Angelman Syndrome (AS) is a neurodevelopmental disorder most commonly caused by the impaired expression of the maternal "UBE3A" gene on chromosome 15. Though anxiety has been identified as a frequently present characteristic in AS, there are limited studies examining anxiety in this population. Studies of anxiety in other…

Fragile X syndrome (FXS) is characterized by variable neurobehavioral abnormalities, which leads to difficulties in developing and evaluating treatments and in determining accurate prognosis. We employed a pediatric cross-sectional sample (1,072 males, 338 females) from FORWARD, a clinic-based natural history study, to identify behavioral subtypes…

Cornelia de Lange syndrome (CdLS) is associated with repetitive and self-injurious behaviors (RBs, SIB). Evaluating children with CdLS, this study: (1) characterizes the spectrum of RBs; (2) characterizes the impact and severity of RBs including SIB; (3) describes how age and adaptive functioning relate to RBs including SIB. Fifty children…

The present study examined, within a longitudinal family-informed design and across middle childhood, the predictive associations between preference for solitude and social wariness, two forms of social withdrawal, and peer difficulties. Specifically, preference for solitude, rather than social wariness, was expected to predict peer victimization…

Background: Evocative gene-environment correlation (rGE) describes a process through which children's heritable characteristics influence their rearing environments. The current study examined if heritable influences on parenting and children's behavioral outcomes operate through child negative emotionality. Method: Using data from the Early…

To identify similarities and differences in the behavioral profile of children with Williams syndrome from Spain (n = 53) and the United States (n = 145), we asked parents of 6- to 14-year-olds with Williams syndrome to complete the Child Behavior Checklist 6-18. The distribution of raw scores was significantly higher for the Spanish sample than…

Background: Williams syndrome (WS) phenotype is described as unique and intriguing. The aim of this study was to investigate the associations between speech-language abilities, general cognitive functioning and behavioural problems in individuals with WS, considering age effects and speech-language characteristics of WS sub-groups. Methods: The…

Introduction: Intellectual disability (ID) is characterized by limitations in cognitive and adaptive functioning. The aim of this study is to examine sociodemographic characteristics, perinatal and childhood risk factors, and prevalence of psychiatric and biomedical comorbidities in children with ID. Methods: 260 patients with ID were included in…

We examined the prediction that the interaction between Glucocorticoid Receptor Gene ("NR3C1") methylation, stress, and experienced maternal support predicts anxious and avoidant attachment development. This was tested in a general population sample of 487 children and adolescents (44% boys, M[subscript age] = 11.84, SD[subscript age] =…

Background: Children with 22q11.2 deletion syndrome (22q11.2DS) are reported to have socio-communicative impairments. Although many of these children are diagnosed with intellectual disability (ID) and/or autism spectrum disorder (ASD), these populations are seldom used as control groups. Hence, information regarding syndrome-specific…

Objective: A potentially useful tool for understanding the distribution and determinants of emotional dysregulation in children is a Child Behavior Checklist profile, comprising the Attention Problems, Anxious/Depressed, and Aggressive Behavior clinical subscales (CBCL-DP). The CBCL-DP indexes a heritable trait that increases susceptibility for…

Prior work has suggested that inter-parental conflict likely plays an etiological role in child behavior problems. However, family-level measurement of inter-parental conflict in most traditional child twin studies has made it difficult to tease apart the specific causal mechanisms underlying this association. The Children's Perception of…

Background: Supernumerary sex chromosome aneuploidies (X/Y-aneuploidies), the presence of extra X and/or Y chromosomes, are associated with heightened rates of language impairments and social difficulties. However, no single study has examined different language domains and social functioning in the same sample of children with tri-, tetra-, and…

Purpose: Individuals with Williams syndrome (WS) are recognized as having a strong desire for social relationships, yet many of them have difficulty forming and maintaining peer relationships. One cause may be impairments in pragmatic language. The current study compared the assessment of pragmatic language skills in individuals with WS using the…

Animal studies elucidating the neurobiology of fragile X syndrome (FXS) have led to multiple controlled trials in humans, with the Aberrant Behavior Checklist-Community (ABC-C) commonly adopted as a primary outcome measure. A multi-site collaboration examined the psychometric properties of the ABC-C in 630 individuals (ages 3-25) with FXS using…