Case report of limb girdle muscular dystrophy type 2S caused by maternal uniparental disomy on chromosome 4 / 中华实用儿科临床杂志

A case of limb girdle muscular dystrophy type 2S (LGMD2S) caused by maternal uniparental disomy on chromosome 4 at the First Affiliated Hospital of Henan University of Chinese Medicine in March 2020 was reported.The female child, aged 9 months and 4 days, presented with developmental delay after bacterial meningitis in early infancy, decreased muscle strength in infancy and increased muscle and liver enzymes.Family genetic analysis showed that the child′s monodiploid in chromosome 4 was maternal origin, and the homozygous c. 1066T > G (p.Y356D) of TRAPPC11 gene may had pathogenic variation, which came from the child′s mother.The final diagnosis of LGMD2S was made according to the clinical manifestations and gene test results.LGMD2S is a rare autosomal recessive disease caused by the pathogenic variation of TRAPPC11 gene.Its clinical characteristics include proximal limb weakness, motor and intellectual retardation, seizures, motor disorders, elevated serum creatine kinase and muscular dystrophy like pathological changes in children.

Distrofia muscular de cinturas 2J, revisión bibliográfi-ca y reporte de un caso pediátrico en Ecuador / 2J girdle muscular dystrophy, bibliographic review and report of a pediatric case in Ecuador

RESUMEN La distrofia muscular de cinturas de las extremidades (LGMD, por sus siglas en inglés) incluye varios trastornos con etiologías heterogéneas. Se heredan en patrón autosómico recesivo o autosómico dominante y constituyen la cuarta causa genética más común de debilidad muscular, reportando una prevalencia de 1 en 20,000. Las manifestaciones clínicas son inespecíficas, pueden presentarse desde la primera infancia hasta la edad adulta, dependiendo del subtipo de la enfermedad y de la proteína afectada. El diagnóstico inicial se realiza mediante pruebas genéticas antes de obtener una biopsia muscular. Hasta la actualidad no hay tratamientos que modifiquen la evolución de la enfermedad. El propósito de la terapia es conservar la independencia funcional y tratar las complicaciones asociadas, manteniendo al máximo la calidad de vida.A continuación se reporta el caso de un paciente pediátrico, residente en Quito, Ecuador sin antecedentes patológicos ni familiares previos, con alteración de la motricidad fina progresiva dado por trastorno motor en manos, dedos en flexión, hipotrofia de eminencias tenar e hipotenar y atrofia de interóseos de manos, se realizan estudios en relación a neuropatía periférica distal con afectación de sensibilidad bilateral y simétrica, encontrando como única variante, cambios electromiográficos: polineuropatía crónica, sensitiva y motora de predominio axonal, (desmielinizante en menor grado), de grado marcado presumi-blemente de etiología hereditaria. El diagnostico final lo determinó estudio genético con mutación del gen TTN en relación con: Distrofia muscular de cinturas, tipo 2J (CINTURA ESCAPULAR DE PREDOMINIO DISTAL).

ABSTRACT Limb girdle muscular dystrophy (LGMD) includes several disorders with heterogeneous etiologies. They are inherited in an autosomal recessive or autosomal dominant pattern and constitute the fourth most common genetic cause of muscle weakness, reporting a prevalence of 1 in 20,000. The clinical manifestations are nonspecific, can begin from early childhood to adulthood depending on the subtype of the disease and the protein affected. The initial diagnosis is made by genetic testing before obtaining a muscle biopsy. To date there are no treatments that modify the evolution of the disease. The purpose of therapy is to preserve functional independence and treat associated complications, maintaining quality of life as much as possible.The following is the case of a pediatric patient, resident in Quito, Ecuador with no prior family or pathological history, with progressive fine motor disorder due to motor disorder in the hands, flexed fingers, hypotrophy of tenar and hypothenar eminences, and atrophy of interosseous hands, studies are performed in relation to distal peripheral neuropathy with bilateral and symmetrical sensitivity involvement, finding electromyographic changes as the only variant: chronic, sensitive and motor polyneuropathy with axonal predominance (demyelinating to a lesser degree), of marked degree presumably of hereditary etiology. The final diagnosis was determined by a genetic study with a mutation of the TTN gene in relation to: Girdle Muscular dystrophy, type 2J (DISTAL PREDOMINANT SCAPULAR GIRDLE).

Effect Of Structured Exercise Regimen On Quality Of Life, Balance And Strength On A Patient With Miyoshi Myopathy – A Case Report

Background: Dysferlinopathy is an autosomal recessive disease seen in adolescence or young adulthood. Miyoshi Myopathy is characterized by weakness and wasting of posterior compartment leg muscles rather than the anterior compartment and distal upper limb muscles. Still, the intrinsic muscles of the foot and hands are spared. There are several undiagnosed cases in India and also around the world with dysferlinopathy. Diagnosis for the same requires advanced biological laboratories along with high economic funding for diagnostic purposes. Case Summary: This case report presents a 22-year-old male diagnosed with Miyoshi myopathy/LGMD2b (dysferlinopathy). The subject complained about a loss of balance, strength, and difficulty in performing activities of daily living. The patient was given Aquatic Therapy along with conventional physical therapy for a duration of 6weeks, which included three days of supervised therapy along with 3days home protocol and a rest day kept at the end of every week. Outcome Measures: Standardized scales like the Barthel Index and the Berg Balance Scale were used for the assessment of pre and post the progress of the subject for Quality of Life and Balance, respectively. Manual Muscle testing was used for assessments for pre and post muscle strength of the subject. Conclusion: The timely diagnosis of a rare condition before the advancement of the disorder and thus the use of appropriate intervention of physiotherapy, which consisted of progressive muscle-strengthening exercises along with balance training proved to be promising in preventing falls, muscle atrophy and thus making the patient independent for doing daily activities.

Muscle Magnetic Resonance Imaging in Patients with Various Clinical Subtypes of -Related Muscular Dystrophy / 中华医学杂志(英文版)

<p><b>Background</b>LMNA-related muscular dystrophy can manifest in a wide variety of disorders, including Emery-Dreifuss muscular dystrophy (EDMD), limb-girdle muscular dystrophy (LGMD), and LMNA-associated congenital muscular dystrophy (L-CMD). Muscle magnetic resonance imaging (MRI) has become a useful tool in the diagnostic workup of patients with muscle dystrophies. This study aimed to investigate whether there is a consistent pattern of MRI changes in patients with LMNA mutations in various muscle subtypes.</p><p><b>Methods</b>Twenty-two patients with LMNA-related muscular dystrophies were enrolled in this study. MRI of the thigh and/or calf muscles was performed in them. The muscle MRI features of the three subtypes were compared by the Mann-Whitney U-test. The relationship between the clinical and MRI findings was also investigated by Spearman's rank analyses.</p><p><b>Results</b>The present study included five EDMD, nine LGMD, and eight L-CMD patients. The thigh muscle MRI revealed that the fatty infiltration of the adductor magnus, semimembranosus, long and short heads of the biceps femoris, and vasti muscles, with relative sparing of the rectus femoris, was the predominant change observed in the EDMD, LGMD, and advanced-stage L-CMD phenotypes, although the involvement of the vasti muscles was not prominent in the early stage of L-CMD. At the level of the calf, six patients (one EDMD, four LGMD, and one L-CMD) also showed a similar pattern, in which the soleus and the medial and lateral gastrocnemius muscles were most frequently observed to have fatty infiltration. The fatty infiltration severity demonstrated higher scores associated with disease progression, with a corresponding rate of 1.483 + 0.075 × disease duration (X) (r = 0.444, P = 0.026). It was noteworthy that in six L-CMD patients with massive inflammatory cell infiltration in muscle pathology, no remarkable edema-like signals were observed in muscle MRI.</p><p><b>Conclusions</b>EDMD, LGMD and advanced-staged L-CMD subtypes showed similar pattern of muscle MRI changes, while early-staged L-CMD showed somewhat different changes. Muscle MRI of L-CMD with a muscular dystrophy pattern in MRI provided important clues for differentiating it from childhood inflammatory myopathy. The fatty infiltration score could be used as a reliable biomarker for outcome measure of disease progression.</p>

Early-Onset LMNA-Associated Muscular Dystrophy with Later Involvement of Contracture

BACKGROUND AND PURPOSE: The early diagnosis of LMNA-associated muscular dystrophy is important for preventing sudden arrest related to cardiac conduction block. However, diagnosing early-onset Emery-Dreifuss muscular dystrophy (EDMD) with later involvement of contracture and limb-girdle muscular dystrophy type 1B is often delayed due to heterogeneous clinical presentations. We aimed to determine the clinical features that contribute to a delayed diagnosis. METHODS: We reviewed four patients who were recently diagnosed with LMNA-associated muscular dystrophy by targeted exome sequencing and who were initially diagnosed with nonspecific or other types of muscular dystrophy. RESULTS: Certain clinical features such as delayed contracture involvement and calf hypertrophy were found to contribute to a delayed diagnosis. Muscle biopsies were not informative for the diagnosis in these patients. CONCLUSIONS: Genetic testing of single or multiple genes is useful for confirming a diagnosis of LMNA-associated muscular dystrophy. Even EDMD patients could experience the later involvement of contracture, so clinicians should consider early genetic testing for patients with undiagnosed muscular dystrophy or laminopathy.

Clinical and Pathological Heterogeneity of Korean Patients with CAPN3 Mutations

PURPOSE: This study was designed to investigate the characteristics of Korean patients with calpainopathy. MATERIALS AND METHODS: Thirteen patients from ten unrelated families were diagnosed with calpainopathy via direct or targeted sequencing of the CAPN3 gene. Clinical, mutational, and pathological spectra were then analyzed. RESULTS: Nine different mutations, including four novel mutations (NM_000070: c.1524+1G>T, c.1789_1790inA, c.2184+1G>T, and c.2384C>T) were identified. The median age at symptom onset was 22 (interquartile range: 15-28). Common clinical findings were joint contracture in nine patients, winged scapula in four, and lordosis in one. However, we also found highly variable clinical features including early onset joint contractures, asymptomatic hyperCKemia, and heterogeneous clinical severity in three members of the same family. Four of nine muscle specimens revealed lobulated fibers, but three showed normal skeletal muscle histology. CONCLUSION: We identified four novel CAPN3 mutations and demonstrated clinical and pathological heterogeneity in Korean patients with calpainopathy.

Evolução funcional da distrofia muscular do tipo Cinturas em indivíduos de uma mesma família / Functional evolution of Girdle Muscular Dystrophy in individuals of the same family

A Distrofia Muscular de Cinturas (DMC) possui herança autossômica dominante ou recessiva e caracteriza-se por paresia progressiva que induz à deterioração funcional e dificuldades no desempenho de atividades cotidianas. O objetivo do presente estudo foi analisar a evolução funcional de indivíduos com diagnóstico de DMC de uma mesma família. Nove indivíduos foram avaliados por um questionário para identificação do parentesco, idade de inicio dos primeiros sintomas e queixas principais, e pelas Escalas de Vignos (EV) e Hammersmith (EMFH). O projeto foi aprovado pelo CEP/UFVJM, protocolo nº061/12. A idade média foi de 33 ± 8.1 anos, com seis indivíduos sendo do sexo masculino, a idade de aparecimento dos primeiros sintomas foi aos 9± 2,83 anos e os sintomas iniciais mais frequentes foram dificuldade de correr, quedas e marcha equina. Os sujeitos pontuaram 4, 6 e 7 na EV e no exame físico verificou-se acometimento principalmente dos membros inferiores. Foi encontrado correlação negativa entre idade dos sujeitos e escore na EMFH (r2=-0,839) e entre pontuação na EV e EMFH (r2 =-0,819), e correlação positiva entre EV e uso de dispositivos (r2=0,866). Nossos achados sugerem que a mesma patologia diagnosticada em indivíduos de uma mesma família apresenta repercussões funcionais diferentes. O aspecto ambiente deve ser levado em consideração ao avaliar a funcionalidade desses indivíduos uma vez que, independente do diagnóstico em comum, da idade, e limitações físicas, os indivíduos apresentaram adaptações particulares com objetivo de manutenção do seu deslocamento de acordo com as características do ambiente em que vive.(AU)

Limb Girdle Muscular Dystrophy (LGMD) is an autosomal-dominant or recessive hereditary disease. Progressive muscular weakness leads to functional damage and difficulty to perform activities of daily life. The present study aimed to analyze the functional evolution of LGMD individuals of the same family. Nine individuals were assessed using a questionnaire (to identify their relationship, age of onset of the first signs of the disease and main complaints) and by Vignos and Hammersmith Scales. Projetct was aproved by Ethics Committee of UFVJM, protocol nº061/12. Mean age was 33±8.1 years old, six male, mean age of onset of the first signs was 9± 2,83 years old and the most frequent signs were difficulty to run, falls and gait with ankle on plantar flexion. Subjects scored 4, 6 and 7 on Vignos Scale and on physical exam, lower limbs were the most affected. Negative correlation between age and Hammermith scale (r 2=-0,839), Vignos and Hammersmith Scale (r2=-0,819) were found. Positive correlation between Vignos Scale and use of assistive devices (r2=0,866). Our finds suggest that the same disease in individuals of the same family leads to different functional impairment. The environmental aspect should be considered when assessing functionality of individuals with LGMD once although they present the same diagnosis, they present particular adaptations with the aim of maintain displacement according to characteristics of the environment where they live.(AU)

Clinical aspects of patients with sarcoglycanopathies under steroids therapy / Aspectos clínicos de pacientes com sarcoglicanopatias sob efeito de corticoterapia

Patients with sarcoglycanopathies, which comprise four subtypes of autosomal recessive limb-girdle muscular dystrophies, usually present with progressive weakness leading to early loss of ambulation and premature death, and no effective treatment is currently available. Objective To present clinical aspects and outcomes of six children with sarcoglycanopathies treated with steroids for at least one year. Method Patient files were retrospectively analyzed for steroid use. Results Stabilization of muscle strength was noted in one patient, a slight improvement in two, and a slight worsening in three. In addition, variable responses of forced vital capacity and cardiac function were observed. Conclusions No overt clinical improvement was observed in patients with sarcoglycanopathies under steroid therapy. Prospective controlled studies including a larger number of patients are necessary to determine the effects of steroids for sarcoglycanopathies. .

Pacientes com sarcoglicanopatias, que compreendem quatro subtipos de distrofias musculares de cinturas autossômicas recessivas, geralmente apresentam fraqueza progressiva, levando à perda precoce da deambulação e morte prematura, e não há tratamento eficaz disponível até o momento. Objetivo Descrever os aspectos clínicos e a evolução de seis crianças com sarcoglicanopatias tratados com corticosteróides por pelo menos um ano. Método Prontuários dos pacientes foram analisados retrospectivamente. Resultados Estabilização da força muscular foi observada em um paciente, uma ligeira melhora em dois, e um ligeiro agravamento em três. Além disso, foram observadas respostas variáveis de capacidade vital forçada e da função cardíaca. Conclusões Não houve melhora clínica evidente em pacientes com sarcoglicanopatias sob terapia com corticosteróides. Estudos prospectivos controlados incluindo maior número de pacientes são necessários para determinar os efeitos dos corticosteróides para sarcoglicanopatias. .

Clinical and molecular genetic study of limb-girdle muscular dystrophy type 2A in a Chinese family / 中华实用儿科临床杂志

Objective To analyze the clinical,muscle pathological features and molecular mutations in the 2 Chinese Han siblings with limb-girdle muscular dystrophy(LGMD) and conclude the phenotype/genotype correlations.Methods Clinical and muscle pathological data were collected.Genomic DNA of the two siblings and their parents were extracted using standard procedures from the peripheral leukocytes.A custom of targeted gene panel including 61 neuromuscular genes were designed by using the Agilent Sureselect Target Enrichment Kit.Targeted next generation sequencing(NGS) was performed in the proband,and CAPN3 gene mutation was verified with Sanger sequencing in the two siblings and their parents.The dbSNP138 and http://www.dmd.nl were searched to determine the disease-causing mutations.Results The proband slowly showed muscle weakness profoundly with pelvic muscles,developed difficulty in squatting and standing and climbing stairs.She had a tight Achilles tendon,high CK level (1 908-9 241 IU/L),without winging scapula and hypertrophy calf.The affected brother was only diagnosed hyper CKemia.By using the targeted NGS,the two siblings possessed the same two compound heterozygous mutations(c.717delT and c.2243G ＞ A) in CAPN3 gene.The two mutations both were verified by Sanger sequencing and had been reported before.Conclusions LGMD is clinically and genetically heterogeneous,and targeted NGS is powerful in defining the causal mutation of LGMD and helpful in investigating the exact genotype/phenotype analysis.

Analysis of calpain-3 protein in muscle biopsies of different muscular dystrophies from India.

Background & objectives: Calpain-3, a Ca2+-dependent protease has been implicated in the pathology of neuromuscular disorders (NMDs). The current study aimed to analyze calpain-3 expression in cases diagnosed as muscular dystrophy from the Indian population. Methods: Calpain-3 Western blot analysis in muscle biopsies of immunohistochemically confirmed cases of Duchenne muscular dystrophy (DMD) (n=10), dysferlinopathy (n=30) and sarcoglycanopathy (n=8) was carried out. Calpain-3 Western blotting was also used in a blinded study to identify cases of calpain-3 deficiency in 28 NMD patients with potential muscular dystrophy. Results: Calpain-3 appeared as a full length 94 kDa band with an autolytic product (~60 kDa) on Western blots with antibody NCL-CALP-12A2 (Ab-2). Eight of the 10 DMD samples showed absence of 94 kDa band but presence of 60 kDa band while one case of sarcoglycanopathy showed absence of both. Twenty one of the 30 dysferlinopathy samples showed both bands while six showed only the 60 kDa band and three showed absence of both. In the blinded study, five NMD cases with potential muscular dystrophy that showed complete absence of both bands in retrospect exhibited clinical features of limb girdle muscular dystrophy 2A (LGMD2A). Interpretation & conclusions: While the study revealed a consistent pattern of calpain-3 in DMD, one sarcoglycanopathy and three dysferlinopathy samples exhibited secondary reduction in calpain-3. It was recognized that both calpain-3 bands should be considered to confirm calpain deficiency. Further, western blot offers an economical and fast preliminary screening method for LGMD2A especially in cases of complete absence of calpain-3 prior to conclusive diagnosis by genetic testing.

Heterogeneous Characteristics of Korean Patients with Dysferlinopathy

Dysferlinopathy is caused by mutations in the DYSF gene. To characterize the clinical spectrum, we investigated the characteristics of 31 Korean dysferlinopathy patients confirmed by immunohistochemistry. The mean age of symptom onset was 22.23 +/- 7.34 yr. The serum creatine kinase (CK) was highly increased (4- to 101-fold above normal). The pathological findings of muscle specimens showed nonspecific dystrophic features and frequent inflammatory cell infiltration. Muscle imaging studies showed fatty atrophic changes dominantly in the posterolateral muscles of the lower limb. The patients with dysferlinopathy were classified by initial muscle weakness: fifteen patients with Miyoshi myopathy phenotype (MM), thirteen patients with limb girdle muscular dystrophy 2B phenotype (LGMD2B), two patients with proximodistal phenotype, and one asymptomatic patient. There were no differences between LGMD2B and MM groups in terms of onset age, serum CK levels and pathological findings. Dysferlinopathy patients usually have young adult onset and high serum CK levels. However, heterogeneity of clinical presentations and pathologic findings upon routine staining makes it difficult to diagnose dysferlinopathy. These limitations make immunohistochemistry currently the most important method for the diagnosis of dysferlinopathy.

Dysferlinopathy: Spectrum of pathological changes in skeletal muscle tissue.

Background: Dysferlinopathy is an autosomal recessive-limb girdle muscular dystrophy (AR-LGMD) caused due to the defect in gene encoding dysferlin, a sarcolemmal protein. Awareness of the variants and their relative frequency is essential for accurate diagnosis. Aim: To study the spectrum of morphologic changes in immunohistochemically proven cases of dysferlinopathies, to correlate the findings with clinical phenotype and durations of illness and determine the frequency. Materials and Methods: Dysferlinopathies seen over a period of 2 years at a tertiary neurological center were analyzed. Results: Clinically, majority had Miyoshi phenotype (46.6%) with distal involvement and LGMD phenotype (40%) with proximal muscle involvement. In addition, a proximo-distal and tibial muscle phenotype was encountered. Morphologically, rimmed vacuoles were noted in the Miyoshi phenotype. The presence of ragged red fibers, lobulated fibers and inflammation had no preference to a particular phenotype. Significant atrophy and lobulated fibers were noted in patients with longer duration of illness. Conclusions: Dysferlinopathy was the second most common identifiable cause (21%) of LGMD next to sarcoglycanopathies (27%).

Clinical and electrophysiological analysis of limb-girdle muscular dystrophy:A geneological report / 中华物理医学与康复杂志

Objective To analyze the clinical and electrophysiological features of one geneology with limbgirdle muscular dystrophy(LGMD). Methods Twenty-seven members of one family with limb-girdle muscular dystrophy(LGMD)were investigated.Fourteen of them were examined with electromyography(EMG)and their motor conduction velocities(MCV)and sensory conduction velocities(SCV)were measured.Among them,10 had no clinical manifestations,while 4 demonstrated symptoms and signs of LGMD. Results Three of the 4 patients had suffered from LGMD when young.They demonstrated the typical clinical features,including the progressive muscle weakness in the upper and lower extremities,positive Gower signs,duck gait,muscle atrophy distributed tO the proximal extremity,and no gastrocnemius hypertrophy.One subject presented atypical characteristics.The MCVs and SCVs of the 4 patients were normal,but neuropathic manifestations were found in the EMGS of 3 of them.and mixed neuropathic and myopathic manifestations were found in the EMG of the other.Conclusion LGMD patients in the same family can vary in their clinical characteristics.The longer the duration,the more severe the clinical features.Electrophysiological examination can reveal normal MCV and SCV but abnormal elctromyography.

Mutations of CAPN3 in Korean Patients with Limb-Girdle Muscular Dystrophy

The limb-girdle muscular dystrophy type 2A (LGMD2A) is a recessively inherited disease caused by a mutation of the calpain 3 gene (CAPN3), and is considered one of the most prevalent subtypes of limb-girdle muscular dystrophy (LGMD). In this study, we aimed to identify CAPN3 mutations and to characterize the phenotype of Korean patients with LGMD2A. Among 35 patients with LGMD, four patients, who showed calpain 3 deficiency on western blot analysis, were analyzed in this study. Total RNA extracted from frozen muscle tissue was amplified by reverse transcriptase polymerase chain reaction (RT-PCR) using six primer pairs covering all coding sequences of CAPN3, and direct sequencing was performed. Clinical and pathological features of the patients were also reviewed. We found four different mutations in five alleles from three patients. Of the pathogenic mutations identified, two were novel (c.2125T>C and c.2355-2357delTTC), and the others had been reported elsewhere (c.440G>C, c.1076C>T). All patients showed a high CK level with predominant proximal leg weakness, and the onset was in their childhood except for one patient. Among two novel CAPN3 mutations, one was a missense mutation (c.2125T>C [p.709Ser>Pro]), and the other was a small in-frame deletion causing omission of a single amino acid (c.2355-2357delTTC [p.786delPhe]). The clinical features of our patients were generally compatible with the characteristics of LGMD2A patients described in the previous studies.

Mutation analysis of dysferlin gene in a Chinese family with Miyoshi myopathy / 临床检验杂志

Objective Two autosomal recessive forms of muscular dystrophy:LGMD2B and Miyoshi myopathy may be indused by dysferlin gene mutation.The purpose of this study was to define molecular defects in dysferlin gene in a family with Miyoshi myopathy.Methods mRNA from peripheral blood in a Chinese Miyoshi myopathy pedigree was amplified by RT-PCR and the mutation was determined by sequencing the amplified products.Results The results of sequencing revealed a novel homozygous mutation,a 6429delG,on exon 53 of the dysferlin gene for the patients.Conclusion The 6429delG mutation in the dysferlin gene of patients creates a frameshift mutation which induces a stop codon at 2035 on exon 54 and the premature dysferlin contributes to the Miyoshi myopathy in the Chinese pedigree.

Molecular and Pathological Diagnosis of Muscular Dystrophies / 한양의대학술지

The muscular dystrophies are a diverse group of inherited muscle disorders characterized by progressive muscle weakness and wasting with characteristic histologic abnormalities such as degeneration, necrosis, and regeneration of muscle fibers. With progress in molecular genetics methods, new discoveries of dystrophin and related molecules have dramatically changed the understanding and diagnosis of a large group of muscular dystrophy patients. Dystrophin and its related molecular associates are tightly associated and form an essential cytoskeletal system (dystrophin-glycoprotein complex) at the muscle fiber surface membrane, which is critical for maintaining the integrity of the sarcolemma and muscle fibers. Deficiency of one of these sarcolemmal proteins, including dystrophin, dystroglycans, sarcoglycans, and laminin-2, leads to the breakdown and instability of muscle fibers and to clinically observed progressive muscle weakness. Identification of the molecular cause of muscular dystrophies would allow a genetic oriented classification and diagnosis using DNA or protein analysis. However, definition of the molecular pathogenesis of muscular dystrophies has not been completely possible until now. Future advances in this field should allow the exact diagnosis and treatment of muscular dystrophies.

Clinical and pathological features of limb-girdle muscular dystrophy type 2B / 临床神经病学杂志

Objective To investigate the clinical and pathological features of limb-girdle muscular dystrophy type 2B(LGMD2B).Methods The clinical data and the pathological result of skeletal muscle in five patients with LGMD2B were analyzed retrospectively.Results Five patients presented muscle atrophy and weakness(four limbs in three patients and both lower limbs in two patients),and the chronic onset,and the progressive deterioration.The pathological examination showed that the muscle fibers degenerating,necrotic and regenerating in different extents were observed,and the infiltration of inflammatory cells were appeared on all of cases.Immunohistochemical stains showed that the expression of anti-dysferlin monoclonal antibody was negative,anti-Dystrophy,Sarcoglycan and dystroglycan monoclonal antibodies were positive normaly,anti-CD8+T cell monoclonal antibody was negative,and anti-MHC-1 monoclonal antibody was up-regulated in five patients.Conclusions The clinical characters of LGMD2B are chronic onset,progressive muscle atrophy and weakness in four limbs or both lower limbs.The pathological characters of LGMD2B are similar to the changes of polymyositis.