1. Department of Psychiatry; University of California; San Francisco U.S.A
2. Center for Autism and the Developing Brain; Weill Cornell Medical College; White Plains U.S.A
3. Department of Psychiatry; Vanderbilt University School of Medicine; Nashville U.S.A
4. Lovisenberg Hospital and the Norwegian Institute of Public Health; Oslo Norway
5. Department of Biostatistics; King's College London; London U.K.
6. Division of Developmental and Behavioral Pediatrics; Cincinnati Children's Hospital Medical Center Cincinnati; U.S.A
7. Division of Research; Kaiser Permanente Northern California; Oakland U.S.A