Clinical and Pathologic Findings of Korean Patients with RYR1-Related Congenital Myopathy

BACKGROUND AND PURPOSE This study was designed to investigate clinical and pathologic characteristics of five Korean patients with RYR1-related congenital myopathy (CM). METHODS Five patients from unrelated families were diagnosed with RYR1-related CM via direct or targeted sequencing of RYR1. Their clinical, mutational, and pathologic findings were then analyzed. RESULTS Seven different mutations were identified, including two novel mutations: c.5915A>T and c.12250C>T. All of the patients presented at infancy with proximal dominant weakness and delayed motor milestones. Other clinical findings were scoliosis in three patients, winged scapula in two, hip dislocation in one, and pectus excavatum in one. Ophthalmoplegia was observed in one patient with a novel recessive mutation. Two of three muscle specimens revealed a myopathic pattern with core. CONCLUSIONS We have identified a novel compound heterozygous RYR1 mutation and demonstrated clinical and pathologic findings in five Korean patients with RYR1-related CM.