Clinical heterogeneity and molecular characteristics in a group of Chinese patients with dysferlinopathy

Abstract Background Dysferlinopathy is an autosomal recessive muscular dystrophy caused by mutations in the dysferlin (DYSF) gene. This study presents the clinical features and mutational spectrum of a Chinese cohort. Methods We reviewed the clinical, pathological data and results of DYSF mutations of 26 Chinese patients with dysferlinopathy screened by immunohistochemistry staining and mutations in DYSF genes. Results Among 26 patients with dysferlinopathy, 18 patients (69.2%) presented as LGMD2B, 4 (15.4%) had a phenotype of Miyoshi myopathy (MM), and 4 (15.4%) presented as atypical asymptomatic hyperkalemia(hyperCKemia). 15 patients (57.7%) were originally misdiagnosed as inflammatory myopathy or other diseases. 15 novel mutations were identified among the 40 mutation sites identified in this cohort. Conclusions Dysferlinopathy is a clinically heterogeneous group of disorders with various phenotypes, and has a high proportion of novel mutations and a high rate of misdiagnosis before immunohistochemistry staining and genetic analysis.