1. Department of Neurology, University Medical Center Groningen, University of Groningen, 9700RB Groningen, The Netherlands
2. Expertise Center Movement Disorders Groningen, University Medical Center Groningen, 9700RB Groningen, The Netherlands
3. Department of Gastroenterology and Hepatology, University Medical Center Groningen, University of Groningen, 9700RB Groningen, The Netherlands
4. Department of Clinical Sciences, Lund University, Box 117, 221 00 Lund, Sweden
5. Department of Genetics, University Medical Center Groningen, University of Groningen, 9700RB Groningen, The Netherlands
6. Department of Medical Microbiology, University Medical Center Groningen, University of Groningen, 9700RB Groningen, The Netherlands
7. Laboratory of Metabolic Diseases, Department of Laboratory Medicine, University Medical Center Groningen, University of Groningen, 9700RB Groningen, The Netherlands