3q29 deletion syndrome (3q29del) is associated with a significantly increased risk for neurodevelopmental and neuropsychiatric disorders. However, the full spectrum of behavioral phenotypes associated with 3q29del is still evolving. Individuals with 3q29del (n = 96, 60.42% male) or their guardian completed the Achenbach Child or Adult Behavior…

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…

CHARGE syndrome is a rare genetic disorder which can impact every sensory system and is often associated with significant medical, communicative, developmental, and behavioral difficulties. Due to the rarity and complexity of CHARGE syndrome, educators often lack the expertise required to effectively understand and accommodate the needs of these…

Background: Fragile X syndrome (FXS) is the most common cause of inherited intellectual disability among men. This syndrome is frequently underdiagnosed in adults. The aim of this study was to develop and validate a French translation of the screening checklist "Fragiele-X screeningslijst." Method: The validation sample for the…

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…

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…

Extensive empirical evidence indicates that the lesser variant of Autism Spectrum Disorders (ASD) involves a communication impairment that is similar to, but milder than, the deficit in clinical ASD. This research explored the relationship between the broader autism phenotype (BAP) among parents, an index of genetic liability for ASD, and proband…

Children with 22q11.2 deletion syndrome exhibit high rates of social-behavioral problems, particularly in the internalizing domain, indicating an area in need of intervention. The current investigation was designed to obtain information regarding parent and teacher ratings of the social-emotional behavior of children with 22q11DS. Using the Child…

Background: Obsessive-compulsive (O-C) traits, and excessive food intake are well known behavioural manifestations among individuals with Prader-Willi Syndrome (PWS). Other unwanted behaviours are also frequently observed, but they need a more specific investigation, especially in the adult population. Methods: The behaviour of 31 PWS adults was…

The study explored the nature of the interactive play behaviours of children with albinism and children without albinism and compared the interactive behaviours of both children with albinism and children without albinism. Naturalistic observations were conducted during periods of free play, using the interactive play behaviour checklist aided by…

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…