BACKGROUND: For the differential diagnosis between the various subtypes of muscular dystrophy, the analysis of the protein expression pattern from the biopsied skeletal muscle tissue is essential. Authors performed the immunohistochemical study (IHC) using sets of antibodies for the differentiation of subtypes of muscular dystrophy. METHODS: Antibodies against dystrophin C-terminal, dystrophin rod domain, dystrophin N-terminal, alpha-, beta-, gamma-sarcoglycans, laminin alpha2 chain, dysferlin, and beta-dystroglycan were used for the IHC study in 43 patients with muscular dystrophy. The reactivity against the specific antibodies was graded and the clinical findings were assessed. RESULTS: We found 15 cases of dystrophin deficiency and 7 cases of dysferlin deficiency. Those with dystrophin deficiency were clinically classified previously as follows, 11 cases with Duchenne's muscular dystrophy (DMD), two with congenital muscular dystrophy (CMD), one with Becker's muscular dystrophy (BMD), and a female patient with limb-girdle muscular dystrophy (LGMD). Those with dysferlin deficiency consisted of 4 cases with LGMD phenotype and 3 with distal myopathy. CONCLUSIONS: The results of our study confirm the dystrophin immunostain is essential for the identification of dystrophinopathies among the various subtypes of muscular dystrophy. Also, the identification of 7 cases with dysferlin deficiency suggests dysferlinopathy is the common cause of muscular dystrophy in Korea.
Antibodies ; Diagnosis, Differential ; Distal Myopathies ; Dystroglycans ; Dystrophin ; Female ; Humans ; Immunohistochemistry ; Korea ; Laminin ; Muscle, Skeletal ; Muscular Dystrophies* ; Muscular Dystrophies, Limb-Girdle ; Muscular Dystrophy, Duchenne ; Phenotype ; Sarcoglycans

OBJECTIVETo elucidate the usefulness of next generation sequencing for diagnosis of inherited myopathy, and to analyze the relevance between clinical phenotype and genotype in inherited myopathy.

METHODRelated genes were selected for SureSelect target enrichment system kit (Panel Version 1 and Panel Version 2). A total of 134 patients who were diagnosed as inherited myopathy clinically underwent next generation sequencing in Department of Pediatrics, Peking University First Hospital from January 2013 to June 2014. Clinical information and gene detection result of the patients were collected and analyzed.

RESULTSeventy-seven of 134 patients (89 males and 45 females, visiting ages from 6-month-old to 26-year-old, average visiting age was 6 years and 1 month) underwent next generation sequencing by Panel Version 1 in 2013, and 57 patients underwent next generation sequencing by Panel Version 2 in 2014. The gene detection revealed that 74 patients had pathogenic gene mutations, and the positive rate of genetic diagnosis was 55.22%. One patient was diagnosed as metabolic myopathy. Five patients were diagnosed as congenital myopathy; 68 were diagnosed as muscular dystrophy, including 22 with congenital muscular dystrophy 1A (MDC1A), 11 with Ullrich congenital muscular dystrophy (UCMD), 6 with Bethlem myopathy (BM), 12 with Duchenne muscular dystrophy (DMD) caused by point mutations in DMD gene, 5 with LMNA-related congenital muscular dystrophy (L-CMD), 1 with Emery-Dreifuss muscular dystrophy (EDMD), 7 with alpha-dystroglycanopathy (α-DG) patients, and 4 with limb-girdle muscular dystrophy (LGMD) patients.

CONCLUSIONNext generation sequencing plays an important role in diagnosis of inherited myopathy. Clinical and biological information analysis was essential for screening pathogenic gene of inherited myopathy.

Adolescent ; Child ; Child, Preschool ; Contracture ; DNA Mutational Analysis ; Female ; Genetic Diseases, Inborn ; diagnosis ; genetics ; Genetic Testing ; Genotype ; High-Throughput Nucleotide Sequencing ; Humans ; Infant ; Male ; Molecular Diagnostic Techniques ; Muscular Diseases ; diagnosis ; genetics ; Muscular Dystrophies ; congenital ; Muscular Dystrophies, Limb-Girdle ; Muscular Dystrophy, Duchenne ; Muscular Dystrophy, Emery-Dreifuss ; Mutation ; Phenotype ; Sclerosis ; Walker-Warburg Syndrome ; Young Adult

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.
Biopsy ; Contracture* ; Delayed Diagnosis ; Diagnosis ; Early Diagnosis ; Exome ; Genetic Testing ; Humans ; Hypertrophy ; Muscular Dystrophies* ; Muscular Dystrophies, Limb-Girdle ; Muscular Dystrophy, Emery-Dreifuss

OBJECTIVE: To explore the correlation between clinical manifestations of Limb-girdle muscular dystrophy autosomal recessive 9 FKRP-related (R9 FKRP-related) and variants of the FKRP gene. METHODS: Two children who had presented at the Children's Hospital of Nanjing Medical University respectively due to increased serum myocardial zymogram and hepatic dysfunction on September 30, 2018 and August 3, 2018 were selected as the study subjects. Clinical data of the children were collected. Both children were suspected for Duchenne or Becker muscular dystrophy for asymptomatic high creatine kinase (CK) levels. Peripheral blood samples of the children and their parents were collected for whole exome sequencing, and candidate variants were validated by Sanger sequencing. RESULTS: Genetic testing revealed that both children have carried compound heterozygous variants of the FKRP gene. The c.545A>G and c.941C>T variants in child 1 have been reported previously, among which the c.545A>G is a hot spot mutation in the Chinese population. Child 2 has carried c.602T>C and c.961G>A variants, both of which were unreported previously. CONCLUSION Both children have met the diagnostic criteria for LGMD R9 FKRP-related. Carriers of the c.545A>G variant may present milder symptoms. Compared with patients carrying null variants, carriers of compound heterozygous missense variants may present with a milder phenotype, manifesting as asymptomatic high CK level.
Humans ; Child ; Asian People/genetics* ; Genetic Testing ; Muscular Dystrophies, Limb-Girdle/genetics* ; Muscular Dystrophy, Duchenne ; Pentosyltransferases/genetics*

BackgroundLMNA-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.

MethodsTwenty-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.

ResultsThe 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.

ConclusionsEDMD, 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.

Adolescent ; Adult ; Child ; Child, Preschool ; Female ; Humans ; Magnetic Resonance Imaging ; methods ; Male ; Muscular Dystrophies ; diagnostic imaging ; Muscular Dystrophies, Limb-Girdle ; diagnostic imaging ; Muscular Dystrophy, Emery-Dreifuss ; diagnostic imaging ; Young Adult

OBJECTIVETo establish a specific technique for diagnosing and classifying Duchenne muscular dystrophy (DMD), Becker muscular dystrophy (BMD), facioscapulohumeral muscular dystrophy (FSHD) and neurologic dystrophy.

METHODSForty-seven cases were detected by immunofluorescence technique for analyzing dystrophin located in skeletal muscle cell membrane with the use of mouse monoclonal antibodies, goat and rabbit polyclonal antibodies.

RESULTSThe normal individuals showed ringed positive staining stripe around muscle fibers. Negative result of staining was seen in 16 DMD patients. Eleven BMD patients had discontinuous or a patchy positive staining pattern, and all of 10 FSHD and 10 neurological amyotrophic patients showed positive dystrophin staining.

CONCLUSIONDetecting dystrophin in the skeletal muscle cell membrane of muscular patients is an efficient technique for diagnosing and classifying various types of muscular dystrophy.

Adolescent ; Adult ; Child ; Child, Preschool ; Diagnosis, Differential ; Dystrophin ; analysis ; Female ; Fluorescent Antibody Technique ; methods ; Humans ; Male ; Muscle, Skeletal ; chemistry ; pathology ; Muscular Dystrophies ; diagnosis ; metabolism ; Muscular Dystrophy, Duchenne ; diagnosis ; metabolism ; Muscular Dystrophy, Facioscapulohumeral ; diagnosis ; metabolism ; Neuromuscular Diseases ; diagnosis ; metabolism

Analysis of gene mutation at AND degree on 2 patients with Duchenne having clinical complications: muscle weakness occurred early and progressive, enlarged leg muscles, increased CK level in peripheral blood, muscle biopsy present specific image of the disease. 19 exon were the most commonly mutated on dystrophin gene were selected to implement PCR reaction. Results showed that exon 45 had partial deletion phenomenon in all two patients while exon 44 and 48 had not this model. The patients were determined as bearing consecutive partial delete mutation of three exon 45, 46, 47 on dystrophin gene. This mutation caused incorrect coding frame
Muscular Dystrophy, Duchenne ; Muscular Dystrophies ; Genes

No abstract available.
Humans ; Muscular Dystrophies, Limb-Girdle*

OBJECTIVES: To summarize the skeletal muscle magnetic resonance imaging (MRI) features of the lower limbs in common subtypes of muscular dystrophy (MD) and the experience in the application of MRI in the diagnosis of MD. METHODS: A total of 48 children with MD who were diagnosed by genetic testing were enrolled as subjects. The muscle MRI features of the lower limbs were analyzed. Cumulative fatty infiltration score was calculated for each subtype, and the correlation of cumulative fatty infiltration score with clinical indices was analyzed for Duchenne muscular dystrophy (DMD). RESULTS: DMD was characterized by the involvement of the gluteus maximus and the adductor magnus. Becker muscular dystrophy was characterized by the involvement of the vastus lateralis muscle. Limb-girdle muscular dystrophy was characterized by the involvement of the adductor magnus, the vastus intermedius, the vastus medialis, and the vastus lateralis muscle. For DMD, the cumulative fatty infiltration score of the lower limb muscles was significantly correlated with age, course of the disease, muscle strength, and motor function (P<0.05), while it was not significantly correlated with the serum creatine kinase level (P>0.05). CONCLUSIONS Different subtypes of MD have different MRI manifestations, and MRI may help with the diagnosis and assessment of MD.
Child ; Humans ; Muscular Dystrophy, Duchenne/diagnostic imaging* ; Muscular Dystrophies, Limb-Girdle/pathology* ; Muscle, Skeletal/diagnostic imaging* ; Magnetic Resonance Imaging/methods* ; Thigh/pathology*

Humans ; Muscular Dystrophies, Limb-Girdle ; pathology