1International Parkinson's Centre of Excellence, King's College and King's College Hospital London UK
2Queen Elizabeth Hospital, Woolwich, Lewisham & Greenwich NHS Trust London UK
3Department of Clinical Neurosciences, Psychiatry, Pediatrics and Community Health Sciences, University of Calgary, Calgary, Canada
4Birmingham and Solihull Mental Health National Health Service Foundation Trust, Department of Neuropsychiatry, The Barberry National Centre for Mental Health Birmingham UK
5Department of Neuroscience, University of Rome “La Sapienza”, Rome, Italy
6Centre de Reference National Maladie Rare: “Syndrome Gilles de la Tourette,” Departement de Neurologie, Pole des Maladies du Systeme Nerveux Paris France
7Child Study Center, Yale University, New Haven, Connecticut, USA
8Department of Biostatistics School of Public Health, The University of Texas Health Science Center at Houston Houston Texas USA
9Department of Paediatric and Adult Movement Disorders and Neuropsychiatry Institut of Neurogenetics, University of Lübeck Lübeck Germany
10Department of Neurological Sciences Rush University Medical Center Chicago Ilinois USA
11National Center of Epidemiology and Centro Investigación Biomédica en Red Enfermedades Neurodegenerativas, Carlos III Institute of Health Madrid Spain