1Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, NAB 2015, Houston, TX 77030, USA
2Department of Genetics, Children’s Hospital Eastern Ontario, Canada
3Department of Pediatrics, University of Colorado Denver, Aurora, CO, USA
4Children's National Medical Center, Washington, DC, USA
5Department of Human Genetics, Emory University, Decatur, GA, USA
6Division of Medical Genetics, Department of Pediatrics, University of Iowa, Iowa City, IA, USA
7Division of Developmental Medicine and Cognition, Department of Pediatrics, Vanderbilt University School of Pediatrics, TN, USA
8Departments of Psychiatry, Pediatrics and Human Genetics UCLA School of Medicine, Los Angeles, CA, USA
9Howard Hughes Medical Institute, USA