We aimed to identify unique constellations of sensory phenotypes for genetic etiologies associated with diagnoses of autism spectrum disorder (ASD) and intellectual disability (ID). Caregivers reported on sensory behaviors via the Sensory Profile for 290 participants (younger than 25 years of age) with ASD and/or ID diagnoses, of which…

"DDX[subscript 3]X" variants are a common cause of intellectual disability (ID) in females, and have been associated with autism spectrum disorder and emotional-behavioural difficulties. In this study, we compared phenotypic data for 23 females with "DDX[subscript 3]X" variants, to 23 females with ID and other genetic…

High levels of parenting stress have been detected in mothers of children with Autism (ASD) and children with attention deficit hyperactivity disorder (ADHD) comparing with mothers of typically developing (TD) children. The current study explored the implications of social support (confidant and affective support) and child characteristics…

This study examined the similarities/differences between the social phenotypes of Williams syndrome (WS) and autism spectrum disorder (ASD). As cultural norms may affect symptom evaluation, this study administered the Social Responsiveness Scale-2 to Japanese individuals with WS (n = 78, 4.4-44.0 years) and ASD (n = 75, 4.7-55.4 years). The scores…

Over 50 years of research suggests that toilet training based on behavioral principles is effective for most individuals with intellectual and developmental disabilities (IDD). However, many adults with IDD are never effectively toilet trained. Lack of independent toileting is associated with detrimental physical, mental, and social experiences.…

The causal relationship between emotional outbursts and emotion dysregulation is proposed to be heterogeneous, but cultural influences have not been considered despite established cultural differences in emotional processes (e.g., increased motivation to suppress emotions in interdependent cultures). Responses to the Brazilian Portuguese version…

Grounded in the biopsychosocial models of expressive language in autism spectrum disorder (ASD) and fragile X syndrome (FXS), this dissertation included two novel studies that examined the role of biological (i.e., physiology), psychological (i.e., autistic traits, anxiety symptoms, and child affect) and social (i.e., communication partner…

The purpose of this study was to examine potential differences in social learning between individuals with fragile X syndrome (FXS), the leading known inherited cause of intellectual disability, and individuals with non-syndromic autism spectrum disorder (ASD). Thirty school-aged males with FXS and 26 age and symptom-matched males with…

Adults with autism spectrum disorder and intellectual disability often do not engage in healthy levels of physical activity despite its many benefits. We conducted a randomized control trial to evaluate the effectiveness and feasibility of the Step It Up program, which used supported self-management strategies, on daily step counts, health…