Fragile X syndrome (FXS), as a monogenic cause of intellectual disability and autism spectrum disorder, has been one of the first neurodevelopmental disorders in which molecular and neuronal mechanisms of disease have been identified, leading to the concept of targeting the underlying disease to reverse symptoms. Translating findings in basic…

This meta-analytic review investigated interventions for transition-age youth diagnosed with autism, intellectual disability, or extensive support needs. Nineteen group design studies with 215 effect sizes met inclusion criteria. A robust variance estimation procedure that accounts for the clustering effect sizes within studies was used to…

By adulthood, most males with fragile X syndrome (FXS) require support to navigate day-to-day settings. The present study cross-sectionally: (1) characterized the profile of daily living skills in males with FXS and (2) examined associated participant characteristics (i.e., fragile X mental retardation protein [FMRP] expression, nonverbal…

This study implemented a modified teaching interaction procedure to teach social skills to 4 children diagnosed with autism spectrum disorder with an intellectual disability. A multiple baseline design across social skills and replicated across participants was utilized to evaluate the effects of the modified teaching interaction procedure. The…

The predictive ability of early consonant inventory and intentional communication on later expressive language was examined in 36 boys with fragile X syndrome (FXS). Autism symptom severity was included as a potential moderator. Participants were visited in their homes twice over a 6-year period, and mother-child interactions were videotaped,…

This project sought to identify Medicaid members with intellectual and developmental disabilities (IDD) in five states (Delaware, Iowa, Massachusetts, New York, and South Carolina) to develop a cohort for subsequent analyses of medical conditions and service utilization. We estimated that over 300,000 Medicaid members in these states had IDD. All…

Autism spectrum disorders (ASD) often co-occur with intellectual disability (ID) and are associated with poorer psychosocial and family-related outcomes than ID alone. The present study examined the prevalence, stability, and characteristics of ASD estimates in 2,208 children with ASD and ID identified through the South Carolina Autism and…