Klinefelter syndrome (47,XXY) is associated with problems in social interaction and behavioral adaptation. Sixteen adolescents and adult men with 47,XXY enrolled in a pilot-study evaluating the effectiveness of Social Management Training (SMT), a novel neurocognitive-behavioral treatment program targeted at improving social, emotional, and…

Telehealth is increasingly being employed to extend the reach of behavior analytic interventions to families of children with developmental disorders who exhibit problem behaviors. In this preliminary study, we examined whether function-based behavior analytic interventions could be delivered via telehealth over 12 weeks to decrease problem…

Many males with FXS meet criteria for ASD. This study was designed to (1) describe ASD symptoms in adolescent and young adult males with FXS (n = 44) and (2) evaluate the contributions to ASD severity of cognitive, language, and psychiatric factors, as well as FMRP (the protein deficient in FXS). A few ASD symptoms on the ADOS-2 were universal in…

The present study examined the relationship between salivary cortisol and maternal responsiveness in mothers of boys with fragile X syndrome (FXS). Maternal responsivity is strongly associated with child outcomes, and children with FXS are at risk for compromised development due to intellectual disability and problem behavior. Increased…

Although males with fragile X syndrome (FXS) are frequently described as demonstrating autism symptomatology, there is much debate regarding whether the behavioral symptoms representing the core domains of autism are the result of the same or different underlying neurological/psychological mechanisms. The present study used a cross-sectional…

A cross-sectional analysis was used to examine age-related differences in ASD symptoms and corresponding differences in disruptive behavior and social skills in 281 adult men with fragile X syndrome. Four age groups were created: 18-21, 22-29, 30-39, and 40-49 years. The 18-21 year-old group was reported to have more impairments in verbal…

We examined whether "discrete trial training" (DTT) could be used to identify learning impairments in mathematical reasoning in boys with fragile X syndrome (FXS). Boys with FXS, aged 10-23 years, and age and IQ-matched controls, were trained to match fractions to pie-charts and pie-charts to decimals either on a computer or with a…

The aims of the present study are twofold: (1) to examine cortical morphology (CM) associated with alterations in cognition in fragile X syndrome (FXS); (2) to characterize the CM profile of FXS versus FXS with an autism diagnosis (FXS+Aut) as a preliminary attempt to further elucidate the behavioral distinctions between the two sub-groups. We…

Background: Fragile X syndrome (FXS) is an early diagnosed monogenic disorder, associated with a striking pattern of cognitive/attentional difficulties and a high risk of poor behavioural outcomes. FXS therefore represents an ideal model disorder to study prospectively the impact of early attention deficits on behaviour. Methods: Thirty-seven boys…

Verbal perseveration is a frequently reported language characteristic of males with Fragile X syndrome and may be a defining feature or hallmark of the syndrome. We compared the verbal perseveration of boys with Fragile X syndrome with (n = 29) and without (n = 30) autism spectrum disorder, boys with Down syndrome (n = 27), and typically…

Objective: How does the behavioral expression of autism in fragile X syndrome (FXS + Aut) compare with idiopathic autism (iAut)? Although social impairments and restricted, repetitive behaviors are common to these variants of autism, closer examination of these symptom domains may reveal meaningful similarities and differences. To this end, the…

Basic attentional processes and their impact on developmental trajectories in fragile X syndrome were assessed in a 3-year prospective study. Although fragile X syndrome is a monogenic X-linked disorder, there is striking variability in outcomes even in young boys with the condition. Attention is a key factor constraining interactions with the…

The present study contrasted physiological arousal in infants and toddlers with fragile X syndrome to typically developing control participants and examined physiological predictors early in development to autism severity later in development in fragile X syndrome. Thirty-one males with fragile X syndrome (ages 8-40 months) and 25 age-matched…

This study investigated the relationship between repetitive behaviors and sensory behavior to the parenting stress of mothers of boys with fragile X syndrome and mothers of boys with autism. Participants consisted of two groups: 51 mothers with boys diagnosed with fragile X syndrome (M = 71.3, SD = 56.5) and 30 mothers with boys diagnosed with…

Background: We report the case of a 16-year-old male with Mucopolysaccharidosis III type A (Sanfilippo syndrome) who was commenced on risperidone for behaviour management. He rapidly developed extrapyramidal symptoms that have not resolved. Method: The medication histories of 20 patients with Mucopolysaccharidosis III seen at a Lysosomal Storage…