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Actin filaments form the backbone of dendritic spines, the postsynaptic compartment of most excitatory synapses in the brain. Spine density changes affect brain function, and postsynaptic actin defects have been implicated in various neuropathies. It is mandatory to identify the actin regulators that control spine density. Based on previous studies, we hypothesized a role for the actin regulator profilin1 in spine formation. We report reduced hippocampal spine density in juvenile profilin1 mutant mice together with impairments in memory formation and reduced ultrasonic communication during active social behavior. Our results, therefore, underline a previously suggested function of profilin1 in controlling spine formation and behavior in juvenile mice. ispartof: FRONTIERS IN MOLECULAR NEUROSCIENCE vol:15 ispartof: location:Switzerland status: published

Background Non-pharmacological interventions are recommended for the treatment of challenging behaviours in individuals with intellectual disabilities by clinical guidelines. However, evidence for their effectiveness is ambiguous. The aim of the current meta-analysis is to update the existing evidence, to investigate long-term outcome, and to examine whether intervention type, delivery mode, and study design were associated with differences in effectiveness. Method An electronic search was conducted using the databases Medline, Eric, PsychINFO and Cinahl. Studies with experimental or quasi-experimental designs were included. We performed an overall random-effect meta-analysis and subgroup analyses. Results We found a significant moderate overall effect of non-pharmacological interventions on challenging behaviours (d = 0.573, 95% CI [0.352-0.795]), and this effect appears to be longlasting. Interventions combining mindfulness and behavioural techniques showed to be more effective than other interventions. However, this result should be interpreted with care due to possible overestimation of the subgroup analysis. No differences in effectiveness were found across assessment times, delivery modes or study designs. Conclusions Non-pharmacological interventions appear to be moderately effective on the short and long term in reducing challenging behaviours in adults with intellectual disabilities.

Background Non‐pharmacological interventions are recommended for the treatment of challenging behaviours in individuals with intellectual disabilities by clinical guidelines. However, evidence for their effectiveness is ambiguous. The aim of the current meta‐analysis is to update the existing evidence, to investigate long‐term outcome, and to examine whether intervention type, delivery mode, and study design were associated with differences in effectiveness. Method An electronic search was conducted using the databases Medline, Eric, PsychINFO and Cinahl. Studies with experimental or quasi‐experimental designs were included. We performed an overall random‐effect meta‐analysis and subgroup analyses. Results We found a significant moderate overall effect of non‐pharmacological interventions on challenging behaviours (d = 0.573, 95% CI [0.352–0.795]), and this effect appears to be longlasting. Interventions combining mindfulness and behavioural techniques showed to be more effective than other interventions. However, this result should be interpreted with care due to possible overestimation of the subgroup analysis. No differences in effectiveness were found across assessment times, delivery modes or study designs. Conclusions Non‐pharmacological interventions appear to be moderately effective on the short and long term in reducing challenging behaviours in adults with intellectual disabilities.

Contains fulltext : 239530.pdf (Publisher’s version ) (Open Access) Background: The Family Network Method – Intellectual Disability (FNM-ID) was used to compare perspectives of people with mild intellectual disability and their support workers on family networks of people with intellectual disability. Method: 138 participants with mild intellectual disability and support workers were interviewed, using the FNM-ID. Paired t-tests were used to examine differences in perspectives. Multiple regression analyses were used to examine divergence in perspectives. Results: People with mild intellectual disability perceived their family networks to be larger and to provide more support than support workers did. Living in a residential setting and having higher levels of externalising behaviour were associated with differences in perspectives, whereas a higher level of internalising behaviour was associated with more similar views. Conclusions: Individuals with intellectual disability and support workers are unlikely to provide the same information about family networks of people with mild intellectual disability. Behavioural and emotional problems were associated with divergence in perspectives. 12 p.

Introduction: This article reports the physical abilities and physical wellness of three groups of children with different neurodevelopmental disabilities: Autism, Down Syndrome and Intellectual Disability. Methods: The causal-comparative research method was implemented in this study. The participants comprised 32 students with moderate intellectual disabilities, 18 with autism spectrum disorder, and 22 with down syndrome. The body mass index (BMI), flexibility, standing long jump, sitting height, stroke length, and medicine ball throwing levels were measured for physical fitness, and the groups were compared afterward. The Kruskal Wallis-H Test and Mann-Whitney U Test were applied to determine the differences between the groups' physical fitness averages for the statistical analysis. Results: Statistically significant differences were obtained in BMI, standing long jump, stroke length, and medicine ball throwing variables (p < 0.05). However, no statistically significant difference was discovered for the flexibility and sitting height variables (p > 0.05). The BMI, sitting height, and stroke length levels for the group with autism spectrum disorder were higher than the other groups, as the flexibility levels of the group with down syndrome were higher than the other groups. Students with intellectual disabilities were demonstrated to have better values than other groups regarding standing long jump and medicine ball throwing performances. Conclusions: Objective information about the physical fitness of individuals with children with different neurodevelopmental disabilities was obtained. In addition, the data obtained with these children will contribute to future plans for movement training as well as the content and frequency of the interventions, and will guide the development of new strategies to develop physical abilities and physical wellness.

Background Tuberous sclerosis complex (TSC)–associated neuropsychiatric disorders (TAND) is an umbrella term for the behavioural, psychiatric, intellectual, academic, neuropsychological and psychosocial manifestations of TSC. Although TAND affects 90% of individuals with TSC during their lifetime, these manifestations are relatively under-assessed, under-treated and under-researched. We performed a comprehensive scoping review of all TAND research to date (a) to describe the existing TAND research landscape and (b) to identify knowledge gaps to guide future TAND research. Methods The study was conducted in accordance with stages outlined within the Arksey and O’Malley scoping review framework. Ten research questions relating to study characteristics, research design and research content of TAND levels and clusters were examined. Results Of the 2841 returned searches, 230 articles published between 1987 and 2020 were included (animal studies = 30, case studies = 47, cohort studies = 153), with more than half published since the term TAND was coined in 2012 (118/230; 51%). Cohort studies largely involved children and/or adolescents (63%) as opposed to older adults (16%). Studies were represented across 341 individual research sites from 45 countries, the majority from the USA (89/341; 26%) and the UK (50/341; 15%). Only 48 research sites (14%) were within low–middle income countries (LMICs). Animal studies and case studies were of relatively high/high quality, but cohort studies showed significant variability. Of the 153 cohort studies, only 16 (10%) included interventions. None of these were non-pharmacological, and only 13 employed remote methodologies (e.g. telephone interviews, online surveys). Of all TAND clusters, the autism spectrum disorder–like cluster was the most widely researched (138/230; 60%) and the scholastic cluster the least (53/200; 27%). Conclusions Despite the recent increase in TAND research, studies that represent participants across the lifespan, LMIC research sites and non-pharmacological interventions were identified as future priorities. The quality of cohort studies requires improvement, to which the use of standardised direct behavioural assessments may contribute. In human studies, the academic level in particular warrants further investigation. Remote technologies could help to address many of the TAND knowledge gaps identified.

Perturbation and mechanistic studies have shown that the DNA-binding transcription factor Zeb2 controls cell fate decision, differentiation and/or maturation in multiple cell lineages in embryos and after birth. In cultured embryonic stem cells (ESCs) Zeb2s strong upregulation is necessary for their exit from primed pluripotency and entering neural and general differentiation. We engineered mouse ESCs to produce epitope-tagged Zeb2 from one of its two endogenous alleles. Using crosslinking ChIP-sequencing, we mapped for the first time 2,432 DNA-binding sites of Zeb2 in ESC-derived neuroprogenitor cells (NPCs). A new, major site maps promoter-proximal to Zeb2 itself, and its homozygous removal demonstrates that Zeb2 autoregulation is necessary to elicit proper Zeb2 effects in ESC[->]NPC differentiation. We then cross-referenced all Zeb2 DNA-binding sites with transcriptome data from Zeb2 perturbations in ESCs, ventral forebrain in mouse embryos, and adult neurogenesis. While the characteristics of these neurodevelopmental systems differ, we find interesting overlaps. Collectively, these new results obtained in ESC-derived NPCs significantly add to Zeb2s role as neurodevelopmental regulator as well as the causal gene in Mowat-Wilson Syndrome. Also, Zeb2 was found to map to loci mutated in other human congenital syndromes, making variant or disturbed levels of ZEB2 a candidate modifier principle in these. Significance statementZeb2 is needed for exit from primed pluripotency and differentiation of ESCs and being studied in various cell lineages and tissues/organs in knockouts and adult mice. Phenotyping has mainly documented transcriptomes of Zeb2-mutant affected cell types, but ChIP-seq data are still not available to document Zeb2s direct target loci as repressor or activator of transcription. This study maps for the first time the Zeb2 genome-wide binding sites in ESC-derived neuroprogenitors, and discovered Zeb2 autoregulation. Cross-referencing these ChIP-seq data with transcriptome profiles of Zeb2 perturbation further explains Mowat-Wilson Syndrome defects and proposes ZEB2 as candidate modifier gene in other syndromes.

International audience; OBJECTIVE: Terminal 6q deletion is a rare genetic condition associated with a neurodevelopmental disorder characterized by intellectual disability and structural brain anomalies. Interestingly, a similar phenotype is observed in patients harboring pathogenic variants in the DLL1 gene. Our study aimed to further characterize the prenatal phenotype of this syndrome as well as to attempt to establish phenotype-genotype correlations. METHOD: We collected ultrasound findings from 22 fetuses diagnosed with a pure 6qter deletion. We reviewed the literature and compared our 22 cases with 14 fetuses previously reported as well as with patients with heterozygous DLL1 pathogenic variants. RESULTS: Brain structural alterations were observed in all fetuses. The most common findings (>70%) were cerebellar hypoplasia, ventriculomegaly, and corpus callosum abnormalities. Gyration abnormalities were observed in 46% of cases. Occasional findings included cerebral heterotopia, aqueductal stenosis, vertebral malformations, dysmorphic features, and kidney abnormalities. CONCLUSION: This is the first series of fetuses diagnosed with pure terminal 6q deletion. Based on our findings, we emphasize the prenatal sonographic anomalies, which may suggest the syndrome. Furthermore, this study highlights the importance of chromosomal microarray analysis to search for submicroscopic deletions of the 6q27 region involving the DLL1 gene in fetuses with these malformations.

Dendritic spines are small, bulbous protrusions along neuronal dendrites where most of the excitatory synapses are located. Dendritic spine density in normal human brain increases rapidly before and after birth achieving the highest density around 2-8 years. Density decreases during adolescence, reaching a stable level in adulthood. The changes in dendritic spines are considered structural correlates for synaptic plasticity as well as the basis of experience-dependent remodeling of neuronal circuits. Alterations in spine density correspond to aberrant brain function observed in various neurodevelopmental and neuropsychiatric disorders. Dendritic spine initiation affects spine density. In this review, we discuss the importance of spine initiation in brain development, learning, and potential complications resulting from altered spine initiation in neurological diseases. Current literature shows that two Bin Amphiphysin Rvs (BAR) domain-containing proteins, MIM/Mtss1 and SrGAP3, are involved in spine initiation. We review existing literature and open databases to discuss whether other BAR-domain proteins could also take part in spine initiation. Finally, we discuss the potential molecular mechanisms on how BAR-domain proteins could regulate spine initiation.

Pitt-Hopkins syndrome (PTHS) is a neurodevelopmental disorder characterized by intellectual disability, specific facial features, and marked autonomic nervous system dysfunction, especially with disturbances of regulating respiration and intestinal mobility. It is caused by variants in the transcription factor TCF4. Heterogeneity in the clinical and molecular diagnostic criteria and care practices has prompted a group of international experts to establish guidelines for diagnostics and care. For issues, for which there was limited information available in international literature, we collaborated with national support groups and the participants of a syndrome specific international conference to obtain further information. Here, we discuss the resultant consensus, including the clinical definition of PTHS and a molecular diagnostic pathway. Recommendations for managing particular health problems such as dysregulated respiration are provided. We emphasize the need for integration of care for physical and behavioral issues. The recommendations as presented here will need to be evaluated for improvements to allow for continued optimization of diagnostics and care.

Objective To investigate the occurrence of psychosis and serious behavioral problems in females with protocadherin 19 gene (PCDH19) pathogenic variants. Methods We evaluated whether psychosis and serious behavioral problems had occurred in 60 females (age 2-75 years) with PCDH19 pathogenic variants belonging to 35 families. Patients were identified from epilepsy genetics databases in Australia, New Zealand, the United States, and Canada. Neurologic and psychiatric disorders were diagnosed using standard methods. Results Eight of 60 females (13%) from 7 families developed a psychotic disorder: schizophrenia (6), schizoaffective disorder (1), or an unspecified psychotic disorder (1). Median age at onset of psychotic symptoms was 21 years (range 11-28 years). In our cohort of 39 females aged 11 years or older, 8 (21%) developed a psychotic disorder. Seven had ongoing seizures at onset of psychosis, with 2 continuing to have seizures when psychosis recurred. Psychotic disorders occurred in the setting of mild (4), moderate (2), or severe (1) intellectual disability, or normal intellect (1). Preexisting behavioral problems occurred in 4 patients, and autism spectrum disorder in 3. Two additional females (3%) had psychotic features with other conditions: an adolescent had recurrent episodes of postictal psychosis, and a 75-year-old woman had major depression with psychotic features. A further 3 adolescents (5%) with moderate to severe intellectual disability had onset of severe behavioral disturbance, or significant worsening. Significance We identify that psychotic disorders, including schizophrenia, are a later-onset manifestation of PCDH19 Girls Clustering Epilepsy. Affected girls and women should be carefully monitored for later-onset psychiatric disorders.

Background Many people with intellectual disabilities use risperidone long term for the management of challenging behaviours, despite its limited proof of effectiveness and its clear association with adverse events. Therefore, this study aimed to investigate the effectiveness of ongoing treatment with risperidone in reducing challenging behaviours versus controlled discontinuation on behaviour and health parameters. Method This was a placebo-controlled, double-blind, randomised discontinuation trial of risperidone. In the discontinuation group, risperidone was gradually replaced by a placebo over 14 weeks, while the control group maintained their existing dosage. Eight weeks after discontinuation, behaviour (as measured by the 'Aberrant Behavior Checklist') and health parameters (dyskinesia, akathisia, parkinsonism, weight, waist circumference, sedation and laboratory outcomes) were compared in both groups. Results A total of 25 participants were included in the trial, of which 11 were randomised into the discontinuation group and 14 were randomised into the continued treatment group. In the discontinuation group, 82% completely withdrew from risperidone. There was no significant change in irritability, compared with the continuation group, although there was a Group*Time effects on stereotypical behaviour in favour of the continuation group. Significant Group*Time effects were also found for weight, waist, body mass index, prolactin levels and testosterone levels, with beneficial effects for the discontinuation group. Conclusion Discontinuation of long-term risperidone for reducing challenging behaviours is possible, without an increase in irritability. Discontinuation of risperidone may have beneficial effects on weight, waist circumference, prolactin levels and testosterone levels. The study suffered from difficulties in achieving the required sample size, which affected study power and generalizability.

Contains fulltext : 198770.pdf (Publisher’s version ) (Open Access) Background: Informal supportive networks of individuals with intellectual disability have become increasingly important. The aim of this paper is to describe how the Family Network Method - Intellectual Disability (FNM-ID) offers a way to gather the perspective of people with mild intellectual disability on their family support. Method: The FNM is designed to explore how individuals define their family contexts, and more specifically how they perceive existing supportive relationships in these contexts. Results: By carefully piloting ways of questioning people with mild intellectual disability, systematic adaptations were made to the original FNM. Data obtained by the FNM-ID can be analysed using social network analysis. Thereby, the FNM-ID provides rich, theoretically significant information on emotional support in the family networks of individuals with mild intellectual disability. Conclusions: The FNM-ID is a useful and successfully adapted tool for other researchers and professionals to systematically explore the family support experiences of individuals with mild intellectual disability. 12 p.

The inability to maintain a strictly regulated endo(lyso)somal acidic pH through the proton-pumping action of the vacuolar-ATPases (v-ATPases) has been associated with various human diseases including heritable connective tissue disorders. Autosomal recessive (AR) cutis laxa (CL) type 2C syndrome is associated with genetic defects in the ATP6V1E1 gene and is characterized by skin wrinkles or loose redundant skin folds with pleiotropic systemic manifestations. The underlying pathological mechanisms leading to the clinical presentations remain largely unknown. Here, we show that loss of atp6v1e1b in zebrafish leads to early mortality, associated with craniofacial dysmorphisms, vascular anomalies, cardiac dysfunction, N-glycosylation defects, hypotonia, and epidermal structural defects. These features are reminiscent of the phenotypic manifestations in ARCL type 2C patients. Our data demonstrates that loss of atp6v1e1b alters endo(lyso)somal protein levels, and interferes with non-canonical v-ATPase pathways in vivo. In order to gain further insights into the processes affected by loss of atp6v1e1b, we performed an untargeted analysis of the transcriptome, metabolome, and lipidome in early atp6v1e1b-deficient larvae. We report multiple affected pathways including but not limited to oxidative phosphorylation, sphingolipid, fatty acid, and energy metabolism together with profound defects on mitochondrial respiration. Taken together, our results identify complex pathobiological effects due to loss of atp6v1e1b in vivo., Author summary Cutis laxa syndromes are pleiotropic disorders of the connective tissue, characterized by skin redundancy and variable systemic manifestations. Cutis laxa syndromes are caused by pathogenic variants in genes encoding structural and regulatory components of the extracellular matrix or in genes encoding components of cellular trafficking, metabolism, and mitochondrial function. Pathogenic variants in genes coding for vacuolar-ATPases, a multisubunit complex responsible for the acidification of multiple intracellular vesicles, cause type 2 cutis laxa syndromes, a group of cutis laxa subtypes further characterized by neurological, skeletal, and rarely cardiopulmonary manifestations. To investigate the pathomechanisms of vacuolar-ATPase dysfunction, we generated zebrafish models that lack a crucial subunit of the vacuolar-ATPases. The mutant zebrafish models show morphological and functional features reminiscent of the phenotypic manifestations in cutis laxa patients carrying pathogenic variants in ATP6V1E1. In-depth analysis at multiple -omic levels identified biological signatures that indicate impairment of signaling pathways, lipid metabolism, and mitochondrial respiration. We anticipate that these data will contribute to a better understanding of the pathogenesis of cutis laxa syndromes and other disorders involving defective v-ATPase function, which may eventually improve patient treatment and management.

Background Microduplications are a rare cause of disease in X‐linked neurodevelopmental disorders but likely have been under reported due challenges in detection and interpretation. Methods We performed exome sequencing and subsequent microarray analysis in two families with a neurodevelopmental disorder. Results Here, we report on two families each with unique inherited microduplications at Xp21.2 and Xq13.1, respectively. In the first family, a 562.8‐kb duplication at Xq13.1 covering DLG3, TEX11, SLC7A3, GDPD2, and part KIF4A was identified in a boy whose phenotype was characterized by delayed speech development, mild intellectual disability (ID), mild dysmorphic facial features, a heart defect, and neuropsychiatric symptoms. By interrogating all reported Xq13.1 duplications in individuals affected with a neurodevelopmental disorder, we provide evidence that this genomic region and particularly DLG3 might be sensitive to an increased dosage. In the second family with four affected males, we found a noncontinuous 223‐ and 204‐kb duplication at Xp21.2, of which the first duplication covers exon 6 of IL1RAPL1. The phenotype of the male patients was characterized by delayed speech development, mild to moderate ID, strabismus, and neurobehavioral symptoms. The carrier daughter and her mother had learning difficulties. IL1RAPL1 shows nonrecurrent causal structural variation and is located at a common fragile site (FRAXC), prone to re‐arrangement. Conclusion In conclusion, we show that comprehensive clinical and genetic examination of microduplications on the X‐chromosome can be helpful in undiagnosed cases of neurodevelopmental disease., Here, we report on two families each with unique inherited microduplications at Xp21.2 and Xq13.1, respectively. In the first family, a 562.8 kb duplication at Xq13.1 covering DLG3 and part of KIF4A. In the second family with 4 affected males, we found a non‐continuous 223 kb and 204 kb duplication at Xp21.2, of which the first covers exon 6 of IL1RAPL1.

Over 130 X-linked genes have been robustly associated with developmental disorders, and X-linked causes have been hypothesised to underlie the higher developmental disorder rates in males. Here, we evaluate the burden of X-linked coding variation in 11,044 developmental disorder patients, and find a similar rate of X-linked causes in males and females (6.0% and 6.9%, respectively), indicating that such variants do not account for the 1.4-fold male bias. We develop an improved strategy to detect X-linked developmental disorders and identify 23 significant genes, all of which were previously known, consistent with our inference that the vast majority of the X-linked burden is in known developmental disorder-associated genes. Importantly, we estimate that, in male probands, only 13% of inherited rare missense variants in known developmental disorder-associated genes are likely to be pathogenic. Our results demonstrate that statistical analysis of large datasets can refine our understanding of modes of inheritance for individual X-linked disorders., Developmental disorders (DDs) are more prevalent in males, thought to be due to X-linked genetic variation. Here, the authors investigate the burden of X-linked coding variants in 11,044 DD patients, showing that this contributes to ~6% of both male and female cases and therefore does not solely explain male bias in DDs.

Contains fulltext : 234992.pdf (Publisher’s version ) (Closed access) PURPOSE: MED12 is a subunit of the Mediator multiprotein complex with a central role in RNA polymerase II transcription and regulation of cell growth, development, and differentiation. This might underlie the variable phenotypes in males carrying missense variants in MED12, including X-linked recessive Ohdo, Lujan, and FG syndromes. METHODS: By international matchmaking we assembled variant and clinical data on 18 females presenting with variable neurodevelopmental disorders (NDDs) and harboring de novo variants in MED12. RESULTS: Five nonsense variants clustered in the C-terminal region, two splice variants were found in the same exon 8 splice acceptor site, and 11 missense variants were distributed over the gene/protein. Protein truncating variants were associated with a severe, syndromic phenotype consisting of intellectual disability (ID), facial dysmorphism, short stature, skeletal abnormalities, feeding difficulties, and variable other abnormalities. De novo missense variants were associated with a less specific, but homogeneous phenotype including severe ID, autistic features, limited speech and variable other anomalies, overlapping both with females with truncating variants as well as males with missense variants. CONCLUSION: We establish de novo truncating variants in MED12 as causative for a distinct NDD and de novo missense variants as causative for a severe, less specific NDD in females.

Background Previous systematic reviews showed no significant association between epilepsy and challenging behaviours in adults with intellectual disabilities. Aims To identify whether there is an association between epilepsy and challenging behaviour in adults with intellectual disabilities by carrying out a systematic review of published data. PROSPERO registration number: CRD42020178092. Method We searched five databases and hand-searched six journals. Two authors independently screened titles, abstracts and full articles using a standardised eligibility checklist. Several meta-analyses were carried out. Results The narrative analysis of data from 34 included articles (14 168 adults with intellectual disabilities, 4781 of whom also had epilepsy) showed no significant association between epilepsy and challenging behaviour. Meta-analysis was possible on data from 16 controlled studies. This showed no significant intergroup difference but after sensitivity analysis meta-analysis of 10 studies showed a significantly higher rate of overall challenging behaviour in the epilepsy group (effect size: 0.16) compared with the non-epilepsy group. Aggression and self-injurious behaviour both showed a statistically significant higher rate in the epilepsy group, with very small effect sizes (0.16 and 0.28 respectively). No significant intergroup difference was observed in the rate of stereotypy. Conclusions The findings are contradictory and must be interpreted with caution because of the difficulty in pooling data from varied studies, which is likely to introduce confounding. Where significant differences were found, effect sizes are small and may not be clinically significant, and there are major methodological flaws in the included studies, which should be addressed in future large-scale properly controlled studies.

Background: People with intellectual disabilities are more at risk of obesity than the general population. Emerging literature indicates that multicomponent interventions are most effective, however, individual results are variable and little research exists as to why this is the case. Methods: Focus groups were conducted to explore lived experiences between two groups of adults with intellectual disabilities; an overweight group (n= 6) and a group identified as successful in losing weight (n= 6). Similarities and differences were explored across four domains. Transcripts were produced and analysed using Theoretical Thematic Analysis. Results: Similarities included service centre supports, basic food knowledge and issues restricting independence. The successful weight loss group had also internalised health messages, engaged with external reinforcement programmes, responded to positive feedback and demonstrated healthier dietary habits. Conclusion: Weight management interventions would benefit from understanding the influence that internalisation of health messages, effective reinforcement systems and positive feedback can have on supporting the adoption of healthier habits. The author(s) disclosed receipt of the following financial support for the research, authorship and/or publication of this article: This research was supported by funding from the charity RESPECT and the People Programme (Marie Curie Actions) of the European Union’s Seventh Framework Programme (FP7/2007-2013) under REA grant agreement no. PCOFUND-GA-2013-608728. Additional funding for PhD research was provided by Department of Education and Learning (DEL). peer-reviewed

15q13.3 microdeletion is one of several gene copy number variants (CNVs) conferring increased risk of psychiatric and neurological disorders. This microdeletion gives rise to a variable spectrum of pathological phenotypes, ranging from asymptomatic to severe clinical outcomes. The reasons for these varying phenotypic outcomes remain unknown. Using a mouse model of hemizygous deletion of the orthologous region of 15q13.3, the present study examined whether exposure to stressful life events might interact with hemizygous 15q13.3 microdeletion in the development of behavioral dysfunctions. We show that hemizygous 15q13.3 microdeletion alone induces only limited effects on adult behaviors, but when combined with psychological stress in pubescence (postnatal days 30-40), it impairs sensorimotor gating and increases the sensitivity to the psychostimulant drug, amphetamine, at adult age. Stress exposure in adolescence (postnatal days 50-60) did not induce similar interactions with 15q13.3 microdeletion, but led to impaired emotional learning and memory and social behavior regardless of the genetic background. The present study provides the first evidence for interactive effects between hemizygous 15q13.3 microdeletion and exposure to stressful life events, and at the same time, it emphasizes an important influence of the precise timing of postnatal stress exposure in these interactions. Our findings suggest that hemizygous 15q13.3 microdeletion can act as a "disease primer" that increases the carrier's vulnerability to the detrimental effects of peripubertal stress exposure on adult behaviors.

Cognitive impairments have been established as part of the non-motor phenomenology of adult dystonia. In childhood dystonia, the extent of cognitive impairments is less clear. This systematic review aims to present an overview of the existing literature to elucidate the cognitive profile of primary and secondary childhood dystonia.Studies focusing on cognition in childhood dystonia were searched in MEDLINE and PsychInfo up to October 2017. We included studies on idiopathic and genetic forms of dystonia as well as dystonia secondary to cerebral palsy and inborn errors of metabolism.Thirty-four studies of the initial 527 were included. Studies for primary dystonia showed intact cognition and IQ, but mild working memory and processing speed deficits. Studies on secondary dystonia showed more pronounced cognitive deficits and lower IQ scores with frequent intellectual disability. Data are missing for attention, language, and executive functioning.This systematic review shows possible cognitive impairments in childhood dystonia. The severity of cognitive impairment seems to intensify with increasing neurological abnormalities. However, the available data on cognition in childhood dystonia are very limited and not all domains have been investigated yet. This underlines the need for future research using standardized neuropsychological procedures in this group.There is limited data on cognition in childhood dystonia. Primary dystonia showed intact cognition and IQ, but mild working memory and processing speed deficits. Secondary dystonia showed more pronounced deficits and lower IQ, with frequent intellectual disability. There is a strong need for case-control studies assessing cognition using standardized neuropsychological tests.

Although the role of typical Rho GTPases and other Rho-linked proteins in synaptic plasticity and cognitive function and dysfunction is widely acknowledged, the role of atypical Rho GTPases (such as RHOBTB2) in neurodevelopment has barely been characterized. We have now identified de novo missense variants clustering in the BTB-domain-encoding region of RHOBTB2 in ten individuals with a similar phenotype, including early-onset epilepsy, severe intellectual disability, postnatal microcephaly, and movement disorders. Three of the variants were recurrent. Upon transfection of HEK293 cells, we found that mutant RHOBTB2 was more abundant than the wild-type, most likely because of impaired degradation in the proteasome. Similarly, elevated amounts of the Drosophila ortholog RhoBTB in vivo were associated with seizure susceptibility and severe locomotor defects. Knockdown of RhoBTB in the Drosophila dendritic arborization neurons resulted in a decreased number of dendrites, thus suggesting a role of RhoBTB in dendritic development. We have established missense variants in the BTB-domain-encoding region of RHOBTB2 as causative for a developmental and epileptic encephalopathy and have elucidated the role of atypical Rho GTPase RhoBTB in Drosophila neurological function and possibly dendrite development.

The tenets of self-determination theory as applied to support were tested with structural equation modelling for 186 people with ID with a mild to borderline level of functioning. The results showed that (a) perceived autonomy support was positively associated with autonomous motivation and with satisfaction of need for autonomy, relatedness, and competence; (b) autonomous motivation and need satisfaction were associated with higher psychological well-being; (c) autonomous motivation and need satisfaction statistically mediated the association between autonomy support and well-being; and (d) satisfaction of need for autonomy and relatedness was negatively associated with controlled motivation, whereas satisfaction of need for relatedness was positively associated with autonomous motivation. The self-determination theory provides insights relevant for improving support for people with intellectual disability.

After its publication in 1999 as a DNA-binding and SMAD-binding transcription factor (TF) that co-determines cell fate in amphibian embryos, ZEB2 was from 2003 studied by embryologists mainly by documenting the consequences of conditional, cell-type specific Zeb2 knockout (cKO) in mice. In between, it was further identified as causal gene causing Mowat-Wilson Syndrome (MOWS) and novel regulator of epithelial-mesenchymal transition (EMT). ZEB2's functions and action mechanisms in mouse embryos were first addressed in its main sites of expression, with focus on those that helped to explain neurodevelopmental and neural crest defects seen in MOWS patients. By doing so, ZEB2 was identified in the forebrain as the first TF that determined timing of neuro-/gliogenesis, and thereby also the extent of different layers of the cortex, in a cell non-autonomous fashion, i.e., by its cell-intrinsic control within neurons of neuron-to-progenitor paracrine signaling. Transcriptomics-based phenotyping of Zeb2 mutant mouse cells have identified large sets of intact-ZEB2 dependent genes, and the cKO approaches also moved to post-natal brain development and diverse other systems in adult mice, including hematopoiesis and various cell types of the immune system. These new studies start to highlight the important adult roles of ZEB2 in cell-cell communication, including after challenge, e.g., in the infarcted heart and fibrotic liver. Such studies may further evolve towards those documenting the roles of ZEB2 in cell-based repair of injured tissue and organs, downstream of actions of diverse growth factors, which recapitulate developmental signaling principles in the injured sites. Evident questions are about ZEB2's direct target genes, its various partners, and ZEB2 as a candidate modifier gene, e.g., in other (neuro)developmental disorders, but also the accurate transcriptional and epigenetic regulation of its mRNA expression sites and levels. Other questions start to address ZEB2's function as a niche-controlling regulatory TF of also other cell types, in part by its modulation of growth factor responses (e.g., TGFβ/BMP, Wnt, Notch). Furthermore, growing numbers of mapped missense as well as protein non-coding mutations in MOWS patients are becoming available and inspire the design of new animal model and pluripotent stem cell-based systems. This review attempts to summarize in detail, albeit without discussing ZEB2's role in cancer, hematopoiesis, and its emerging roles in the immune system, how intense ZEB2 research has arrived at this exciting intersection. ispartof: GENES vol:12 issue:7 ispartof: location:Switzerland status: published

An X-linked condition characterized by the combination of hypomyelinating leukodystrophy and spondylometaphyseal dysplasia (H-SMD) has been observed in only four families, with linkage to Xq25-27, and recent genetic characterization in two families with a common AIFM1 mutation. In our study, 12 patients (6 families) with H-SMD were identified and underwent comprehensive assessment accompanied by whole-exome sequencing (WES). Pedigree analysis in all families was consistent with X-linked recessive inheritance. Presentation typically occurred between 12 and 36 months. In addition to the two disease-defining features of spondylometaphyseal dysplasia and hypomyelination on MRI, common clinical signs and symptoms included motor deterioration, spasticity, tremor, ataxia, dysarthria, cognitive defects, pulmonary hypertension, nystagmus, and vision loss due to retinopathy. The course of the disease was slowly progressive. All patients had maternally inherited or de novo mutations in or near exon 7 of AIFM1, within a region of 70 bp, including synonymous and intronic changes. AIFM1 mutations have previously been associated with neurologic presentations as varied as intellectual disability, hearing loss, neuropathy, and striatal necrosis, while AIFM1 mutations in this small region present with a distinct phenotype implicating bone. Analysis of cell lines derived from four patients identified significant reductions in AIFM1 mRNA and protein levels in osteoblasts. We hypothesize that AIFM1 functions in bone metabolism and myelination and is responsible for the unique phenotype in this condition. Electronic supplementary material The online version of this article (doi:10.1007/s10048-017-0520-x) contains supplementary material, which is available to authorized users.

Infantile or early onset is estimated to occur in around 10% of all facioscapulohumeral dystrophy (FSHD) patients. Although small series of early onset FSHD patients have been reported, comprehensive data on the clinical phenotype is missing. We performed a systematic literature search on the clinical features of early onset FSHD comprising a total of 43 articles with individual data on 227 patients. Additional data from-four cohorts was provided by the authors. Mean age at reporting was 18.8 years, and 40% of patients were wheelchair-dependent at that age. Half of the patients had systemic features, including hearing loss (40%), retinal abnormalities (37%) and developmental delay (8%). We found an inverse correlation between repeat size and disease severity, similar to adult-onset FSHD. De novo FSHD1 mutations were more prevalent than in adult-onset FSHD. Compared to adult FSHD, our findings indicate that early onset FSHD is overall characterized by a more severe muscle phenotype and a higher prevalence of systemic features. However, similar as in adults, a significant clinical heterogeneity was observed. Based on this, we consider early onset FSHD to be on the severe end of the FSHD disease spectrum. We found natural history studies and treatment studies to be very scarce in early onset FSHD, therefore longitudinal studies are needed to improve prognostication, clinical management and trial-readiness. (C) 2017 Elsevier B.V. All rights reserved.

The "difference or delay paradigm" focuses on the question of whether children with developmental disabilities (DD) develop in a way that is only delayed, compared to typically developing children, or also qualitatively different. The current study aimed to examine whether qualitative differences exist in cognitive development of young children with and without DD on the basis of item scores on the Dutch Bayley-III Cognition scale. Differential item functioning was identified for 15 of the 91 items. The presence of DD was related to a higher number of Guttman errors, hinting at more deviation in the order of skill development. An interaction between group (i.e., with or without DD) and developmental quotient appeared to predict the number of Guttman errors. DD was related to a higher number of Guttman errors for the whole range of developmental quotients; children with DD with a small developmental quotient had the highest number. Combined, the results mean that qualitative differences in development are not to be excluded, especially in cases of severe developmental disabilities. When using the Bayley-III in daily practice, the possibility needs to be taken into account that the instruments' assumption of a fixed order in skill development does not hold. (DIPF/Orig.)

Pathogenic variants in genes encoding components of the BRG1-associated factor (BAF) chromatin remodeling complex have been associated with intellectual disability syndromes. We identified heterozygous, novel variants in ACTL6A, a gene encoding a component of the BAF complex, in three subjects with varying degrees of intellectual disability. Two subjects have missense variants affecting highly conserved amino acid residues within the actin-like domain. Missense mutations in the homologous region in yeast actin were previously reported to be dominant lethal and were associated with impaired binding of the human ACTL6A to beta-actin and BRG1. A third subject has a splicing variant that creates an in-frame deletion. Our findings suggest that the variants identified in our subjects may have a deleterious effect on the function of the protein by disturbing the integrity of the BAF complex. Thus, ACTL6A gene mutation analysis should be considered in patients with intellectual disability, learning disabilities, or developmental language disorder.

Background: People with intellectual disability (ID) frequently use antipsychotic drugs on an off-label base, often for many years. Physicians' decisions to discontinue these drugs not only depend on patient characteristics, like the presence of mental or behavioural disorders, but also on environmental factors, such as inappropriate living circumstances, and on attitudes, knowledge and beliefs of staff, clients and their representatives towards the effects of antipsychotic drug use. In this study, we therefore investigated the influence of participant and setting-related factors on decisions of physicians not to discontinue off-label prescribed antipsychotics. Methods: The study took place in living facilities of six service providers for people with ID spread over the Netherlands and staffed with support professionals, nurses, behavioural scientist and physicians and was part of an antipsychotics discontinuation trial. ID physicians had to decide whether the off-label use of antipsychotics could be discontinued. Medical and pharmaceutical records were used to establish the prevalence of antipsychotic drug use in the study population, along with duration of use and whether the use was off-label. Reasons of physicians not to discontinue the prescription of antipsychotics in those participants who used off-label antipsychotics for more than a year were collected and categorised as related to participant or setting characteristics, including lack of consent to discontinue, and staff members, participants or their legal representatives. Results: Of the 3299 clients of the service providers, 977 used one or more antipsychotic drugs. The prevalence of antipsychotic drug use was 30%. Reasons for use were in 5% of cases, a chronic psychotic disorder classified according to Diagnostic System Mental Disorders, Fourth Edition, criteria, in 25%, present or past (suspected) non-schizophrenia-related psychotic symptoms and in 69%, challenging behaviours. Overall, physicians were willing to discontinue their prescriptions in 51% of cases, varying from 22% to 87% per service provider. The odds for decisions of physicians to discontinue off-label prescriptions varied from 0.19 to 13.95 per service provider. The variables a living situation with care and support' and challenging behaviour' were associated with a higher chance of discontinuation. The main reasons for decisions not to discontinue were concerns for symptoms of restlessness, the presence of an autism spectrum disorder, previously unsuccessful attempts to discontinue and objections against discontinuation of legal representatives. Reasons for physicians' decisions not to discontinue the off-label use of antipsychotics varied largely between the service providers. Conclusions: The prevalence of antipsychotic drug use for off-label indications in people with ID remains high. The results of this study indicate that there is a large variation in clinical practice of physicians regarding discontinuation of long-term antipsychotic drug prescriptions, which may be partially related to environmental factors as setting culture and attitudes of staff towards off-label antipsychotic drug use in persons with ID.

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Background/Aims: Kabuki syndrome (KS) is a rare genetic malformation syndrome, resulting in characteristic features such as short stature. We investigate whether growth hormone (GH) treatment increases linear height and influences body proportions in KS children. Methods: In this prospective study, 18 genetically confirmed prepubertal KS children (9 females and 9 males) aged from 3.8 to 10.1 years (mean 6.8 ± 2.1 years) were treated with recombinant human GH (rhGH) for 1 year. Calculations for height, height velocity, BMI, sitting height, and subischial leg length were made. Bone age, insulin-like growth factor (IGF-I), and IGF binding protein 3 (IGFBP-3) were also measured. Results: This study showed an increase in height standard deviation score (SDS) for the whole group from –2.40 to –1.69 (p < 0.05) after 1 year of rhGH treatment. The change in height SDS within 1 year was >0.7 SDS for 10 subjects and >0.5 SDS for 3 subjects. The mean IGF-I SDS at the start of the study was –0.70 (±1.07), which increased after 12 months to 1.41 (±0.91) (p < 0.05). KS children who received rhGH at a younger age displayed significantly greater increases in height than those who started when they were older. The same was true for both gene mutation KMT2D versus KDM6A and for GH deficiency versus non-GH deficiency KS children (p < 0.05). Throughout the course of rhGH treatment, the subjects’ body proportions remained normal. Conclusions: All participants experienced catch-up growth during the year of rhGH treatment, but without an influence on body proportions.

In human embryonic stem cells (ESCs) the transcription factor Zeb2 regulates neuroectoderm versus mesendoderm formation, but it is unclear how Zeb2 affects the global transcriptional regulatory network in these cell-fate decisions. We generated Zeb2 knockout (KO) mouse ESCs, subjected them as embryoid bodies (EBs) to neural and general differentiation and carried out temporal RNA-sequencing (RNA-seq) and reduced representation bisulfite sequencing (RRBS) analysis in neural differentiation. This shows that Zeb2 acts preferentially as a transcriptional repressor associated with developmental progression and that Zeb2 KO ESCs can exit from their naïve state. However, most cells in these EBs stall in an early epiblast-like state and are impaired in both neural and mesendodermal differentiation. Genes involved in pluripotency, epithelial-to-mesenchymal transition (EMT), and DNA-(de)methylation, including Tet1, are deregulated in the absence of Zeb2. The observed elevated Tet1 levels in the mutant cells and the knowledge of previously mapped Tet1-binding sites correlate with loss-of-methylation in neural-stimulating conditions, however, after the cells initially acquired the correct DNA-methyl marks. Interestingly, cells from such Zeb2 KO EBs maintain the ability to re-adapt to 2i + LIF conditions even after prolonged differentiation, while knockdown of Tet1 partially rescues their impaired differentiation. Hence, in addition to its role in EMT, Zeb2 is critical in ESCs for exit from the epiblast state, and links the pluripotency network and DNA-methylation with irreversible commitment to differentiation.

Secondary data analysis using the National Longitudinal Transition Study-2 data set was conducted to examine the degree to which autonomy, psychological empowerment, and self-realization (3 of 4 essential characteristics of self-determination) play a mediating role in the relationship between school-based factors and postschool outcomes. The results suggest that autonomy, psychological empowerment, and self-realization play a large and significant role in mediating the relationship between school-based factors and postschool outcomes. With over 50% of the indirect effects (i.e., the aggregated effects of the school-based factors on the outcome constructs through the self-determination constructs) significant, this provides support for the essential role of self-determination in secondary transition services and supports. Implications for research and practice are discussed.

Contains fulltext : 174704.pdf (Publisher’s version ) (Open Access) Yin and yang 1 (YY1) is a well-known zinc-finger transcription factor with crucial roles in normal development and malignancy. YY1 acts both as a repressor and as an activator of gene expression. We have identified 23 individuals with de novo mutations or deletions of YY1 and phenotypic features that define a syndrome of cognitive impairment, behavioral alterations, intrauterine growth restriction, feeding problems, and various congenital malformations. Our combined clinical and molecular data define "YY1 syndrome" as a haploinsufficiency syndrome. Through immunoprecipitation of YY1-bound chromatin from affected individuals' cells with antibodies recognizing both ends of the protein, we show that YY1 deletions and missense mutations lead to a global loss of YY1 binding with a preferential retention at high-occupancy sites. Finally, we uncover a widespread loss of H3K27 acetylation in particular on the YY1-bound enhancers, underscoring a crucial role for YY1 in enhancer regulation. Collectively, these results define a clinical syndrome caused by haploinsufficiency of YY1 through dysregulation of key transcriptional regulators.

Item does not contain fulltext Pathogenic variants in genes encoding components of the BRG1-associated factor (BAF) chromatin remodeling complex have been associated with intellectual disability syndromes. We identified heterozygous, novel variants in ACTL6A, a gene encoding a component of the BAF complex, in three subjects with varying degrees of intellectual disability. Two subjects have missense variants affecting highly conserved amino acid residues within the actin-like domain. Missense mutations in the homologous region in yeast actin were previously reported to be dominant lethal and were associated with impaired binding of the human ACTL6A to beta-actin and BRG1. A third subject has a splicing variant that creates an in-frame deletion. Our findings suggest that the variants identified in our subjects may have a deleterious effect on the function of the protein by disturbing the integrity of the BAF complex. Thus, ACTL6A gene mutation analysis should be considered in patients with intellectual disability, learning disabilities, or developmental language disorder.

BACKGROUND: eHealth has recently made rapid progress in care, support and treatment. However, studies on the use of eHealth to support people with a mild intellectual disability in daily life are limited. A systematic review was conducted to provide an overview of this use of eHealth. METHODS: Seven databases were searched for relevant studies and assessed according to the PRISMA guidelines. Descriptive analyses were deployed using the Matching Person to Technology model to evaluate the key areas contributing to successful eHealth use. RESULTS: Most of the 46 studies included were small-scale case studies and focused on using eHealth to acquire daily living skills and vocational skills. In addition, several studies focused on eHealth use for self-support in daily living, and three studies focused on remote professional support. CONCLUSIONS: eHealth offers opportunities to support people with mild intellectual disability in various different contexts of daily life. Scientific research on this topic is in its early stage, and further high-quality research is needed. ispartof: JOURNAL OF APPLIED RESEARCH IN INTELLECTUAL DISABILITIES vol:33 issue:6 pages:1166-1187 ispartof: location:England status: published

Background: Congenital muscular dystrophies (CMD) with reduced glycosylation of alpha-dystroglycan (α-DG) are a heterogeneous group of conditions associated with mutations in six genes encoding proven or putative glycosyltransferases. Objectives: The aim of the study was to establish the prevalence of mutations in the six genes in the Italian population and the spectrum of clinical and brain MRI findings. Methods: As part of a multicentric study involving all the tertiary neuromuscular centers in Italy, FKRP , POMT1 , POMT2 , POMGnT1 , fukutin , and LARGE were screened in 81 patients with CMD and α-DG reduction on muscle biopsy (n = 76) or with a phenotype suggestive of α-dystroglycanopathy but in whom a muscle biopsy was not available for α-DG immunostaining (n = 5). Results: Homozygous and compound heterozygous mutations were detected in a total of 43/81 patients (53%), and included seven novel variants. Mutations in POMT1 were the most prevalent in our cohort (21%), followed by POMT2 (11%), POMGnT1 (10%), and FKRP (9%). One patient carried two heterozygous mutations in fukutin and one case harbored a new homozygous variant in LARGE. No clear-cut genotype-phenotype correlation could be observed with each gene, resulting in a wide spectrum of clinical phenotypes. The more severe phenotypes, however, appeared to be consistently associated with mutations predicted to result in a severe disruption of the respective genes. Conclusions: Our data broaden the clinical spectrum associated with mutations in glycosyltransferases and provide data on their prevalence in the Italian population.

Item does not contain fulltext Pitt-Hopkins syndrome (PTHS) is a neurodevelopmental disorder characterized by intellectual disability, specific facial features, and marked autonomic nervous system dysfunction, especially with disturbances of regulating respiration and intestinal mobility. It is caused by variants in the transcription factor TCF4. Heterogeneity in the clinical and molecular diagnostic criteria and care practices have prompted a group of international experts to establish guidelines for diagnostics and care. For issues, for which there was limited information available in international literature, we collaborated with national support groups and the participants of a syndrome specific international conference to obtain further information. Here, we discuss the resultant consensus, including the clinical definition of PTHS and a molecular diagnostic pathway. Recommendations for managing particular health problems such as dysregulated respiration are provided. We emphasize the need for integration of care for physical and behavioral issues. The recommendations as presented here will need to be evaluated for improvements to allow for continued optimization of diagnostics and care. 17 p.

Pathogenic variants in the X-linked gene ZC4H2, which encodes a zinc-finger protein, cause an infrequently described syndromic form of arthrogryposis multiplex congenita (AMC) with central and peripheral nervous system involvement. We present genetic and detailed phenotypic information on 23 newly identified families and simplex cases that include 19 affected females from 18 families and 14 affected males from nine families. Of note, the 15 females with deleterious de novo ZC4H2 variants presented with phenotypes ranging from mild to severe, and their clinical features overlapped with those seen in affected males. By contrast, of the nine carrier females with inherited ZC4H2 missense variants that were deleterious in affected male relatives, four were symptomatic. We also compared clinical phenotypes with previously published cases of both sexes and provide an overview on 48 males and 57 females from 42 families. The spectrum of ZC4H2 defects comprises novel and recurrent mostly inherited missense variants in affected males, and de novo splicing, frameshift, nonsense, and partial ZC4H2 deletions in affected females. Pathogenicity of two newly identified missense variants was further supported by studies in zebrafish. We propose ZC4H2 as a good candidate for early genetic testing of males and females with a clinical suspicion of fetal hypo-/akinesia and/or (neurogenic) AMC. Sin financiación 4.124 JCR (2019) Q1, 45/178 Genetics & Heredity 2.410 SJR (2019) Q1, 43/356 Genetics No data IDR 2019 UEM

BACKGROUND: People with severe or profound intellectual and motor disabilities (SPIMD) experience numerous serious physical health problems and comorbidities. Knowledge regarding the prevalence of these problems is needed in order to detect and treat them at an early stage. Data concerning these problems in individuals with SPIMD are limited. Therefore, the aim of this study was to determine the prevalence of reported physical health problems in adults with SPIMD through a review of medical records and care plans. METHOD: We conducted a cross-sectional study employing data obtained from medical and support records. A sample of adults with SPIMD was recruited in eight residential care settings. Physical health problems that had occurred during the previous 12 months or were chronic were recorded. RESULTS: The records of 99 participants were included. A wide range of physical health problems were found with a mean of 12 problems per person. Very high prevalence rates (>50%) were found for constipation, visual impairment, epilepsy, spasticity, deformations, incontinence and reflux. CONCLUSIONS: The results suggest that people with SPIMD simultaneously experience numerous, serious physical health problems. The reliance on reported problems may cause an underestimation of the prevalence of health problems with less visible signs and symptoms such as osteoporosis and thyroid dysfunction.

Purpose The purpose of this paper is to give an overview of studies that focused on variables likely to affect staff ability to carry out behavioural strategies for challenging behaviours in individuals with intellectual disabilities. Design/methodology/approach Literature review: studies that were published in a peer reviewed journal, between 1999 and 2016, were selected for this review. Findings In total, 29 articles were selected. Several factors likely affect staff ability to appropriately carry out behavioural interventions were identified: staff assumptions, distressing emotions elicited by challenging behaviours, reciprocal reinforcement systems, service characteristics and cultural systems. Originality/value These findings raise the question what staff need in order to be able to change their naturally occurring behaviours in response to challenging behaviours and to carry out behavioural interventions. Future research may identify barriers and facilitators underlying the provision of effective interventions, taking into account the possible role of staff beliefs, their emotions, service characteristics and cultural systems.