Two common mutations (p.Gln832X and c.663+1G>C) account for about a third of the DYSF mutations in Korean patients with dysferlinopathy

Abstract

Dysferlinopathy refers to autosomal recessive muscular dystrophies caused by mutations in dysferlin gene (DYSF). It includes two major distinct disorders, Miyoshi myopathy and limb-girdle muscular dystrophy type 2B. Twenty-three Korean patients were recruited. Full sequence analysis of DYSF detected 10 novel and 9 known mutations. The p.Gln832X showed the highest allele frequency (10/46) as a unique recurrent mutation among Korean population, and two common mutations (p.Gln832X and c.663+1G>C) accounted for 34.8% of the identified mutations. Korean DYSF mutations appeared to cluster in the N-terminal region. Notably, none of homozygous mutations was found in this study. Clinical features were similar to previous reports showing onset in early adulthood, high serum CK and inflammatory reactions on muscle pathology. In Miyoshi myopathy, gastrocnemius muscle was first affected on muscle CT scans, and anterior lower legs and thigh muscles were then affected with disease progression. Despite the genetic variety of DYSF mutations, clinical features were rather invariable among the patients.