1. The Heart Institute, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA.
2. NSCT Diagnostic & Advisory Service for Rare Neuromuscular Diseases, Institute of Genetic Medicine, Newcastle upon Tyne NE2 4AZ, UK.
3. Powell Gene Therapy Center, University of Florida, Gainesville, FL 32610, USA.
4. Department of Neurology, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA.
5. Department of Biomathematics, University of California, Los Angeles Graduate Division, Los Angeles, CA 90095, USA.
6. Department of Biostatistics, School of Public Health, University of California, Los Angeles, Los Angeles, CA 90095, USA.