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New Insights into the Neuromyogenic Spectrum of a Gain of Function Mutation in SPTLC1. Genes (Basel) 2022; 13:genes13050893. [PMID: 35627278 PMCID: PMC9140917 DOI: 10.3390/genes13050893] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Revised: 05/12/2022] [Accepted: 05/13/2022] [Indexed: 02/04/2023] Open
Abstract
Serine palmitoyltransferase long chain base subunit 1 (SPTLC1) encodes a serine palmitoyltransferase (SPT) resident in the endoplasmic reticulum (ER). Pathological SPTLC1 variants cause a form of hereditary sensory and autonomic neuropathy (HSAN1A), and have recently been linked to unrestrained sphingoid base synthesis, causing a monogenic form of amyotrophic lateral sclerosis (ALS). It was postulated that the phenotypes associated with dominant variants in SPTLC1 may represent a continuum between neuropathy and ALS in some cases, complicated by additional symptoms such as cognitive impairment. A biochemical explanation for this clinical observation does not exist. By performing proteomic profiling on immortalized lymphoblastoid cells derived from one patient harbouring an alanine to serine amino acid substitution at position 20, we identified a subset of dysregulated proteins playing significant roles in neuronal homeostasis and might have a potential impact on the manifestation of symptoms. Notably, the identified p.(A20S)-SPTLC1 variant is associated with decrease of transcript and protein level. Moreover, we describe associated muscle pathology findings, including signs of mild inflammation accompanied by dysregulation of respective markers on both the protein and transcript levels. By performing coherent anti-Stokes Raman scattering microscopy, presence of protein and lipid aggregates could be excluded.
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Pathak P, Sharma MC, Jha P, Sarkar C, Faruq M, Jha P, Suri V, Bhatia R, Singh S, Gulati S, Husain M. Mutational Spectrum of CAPN3 with Genotype-Phenotype Correlations in Limb Girdle Muscular Dystrophy Type 2A/R1 (LGMD2A/LGMDR1) Patients in India. J Neuromuscul Dis 2021; 8:125-136. [PMID: 33337384 DOI: 10.3233/jnd-200547] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND Limb girdle muscular dystrophy recessive type 1 (LGMDR1, Previously LGMD2A) is characterized by inactivating mutations in CAPN3. Despite the significant burden of muscular dystrophy in India, and particularly of LGMDR1, its genetic characterization and possible phenotypic manifestations are yet unidentified. MATERIAL AND METHODS We performed bidirectional CAPN3 sequencing in 95 LGMDR1 patient samples characterized by calpain-3 protein analysis, and these findings were correlated with clinical, biochemical and histopathological features. RESULTS We identified 84 (88.4%) cases of LGMDR1 harboring 103 CAPN3 mutations (71 novel and 32 known). At least two mutant alleles were identified in 79 (94.2%) of patients. Notably, 76% exonic variations were enriched in nine CAPN3 exons and overall, 41 variations (40%) correspond to only eight exonic and intronic mutations. Patients with two nonsense/out of frame/splice-site mutations showed significant loss of calpain-3 protein as compared to those with two missense/inframe mutations (P = 0.04). We observed a slow progression of disease and less severity in our patients compared to European population. Rarely, presenting clinical features were atypical, and mimicked other muscle diseases like FSHMD, distal myopathy and metabolic myopathies. CONCLUSION This is first systematic study to characterize the genetic framework of LGMDR1 in the Indian population. Preliminary calpain-3 immunoblot screening serves well to direct genetic testing. Our findings prioritized nine CAPN3 exons for LGMDR1 diagnosis in our population; therefore, a targeted-sequencing panel of nine exons could serve well for genetic diagnosis, carrier testing, counseling and clinical trial feasibility study in LGMDR1 patients in India.
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Affiliation(s)
- Pankaj Pathak
- Department of Pathology, All India Institute of Medical Sciences, New Delhi, India.,Department of Biotechnology, Jamia Millia Islamia (A Central University), New Delhi, India.,Neurogenetics Branch, National Institute of Neurological Disorders and Stroke, Bethesda, MD, USA
| | - Mehar Chand Sharma
- Department of Pathology, All India Institute of Medical Sciences, New Delhi, India
| | - Pankaj Jha
- CSIR - Institute of Genomics and Integrative Biology, New Delhi, India
| | - Chitra Sarkar
- Department of Pathology, All India Institute of Medical Sciences, New Delhi, India
| | - Mohammed Faruq
- CSIR - Institute of Genomics and Integrative Biology, New Delhi, India
| | - Prerana Jha
- Department of Pathology, All India Institute of Medical Sciences, New Delhi, India
| | - Vaishali Suri
- Department of Pathology, All India Institute of Medical Sciences, New Delhi, India
| | - Rohit Bhatia
- Department of Neurology, All India Institute of Medical Sciences, New Delhi, India
| | - Sumit Singh
- Department of Neurology, Medanta, Gurgaon, Haryana, India
| | - Sheffali Gulati
- Department of Paediatric Neurology, All India Institute of Medical Sciences, New Delhi, India
| | - Mohammad Husain
- Department of Biotechnology, Jamia Millia Islamia (A Central University), New Delhi, India
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Hermanová M, Zapletalová E, Sedlácková J, Chrobáková T, Letocha O, Kroupová I, Zámecník J, Vondrácek P, Mazanec R, Maríková T, Vohánka S, Fajkusová L. Analysis of histopathologic and molecular pathologic findings in Czech LGMD2A patients. Muscle Nerve 2006; 33:424-32. [PMID: 16372320 DOI: 10.1002/mus.20480] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Limb-girdle muscular dystrophy type 2A (LGMD2A) is an autosomal-recessive disorder characterized by selective atrophy and progressive weakness of proximal girdle muscles. LGMD2A, the most prevalent form of LGMD, is caused by mutations in the CAPN3 gene that encodes the skeletal muscle-specific member of the calpain family, calpain-3 (p 94). We examined the histopathologic and molecular pathologic findings in 14 Czech LGMD2A patients. Analysis of the CAPN3 gene was performed at the mRNA level, using reverse transcription-polymerase chain reaction (RT-PCR) and sequencing, and/or DNA level, using PCR and denaturing high-performance liquid chromatography (DHPLC). Our results confirm that mutation 550 delA is the most frequent CAPN3 defect in Czech LGMD2A patients (9 alleles of 28). Furthermore, we established that, in a patient with the 550 delA/R490W genotype, mRNA carrying frameshift mutation 550 delA was not detected, probably due to its degradation by nonsense-mediated mRNA decay. In muscle biopsies of two LGMD2A patients, a neurogenic pattern simulating a neurogenic lesion was observed. Immunoblot analysis revealed the deficiency of p 94 in all genetically confirmed cases of LGMD2A, and secondary dysferlin deficiency was demonstrated on muscle membranes in 6 patients using immunofluorescence. Thus, we find a combination of DNA and mRNA mutational analysis to be useful in the diagnosis of LGMD2A. Moreover, our study expands the spectrum of calpainopathies to cases that simulate a neurogenic lesion in muscle biopsies, and the knowledge of possible secondary deficiencies of muscular proteins also contributes to a diagnosis of LGMD2A.
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Affiliation(s)
- Markéta Hermanová
- Department of Pathology, University Hospital Brno, Jihlavská 20, 625 00, Brno, Czech Republic.
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Haslbeck KM, Friess U, Schleicher ED, Bierhaus A, Nawroth PP, Kirchner A, Pauli E, Neundörfer B, Heuss D. The RAGE pathway in inflammatory myopathies and limb girdle muscular dystrophy. Acta Neuropathol 2005; 110:247-54. [PMID: 15986224 DOI: 10.1007/s00401-005-1043-3] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2004] [Revised: 05/05/2005] [Accepted: 05/17/2005] [Indexed: 10/25/2022]
Abstract
Oxidative stress and nuclear factor-kappaB (NF-kappaB) activation are linked to the pathogenesis of many metabolic, degenerative, and chronic inflammatory diseases. Activation of the receptor for advanced glycation end products (RAGE) by its specific ligand N(epsilon)-carboxymethyllysine (CML) results in the activation of NF-kappaB and the production of proinflammatory cytokines. To determine whether engagement of RAGE contributes to the pathogenesis of inflammatory myopathies, we performed immunohistochemical studies on the presence of CML-modified proteins, RAGE and activated NF-kappaB in muscle biopsies of patients with polymyositis (PM, n=10), dermatomyositis (DM, n=10), limb girdle muscular dystrophy (LGMD, n=10) and in 10 controls with normal muscle biopsy results. In inflammatory myopathies CML, RAGE and NF-kappaB were detected in mononuclear cells and in regenerating muscle fibers. CML, NF-kappaB and, to a lesser extent, RAGE were also found in degenerating muscle fibers, but colocalization of CML, RAGE and NF-kappaB was only seen in infiltrating mononuclear cells and regenerating muscle fibers. Immunofluorescence double labeling demonstrated an expression of CML, RAGE and NF-kappaB in CD4-, CD8-, CD22- and CD68-positive mononuclear cells. Western blot analysis showed an increased immunoreactivity for CML-modified proteins in PM and DM. In LGMD, CML, RAGE and NF-kappaB were found in regenerating muscle fibers and less frequently in degenerating muscle fibers, and with lower staining intensities than in inflammatory myopathies. Our data suggests that the CML-RAGE-NF-kappaB pathway is an evident proinflammatory pathomechanism in mononuclear effector cells in PM and DM. RAGE-mediated NF-kappaB activation may be involved in muscle fiber regeneration in inflammatory myopathies and LGMD.
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MESH Headings
- Adult
- Aged
- Dermatomyositis/immunology
- Dermatomyositis/metabolism
- Dermatomyositis/physiopathology
- Glycation End Products, Advanced
- Humans
- Immunohistochemistry
- Leukocytes, Mononuclear/immunology
- Leukocytes, Mononuclear/metabolism
- Lysine/analogs & derivatives
- Lysine/metabolism
- Middle Aged
- Muscle Fibers, Skeletal/metabolism
- Muscle Fibers, Skeletal/pathology
- Muscle, Skeletal/immunology
- Muscle, Skeletal/metabolism
- Muscle, Skeletal/physiopathology
- Muscular Dystrophies, Limb-Girdle/immunology
- Muscular Dystrophies, Limb-Girdle/metabolism
- Muscular Dystrophies, Limb-Girdle/physiopathology
- Myositis/immunology
- Myositis/metabolism
- Myositis/physiopathology
- NF-kappa B/metabolism
- Polymyositis/immunology
- Polymyositis/metabolism
- Polymyositis/physiopathology
- Receptor for Advanced Glycation End Products
- Receptors, Immunologic/immunology
- Receptors, Immunologic/metabolism
- Regeneration/physiology
- Signal Transduction
- Transcriptional Activation/physiology
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Affiliation(s)
- K M Haslbeck
- Department of Neurology, University Erlangen-Nürnberg, Schwabachanlage 6, 91054, Erlangen, Germany,
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Franczak MB, Ulmer JL, Jaradeh S, McDaniel JD, Mark LP, Prost RW. Spin-lock magnetic resonance imaging of muscle in patients with autosomal recessive limb girdle muscular dystrophy. J Neuroimaging 2000; 10:73-7. [PMID: 10800259 DOI: 10.1111/jon200010273] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Spin-lock imaging is a new magnetic resonance imaging (MRI) technique used to reflect the microstructural integrity of muscle. The purpose of this study was to characterize spin-lock contrast (SLC) of calf muscles in limb girdle muscular dystrophy (LGMD). The calf muscles of 5 patients with LGMD and 10 healthy volunteers were imaged with an off-resonance magnetic resonance (MR) spin-lock suppression pulse. Spin-lock suppression ratios were calculated for anterior tibialis, posterior tibialis, soleus, and gastrocnemius muscles. Clinical assessments of muscle strength were compared to the spin-lock suppression ratios in the LGMD group. Strong SLC was observed in healthy muscles, with mean (+/- SD) suppression ratios ranging from 51.2% (+/- 3.6%) to 56.3% (+/- 1.3%). In diseased muscle, spin-lock signal suppression was reduced by 8%-70%, demonstrating an inverse correlation between symptom duration and suppression ratios. Spin-lock contrast in the patients with LGMD, as a reflection of tissue integrity, was best preserved in posterior tibialis, anterior tibialis, soleus, and gastrocnemius muscles in descending order. Clinical assessments did a poorer job of differentiating than SLC did and were in poor agreement with spin-lock suppression ratios. Spin-lock MRI can quantify microstructural changes in LGMD and appears to provide information not obtainable from clinical evaluations. This suggests that this noninvasive technique may be useful in evaluating the extent, progression, and response to therapy of LGMD.
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Affiliation(s)
- M B Franczak
- Department of Neurology, Medical College of Wisconsin, Froedtert Memorial Lutheran Hospital, Milwaukee 53226, USA
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Rowin J, Meriggioli MN, Cochran EJ, Sanders DB. Prominent inflammatory changes on muscle biopsy in patients with Miyoshi myopathy. Neuromuscul Disord 1999; 9:417-20. [PMID: 10545047 DOI: 10.1016/s0960-8966(99)00041-3] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Miyoshi myopathy is a rare autosomal recessive distal myopathy characterized by early and prominent involvement of the posterior compartment of the legs. We describe two patients with the clinical diagnosis of Miyoshi myopathy who demonstrated marked inflammatory changes on muscle biopsy of clinically less affected muscles. This report illustrates the importance of recognizing the marked variability in histopathology of Miyoshi myopathy which may include an inflammatory infiltrate on muscle biopsy which mimics the histopathologic picture of an inflammatory myopathy.
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Affiliation(s)
- J Rowin
- Department of Neurological Sciences, Rush University, Rush-Presbyterian-St. Luke's, Medical Center, Chicago, IL, USA
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Abstract
The clinical heterogeneity which has long been recognized in the limb-girdle muscular dystrophies (LGMD) has been shown to relate to the involvement of a large number of different genes. At least eight forms of autosomal recessive LGMD and three forms of autosomal dominant disease are now recognized and can be defined by the primary gene or protein involved, or by a genetic localization. These advances have combined the approaches of positional cloning and candidate gene analysis to great effect, with the pivotal role of the dystrophin-associated complex confirmed through the involvement of at least four dystrophin-associated proteins in different subtypes of autosomal recessive LGMD (the sarcoglycanopathies). Two novel mechanisms may have to be postulated to explain the involvement of the calpain 3 and dysferlin genes in other forms of LGMD. Using the diagnostic tools which have become available as a result of this increased understanding, the clinical features of the various subtypes are also becoming clearer, with useful diagnostic and prognostic information at last available to the practising clinician.
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Affiliation(s)
- K M Bushby
- Department of Biochemistry and Genetics, University of Newcastle-upon-Tyne, UK.
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