There is a very substantial literature over the past 50 years on the advantages of early detection and intervention on the cognitive, communicative, and social-emotional development of infants and toddlers at risk for developmental delay due to premature birth or social disadvantage. Most of these studies excluded children with severe delays or…

Smith-Magenis syndrome (SMS) is a neurobehavioral disorder associated with deletions and mutations of the "RAI1" gene on chromosome 17p11.2. Clinical features of the syndrome include intellectual disability, sleep disturbance, craniofacial differences, and a distinctive profile of stereotypic and self-injurious behaviors. Although the functional…