1. Department of Neurology, The University of Utah, UT, USA
2. Department of Orthopaedics, The University of Utah, UT, USA
3. Division of Epidemiology, The University of Utah, UT, USA
4. Division of Public Health, The University of Utah, UT, USA
5. The Myotonic Dystrophy Foundation, CA, USA
6. The Department of Neurology, Stanford University, CA, USA
7. The Department of Neurology, University of Rochester, NY, USA