title: Neurodevelopment of children under 3 years of age with Smith-Magenis syndrome.
abstract: Systematic data regarding early neurodevelopmental functioning in Smith-Magenis syndrome are limited. Eleven children with Smith-Magenis syndrome less than 3 years of age (mean, 19 months; range, 5-34 months) received prospective multidisciplinary assessments using standardized measures. The total sample scored in the moderately to severely delayed range in cognitive functioning, expressive language, and motor skills and exhibited generalized hypotonia, oral-motor abnormalities, and middle ear dysfunction. Socialization skills were average, and significantly higher than daily living, communication, and motor abilities, which were below average. Mean behavior ratings were in the nonautistic range. According to exploratory analyses, the toddler subgroup scored significantly lower than the infant subgroup in cognition, expressive language, and adaptive behavior, suggesting that the toddlers were more delayed than the infants relative to their respective peers. Infants aged approximately 1 year or younger exhibited cognitive, language, and motor skills that ranged from average to delayed, but with age-appropriate social skills and minimal maladaptive behaviors. At ages 2 to 3 years, the toddlers consistently exhibited cognitive, expressive language, adaptive behavior, and motor delays and mildly to moderately autistic behaviors. Combining age groups in studies may mask developmental and behavioral differences. Increased knowledge of these early neurodevelopmental characteristics should facilitate diagnosis and appropriate intervention.
authors.affiliation: Medical Illness Counseling Center, Chevy Chase, MD, USA. woltersp@mail.nih.gov
authors.forename: Pamela L
authors.initials: PL
authors.lastname: Wolters
authors.forename: Andrea L
authors.initials: AL
authors.lastname: Gropman
authors.forename: Staci C
authors.initials: SC
authors.lastname: Martin
authors.forename: Michaele R
authors.initials: MR
authors.lastname: Smith
authors.forename: Hanna L
authors.initials: HL
authors.lastname: Hildenbrand
authors.forename: Carmen C
authors.initials: CC
authors.lastname: Brewer
authors.forename: Ann C M
authors.initials: AC
authors.lastname: Smith
mesh_terms: D002652:Child Behavior; D002657:Child Development; D002663:Child Language; D002675:Child, Preschool; D003071:Cognition; D005260:Female; D030342:Genetic Diseases, Inborn / Q000473:pathology; D006801:Humans; D007223:Infant; D008297:Male; D009043:Motor Activity; D009460:Neurologic Examination; D009483:Neuropsychological Tests; D013577:Syndrome