Natural history of patients with nonsense mutation Duchenne muscular dystrophy treated with ataluren in Spain.

Introduction: Duchenne muscular dystrophy (DMD) is a progressive neuromuscular disease linked to the X chromosome caused by the lack of functional dystrophin. About 10-15% of cases are caused by nonsense mutations, and their natural history is thought to be similar to DMD by other causes. Ataluren is a new therapeutic option that promotes the readthrough of nonsense mutations leading to the production of functional dystrophin proteins. Objective: To describe the natural history of patients with nonsense mutations DMD (nmDMD) and evaluate the impact of corticosteroids and ataluren on disease progression. Methods: It is a retrospective, longitudinal case-series study of all male patients with nmDMD treated at Sant Joan de Déu Hospital in Barcelona, Spain, since 2007. Results: 28 patients from 3.7 to 22 years old were included. The mean age at symptom onset was 3.5 years, and at genetic diagnosis was 4.5 years. All patients were treated with corticosteroids, and 17 patients also received ataluren. Patients treated with ataluren delayed the loss of ambulation by three years (14 vs 10.9 years). No patients treated with ataluren required non-invasive ventilation. Conclusions: Patients with DMD caused by nonsense mutations present a similar phenotype to those with DMD with other types of mutations. Patients treated with ataluren delayed the loss of ambulation and appeared to maintain upper limb and respiratory function better than those not treated with ataluren.