1. Department of Child Psychiatry, Komagino Hospital, Tokyo; Japan
2. Center for Medical Genetics, Keio University School of Medicine, Tokyo; Japan
3. Department of Psychology, Graduate School of Human Relations, Keio University, Tokyo; Japan
4. Japan Portage Association, Tokyo; Japan
5. Department of Pediatrics, Keio University School of Medicine, Tokyo; Japan
6. Division of Clinical Genetics and Molecular Medicine, National Center for Child Health and Development, Tokyo; Japan
7. Division of Medical Genetics, Tokyo Metropolitan Children's Medical Center, Tokyo; Japan
8. Department of Pediatrics, Saiseikai Utsunomiya Hospital, Tochigi; Japan
9. Department of Psychology, Faculty of Letters, Keio University, Tokyo; Japan