Clinical heterogeneity and a high proportion of novel mutations in a Chinese cohort of patients with dysferlinopathy

BACKGROUND AND AIMS: Dysferlinopathies are a group of autosomal recessive muscular dystrophies caused by mutations in the dysferlin gene. This study presents clinical features and the mutational spectrum in the largest cohort of Chinese patients analyzed to date. PATIENTS AND METHODS: A total of 36 unrelated Chinese patients with diagnostic suspicion of dysferlinopathy were clinically and genetically characterized. RESULTS: Patients were divided into five phenotypes: 19 patients with limb girdle muscular dystrophy (LGMD) type 2B, 10 with Miyoshi myopathy (MM), 1 with distal anterior compartment myopathy (DACM), 3 with exercise intolerance, and 3 with asymptomatic hypercreatine phosphokinasemia (hyperCPKemia). Thirty-one patients showed an absence or drastic reduction of dysferlin expression by Westernblot. Forty-three mutations were identified in DYSF, including 31 novel. CONCLUSION: Our study underlines clinical heterogeneity and a high proportion of novel mutations in Chinese patients affected with dysferlinopathy.