[1] Vanderbilt Univ, Med Ctr, Dept Psychiat & Behav Sci, Nashville, TN USA
[2] Vanderbilt Univ, Med Ctr, Dept Pediat, Nashville, TN 37232 USA
[3] Vanderbilt Kennedy Ctr, Treatment & Res Inst Autism Spectrum Disorders, Nashville, TN USA
[4] Roche, Basel, Switzerland
[5] Massachusetts Gen Hosp, Biostat Ctr, Boston, MA 02114 USA
[6] Harvard Med Sch, Boston, MA 02115 USA
[7] Vanderbilt Univ, Dept Special Educ, 221 Kirkland Hall, Nashville, TN 37235 USA