COVID-19 and myotonic dystrophy: Case reports and systematic review

Introduction: Steinert's disease is a rare genetic disorder characterized by progressive myotonia and multi-organ damage. It is associated with respiratory and cardiological complications often leading patients to exitus. These conditions are also traditional risk factors for severe COVID-19. SARS-CoV-2 has affected people with chronic diseases, but the impact on people with Steinert's disease is poorly defined, with only a few reported and described. More data are needed to understand whether this genetic disease is a risk factor for more serious evolution or death in patients with COVID-19.Methodology: The study describes two cases of patients with SD and COVID-19 and summarizes available evidence of the clinical outcome of COVID-19 in patients with Steinert's disease, by performing a systematic review of the literature (following PRISMA statements and performing PROSPERO registration).Results: Overall, 5 cases were retrieved from the literature review, with a median age of 47 years, of whom 4 had advanced SD and unfortunately died. By contrast, the 2 patients from our clinical practice and 1 from literature had a good clinical outcomes. Mortality ranged from 57% (all cases) to 80% (only literature review).Conclusions: There is a high mortality rate in patients with both Steinert's disease and COVID-19. It highlights the importance of strengthening prevention strategies, especially vaccination. All SD with SARS-CoV-2 infection/COVID-19 patients should be identified early and treated to avoid complications. It is still unknown which treatment regimen is best to use in those patients. Studies on a greater number of patients are necessary to provide clinicians with further evidence.