1. Department of Neurology, University of Pavol Jozef Šafárik, Košice, Slovakia
2. Department of Neurology, University Hospital of L. Pasteur, Košice, Slovakia
3. CENTOGENE GmbH, Rostock, Germany
4. University College London, Institute of Neurology, Department of Neuromuscular Disorders, Queen Square, WC1N 3BG London, UK