Genetic analysis of the DMD gene in 750 patients with suspected Duchenne or Becker muscular dystrophy identified large deletions in 71.21%, point mutations in 14.93%, and large duplications in 9.73%.
Observational (n=750)
No
What is the spectrum of genetic variants in the dystrophin gene among patients with suspected Duchenne or Becker muscular dystrophy in southern Italy?
In a large southern Italian cohort of patients with suspected Duchenne or Becker muscular dystrophy, large deletions were the most frequent genetic variation (71.21%), and the use of Next-Generation Sequencing has increased the identification of point mutations.
Dystrophinopathies are X-linked recessive muscle disorders caused by mutations in the dystrophin (DMD) gene that include deletions, duplications, and point mutations. Correct diagnosis is important for providing adequate patient care and family planning, especially at this time when mutation-specific therapies are available. We report a large single-centre study on the spectrum of DMD gene variants observed in 750 patients analyzed for suspected Duchenne (DMD) or Becker (BMD) muscular dystrophy, over the past 30 years, at the Cardiomyology and Medical Genetics of the University of Campania. We found 534 (71.21%) large deletions, 73 (9.73%) large duplications, and 112 (14.93%) point mutations, of which 44 (5.9%) were small ins/del causing frame-shifts, 57 (7.6%) nonsense mutations, 8 (1.1%) splice site and 3 (0.4%) intronic mutations, and 31 (4.13%) non mutations. Moreover, we report the prevalence of the different types of mutations in patients with DMD and BMD according to their decade of birth, from 1930 to 2020, and correlate the data to the different techniques used over the years. In the most recent decades, we observed an apparent increase in the prevalence of point mutations, probably due to the use of Next-Generation Sequencing (NGS). In conclusion, in southern Italy, deletions are the most frequent variation observed in DMD and BMD patients followed by point mutations and duplications, as elsewhere in the world. NGS was useful to identify point mutations in cases of strong suspicion of DMD/BMD negative on deletions/duplications analyses. In the era of personalized medicine and availability of new causative therapies, a collective effort is necessary to enable DMD and BMD patients to have timely genetic diagnoses and avoid late implementation of standard of care and late initiation of appropriate treatment.
Viggiano et al. (Sat,) conducted a observational in Duchenne and Becker muscular dystrophy (n=750). DMD gene variant analysis was evaluated on Prevalence of different types of DMD gene mutations. Genetic analysis of the DMD gene in 750 patients with suspected Duchenne or Becker muscular dystrophy identified large deletions in 71.21%, point mutations in 14.93%, and large duplications in 9.73%.