Novel, de novo dysferlin gene mutations in a patient with Miyoshi myopathy.

Miyoshi myopathy (MM) is an autosomal recessive distal muscular dystrophy caused by mutations in the dysferlin gene (DYSF), a 150-kb gene on chromosome 2p13 that contains 55 coding exons. Many patients with MM harbour mutations in the DYSF gene, and most of these mutations are inherited from the patients' parents. Recently, we encountered novel, de novo mutations in the DYSF gene in a patient with MM. DYSF gene analysis was performed by targeted next-generation sequencing, and we found that the patient had compound heterozygous mutations, including a de novo mutation (c.613C > T) in exon 6 and a novel missense mutation (c.968T > C) in exon 11. The novel missense mutation, predicted to be a disease-causing mutation or affecting protein function by MutationTaster and Polyphen2, confirmed the diagnosis. These findings provide important insights into the pathogenesis and inheritance of MM.