1. Intellectual Disability Medicine Department of General Practice Erasmus MC University Medical Center Rotterdam The Netherlands
2. Department of Medical Biochemistry Amsterdam UMC, University of Amsterdam Amsterdam The Netherlands
3. Department of Clinical Genetics Erasmus MC University Medical Center Rotterdam The Netherlands
4. Department of Human Genetics Radboud University Medical Center Nijmegen The Netherlands
5. Department of Neuroscience Erasmus MC University Medical Center Rotterdam The Netherlands
6. ENCORE Expertise Center for Neurodevelopmental Disorders Erasmus MC University Medical Center Rotterdam The Netherlands
7. ASVZ, Medical Department Care and Service Centre for People with Intellectual Disabilities Sliedrecht The Netherlands