1. Department of Neurology and Developmental Medicine, Kennedy Krieger Institute , Baltimore, MD 21205, USA
2. Department of Pediatrics, Johns Hopkins University School of Medicine , Baltimore, MD 21287, USA
3. Department of Psychiatry, Johns Hopkins University School of Medicine , Baltimore, MD 21205, USA
4. Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health , Baltimore, MD 21205, USA
5. Department of Population, Family and Reproductive Health, Johns Hopkins Bloomberg School of Public Health , Baltimore, MD 21205, USA
6. Department of Mental Health, Johns Hopkins Bloomberg School of Public Health , Baltimore, MD, USA
7. Wendy Klag Center for Autism and Developmental Disabilities, Johns Hopkins Bloomberg School of Public Health , Baltimore, MD 21205, USA
8. Rollins School of Public Health, Emory University , Atlanta, GA 30322, USA