This study describes the profile of repetitive behaviour in individuals with Williams syndrome, utilising cross-syndrome comparisons with people with Prader-Willi and Down syndromes. The Repetitive Behaviour Questionnaire was administered to caregivers of adults with Williams (n = 96), Prader-Willi (n = 103) and Down (n = 78) syndromes. There were…

No studies to date have prospectively examined early autism spectrum disorder (ASD) markers in infants with fragile X syndrome (FXS), who are at elevated risk for ASD. This paper describes the developmental profiles of eight infants with FXS from 9 to 24 months of age. Four meet diagnostic criteria for ASD at 24 months of age, and four do not.…

The present study examined trajectories of adaptive behavior, behavior problems, psychological symptoms, and autism symptoms in adolescents and adults with fragile X syndrome (n = 147) over a three-year period. Adaptive behavior significantly increased over time, particularly for adolescents, and the severity of behavior problems decreased over…

Prader-Willi syndrome (PWS), a neurodevelopmental disorder primarily characterized by hyperphagia and food preoccupations, is caused by the absence of expression of the paternally active genes in the proximal arm of chromosome 15. Although maladaptive behavior and the cognitive profile in PWS have been well characterized, social functioning has…

Recently the "DRD3" gene has been associated with ASD in two independent samples. Follow up analysis of the risk allele of the SNP rs167771 in 91 subjects revealed a significant association with a specific type of repetitive behavior: the factor "insistence on sameness" (IS) derived from the Autism Diagnostic Interview. This risk allele was…

Efforts to understand the causes of autism spectrum disorders (ASDs) have been hampered by genetic complexity and heterogeneity among individuals. One strategy for reducing complexity is to target endophenotypes, simpler biologically based measures that may involve fewer genes and constitute a more homogenous sample. A genome-wide association…

While there is a strong sex bias in the presentation of autism, it is unknown whether this bias is also present in subclinical manifestations of autism among relatives, or the broad autism phenotype. This study examined this question and investigated patterns of co-occurrence of broad autism phenotype traits within families of individuals with…

Each year, the Interagency Autism Coordinating Committee (IACC) releases its annual list of scientific advances that represent significant progress in the field. The 20 studies selected have given new insight into the underlying biology of autism spectrum disorder (ASD) and potential risk factors, examined the state of the science in early…

Each year, the Interagency Autism Coordinating Committee (IACC) releases its annual list of scientific advances that represent significant progress in the field. The 20 studies selected have given new insight into the underlying biology of autism spectrum disorder (ASD) and potential risk factors, tested approaches for improving early screening…

Duplications of 7q11.23, deleted in Williams-Beuren Syndrome, have been implicated in autism spectrum disorders (ASDs). A 1.5 Mb duplication was identified in one girl with severe expressive language deficits and anxiety among 1,142 ASD individuals screened for this duplication. Family-based association studies of Tag-SNPs in three genes ("STX1A,"…

Background: Autism spectrum disorder (ASD) has been identified as a risk marker for self-injurious behaviour. In this study we aimed to describe the prevalence, topography and correlates of self-injury in individuals with ASD in contrast to individuals with Fragile X and Down syndromes and examine person characteristics associated with self-injury…

Mothers of adolescents and adults with fragile X syndrome (FXS) are faced with high levels of parenting stress. The extent to which mothers are negatively impacted by this stress, however, may be influenced by their own genetic status. The present study uses a diathesis-stress model to examine the ways in which a genetic vulnerability in mothers…

Prader-Willi syndrome (PWS) is characterized by temper tantrums, impulsivity, mood fluctuations, difficulty with change in routine, skinpicking, stubbornness and aggression. Many studies on behavior in PWS are limited by sample size, age range, a lack of genetically confirmed diagnosis of PWS and inconsistent assessment of behavior. The aim of…

Background: A number of genetic conditions with associated intellectual disability and/or special educational needs have increasingly well-defined behavioural phenotypes. Thus, the concept of "behavioural phenotype" and aetiology of intellectual disability may be important with regard to school-based interventions. Method: The evidence for…

Specific genetic syndromes affect individuals' sexual development, experiences, and fertility. Individuals with specific syndromes can also display inappropriate sexual behavior resulting from vulnerabilities presented by their genetic makeup. Using clinical case studies, we discuss the specific impact that Down, Prader-Willi, and Williams…