The Spectrum of Dystrophin Gene Deletions and Duplications in a cohort of Patients with Duchenne/Becker Muscular Dystrophy in Türkiye

Duchenne Muscular Dystrophy (DMD) is the most prevalent muscle disease in children, and unfortunately, currently there are no effective treatments for either DMD or Becker Muscular Dystrophy (BMD). Nevertheless, targeted gene therapy treatments have recently emerged, and genetic diagnoses is now the basis of treatment. In addition, genetic and prenatal diagnosis have significantly reduced the incidence rates of these diseases. The aim of this study was to identify the most common deletion and duplication regions in the Turkish population using the Multiplex Ligation-dependent Probe Amplification (MLPA) method, as well as to determine the suitability of patients for current treatments and identify new treatment target regions based on the findings. In clinical practice, data from 103 patients with Duchenne and Becker muscular dystrophy who have been identified with the deletion/duplication using the Multiplex Ligation-dependent Probe Amplification (MLPA) method, as well as 35 participants carrying the deletion/duplication for these diseases, were analyzed. The aim was to detect the most common deletion/duplication regions of the Dystrophin gene in the Turkish population. The majority of patients had deletions (89.9% in males and 75% in females), while a smaller percentage had duplications. The most common deletions occurred in exons 50 and 49, while the most common duplication was in exon 7. The deletions in exons 45-52 accounted for over half of all deletions, and most deletions involved 5 or less exons. The longest deletions involved 30 exons and were found in 2 patients. The findings of this research have provided valuable insights into the prevalence of deletions and duplications in the dystrophin gene among individuals in our population. The results indicate that a significant proportion of patients may be eligible for treatments that are not yet widely available. This study highlights the critical role of population-specific data in advancing the field of dystrophin gene-based therapies.