1 Department of Neuropediatrics and Muscle Disorders, Faculty of Medicine, University of Freiburg, Germany. Electronic address: wibke.janzarik@uniklinik-freiburg.de.
2 Department of Neurology and Clinical Neurophysiology, Faculty of Medicine, University of Freiburg, Germany.
3 Department of Obstetrics and Gynecology, Faculty of Medicine, University of Freiburg, Germany.
4 Institute for Complex Systems and Mathematical Biology, King's College, University of Aberdeen, UK.
5 Division of Genetic Epidemiology, Institute for Medical Biometry and Statistics, Faculty of Medicine, University of Freiburg, Germany.
6 Department of Neurology and Clinical Neurophysiology, Faculty of Medicine, University of Freiburg, Germany; Department of Neurology and Clinical Neurophysiology, Medical Center Esslingen, Academic Teaching Hospital of the University of Tuebingen, Germany.