1. Department of Mental Retardation and Birth Defect Research National Institute of Neuroscience, National Center of Neurology and Psychiatry, Kodaira, Tokyo, Department of Pediatrics (Dr Ozawa), Hamamatsu Medical University, Hamamatsu, Shizuoka, Japan
2. Department of Mental Retardation and Birth Defect Research National Institute of Neuroscience, National Center of Neurology and Psychiatry, Kodaira, Tokyo