory tract insufficiency. CMD1A muscles undergo repeated cycles of degeneration and regeneration accompanied by chronic inflammation. Beyond its established role in bone remodeling, the receptor activator of nuclear factor-κB/receptor activator of nuclear factor-κB ligand (RANKL)/osteoprotegerin signaling axis has also been implicated in muscle pathophysiology. A 10-day treatment with full-length osteoprotegerin fused to an Fc fragment was previously shown to restore muscle function in a Duchenne muscular dystrophy mouse model. In this study, anti-RANKL therapy was evaluated in a more severe mouse model, specifically 4-week-old male dy2J/dy2J mice, which recapitulate key CMD1A features. A 1-month anti-RANKL treatment significantly improved specific muscle strength, increased myofiber cross-sectional area, and reduced edema and immune cell infiltration. It also enhanced bone strength and microarchitecture. However, absolute muscle force and global motor performance remained unchanged. Overall, anti-RANKL treatment improved muscle intrinsic properties and bone parameters in dy2J/dy2J dystrophic mice, but these improvements were insufficient to enhance absolute muscle force or global motor performance.
2026-03-02 | Expanding the phenotypic spectrum of LAMA2-related disorders: Axonal neuropathy in the absence of muscular dystrophy.
The LAMA2 gene encodes the alpha-2 chain of laminin-2, a key component of the basement membrane that maintains muscle fiber stability and integrity. Mutations in this gene are linked with LAMA2-related muscular dystrophies, which includes congenital muscular dystrophy type 1 A (MDC1A) and limb-girdle muscular dystrophy autosomal recessive 23 (LGMDR23). Here, we present two siblings from one of 200 unrelated Iranian Charcot-Marie-Tooth (CMT) families, exhibiting axonal sensorimotor polyneuropathy, without any clinical signs of muscular dystrophy, carrying a homozygous variant in the LAMA2 gene. Following clinical and paraclinical assessments of the patients, genomic DNA was extracted from peripheral blood samples. Whole-exome sequencing (WES) was employed to identify potential genetic variants, and Sanger sequencing was subsequently used to confirm the detected variant. In silico prediction tools were further applied to evaluate the potential pathogenicity and functional impact of the identified variant. A homozygous missense variant in the LAMA2 gene, c.2916 T > G; p.Phe972Leu, was identified and co-segregated with the disease status within the family, whose neurological assessments confirmed axonal sensorimotor polyneuropathy. So far, only two studies have reported LAMA2 variants in patients only manifesting a neuropathy phenotype. None of these studies reported the detailed clinical data of their cases. However, our study provides further evidence of the association between LAMA2 mutations and neuropathy, and includes comprehensive clinical and paraclinical characterization of the affected individuals. Our findings underscore the importance of comprehensive genomic testing in diagnosing neuromuscular disorders and expand the phenotypic spectrum associated with LAMA2 mutations.
2026-02-04 | Dual AAV gene therapy using laminin-linking proteins ameliorates muscle and nerve defects in LAMA2-related muscular dystrophy.
Adeno-associated virus (AAV)-mediated gene replacement holds promise for treating genetic diseases but faces challenges due to the limited packaging capacity and potential immune responses to transgene products, especially in patients lacking endogenous protein. LAMA2-related muscular dystrophy (LAMA2 MD), a severe congenital disorder caused by loss of laminin-α2, presents both hurdles: the LAMA2 gene exceeds AAV capacity, and severely affected patients do not produce the native protein. Here, we developed an AAV-based therapy using two engineered linker proteins derived from endogenously expressed components. These linker proteins restore laminin receptor binding and polymerization, enabling reassembly of a functional basement membrane. Dual AAV delivery of the linkers in a severe LAMA2 MD mouse model resulted in robust expression and significant improvements in muscle histology and function. Employing myotropic capsids enabled therapeutic efficacy at lower vector doses. However, muscle-specific targeting unmasked a LAMA2-related peripheral neuropathy. To address this, we expressed one linker under a muscle-specific promoter and the other under a ubiquitous promoter, delivered via AAV9 or AAV8. This approach achieved near-complete phenotypic restoration when administered neonatally and provided significant benefit when given at progressed disease stages. Our strategy offers a mutation-independent, size-compatible, and potentially immune-tolerable treatment for LAMA2 MD with broad clinical potential.
2026-01-22 | LAMA2 variants associated with muscular dystrophy, brain structural abnormalities, and epilepsy: a genotype-phenotype study.
LAMA2-related congenital muscular dystrophy (LAMA2-MD) is a genetically heterogeneous disorder defined by progressive muscle weakness, brain structural abnormalities, epilepsy, and multisystem involvement. The primary goal of this study was to characterize the clinical features, temporal progression, and genotype-phenotype correlations of LAMA2-MD. Medical records of patients with genetically confirmed LAMA2-MD were extracted from a clinical data repository and analyzed retrospectively. Clinical manifestations, laboratory findings, and neuroimaging features were systematically reviewed and compared across different age groups. Variant data were retrieved from public databases to perform comprehensive genetic analyses. A total of five patients (two males and three females) were enrolled, delayed motor milestones and varying degrees of ankle contractures and persistent motor impairment in all patients were the initial presenting symptom at diagnosis in all cases, and two patients also exhibited cognitive delays. Laboratory analysis of muscle enzymes showed varying degrees of abnormalities, with creatine kinase (CK) levels displaying the most significant elevation. Cranial magnetic resonance imaging (MRI) revealed symmetrical white matter abnormalities in four patients. Seizures were documented in three school-aged patients. All patients carried compound heterozygous variants in the LAMA2 gene. A literature review indicated that the most common variant types were stop-gain and missense variants: stop-gain variants were predominantly associated with complete merosin deficiency (MDC1A), whereas missense variants typically correlated with late-onset limb-girdle muscular dystrophy. LAMA2-MD exhibits a broad phenotypic spectrum and a progressive disease course. Early manifestations include muscle weakness, delayed achievement of developmental milestones, joint contractures, seizures and characteristic intracranial abnormalities.
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Drug Discovery Landscape
3 orphan drug designations for Laminin subunit alpha 2-related congenital muscular dystrophy.
3 orphan drug designations for Laminin subunit alpha 2-related congenital muscular dystrophy.
Drug | Therapy type | Regulator | Orphan designation | Approval | Sponsor |
|---|---|---|---|---|---|
muscle-tropic derivative adeno-associated virus serotype 9 (AAV9) gene therapy product (MYO-AAV3A.CK8.GNDM.U6.sgHu) | gene therapies | FDA | 2024-10-24 | — | Modalis Therapeutics |
human laminin-111 | proteins | FDA | 2011-09-23 | — | Prothelia, Inc. |
Omigapil maleate | small molecules | EMA | 2008-05-08 | — | Santhera Pharmaceuticals (Deutschland) GmbH |
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