1 Muscle Disease Unit, Laboratory of Muscle Stem Cells and Gene Regulation, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, 50 South Drive, Room 1141, Building 50, MSC 8024, Bethesda, MD, 20892, USA. andrew.mammen@nih.gov.
2 Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA. andrew.mammen@nih.gov.
3 Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA. andrew.mammen@nih.gov.
4 Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
5 Center for Genetic Muscle Disorders at Kennedy Krieger Institute, Baltimore, MD, USA.