Behavioral phenotypes in four mental retardation syndromes: fetal alcohol syndrome, Prader-Willi syndrome, fragile X syndrome, and tuberosis sclerosis.

Behavioral phenotypes were studied in four mental retardation syndromes using the Developmental Behavior Checklist (DBC). The four samples comprised fetal alcohol syndrome (FAS), Prader-Willi syndrome (PWS), fragile X syndrome (FRAX), and tuberosis sclerosis (TSC). Both on the item and the subscale level, there were clear behavioral differentiations across the four syndromes. FAS and FRAX proved to be most clearly differentiated from the other two samples, with PWS and TSC showing lower scores and less abnormal behavior profiles. Neither intelligence nor gender nor age contributed to variations in the number of behavior abnormalities. It was concluded that the DBC as a quantitative approach contributes significantly to the differentiation of behavioral phenotypes in various mental retardation syndromes.