Affiliation: | 1. The Departments of Pathology and Pediatrics and the Joseph P. Kennedy Jr. Mental Retardation Research Center, The University of Chicago, Chicago, IL 60637, U.S.A.;2. Bullard and Denny-Brown Laboratories and the Behavioral Neurology Section of the Harvard Neurology Department and the Charles A. Dana Research Institute of the Beth Israel Hospital, Boston, MA 02215, U.S.A. |