A systematic review of risk factors associated with muscular dystrophies

•Muscular Dystrophy (MD) is a group of neuromuscular disorders causing progressive weakness and loss of muscle mass. In muscular dystrophy, abnormal genes (mutations) interfere with the production of proteins needed to form healthy muscle.•The most common form is Duchenne Muscular Dystrophy (DMD) − symptoms of DMD begin in childhood, primarily in boys. Other types such as Becker Muscular Dystrophy (BMD), Facioscapulohumeral Muscular Dystrophy (FSHD), and Emery-Dreifuss Muscular Dystrophy (EDMD) don't surface until adulthood.•Genetic risk factors are known to affect the onset and progression of MD.•More studies are needed to investigate the role of environmental factors in the onset and progression of MD. The purpose of this study was to systematically review, assess, and prioritize factors (including biological, socioeconomic, environmental, psychosocial, comorbid, and genetic) for the onset and natural progression of Muscular Dystrophy. Comprehensive review of current literature of these factors was carried out in order to provide a basis for policy makers to identify appropriate measures to mitigate the burden of disease in Canada. A three-stage approach to searching for relevant studies was conducted in multiple databases. Using variations of MeSH terms and keywords, Systematic reviews or meta-analyses published in English or French that meet the inclusion criteria were first identified, then searched for relevant observational studies. Two independent reviewers screened abstracts, then qualifying articles, conducted quality assessment, and finally extracted relevant data using the application, DistillerSR. No existing systematic reviews, meta-analyses, or non-genetic observational studies were identified that met the inclusion criteria. A number of existing systematic reviews and observational studies focused on pharmacological or therapeutic interventions, which was beyond the scope of this study. Four genetic observational studies were identified that focused on aspects of disease progression of Duchenne and Becker Muscular Dystrophy. While this systematic review found that certain genetic polymorphisms and mutations may be a factor for Duchenne or Becker Muscular Dystrophy disease progression, further investigation into other genetic factors and environmental factors is still warranted. Much of the current literature focuses on these Muscular Dystrophies, however, other types of Muscular Dystrophy and their associated risk factors have yet to be ext