Consecutive analysis of mutation spectrum in the dystrophin gene of 507 Korean boys with Duchenne/Becker muscular dystrophy in a single center

Introduction: Duchenne and Becker muscular dystrophies (DMD. and BMD.) are allelic X-linked recessive muscle diseases caused by mutations in the large and complex dystrophin gene. Methods: We analyzed the dystrophin gene in 507 Korean DMD./BMD. patients by multiple ligation-dependent probe amplification and direct sequencing. Results: Overall, 117 different deletions, 48 duplications, and 90 pathogenic sequence variations, including 30 novel variations, were identified. Deletions and duplications accounted for 65.4% and 13.3% of Korean dystrophinopathy, respectively, suggesting that the incidence of large rearrangements in dystrophin is similar among different ethnic groups. We also detected sequence variations in >100 probands. The small variations were dispersed across the whole gene, and 12.3% were nonsense mutations. Conclusions: Precise genetic characterization in patients with DMD./BMD. is timely and important for implementing nationwide registration systems and future molecular therapeutic trials in Korea and globally. Muscle Nerve 55: 727–734, 2017.