1. Fondazione Policlinico Universitario A.Gemelli; IRCCS UOC Genetica
2. Università Cattolica Sacro Cuore; Istituto di Medicina Genomica; Roma Italy
3. Institute of Human Genetics; Friedrich-Alexander-Universität Erlangen-Nürnberg; Erlangen Germany
4. Jonx Department of (Youth) Mental Health and Autism; Lentis Psychiatric Institute; Groningen The Netherlands
5. Rob Giel Research Centre, Department of Psychiatry; University Medical Center Groningen; Groningen The Netherlands
6. Division of Medical Genetics and Metabolism; Massachusetts General Hospital for Children; Boston Massachusetts
7. Department of Molecular and Human Genetics; Baylor College of Medicine; Houston Texas
8. Department of Clinical Genetics; Leiden University Medical Center; Leiden The Netherlands
9. Department of Pediatrics; University of Texas Health Science Center at San Antonio; San Antonio Texas
10. Sorbonne Université, INSERM, UMR_S 933, Assistance Publique Hôpitaux de Paris, Département de Génétique Médicale; Hôpital Trousseau; Paris France
11. Rare and Genetic Diseases Unit; Bambino Gesù Children's Hospital; Rome Italy
12. Department of Pediatrics, Division of Pediatrics and Rare Disorders; Wroclaw Medical University; Wroclaw Poland
13. Department of Neurology; Massachusetts General Hospital and Harvard Medical School; Boston Massachusetts
14. Dutch Pitt-Hopkins Syndrome Foundation, Vlaggeschip; Oosterhout The Netherlands
15. Manchester Centre for Genomic Medicine, St Mary's Hospital, and Division of Evolution and Genomic Sciences School of Biological Sciences; University of Manchester; Manchester UK
16. Organisation for Individuals with Intellectual Disabilities, Trajectum; Zwolle The Netherlands
17. Department of Pedagogical Sciences; Radboud University Nijmegen; Nijmegen The Netherlands
18. Department of Pediatrics; Academic Medical Centre, Amsterdam UMC; Amsterdam The Netherlands
19. Department of Orthopedic Surgery; Sophia Children's Hospital, UMCR; Rotterdam The Netherlands
20. Department of Medical Genetics; University of Siena; Siena Italy
21. Karolinska Center for Rare Diseases; Karolinska University Hospital; Stockholm Sweden
22. Pitt Hopkins UK; Ilford UK
23. Center for Pediatric Genomic Medicine; Children's Mercy Hospital; Kansas City Missouri
24. Department of Genetics; Wroclaw Medical University; Wroclaw Poland
25. Behavioral Science Institute; Radboud University Nijmegen; Nijmegen The Netherlands