Molecular and genetic characteristics of patients from the National Registry of Duchenne/Becker Muscular Dystrophy in the Russian Federation: Pilot analysis

Background: There is currently no reliable epidemiological data in the Russian Federation nor data on patient routing and evaluation of the efficacy and feasibility of diagnostic and therapeutic approaches to patients with suspected Duchenne/Becker muscular dystrophy (DMD/BMD).Objective: To record and monitor all patients with DMD/BMD in Russia.Methods: Observational multicenter prospective & retrospective Registry of patients with DMD/BMD.Results: Almost half of the 626 included patients live in the Central and Volga Federal Districts. The most common cause of the disease was large deletions of one or more exons (328 patients, 52.4%). Large duplications were identified in 92 patients (14.7%). Point mutations were identified in 206 patients, 32.9%. Among 448 patients with a known family history, 20% had a first-line relative diagnosed with DMD/BMD. The mean delay in diagnosis (the time from onset to clinically confirmed diagnosis) was 24.3 months.Conclusions: These data demonstrate the preliminary results of the Registry and indicate a considerable delay in diagnosis in Russia.