Department of Clinical Medicine (K1), University of Bergen, Bergen, Norway. Neuro-SysMed, Center of Excellence for Clinical Research in Neurological Diseases, Haukeland University Hospital, Bergen, Norway. Department of Neurology, Beijing Tongren Hospital, Capital Medical University, Beijing, China. State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China School of Stomatology, Sichuan University, Chengdu, China. Department of Head and Neck Cancer Surgery, West China Hospital of Stomatology, Sichuan University, Chengdu, China. Centre for International Health, University of Bergen, Bergen, Norway. Department of Clinical Molecular Biology, Akershus University Hospital, University of Oslo, Oslo, Norway. The Norwegian Centre on Healthy Ageing, Oslo, Norway. Norwegian Center for Stem Cell Research, University of Oslo, 0317, Oslo, Norway. Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, 0317, Oslo, Norway. Institute of Immunology, Oslo University Hospital, Oslo, Norway. Department of Pediatric Research, Oslo University Hospital, Oslo, Norway. Department of Paediatrics and Inherited Metabolic Disorders, First Faculty of Medicine, Charles University, Prague, Czech Republic. KG Jebsen Center for Parkinson's disease, University of Bergen, Bergen, Norway. Department of Neurology, Haukeland University Hospital, Bergen, Norway. National Advisory Unit for Congenital Metabolic Diseases, Oslo University Hospital, Oslo, Norway.