This application requests funds for a five-year continuation of the fragile X syndrome (FXS) Research Center, the focus of which is on family adaptation to FXS. Thirteen investigators from eleven disciplines (anthropology, developmental psychology, educational psychology, clinical psychology, forensic medicine, social work, law, medical genetics, special education, speech and hearing sciences, and psychiatry), based at the Mental Retardation and Developmental Disabilities Research Centers at the University of North Carolina at Chapel Hill, the University of Kansas, and University of Wisconsin - Madison, as well as in partnership with RTI International, are collaborating on an integrated and longitudinal set of studies: Project I: Maternal Responsivity and the Development of Children with FXS; Project II: Adaptations of Families of Adolescents and Adults with FXS; and Project III: Family Adaptation to Newborn Screening for FXS. The projects are supported by one existing MRDDRC core (Design and Statistical Computing) as well as two new cores (Administrative and Ethnographic and Qualitative Methods). Center investigators will collect data using a range of methods, including biologic samples, direct observation, speech samples, daily diaries, surveys, and semi-structured interviews. A range of mixed methods will be used to analyze these data. [unreadable] [unreadable] [unreadable]