1. Folkhälsan Institute of Genetics and Department of Medical Genetics, Haartman Institute, University of Helsinki, Helsinki, Finland
2. Albert Einstein College of Medicine, Departments of Medicine– Endocrinology and Molecular Pharmacology, Bronx, NY, USA
3. Neuromuscular Research Center, University of Tampere and Tampere University Hospital, Tampere, Finland
4. Department of Neurology, Vaasa Central Hospital, Vaasa, Finland