[1] Univ Washington, Dept Neurol, Seattle, WA 98105 USA
[2] Univ Washington, Ctr Human Dev & Disabil, Seattle, WA 98105 USA
[3] Univ Washington, Dept Pediat & Psychol, Seattle, WA 98105 USA
[4] Childrens Hosp & Reg Med Ctr, Seattle, WA 98105 USA
[5] Columbia Univ Coll Phys & Surg, Dept Neurol, New York, NY 10032 USA
[6] Columbia Univ Coll Phys & Surg, Dept Pharmacol & Psychiat, New York, NY 10032 USA
[7] Univ Calif Los Angeles, David Geffen Sch Med, Mental Retardat Res Ctr, Los Angeles, CA 90095 USA
[8] Columbia Univ Coll Phys & Surg, Ctr Neurobiol & Behav, New York, NY 10032 USA
[9] New York State Psychiat Inst & Hosp, Div Mol Therapeut, New York, NY 10032 USA