1. Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, USA.
2. Department of Clinical Genetics, National University Hospital Rigshospitalet, Copenhagen, Denmark.
3. Department of Neurology and Copenhagen Muscle Research Center, National University Hospital Rigshospitalet, Copenhagen, Denmark.
4. Howard Hughes Medical Institute, Chevy Chase, MD, USA.
5. Department of Epileptology, University of Bonn Medical Center, Bonn, Germany.