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

ABSTRACT 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