Diagnosis and management in Rubinstein-Taybi syndrome: first international consensus statement.

Rubinstein-Taybi syndrome (RTS) is an archetypical genetic syndrome that is characterised by intellectual disability, well-defined facial features, distal limb anomalies and atypical growth, among numerous other signs and symptoms. It is caused by variants in either of two genes (CREBBP, EP300) which encode for the proteins CBP and p300, which both have a function in transcription regulation and histone acetylation. As a group of international experts and national support groups dedicated to the syndrome, we realised that marked heterogeneity currently exists in clinical and molecular diagnostic approaches and care practices in various parts of the world. Here, we outline a series of recommendations that document the consensus of a group of international experts on clinical diagnostic criteria for types of RTS (RTS1: CREBBP; RTS2: EP300), molecular investigations, long-term management of various particular physical and behavioural issues and care planning. The recommendations as presented here will need to be evaluated for improvements to allow for continued optimisation of diagnostics and care.

Diagnosis and management of Cornelia de Lange syndrome: first international consensus statement.

Cornelia de Lange syndrome (CdLS) is an archetypical genetic syndrome that is characterized by intellectual disability, well-defined facial features, upper limb anomalies and atypical growth, among numerous other signs and symptoms. It is caused by variants in any one of seven genes, all of which have a structural or regulatory function in the cohesin complex. Although recent advances in next-generation sequencing have improved molecular diagnostics, marked heterogeneity exists in clinical and molecular diagnostic approaches and care practices worldwide. Here, we outline a series of recommendations that document the consensus of a group of international experts on clinical diagnostic criteria, both for classic CdLS and non-classic CdLS phenotypes, molecular investigations, long-term management and care planning.

Direct assessment of overnight parent-child proximity in children with behavioral insomnia: Extending models of operant and classical conditioning.

INTRODUCTION: Explanatory models of behavioral insomnia typically draw on operant learning theory with behavioral techniques focused on altering parent-child interactions to improve sleep. However, there are no data describing parent-child interactions overnight beyond parent report. In this study we used radio frequency identification technology to quantify parent-child proximity overnight in two groups at elevated risk of behavioral insomnia, Angelman syndrome (AS) and Smith-Magenis syndrome (SMS). MATERIALS AND METHODS: Nineteen children aged 4-15 years (8 with AS, 11 with SMS) participated in a week-long at-home assessment of sleep and overnight parent-child proximity. Sleep parameters were recorded using the Philips Actiwatch 2 and proximity data were recorded using custom-built radio frequency identification watches. RESULTS: Three patterns of proximity data between parent-child dyads overnight were evident: "checking" (six with AS, five with SMS), "co-sleeping" (four with SMS) and those who had "no proximity" overnight (two with AS, two with SMS). In the AS group, 25.45% of actigraphy-defined wakes resulted in a parent-child interaction. In the SMS group, 39.34% of wakes resulted in a parent-child interaction. Children who interacted with their parents when settling to sleep were not significantly more likely to interact at waking. DISCUSSION: The novel application of radio frequency identification technology is a feasible method for studying overnight parent-child proximity. Profiles of proximity between participants that are not closely aligned with operant models of behavioral insomnia were evident. These results have significant implications for the etiology of poor sleep and the application of behavioral sleep interventions.

Cornelia de Lange syndrome and the Cohesin complex: Abstracts from the 9th Biennial Scientific and Educational Virtual Symposium 2020.

Cornelia de Lange syndrome (CdLS) is a spectrum disorder due to variants in genes of the cohesin protein complex. The following abstracts are from the Cornelia de Lange Syndrome Scientific and Educational Symposium held virtually in October 2020. Aspects of behavior, including autistic features, impulsivity, adaptive skills, executive function, and anxiety are described. Applied behavioral analysis is a promising approach for autism, and an N-acetylcysteine trial is proposed. Children below 6 years with CdLS have an increased number of and further travel to medical providers, with insurance type comprising a significant barrier. Speech, language, and feeding abilities fall significantly below expectations for age in CdLS. Augmentative alternative communication can yield potential barriers as well as interesting benefits. Developmentally, studies in animal models further elucidate the mechanisms and roles of cohesin: link with mediator transcriptional complex; facilitation of enhancer-promoter communication; regulation of gene expression; allocation of cells to germ layers; and repair of spontaneous DNA damage in placental cells. Genome and RNA sequencing can help identify the molecular cause in the 20% of individuals with suspected CdLS and negative testing. The phenotypes in individuals with variants in the SMC1A gene are distinct, and that with intractable seizures has been further evaluated. AMA CME credits provided by GBMC, Baltimore, MD. All studies approved by an ethics committee.

Acquired mild cognitive impairment in adults with Down syndrome: Age-related prevalence derived from single point assessment data normed by degree of intellectual disability.

BACKGROUND: Individuals with Down syndrome (DS) are at significant risk for early onset Alzheimer's disease (AD), likely due to the triplication of genes on chromosome 21 that facilitate AD neuropathology. To aid the effective early diagnosis of dementia in DS, we demonstrate the strategy of using single point assessment of cognitive performance with scoring normed for degree of intellectual disability to generate age related prevalence data for acquired mild cognitive impairment (AMCI). METHODS: Four hundred and twelve adults with DS were assessed using the Neuropsychological Assessment of dementia in adults with Intellectual Disability. Normative data, banded by degree of intellectual disability, allowed identification of AMCI by atypical deviation from expected performance. RESULTS: AMCI was evident in approximately 20% of adults with DS aged 40 and under, 40% aged 41-50 and 45% aged 51 and over. Relative risk increased significantly in those aged 46 and over. Analysis of prevalence by 5-year age bands revealed two peaks for higher prevalence of AMCI. CONCLUSIONS: Psychometric data indicate single point assessment of AMCI is possible for the majority of adults with DS. Two peaks for age-related prevalence of AMCI suggest the risk for onset of AD conferred by trisomy of chromosome 21 is moderated by another factor, possibly ApoE status.

Anxiety characteristics in individuals with Williams syndrome.

BACKGROUND: Williams syndrome anxiety research predominantly focuses on disorder prevalence and symptomatology, categorised using standardised mental health classifications. However, the use of these assessments may not fully capture the phenotypic features of anxiety in Williams syndrome. In this study, we examined characteristics of anxiety using a formulation framework. METHOD: A semi-structured interview was conducted with thirteen parents of individuals with Williams syndrome (median age: 19, age range: 12-45, 8 females). RESULTS: Various anxiety triggers were reported, including anxiety triggered by phobias, uncertainty and negative emotions in others. The range of described behaviours was diverse with both avoidant and active coping strategies for anxiety management reported. CONCLUSIONS: Many of the characteristics described were consistent with findings in the intellectual disability and typically developing literature, although novel information was identified. The study demonstrates the utility of a formulation framework to explore anxiety characteristics in atypical populations and has outlined new avenues for research.

Communication in Angelman syndrome: a scoping review.

AIM: A scoping review was conducted to examine and evaluate empirical data on the communication profile of Angelman syndrome beyond the described dissociation between receptive language and speech. METHOD: Three databases (PsycINFO, Embase, and Web of Science) were searched to retrieve articles investigating communication in Angelman syndrome. Seventeen articles investigating the broader communication profile were found; their methodology was evaluated against quality criteria. RESULTS: Despite the absence of speech, individuals with Angelman syndrome have a wide repertoire of non-verbal communicative behaviours, mainly characterized by gestures, although advanced forms such as symbolic communication are used by some individuals. The use of communicative forms differs between the genetic aetiologies of Angelman syndrome; individuals with non-deletion aetiologies typically have greater communicative abilities. INTERPRETATION: The broader communication profile of Angelman syndrome is characterized by diverse and multimodal abilities, including some use of symbolic forms of communication that appears atypical given the absence of speech. This is suggestive of a probable dissociation between speech and other expressive forms of communication, indicating an isolated speech production impairment. This highlights a need in this population for alternative communication and specific input from services tailored to support the nuances of the communication profile of Angelman syndrome. WHAT THIS PAPER ADDS: Although absent speech is near universal, a diverse profile of other communicative abilities has been reported. Parental reporting has been predominantly used to assess the communication profile of Angelman syndrome. Literature that investigates the specificities and possible dissociations in such a communication profile is limited.

Temper outbursts in Lowe syndrome: Characteristics, sequence, environmental context and comparison to Prader-Willi syndrome.

BACKGROUND: There is limited research into the nature and aetiology of temper outbursts in people with intellectual disabilities. In this study, we describe the phenomenology and environmental context of temper outbursts in Lowe syndrome, a rare genetic syndrome in which outbursts are purportedly frequent. METHOD: A temper outburst interview (TOI) was conducted with caregivers of seventeen individuals with Lowe syndrome to generate an account of the behavioural sequence, common antecedents and consequences of temper outbursts, and to enable comparisons with similar work on Prader-Willi syndrome. RESULTS: Outbursts in Lowe syndrome were frequently triggered by thwarted goal-directed behaviour and were associated with high levels of physical aggression and property destruction. CONCLUSIONS: Form and sequence of outbursts showed similarities to Prader-Willi syndrome and to behaviours reported in literature on typically developing children. The results highlight the importance of considering shared aetiology as well as syndrome-specific pathways in the development of outbursts.

Genotype-phenotype correlations in Cornelia de Lange syndrome: Behavioral characteristics and changes with age.

Cornelia de Lange syndrome (CdLS) is a multisystem genetic disorder associated with unusual facial features, limb abnormalities, a wide range of health conditions, and intellectual disability. Mutations in five genes that encode (SMC1A, SMC3, RAD21) or regulate (NIPBL, HDAC8) the cohesin complex have been identified in up to 70% of individuals. Genetic cause remains unknown for a proportion of individuals. There is substantial heterogeneity in all aspects of CdLS but very little is known about what predicts phenotypic heterogeneity. In this study, we evaluated genotype-phenotype associations in 34 individuals with CdLS. Participants with NIPBL mutations had significantly lower self help skills and were less likely to have verbal skills relative to those who were negative for the NIPBL mutation. No significant differences were identified between the groups in relation to repetitive behavior, mood, interest and pleasure, challenging behavior, activity, impulsivity, and characteristics of autism spectrum disorder whilst controlling differences in self help skills. Significant correlations indicating lower mood, interest and pleasure, and increased insistence on sameness with older age were identified for those who were NIPBL mutation positive. The findings suggest similarities in the behavioral phenotype between those with and without the NIPBL mutation once differences in self help skills are controlled for. However, there may be subtle differences in the developmental trajectory of these behaviors according to genetic mutation status in CdLS.

Phenotypes and genotypes in individuals with SMC1A variants.

SMC1A encodes one of the proteins of the cohesin complex. SMC1A variants are known to cause a phenotype resembling Cornelia de Lange syndrome (CdLS). Exome sequencing has allowed recognizing SMC1A variants in individuals with encephalopathy with epilepsy who do not resemble CdLS. We performed an international, interdisciplinary study on 51 individuals with SMC1A variants for physical and behavioral characteristics, and compare results to those in 67 individuals with NIPBL variants. For the Netherlands all known individuals with SMC1A variants were studied, both with and without CdLS phenotype. Individuals with SMC1A variants can resemble CdLS, but manifestations are less marked compared to individuals with NIPBL variants: growth is less disturbed, facial signs are less marked (except for periocular signs and thin upper vermillion), there are no major limb anomalies, and they have a higher level of cognitive and adaptive functioning. Self-injurious behavior is more frequent and more severe in the NIPBL group. In the Dutch group 5 of 13 individuals (all females) had a phenotype that shows a remarkable resemblance to Rett syndrome: epileptic encephalopathy, severe or profound intellectual disability, stereotypic movements, and (in some) regression. Their missense, nonsense, and frameshift mutations are evenly spread over the gene. We conclude that SMC1A variants can result in a phenotype resembling CdLS and a phenotype resembling Rett syndrome. Resemblances between the SMC1A group and the NIPBL group suggest that a disturbed cohesin function contributes to the phenotype, but differences between these groups may also be explained by other underlying mechanisms such as moonlighting of the cohesin genes.

Behaviour in Cornelia de Lange syndrome: a systematic review.

AIM: Careful study and accurate description of behaviour are important to understand developmental challenges for individuals with Cornelia de Lange syndrome (CdLS). Here we present a systematic review of current understanding of behaviour in CdLS. METHOD: A systematic search was performed for articles published between January 1946 and December 2015 evaluating autism, self-injury, and/or cognition in CdLS. After study-selection, 43 papers were included. The Cochrane quality criteria were adjusted to assign quality scores to the included studies. RESULTS: Participants were mostly categorized in the severe/profound developmental level. Methodology and quality were very heterogeneous, as well as reporting occurrence of autism. Self-injurious behaviour was reported in 15 papers. Physical conditions were reported in 21 studies, mostly related to hearing and vision. Only nine studies mentioned details about medication. INTERPRETATION: Comparison of presented results was hindered by heterogeneous assessment methods. Improving our understanding of behavioural characteristics in CdLS requires more uniform methodology. We propose a criterion standard of instruments that can ideally be used in assessment of behaviour and development. This will improve understanding of behaviour in the context of developmental level and daily functioning.

Associations between behaviours that challenge in adults with intellectual disability, parental perceptions and parental mental health.

OBJECTIVES: This study examined parental perceptions of behaviours that challenge (CB) in their adult children with intellectual disability (ID), and explored whether perceptions mediated associations between CB and parental psychological distress. DESIGN: A within-group correlational design was employed. METHODS: Sixty-five parents reported on individuals with genetic syndromes and ID who had chronic CB. Parents completed the Illness Perception Questionnaire-Revised (IPQ-R) adapted to measure perceptions of self-injury, aggression or property destruction, alongside assessments of parental locus of control, attributions about behaviour, parental psychological distress, and CB. RESULTS: A high proportion of parents evidenced anxiety and depression at clinically significant levels (56.9% and 30.8%, respectively). Contrary to predictions, psychological distress was not significantly associated with CB. The perception that the adult with ID exerted control over the parent's life mediated the association between CB and parental psychological distress. Few parents endorsed operant reinforcement as a cause of CB (< 10%). CONCLUSIONS: The high levels of psychological distress in parents is notable and of concern. Further research should consider the reasons why parents have causal attributions that might be inconsistent with contemporary interventions. PRACTITIONER POINTS: Parents experience high levels of psychological distress while supporting adults with ID who engage in chronic behaviours that challenge. A stronger belief that the adult with ID exerts control over the parent's life may mediate an association between CB exhibited by the individual with ID and parental psychological distress. Few parents endorsed operant reinforcement as a cause of behaviours that challenge.

A Comparison of Two Methods for Recruiting Children with an Intellectual Disability.

BACKGROUND: Recruitment is a widely cited barrier of representative intellectual disability research, yet it is rarely studied. This study aims to document the rates of recruiting children with intellectual disabilities using two methods and discuss the impact of such methods on sample characteristics. METHODS: Questionnaire completion rates are compared between (i) participants being approached in child development centre waiting rooms and (ii), one year later, the same participants being invited to take part by phone, email and/or post. RESULTS: The face-to-face recruitment method resulted in a better recruitment rate (58.5% compared to 18.5%) and a larger sample (n = 438) than the telephone/email/post sample (n = 40). It also required less hours of researcher time per completed questionnaire. CONCLUSIONS: In-line with previous research, recruitment of participants with intellectual disabilities (or their parents/carers) requires significant time and resources to get a sample of an acceptable size.

Contrasting age related changes in autism spectrum disorder phenomenology in Cornelia de Lange, Fragile X, and Cri du Chat syndromes: Results from a 2.5 year follow-up.

Little is known about the way in which the characteristics of autism spectrum disorder (ASD) develop and manifest across the age span in individuals with genetic syndromes. In this study we present findings from a two and a half year follow-up of the characteristics associated with ASD in three syndromes: Cornelia de Lange (CdLS), Fragile X (FXS), and Cri du Chat (CdCS). Parents and carers of 251 individuals (CdLS=67, CdCS=42, and FXS=142) completed the Social Communication Questionnaire (SCQ) at Time 1 (T1) and again two and a half years later (T2). The FXS and CdLS groups were more likely to meet the cut-offs for both autism and ASD and show greater severity of ASD related behaviors, at both T1 and T2, compared to the CdCS group. Older individuals (>15yrs) with CdLS were more likely to meet the cut off for ASD than younger individuals (≤15 yrs) with the syndrome and more likely to show greater severity of social impairments. In FXS repetitive behaviors were found to become less prominent with age and in CdCS social impairments were reported to be more severe with age. There were no significant changes between T1 and T2 in the severity of ASD characteristics in the CdCS and CdLS groups. The FXS group showed significantly fewer repetitive behaviors and less severe impairments in social interaction over this time frame. The findings suggest that while there may be similarities in overall severity and presentation of ASD characteristics in CdLS and FXS, these characteristics have divergent patterns of development within these groups.

A national survey of Rett syndrome: age, clinical characteristics, current abilities, and health.

As part of a wider study to investigate the behavioral phenotype of a national sample of girls and women with Rett syndrome (RTT) in comparison to a well-chosen contrast group and its relationship to parental well-being, the development, clinical severity, current abilities and health of 91 participants were analyzed in relation to diagnostic, clinical and genetic mutation categories. Early truncating mutations or large deletions were associated with greater severity. Early regression was also associated with greater severity. All three were associated with lower current abilities. Epilepsy and weight, gastrointestinal and bowel problems were common co-morbidities. Participants with classic RTT had greater health problems than those with atypical RTT. A substantial minority of respondents reported fairly frequent signs of possible pain experienced by their relative with RTT. Overall, the study provides new data on the current abilities and general health of people with RTT and adds to the evidence that the severity of the condition and variation of subsequent disability, albeit generally within the profound range, may be related to gene mutation. The presence of certain co-morbidities represents a substantial ongoing need for better health. The experience of pain requires further investigation.

The behavioral characteristics of Sotos syndrome.

In this study we describe the levels of clinically significant behavior in participants with Sotos syndrome relative to three matched contrast groups in which the behavioral phenotype is well documented (Autism Spectrum Disorder, ASD; Prader-Willi, and Down syndromes). Parents and carers of 38 individuals with Sotos syndrome (mean age = 17.3; SD = 9.36), completed questionnaires regarding self-injury, aggression, repetitive behavior, autism spectrum phenomenology, overactivity, impulsivity and mood, interest and pleasure. Individuals with Sotos syndrome showed an increased risk of self-injurious behavior, physical aggression, and destruction of property relative to the Down syndrome group but not a greater risk of stereotyped behavior. Impulsivity and levels of activity were also significantly higher relative to those with Down syndrome and comparable to those with ASD. A large proportion of participants met the cut off score for ASD (70.3%) and Autism (32.4%) on the Social Communication Questionnaire. Social impairments were particularly prominent with repetitive behavior and communication impairments less characteristic of the syndrome. Interestingly, preference for routine and repetitive language were heightened in individuals with Sotos syndrome and the repetitive behavior profile was strikingly similar to that observed in individuals with Prader-Willi syndrome. These findings build upon previous research and provide further evidence of the behavioral phenotype associated with Sotos syndrome.

Behavioral characteristics associated with 19p13.2 microdeletions.

A small number of recent papers have described individuals with intellectual disabilities and microdeletions in chromosome band 19p13.2. However, little is known about the behavioral characteristics of individuals with microdeletions in this area. The current study examines behavioral characteristics of a series of 10 participants ranging in age from 2 to 20 years with 19p13.2 microdeletions. Parents/caregivers completed a series of established behavioral measures which have aided the elucidation of the behavioral phenotypes of a number of genetic neurodevelopmental syndromes. All but the youngest two participants (aged 2 and 3 years) were verbal, ambulant, and classified as "partly able" or "able" with regard to self-help skills. Six of eight participants for whom a screening measure for autism spectrum disorders (ASD) could be deployed met criteria for an ASD. Six of the 10 participants had displayed self-injurious behavior in the month prior to assessment, eight had displayed destruction/disruption of property, and eight had shown physically aggressive behaviors. Repetitive behaviors were prevalent in the sample (with all participants displaying at least one repetitive behavior to a clinically relevant level), as were problems with sleep. Low mood was not prevalent in this group, and nor were overactivity or impulsivity. Full determination of a behavioral phenotype for this group would require a larger sample size, distinguishing between genetic subtypes. However, the current data suggest that ASD characteristics, repetitive, and challenging behaviors (such as aggression and self-injury) might be associated with 19p13.2 microdeletions, providing a basis for future investigation.

Are Angelman and Prader-Willi syndromes more similar than we thought? Food-related behavior problems in Angelman, Cornelia de Lange, fragile X, Prader-Willi and 1p36 deletion syndromes.

Food-related behavior problems are well documented in Prader-Willi syndrome (PWS), with impaired satiety, preoccupation with food and negative food-related behaviors (such as taking and storing food) frequently reported as part of the behavioral phenotype of older children and adults. Food-related behavior problems in other genetic neurodevelopmental syndromes remain less well studied, including those seen in Angelman Syndrome (AS), the 'sister imprinted disorder' of PWS. Food-related behavior problems were assessed in 152 participants each with one of five genetic neurodevelopmental syndromes ­ PWS, AS, 1p36 deletion, Cornelia de Lange, and fragile X. Predictably, levels of food-related behavior problems reported in participants with PWS significantly exceeded those of at least one other groups in most areas (impaired satiety; preoccupation with food; taking and storing food; composite negative behavior). However, in some areas people with AS were reported to display food-related problems at least as severe as those with PWS, with the AS group reported to display significantly more food-related behavior problems than at least one comparison group on measures of taking and storing food, composite negative behaviors, impaired satiety and preoccupation with food. Over 50% of participants in the AS group scored above the median point of the distribution of PWS scores on a measure of taking and storing food. These findings indicate further investigation of eating problems in AS are warranted and have implications for current theoretical interpretations of the behavioral differences between AS and PWS.

Practitioner Review: Self-injurious behaviour in children with developmental delay.

BACKGROUND: Self-injurious behaviour is shown by a significant minority of children with developmental delay and has a substantial impact on child and carer wellbeing. Characteristics such as a greater degree of intellectual disability, autism spectrum disorder, some genetic syndromes and repetitive and impulsive behaviours are positively associated with self-injury. Prevalence generally increases with age into midadulthood and the behaviour is notably persistent. SCOPE: In this review, we discuss the dominant causal theory of self-injury which draws on the principles of operant learning. We evaluate the utility of this theory to account for all empirical observations of self-injury. FINDINGS: A model of self-injury is presented that extends a previous model described by Guess and Carr. The new model integrates child characteristics and operant learning principles in a phenotype × environment paradigm to explain the variance in developmental trajectory of the severity of self-injury. CONCLUSIONS: Behaviour dysregulation, as evidenced by the associations between self-injury, self-restraint, repetitive and impulsive behaviours, is identified as potentially influencing the severity and persistence of self-injury. Risk markers for self-injury are identified and the extended model indicates points of intervention and highlights the possibility of risk-related, targeted early intervention. The need for increased training of practitioners in the delivery of demonstrably effective interventions for self-injury is identified.