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…

Background: International literature has underlined the complex interplay between genetic and environmental variables in shaping children's emotional-behavioral functioning. Objective: This study aimed to explore the dynamic relationship between children's Dopamine Transporter (DAT1) genotype and methylation, and maternal and paternal affective…

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…

Symptoms of anxiety and depression are commonly comorbid and partially share a genetic etiology. Mean levels of anxiety and depression increase over the transition to adolescence, particularly in girls, suggesting a possible role of pubertal development in the activation of underlying genetic risks. The current study examined how genetic and…

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…

Understanding the role of negative emotionality in the development of executive functioning (EF) and language skills can help identify developmental windows that may provide promising opportunities for intervention. In addition, because EF and language skills are, in part, genetically influenced, intergenerational transmission patterns are…

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…

Sex differences in typical development can provide context for understanding ASD. Baron-Cohen ("Trends Cogn Sci" 6(6):248-254, 2002) suggested ASD could be considered an extreme expression of normal male, compared to female, phenotypic profiles. In this paper, sex-specific M-CHAT scores from N = 53,728 18-month-old toddlers, including n…

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…