1. IRCCS Istituto delle Scienze Neurologiche di Bologna UOC Neuropsichiatria dell'età Pediatrica Bologna Italy
2. Dipartimento di Scienze Mediche e Chirurgiche (DIMEC) Università di Bologna Bologna Italy
3. Department of Genetic and Molecular Medicine and Pediatric Institute of Rare Diseases Hospital Sant Joan de Déu Barcelona Barcelona Spain
4. Department of Statistics Institut de Recerca Sant Joan de Déu Barcelona Spain
5. U‐703 Centre for Biomedical Research on Rare Diseases (CIBER‐ER) Instituto de Salud Carlos III Barcelona Spain
6. Movement Disorders Unit, Pediatric Neurology Department, Institut de Recerca Hospital Sant Joan de Déu Barcelona Barcelona Spain
7. European Reference Network for Rare Neurological Diseases (ERN‐RND) Barcelona Spain