Limb-girdle Muscular Dystrophy Patients Research Articles

Defining clinical endpoints in limb girdle muscular dystrophy: a GRASP-LGMD study

BackgroundThe Limb Girdle Muscular Dystrophies (LGMDs) are characterized by progressive weakness of the shoulder and hip girdle muscles as a result of over 30 different genetic mutations. This study is designed to develop clinical outcome assessments across the group of disorders.Methods/designThe primary goal of this study is to evaluate the utility of a set of outcome measures on a wide range of LGMD phenotypes and ability levels to determine if it would be possible to use similar outcomes between individuals with different phenotypes. We will perform a multi-center, 12-month study of 188 LGMD patients within the established Genetic Resolution and Assessments Solving Phenotypes in LGMD (GRASP-LGMD) Research Consortium, which is comprised of 11 sites in the United States and 2 sites in Europe. Enrolled patients will be clinically affected and have mutations in CAPN3 (LGMDR1), ANO5 (LGMDR12), DYSF (LGMDR2), DNAJB6 (LGMDD1), SGCA (LGMDR3), SGCB (LGMDR4), SGCD (LGMDR6), or SGCG (LGMDR5, or FKRP-related (LGMDR9).DiscussionTo the best of our knowledge, this will be the largest consortium organized to prospectively validate clinical outcome assessments (COAs) in LGMD at its completion. These assessments will help clinical trial readiness by identifying reliable, valid, and responsive outcome measures as well as providing data driven clinical trial decision making for future clinical trials on therapeutic agents for LGMD. The results of this study will permit more efficient clinical trial design. All relevant data will be made available for investigators or companies involved in LGMD therapeutic development upon conclusion of this study as applicable.Trial registrationClinicaltrials.gov NCT03981289; Date of registration: 6/10/2019.

Novel Biomarkers for Limb Girdle Muscular Dystrophy (LGMD).

To identify novel biomarkers as an alternative diagnostic tool for limb girdle muscular dystrophy (LGMD). LGMD encompasses a group of muscular dystrophies characterized by proximal muscles weakness, elevated CK levels and dystrophic findings on muscle biopsy. Heterozygous CAPN3 mutations are associated with autosomal dominant LGMD-4, while biallelic mutations can cause autosomal recessive LGMD-1. Diagnosis is currently often based on invasive methods requiring muscle biopsy or blood tests. In most cases Western blotting (WB) analysis from muscle biopsy is essential for a diagnosis, as muscle samples are currently the only known tissues to express the full-length CAPN3 isoform. We analyzed CAPN3 in a cohort including 60 LGMD patients. Selected patients underwent a complete neurological examination, electromyography, muscle biopsy, and skin biopsies for primary fibroblasts isolation. The amount of CAPN3 was evaluated by WB analysis in muscle and skin tissues. The total RNA isolated from muscle, fibroblast and urine was processed, and cDNA was used for qualitative analysis. The expression of CAPN3 was investigated by qRT-PCR. The CAPN3 3D structure has been visualized and analyzed using PyMOL. Among our patients, seven different CAPN3 mutations were detected, of which two were novel. After sequencing CAPN3 transcripts from fibroblast and urine, we detected different CAPN3 isoforms surprisingly including the full-length transcript. We found comparable protein levels from fibroblasts and muscle tissue; in particular, patients harboring a novel CAPN3 mutation showed a 30% reduction in protein compared to controls from both tissues. Our findings showed for the first time the presence of the CAPN3 full-length transcript in urine and skin samples. Moreover, we demonstrated surprisingly comparable CAPN3 protein levels between muscle and skin samples, thus allowing us to hypothesize the use of skin biopsy and probably of urine samples as an alternative less invasive method to assess the amount of CAPN3 when molecular diagnosis turns out to be inconclusive.

The Profiling of 179 miRNA Expression in Serum from Limb Girdle Muscular Dystrophy Patients and Healthy Controls.

Limb girdle muscular dystrophies (LGMDs) are a group of genetically inherited neuromuscular diseases with a very variable clinical presentation and overlapping traits. Over the last few years there has been an increasing interest in the use of non-invasive circulating biomarkers to monitor disease progression and to evaluate the efficacy of therapeutic approaches. Our aim was to identify the miRNA signature with potential value for LGMD patient screening and stratification. Using miRCURY LNA miRNA qPCR Serum/Plasma Panel, we analyzed 179 miRNAs from 16 patients, divided in four pools based on their genetic diagnosis, and from healthy controls. The miRNAs analysis showed a total of 107 dysregulated miRNAs in LGMD patients when compared to the healthy controls. After filtering via skeletal tissue expression and gene/pathways target analysis, the number of dysregulated miRNAs drastically reduced. Six selected miRNAs-let-7f-5p (in LGMDR1), miR-20a-5p (in LGMDR2), miR-130b-5p, miR-378a-5p (both in LGMDR3), miR-376c-3p and miR-382-5p (both in LGMDR4)-whose expression was significantly lower compared to controls in the different LGMD pools, were further investigated. The bioinformatic analysis of the target genes in each selected miRNA revealed ECM-receptor interaction and TGF-beta signaling as the most involved pathways. The correlation analysis showed a good correlation of let-7f-5p with fibrosis and with the cross sectional area of type I and type II fibers, while miR-130b-5p showed a good correlation with the age of onset of the disease. The receiver operating characteristic curves showed how single miRNAs were able to discriminate a specific group of LGMD patients and how the combination of six miRNAs was able to discriminate LGMD patients from controls.

Novel mutations in the SGCA gene in unrelated Vietnamese patients with limb-girdle muscular dystrophies disease.

Background: Limb-girdle muscular dystrophy (LGMD) is a group of inherited neuromuscular disorders characterized by atrophy and weakness in the shoulders and hips. Over 30 subtypes have been described in five dominant (LGMD type 1 or LGMDD) and 27 recessive (LGMD type 2 or LGMDR). Each subtype involves a mutation in a single gene and has high heterogeneity in age of onset, expression, progression, and prognosis. In addition, the lack of understanding of the disease and the vague, nonspecific symptoms of LGMD subtypes make diagnosis difficult. Even as next-generation sequencing (NGS) genetic testing has become commonplace, some patients remain undiagnosed for many years. Methods: To identify LGMD-associated mutations, Targeted sequencing was performed in the patients and Sanger sequencing was performed in patients and family members. The in silico analysis tools such as Fathmm, M-CAP, Mutation Taster, PolyPhen 2, PROVEAN, REVEL, SIFT, MaxEntScan, Spliceailookup, Human Splicing Finder, NetGene2, and Fruitfly were used to predict the influence of the novel mutations. The pathogenicity of the mutation was interpreted according to the ACMG guidelines. Results: In this study, six patients from four different Vietnamese families were collected for genetic analysis at The Center for Gene and Protein Research and The Department of Molecular Pathology Faculty of Medical Technology, Hanoi Medical University, Hanoi, Vietnam. Based on clinical symptoms and serum creatine kinase (CK) levels, the patients were diagnosed with limb-girdle muscular dystrophies. Five mutations, including four (c.229C>T, p.Arg77Cys; exon one to three deletion; c.983 + 5G>C; and c.257_258insTGGCT, p.Phe88Leufs*125) in the SGCA gene and one (c.946-4_946-1delACAG) in the CAPN3 gene, were detected in six LGMD patients from four unrelated Vietnamese families. Two homozygous mutations (c.983 + 5G>C and c.257_258insTGGCT) in the SGCA gene were novel. These mutations were identified as the cause of the disease in the patients. Conclusion: Our results contribute to the general understanding of the etiology of the disease and provide the basis for definitive diagnosis and support genetic counseling and prenatal screening.

VP306 Computed tomography with color reconstruction in a group of R9 limb-girdle muscular dystrophy patients with c.1387A>G mutation

VP306 Computed tomography with color reconstruction in a group of R9 limb-girdle muscular dystrophy patients with c.1387A>G mutation

Genetic findings in Czech patients with limb girdle muscular dystrophy.

Limb girdle muscular dystrophies (LGMD) are a genetically heterogeneous group of muscular dystrophies. The study presents an overview of molecular characteristics of a large cohort of LGMD patients who are representative of the Czech LGMD population. We present 226 LGMD probands in which 433 mutant alleles carrying 157 different variants with a supposed pathogenic effect were identified. Fifty-four variants have been described only in the Czech LGMD population so far. LGMD R1 caplain3-related is the most frequent subtype of LGMD involving 53.1% of patients with genetically confirmed LGMD, followed by LGMD R9 FKRP-related (11.1%), and LGMD R12 anoctamin5-related (7.1%). If we consider identified variants, then all but five were small-scale variants. One large gene deletion was identified in the LAMA2 gene and two deletions in each of CAPN3 and SGCG. We performed comparison our result with other published studies. The results obtained in the Czech LGMD population clearly differ from the outcome of other LGMD populations in two aspects-we have a more significant proportion of patients with LGMD R1 calpain3-related and a smaller proportion of LGMD R2 dysferlin-related.

Large Region of Homozygous (ROH) Identified in Indian Patients with Autosomal Recessive Limb-Girdle Muscular Dystrophy with p.Thr182Pro Variant in SGCB Gene

The sarcoglycanopathies are autosomal recessive limb-girdle muscular dystrophies (LGMDs) caused by the mutations in genes encoding the α, β, γ, and δ proteins which stabilizes the sarcolemma of muscle cells. The clinical phenotype is characterized by progressive proximal muscle weakness with childhood onset. Muscle biopsy findings are diagnostic in confirming dystrophic changes and deficiency of one or more sarcoglycan proteins. In this study, we summarized 1,046 LGMD patients for which a precise diagnosis was identified using targeted sequencing. The most frequent phenotypes identified in the patients are LGMDR1 (19.7%), LGMDR4 (19.0%), LGMDR2 (17.5%), and MMD1 (14.5%). Among the reported genes, each of CAPN3, SGCB, and DYSF variants was reported in more than 10% of our study cohort. The most common variant SGCB p.Thr182Pro was identified in 146 (12.5%) of the LGMD patients, and in 97.9% of these patients, the variant was found to be homozygous. To understand the genetic structure of the patients carrying SGCB p.Thr182Pro, we genotyped 68 LGMD patients using a whole genome microarray. Analysis of the array data identified a large ~1 Mb region of homozygosity (ROH) (chr4:51817441-528499552) suggestive of a shared genomic region overlapping the recurrent missense variant and shared across all 68 patients. Haplotype analysis identified 133 marker haplotypes that were present in ~85.3% of the probands as a double allele and absent in all random controls. We also identified 5 markers (rs1910739, rs6852236, rs13122418, rs13353646, and rs6554360) which were present in a significantly higher proportion in the patients compared to random control set ( n = 128 ) and the population database. Of note, admixture analysis was suggestive of greater proportion of West Eurasian/European ancestry as compared to random controls. Haplotype analysis and frequency in the population database indicate a probable event of founder effect. Further systematic study is needed to identify the communities and regions where the SGCB p.Thr182Pro variant is observed in higher proportions. After identifying these communities and//or region, a screening program is needed to identify carriers and provide them counselling.

P518: Limb-girdle muscular dystrophy and other myopathy patients diagnostic yield in large cohort of more than 6000 patients*

P518: Limb-girdle muscular dystrophy and other myopathy patients diagnostic yield in large cohort of more than 6000 patients*

‘It becomes the new everyday life’ – experiences of chronic pain in everyday life of people with limb-girdle muscular dystrophy

Purpose To investigate experiences and reflections on challenges in everyday life of people living with limb-girdle muscular dystrophy (LGMD) and chronic pain in order to improve rehabilitation services. Materials and methods The design for this study was qualitative using the Interpretive Description methodology and the salutogenic theory of Sense of Coherence as the theoretical framework. Four semi-structured focus group interviews were conducted with 19 adults with LGMD from April to May 2021. The interviews were conducted online due to COVID-19. Results Living with chronic pain and LGMD affected everyday life in terms of the participants’ overall Sense of Coherence. Beneficial or unfavorable coping strategies were identified within four interrelated categorical themes: pain management, normality comprehension, affected emotional sentiment and altered identity. Conclusion Healthcare professionals should acknowledge possible chronic pain secondary to LGMD. Chronic pain appears to be a prevalent problem in people with LGMD with negative impact on everyday life, yet patients with LGMD did not receive sufficient information and necessary tools from health professionals to cope with chronic pain. Thus, adequate pain management appeared to be a difficult and self-taught process. Educating health professionals on how to support patients with LGMD and chronic pain is needed. IMPLICATIONS FOR REHABILITATION Health professionals should acknowledge and address the possibility of chronic pain secondary to limb-girdle muscular dystrophy (LGMD) and educate patients in pain management. Physiotherapy, energy management and engagement in meaningful activities may help patients gain some control of pain and limit the consequences of pain on everyday life. Supporting patients to accept pain and to shift focus towards their current capabilities may potentially improve pain management. Educating health professionals on how to support patients with LGMD and chronic pain is needed.

Inducible Heat Shock Protein 70 Levels in Patients and the mdx Mouse Affirm Regulation during Skeletal Muscle Regeneration in Muscular Dystrophy.

Stress-inducible heat shock protein 70 (HSP70) is both a protective chaperone involved in protein homeostasis and an immune regulator. In both capacities, HSP70 has been implicated in muscle disorders, yet with fragmented and differing results. In this study we aimed to compare results obtained in the mouse model for the severest form of muscular dystrophy (MD) equivalent to Duchenne MD, termed the mdx mouse, with results obtained in human MD. Skeletal muscle and serum samples were obtained from 11 healthy controls, 11 fully characterized patients diagnosed with Becker MD and limb girdle MD (LGMD), and six muscle disease controls. In addition, muscle extracts were prepared from tibialis anterior of mdx and control mice at ages 4, 8 and 12 weeks. The HSP70 levels were quantified using RT-PCR, western blotting and protein arrays, and localized in muscle tissue sections using double immunofluorescence. We found selective and significant 2.2-fold upregulation of HSP70 protein in mdx tibialis muscle at the earliest disease phase only. In LGMD and Becker MD patients, HSP70 protein levels were not significantly different from those of healthy muscle and serum. HSP70 was localized to regenerating muscle fibers both in mouse and human MD skeletal muscle tissues. Toll-like receptor (TLR) 2 and TLR4 expression was moderately increased on the sarcolemma in MD muscle, yet protein levels were not significantly different from normal controls. HSP70 upregulation in MD appears disease stage-dependent, marking the phase of most active muscle regeneration in the mdx mouse. We postulate that well-timed supportive therapeutic interventions with HSP70 agonists could potentially improve muscle tissue's regenerative capacities in MD, attenuating loss of muscle mass while we await gene therapies to become more widely available.

Patterns of cardiac involvement in different muscular dystrophies assessed by magnetic resonance imaging.

In muscular dystrophies, it is not only skeletal muscles that can be affected, but also the myocardium. This cardiac involvement can represent a major cause of morbidity and mortality. To investigate cardiac involvement in Duchenne (DMD), Becker (BMD), and limb girdle muscular dystrophy (LGMD) patients, and carriers of DMD/BMD by cardiac magnetic resonance (CMR) imaging and to search for differences in the pattern of cardiac involvement. All patients with genetically or histologically proven DMD, BMD, and LGMD, or confirmed carriers of DMD/BMD who had undergone CMR at our clinic between January 2008 and November 2018 were retrospectively included and re-evaluated for regional and global left ventricular function, increased trabecularization, and late enhancement. A total of 26 DMD, 10 BMD, 11 LGMD, and seven DMD/BMD carriers were included. Only one carrier of DMD presented with normal CMR results; all other participants showed cardiac abnormalities. Regional wall motion abnormalities (RWMA; prevalence in LGMD patients: 55%) and late enhancement (prevalence in LGMD patients: 82%) were frequent. RWMA were accentuated basal inferolateral in DMD/BMD carriers, while in LGMD they were accentuated apical. In all groups late enhancement was located mainly subepicardial/midmyocardial with a basal inferolateral accentuation. Apart from the different RWMA distribution, no further group-specific differences were found. We found a high rate of cardiac involvement not only in DMD/BMD, but also in LGMD and DMD/BMD carriers with a different RWMA accentuation (apical in LGMD and basal inferolateral in DMD/BMD) as a single group-specific difference.

A Muscle Biosignature Differentiating Between Limb-Girdle Muscular Dystrophy and Idiopathic Inflammatory Myopathy on Magnetic Resonance Imaging.

Background: The overlapping clinical presentations of limb-girdle muscular dystrophy (LGMD) and idiopathic inflammatory myopathy (IIM) make clinical diagnosis challenging. This study provides a comprehensive evaluation of the distributions and characteristics of muscle fat substitution and edema and aims to differentiate those two diseases.Methods: This retrospective study reviewed magnetic resonance imaging (MRI) of seventeen patients with pathologically proved diagnosis, comprising 11 with LGMD and 6 with IIM. The fat-only and water-only images from a Dixon sequence were used to evaluate muscle fat substitution and edema, respectively. The degrees of muscle fat substitution and edema were graded and compared using the appropriate statistical methods.Results: In LGMD, more than 50% of patients had high-grade fat substitution in the majority of muscle groups in the thigh and calf. However, <50% of IIM patients had high-grade fat substitution in all muscle groups. Moreover, LGMD patients had significantly higher grade fat substitution than IIM patients in all large muscle groups (p < 0.05). However, there was no significant difference in edema in the majority of muscle groups, except the adductor magnus (p = 0.012) and soleus (p = 0.009) with higher grade edema in IIM. Additionally, all the adductor magnus muscles in LGMD (100%) showed high-grade fat substitution, but none of them showed high-grade edema.Conclusions: MRI could be a valuable tool to differentiate LGMD from IIM based on the discrepancy in muscle fat substitution, and the adductor magnus muscle could provide a biosignature to categorizing LGMD.

Abstract 13478: Cardiac Magnetic Resonance Imaging Identifies Cardiac Disease in Limb-Girdle Muscular Dystrophy in Previously Low Risk Mutations

Introduction: Limb-Girdle Muscular Dystrophies (LGMD) are an inheritable group of genetic disorders primarily involving progressive weakening and atrophy of the pelvic or shoulder girdle musculature with potential cardiac dysfunction. Prior reports stratified frequency of cardiac disease based on genetic mutations. The general incidence of cardiac muscle involvement in LGMD is variable depending on genetic factors and carry important indications for clinical management. Cardiac magnetic resonance imaging (CMR) is increasingly used in dystrophinopathies and determining management. There is limited CMR data in adult LGMD patients and fewer reports in younger patients. Hypothesis: Therefore, we sought to determine the extent of cardiac involvement based on genetic risk of cardiomyopathy. Methods: This is a retrospective review of LGMD patients followed at our institution who underwent CMR assessment. Patients stratified into Group A (high incidence of cardiomyopathy; LGMDs 1B, 2E, 2F and 2I) and Group B (rare or no reported cardiomyopathy; LGMDs 1A, 1C, 2A, 2B, 2C, 2D, 2G, 2H, 2J) with CMR studies were assessed for presence of cardiac scar defined as late gadolinium enhancement (LGE) and LVEF for each subject. Results: 41 subjects were identified with average age of 21.3±11.5 years (range 6-50) with normal LVEF 58±12.1% and 12/41 (29.3%) with LGE with the youngest patient age 12.4 years. Group A included 14/41 (34%) and 27/41 (66%) were in Group B. Group A had higher incidence of LGE 6/14(42.9%) with preserved LVEF of 58.2±11% compared to Group B with 6/27 (22.2%) with no difference in LVEF of 55.7±16.4% (p = 0.5). When stratified by LGE status, the LGE-positive group was older at 26.4±11.9 years and had preserved LVEF of 61.9±11.1% versus LGE-negative group of 19.1±10.9 years (p = 0.03) with abnormal LVEF of 49.4±9.5% (p =0.0008). Conclusions: This is the largest study of CMR in LGMD patients, confirming presence of cardiac disease by LGE in the high risk group. Surprisingly, nearly 25% of the low risk mutations have evidence of LGE. Abnormal LGE predicted abnormalities in LVEF in both Group A and Group B. Management of LGMD patients should include CMR even in low risk population. Ongoing data collection may reveal disease cluster in previous low risk groups.

Prevalence of chronic pain in a national cohort of patients with limb-girdle muscular dystrophy: a cross-sectional study

Purpose The aim was to investigate the prevalence, characteristics, predictors, and consequences of chronic pain in a national cohort of patients with limb-girdle muscular dystrophy (LGMD). Materials and methods Questionnaires were sent to all Danish LGMD patients (≥18 years of age) registered with the National Rehabilitation Center for Neuromuscular Diseases. Results Of 209 patients, 121 responded. 44.7% of the patients experienced persistent (daily or constant) chronic pain lasting more than 3 months. 21.0% of patients experienced chronic pain that was not daily. Most pain patients experienced three or more pain problems, primarily in the lower back, neck, shoulders, hips, and legs. Symptoms suggestive of neuropathic pain were sometimes present. Patients with persistent chronic pain reported moderate pain interference with daily activities, greater psychological distress, and lower quality of life compared to patients without pain but did not differ regarding physical functioning. Sex, age, LGMD duration, LGMD type, mechanical ventilation use, mobility, arm function, or performance on activities of daily living did not predict chronic pain. Conclusion Chronic pain is common in patients with LGMD. Chronic pain should be considered an important component of LGMD and addressed in the clinic and rehabilitation setting from a biopsychosocial perspective. Implication for rehabilitation Chronic pain is highly prevalent in patients with limb-girdle muscular dystrophy. Health professionals need to systematically ask patients about pain and the influence of pain on everyday life irrespective of LGMD-duration and extent of muscle wastage. Chronic pain and psychological distress need to be addressed in the clinic and rehabilitation setting as an additional disabling component of LGMD and this should be done within a biopsychosocial framework.

Targeted Next-Generation Sequencing Reveals Mutations in Non-coding Regions and Potential Regulatory Sequences of Calpain-3 Gene in Polish Limb-Girdle Muscular Dystrophy Patients.

Limb–girdle muscular dystrophy type R1 (LGMDR1) is caused by mutations in CAPN3 and is the most common type of recessive LGMD. Even with the use of whole-exome sequencing (WES), only one mutant allele of CAPN3 is found in a significant number of LGMDR patients. This points to a role of non-coding, intronic or regulatory, sequence variants in the disease pathogenesis. Targeted sequencing of the whole CAPN3 gene including not only intronic, 3′ and 5′ UTRs but also potential regulatory regions was performed in 27 patients suspected with LGMDR1. This group included 13 patients with only one mutated CAPN3 allele detected previously with exome sequencing. A second rare variant in the non-coding part of CAPN3 was found in 11 of 13 patients with previously identified single mutation. Intronic mutations were found in 10 cases, with c.1746-20C>G variant present in seven patients. In addition, a large deletion of exons 2–8 was found in one patient. In the patients with no causative mutation previously found, we detected rare CAPN3 variants in 5 out of 10 patients and in two of them in a compound heterozygous state. Rare variants within putative regulatory sequences distant from the CAPN3 gene were found in 15 patients, although in 11 of these cases, other variants are deemed causative. The results indicate that intronic mutations are common in Polish LGMDR patients, and testing for non-coding mutations in CAPN3 should be performed in apparently single heterozygous patients.

Validity of Skeletal Muscle Ultrasound in Assessment of Suspected Limb Girdle Muscular Dystrophy Patients

Abstract Background Limb-girdle muscular dystrophies (LGMDs) are a clinically and genetically heterogeneous group of disorders characterized by progressive muscle weakness and degenerative muscle changes. Studies have shown that ultrasound can be useful both for diagnosis and follow-up of LGMDs patients. Objectives This study aims to measure the sensitivity and the specificity of muscle ultrasound in assessment of suspected limb girdle muscular dystrophy patients. Subjects and Methods This cross-sectional descriptive study was conducted on Fifty-five patients with suspected LGMD from neuromuscular unit, myology clinic, Ain Shams University hospitals and eight healthy subjects. Age was above 2 years. Both sexes were included in the study. They underwent real-time B-mode ultrasonography performed with using Logiq p9 General Electric ultrasound machine and General Electric 7-11.5 MHZ linear array ultrasound probe. All ultrasound images have been obtained and scored by a single examiner and muscle echo intensity was visually graded semiquantitative according to Heckmatt's scale. The examiner was blinded to the muscle biopsy results and clinical evaluations. Results Statistical analysis revealed that the diagnostic performance of muscle US (Heckmatt’s score) in LGMD is most sensitive when calculated in all examined upper limb and lower limb muscles, followed by lower limb muscles alone. US of upper limb was found to be the least sensitive. Conclusions Muscle ultrasound is a practical and reproducible and valid tool that can be used in assessment of suspected LGMD patients.

Clinical Features, Diagnosis and Treatment Strategies of Limb Girdle Muscular Dystrophy: An Observational Study from South India

Objective: The present observational study describes the natural course of clinical features, family history, and diagnosis pattern and treatment strategies in rare genetic disorder, Limb girdle muscular dystrophy (LGMD).&#x0D; Research Design: Observational study&#x0D; Methods: Clinically/Immunohistochemically/genetically confirmed LGMD patients diagnosed between February 2019 and March 2021 were ambispectively included. The primary outcomes, secondary outcomes such as clinical presentations, behavioral problems, diagnosis pattern and treatment strategies were studied. A correlation of primary outcomes and steroid, non-steroid regimens were achieved. The demographic data was expressed using descriptive statistics mean ± standard deviation [SD]. The significance level was fixed at α = 0.05&#x0D; Results: 300 LGMD patients were included, out of which 272 patients participated in the study. The mean onset age of symptoms was 8-21 years (13.7 ± 1.9). The mean age of wheelchair bound was found to be between 18 years to 37 years (25.23±1.4) in 123 patients. Bedbound status was attained in 22 patients with a mean age between 18 to 49 years (27.5±2). 7 patients reported death during the study phase with a mean age of 39.2±2.4 (38-45). Comparatively, both steroid and non-steroid regimens using patients exhibited loss of ambulation at 38 years of age. The disease confirmation reported was primarily by clinical examinations (89%) and genetic testing was of minimal number (22%).&#x0D; Conclusion: The outcome measures in the large cohort is similar to that of the Western population despite variability in medical prudence. The contemporary observational study adds to the real-world evidence in approaching better research strategies to treat the LGMD community.

Generation of an induced pluripotent stem cell (iPSC) line (JUCTCi017-A) from a patient with limb-girdle muscular dystrophy (LGMD) due to a homozygous p.Lue287Ser fs14* mutation in the SGCB gene

Limb-girdle muscular dystrophies (LGMDs) are a large group of heterogenous genetic diseases characterized by muscle weakness. In this study, an induced pluripotent stem cell (iPSC) line was generated from LGMD patient’s skin dermal fibroblasts, carrying a homozygous mutation in the Sarcoglycan Beta (SGCB) gene; chr4:52890221, c. 859 delC, p.Lue 287Ser fs14*. The reprogramming process was carried out using Sendai viruses encoding for Yamanaka factors. The resulting iPSCs showed normal morphology and karyotype, expressed pluripotency markers, demonstrated the potential to differentiate in vitro into three germ layers and retained the disease-causing SGCB mutation. This iPSC line represents an ideal source of cells for the investigation of LGMD disease mechanisms.

Circulating miR-206 as a Biomarker for Patients Affected by Severe Limb Girdle Muscle Dystrophies.

Limb-girdle muscular dystrophies (LGMD) are clinically and genetically heterogeneous conditions, presenting with a wide clinical spectrum, leading to progressive proximal weakness caused by loss of muscle fibers. MiR-206 is a member of myomiRNAs, a group of miRNAs with important function in skeletal muscle. Our aim is to determine the value of miR-206 in detecting muscle disease evolution in patients affected by LGMD. We describe clinical features, disease history and progression of eleven patients affected by various types of LGMD: transportinopathy, sarcoglycanopathy and calpainopathy. We analyzed the patients’ mutations and we studied the circulating miR-206 in serum by qRT-PCR; muscle MRI was done with a 1.5 Tesla apparatus. The severe evolution of disease type is associated with the expression levels of miR-206, which was significantly elevated in our LGMD patient cohort in comparison with a control group. In particular, we observed an over-expression of miR-206 that was 50–80 folds elevated in two patients with a severe and early disease course in the transportinopathy and calpainopathy sub-types. The functional impairment was observed clinically and muscle loss and atrophy documented by muscle MRI. This study provides the first evidence that miR-206 is associated with phenotypic expression and it could be used as a prognostic indicator of LGMD disease progression.

Elucidation of the Genetic Cause in Dutch Limb Girdle Muscular Dystrophy Families: A 27-Year's Journey.

A Dutch cohort of 105 carefully selected limb girdle muscular dystrophy (LGMD) patients from 68 families has been subject to genetic testing over the last 20 years. After subsequent targeted gene analysis around two thirds (45/68) of the families had received a genetic diagnosis in 2013. To describe the results of further genetic testing in the remaining undiagnosed limb girdle muscular dystrophy families in this cohort. In the families of the cohort for whom no genetic diagnosis was established (n = 23) further testing using Sanger sequencing, next generation sequencing with gene panel analysis or whole-exome sequencing was performed. In one case DNA analysis for facioscapulohumeral dystrophy type 1 was carried out. In eight families no additional genetic tests could be performed. In 12 of the remaining 15 families in which additional testing could be performed a genetic diagnosis was established: two LGMDR1 calpain3-related families with CAPN3 mutations, one LGMDR2 dysferlin-related family with DYSF mutations, three sarcoglycanopathy families (LGMDR3-5 α-, β- and γ-sarcoglycan-related) with SGCA/SGCB/SGCG mutations, one LGMDR8 TRIM 32-related family with TRIM32 mutations, two LGMDR19 GMPPB-related families with GMPPB mutations, one family with MICU1-related myopathy, one family with FLNC-related myopathy and one family with facioscapulohumeral dystrophy type 1. At this moment a genetic diagnosis has been made in 57 of the 60 families of which DNA was available (95%). A genetic diagnosis is obtained in 95% of the families of the original Dutch LGMD cohort of which DNA was available.