Background: Recent advances in genetics are particularly relevant in the field of intellectual disability (ID), where sub-microscopic deletions or duplications of genetic material are increasingly implicated as known or suspected causal factors. Data-driven reports on the impact of providing an aetiological explanation in ID are needed to help…

Background: Executive function is very important in the children's overall development. The goal of this study was to assess the executive function in children with intellectual disability (ID) through the use of the Behavior Rating Inventory of Executive Function (BRIEF) teacher version. An additional goal was to examine the differences in…

Background: The most prevalent type of structural variation in the human genome is represented by copy number variations that can affect transcription levels, sequence, structure and function of genes. Method: In the present study, we used the multiplex ligation-dependent probe amplification (MLPA) technique and quantitative PCR for the detection…

Background: Studies conducted on mild intellectual disability (MID) in children are infrequent and the prevalence rates vary widely. This study aimed to estimate the prevalence of MID in children in a French county (Isère), to describe the clinical signs and associated comorbidities, and to specify the aetiologies of this disability. Methods: The…

Background: Behavioural interventions conceptualise self-injurious behaviour (SIB) as developing from early repetitive behaviours through acquisition of homeostatic functions in regulating stimulation and subsequent shaping into SIB through socially mediated or automatic operant reinforcement. Despite high success rates, such interventions rarely…

Background: Individuals with an intellectual disability (ID) continue to experience major obstacles towards social, educational and vocational integration. Negative attitudes toward persons with ID has remained relevant over time and has led to discrimination and stigma. Objective: The present study describes the development of a new questionnaire…

Background: Self-injurious behaviour (SIB) is prevalent in neurodevelopmental disorders, but its expression is highly variable within, and between diagnostic categories. This raises questions about the factors that contribute to aetiology and expression of SIB. Expression of SIB is generally described in relation to social reinforcement. However,…

Background: The prevalence, phenomenology aetiology and correlates of four forms of challenging behaviour in 32 children and adults with Smith-Magenis syndrome (SMS) were investigated. Methods: Cognitive assessments, questionnaires and semi-structured interviews were used to gather data on intellectual disability, verbal and physical aggression,…

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…

Objective: To examine the amount, timing and causes/correlates of infant mortality among newborns with Down syndrome. Methods: Using the Tennessee Department of Health Birth, Hospital Discharge and Death records, infants were identified who were born with Down syndrome from 1990 to 2006. Those who died during the first year were separated into…

Background: Self-injurious behaviour is commonly seen in Cornelia de Lange syndrome (CdLS). However, there has been limited research into the aetiology of self-injury in CdLS and whether environmental factors influence the behaviour. Methods: We observed the self-injury of 27 individuals with CdLS and 17 participants who did not have CdLS matched…

Background: Tuberous sclerosis (TSC) is a multi-system disorder caused by heterozygous mutations in the "TSC1" or "TSC2" gene and is often associated with neuropsychiatric symptoms, including intellectual disability, specific neuropsychological deficits, autism, other behavioural disorders and epilepsy. Method: Here, we review evidence from animal…

Background: Determining the aetiology of intellectual disability (ID) enables anticipation of specific comorbidity and can thus be beneficial. Blood sampling, however, is considered stressful for people with ID. Our aim was to evaluate the feasibility of a non-invasive screening technique of nine microdeletions/duplications among adults with ID of…

Background: Decline in orientation skill has been reported as an early indicator of Dementia of Alzheimer's Type (DAT). Orientation subtest of the Working Group's Test Battery was examined whether this test is useful to identify DAT patients among adults with moderate to severe ID. Methods: Sixteen DAT patients and 35 non-demented normal controls…

Background: Children with Autistic Disorder (AD) evidence more co-occurring maladaptive behaviours than their typically developing peers and peers with intellectual disability because of other aetiologies. The present study investigated the prevalence of Clinically Significant maladaptive behaviours during early childhood and identified at-risk…