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

Humans ; Muscular Dystrophies, Limb-Girdle ; pathology

Limb-girdle muscular dystrophy (LGMD) is a group of muscular dystrophies with predominantly proximal muscular weakness, and some genes associated with this disease have been identified at present. LGMD type 2Q (LGMD2Q) is a subtype of LGMD and is associated with PLEC gene mutation. Major phenotypes of PLEC gene mutation include epidermolysis bullosa with late-onset muscular dystrophy and epidermolysis bullosa with other lesions. LGMD2Q without skin lesions is rarely reported. This article reviews the pathogenic gene PLEC and clinical manifestations of LGMD2Q, so as to deepen the understanding of the pathogenic gene and phenotype of LGMD2Q.
Humans ; Muscular Dystrophies, Limb-Girdle ; Mutation ; Phenotype

Heart ; Humans ; Muscular Dystrophies, Limb-Girdle/genetics*

China ; Dysferlin/genetics* ; Humans ; Muscular Dystrophies, Limb-Girdle/genetics* ; Mutation

OBJECTIVE: To analyze variant of SGCA gene in a Chinese pedigree affected with limb-girdle muscular dystrophy type 2D with whole exome sequencing (WGS). METHODS: Multiplex ligation-dependent probe amplification (MLPA) was employed to detect large fragment deletion or duplication of the DMD gene. FastTarget next generation sequencing was used to detect variants of the DMD gene, and the result was verified by Sanger sequencing. After excluding the diagnosis of DMD for the proband, WGS was applied to test the proband and his parents. Suspected pathogenic variants were validated by Sanger sequencing. RESULTS: No variant, deletion or duplication of the DMD gene was detected. Whole exome sequencing showed that the proband has carried compound heterozygous missense variants c.409G>A (p.Glu137Lys) and c.409G>C (p.Glu137Gln) in exon 5 of the SGCA gene, which were respectively inherited from his mother and father. Neither variant was found in DNA derived from the cord blood sample. CONCLUSION The c.409G>A (p.Glu137Lys) and c.409G>C (p.Glu137Gln) compound heterozygous missense variants probably underlie the disease in the proband. Above finding has facilitated genetic counseling and prenatal diagnosis for the family.
Exons ; Female ; Humans ; Muscular Dystrophies, Limb-Girdle ; Pedigree ; Pregnancy

Collagen-VI-related myopathies are caused by mutations in the COL6A1, COL6A2, and COL6A3 and are known to have a wide phenotypic spectrum, including Bethlem myopathy, Ullrich congenital muscular dystrophy, intermediate phenotype, and limb-girdle muscular dystrophy. These patients present with joint hyperextensibility and/or contractures as well as skin changes and muscle weakness, and so clinicians need to notice those extramuscular symptoms in order to achieve a correct diagnosis. We describe the clinical, pathological, and radiological features in a family with Bethlem myopathy caused by a COL6A1 mutation.
Contracture ; Diagnosis ; Humans ; Joints ; Muscle Weakness ; Muscular Diseases ; Muscular Dystrophies ; Muscular Dystrophies, Limb-Girdle ; Phenotype ; Skin

Muscular dystrophy (MD) is a heterogeneous group of inherited muscle disorders caused by the mutations of different genes encoding muscle proteins, and it is now classified according to the results of the linkage analysis and the genes or proteins affected. Except for some subtypes of MD presenting with characteristic manifestations, differential diagnosis is always a challenging task to clinicians because of the similarities in clinical features and muscle pathology findings between subtypes. The immunohistochemical stain (IHC) using a biopsied skeletal muscle is an effective and simplest way to identify defective proteins in MD, so that we can classify MD into its subtypes and target the affected gene. The frozen muscle sections are used for the IHC, and specialized procedures of fixation, blocking, antibody reaction, and detection are serially performed. By using sets of commercially available antibodies, we can identify many different subtypes of MD, which include dystrophinopathies, several forms of limb-girdle muscular dystrophies, and subgroups of congenital muscular dystrophies. Although each disease shows its own characteristic patterns on IHC, there are some exceptional cases including normal expression of the mutated protein and secondary loss of the unaffected protein. Since the quality of the IHC results largely depends on technique and experience, the choice of antibody panel for IHC should be individualized in each laboratory considering the number of muscle biopsy requests, available technicians, and expenses for the study.
Antibodies ; Biopsy ; Diagnosis, Differential ; Immunohistochemistry ; Muscle Proteins ; Muscle, Skeletal ; Muscular Diseases ; Muscular Dystrophies* ; Muscular Dystrophies, Limb-Girdle ; Pathology

BACKGROUND: We describe herein the application of whole exome sequencing (WES) for the molecular genetic diagnosis of a large Korean family with dominantly inherited myopathy. CASE REPORT: The affected individuals presented with slowly progressive proximal weakness and ankle contracture. They were initially diagnosed with limb-girdle muscular dystrophy (LGMD) based on clinical and pathologic features. However, WES and subsequent capillary sequencing identified a pathogenic splicing-site mutation (c.1056+1G>A) in COL6A1, which was previously reported to be an underlying cause of Bethlem myopathy. After identification of the genetic cause of the disease, careful neurologic examination revealed subtle contracture of the interphalangeal joint in the affected members, which is a characteristic sign of Bethlem myopathy. Therefore, we revised the original diagnosis from LGMD to Bethlem myopathy. CONCLUSIONS: This is the first report of identification of COL6A1-mediated Bethlem myopathy in Korea, and indicates the utility of WES for the diagnosis of muscular dystrophy.
Ankle ; Capillaries ; Contracture ; Diagnosis* ; Exome* ; Humans ; Joints ; Korea ; Molecular Biology* ; Muscular Diseases* ; Muscular Dystrophies ; Muscular Dystrophies, Limb-Girdle ; Neurologic Examination

BACKGROUNDMutations of the LMNA gene encoding lamin A and C are associated with dilated cardiomyopathy (DCM), conduction system defects and skeletal muscle dystrophy. Here we report a family with a mutation of the LMNA gene to identify the relationship between genotype and phenotype.

METHODSAll 30 members of the family underwent clinical and genetic evaluation. A mutation analysis of the LMNA gene was performed. All of the 12 exons of LMNA gene were extended with polymerase chain reaction (PCR) and the PCR products were screened for gene mutation by direct sequencing.

RESULTSTen members of the family had limb-girdle muscular dystrophy (LGMD) and 6 are still alive. Two patients suffered from DCM. Cardiac arrhythmias included atrioventricular block and atrial fibrillation; sudden death occurred in 2 patients. The pattern of inheritance was autosomal dominant. Mutation c.73C > G (R25G) in exon 1 encoding the globular domains was confirmed in all of the affected members, resulting in the conversion of arginine (Arg) to glycine (Gly).

CONCLUSIONSThe mutation R25G in exon 1 of LMNA gene we reported here in a Chinese family had a phenotype of malignant arrhythmia and mild LGMD, suggesting that patients with familial DCM, conduction system defects and skeletal muscle dystrophy should be screened by genetic testing for the LMNA gene.

Adult ; Cardiomyopathy, Dilated ; genetics ; Exons ; Humans ; Lamin Type A ; genetics ; Muscular Dystrophies, Limb-Girdle ; genetics ; Mutation