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.

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.

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.