Age related change in social behavior in children with Angelman syndrome

Association Between Challenging Behaviour and Sleep Problems in Adults Enrolled in the Global Angelman Syndrome Registry

Angelman Syndrome (AS) is a rare genetic disorder that impacts 1:20,000 people. Challenging behaviour, such as severe injurious behaviour, aggression and frequent unprovoked episodes of laughter are a significant problem among adults with AS that adversely impacts an individual's quality of life. This study, for the first time, aims understand the characteristic of challenging behaviour, its frequency, and the factors associated with it in adults with AS. Data from participants with AS (N = 37; aged 18-46 years) registered with the Global Angelman Registry, were divided into challenging behaviour and non-challenging behaviour groups based on the presence or absence of 50% of the behaviours recorded in the registry. Descriptive statistics, chi-squared and t-test analysis were conducted to assess the impact of variables on challenging behaviour. Multiple regressions were conducted to investigate the predictors of challenging behaviour. 56% of the sample presented with challenging behaviour. Disorders of arousal, self-injury, behaviour dysregulation, repetitive behaviour, and the lack of physical therapy accounted for 59% of the variance of challenging behaviour in this population. It was found that challenging behaviour was very common in this population. A significant association was found between challenging behaviour and both sleep arousal and the lack of physical therapy. Sleep arousal and the lack of physical therapy were the key factors associated with challenging behaviour in this study. Targeted interventions are needed to decrease challenging behaviour and future research should focus on sleep interventions and increased opportunities for physical therapy.

Outcome measures in Angelman syndrome

BACKGROUND

Angelman syndrome (AS) is a rare neurodevelopmental disorder characterized by severe intellectual disability, little to no expressive speech, visual and motor problems, emotional/behavioral challenges, and a tendency towards hyperphagia and weight gain. The characteristics of AS make it difficult to measure these children's functioning with standard clinical tests. Feasible outcome measures are needed to measure current functioning and change over time, in clinical practice and clinical trials.

AIM

Our first aim is to assess the feasibility of several functional tests. We target domains of neurocognitive functioning and physical growth using the following measurement methods: eye-tracking, functional Near-Infrared Spectroscopy (fNIRS), indirect calorimetry, bio-impedance analysis (BIA), and BOD POD (air-displacement plethysmography). Our second aim is to explore the results of the above measures, in order to better understand the AS phenotype.

METHODS

The study sample consisted of 28 children with AS aged 2-18 years. We defined an outcome measure as feasible when (1) at least 70% of participants successfully finished the measurement and (2) at least 60% of those participants had acceptable data quality. Adaptations to the test procedure and reasons for early termination were noted. Parents rated acceptability and importance and were invited to make recommendations to increase feasibility. The results of the measures were explored.

RESULTS

Outcome measures obtained with eye-tracking and BOD POD met the definition of feasibility, while fNIRS, indirect calorimetry, and BIA did not. The most important reasons for early termination of measurements were showing signs of protest, inability to sit still and poor/no calibration (eye-tracking specific). Post-calibration was often applied to obtain valid eye-tracking results. Parents rated the BOD POD als most acceptable and fNIRS as least acceptable for their child. All outcome measures were rated to be important. Exploratory results indicated longer reaction times to high salient visual stimuli (eye-tracking) as well as high body fat percentage (BOD POD).

CONCLUSIONS

Eye-tracking and BOD POD are feasible measurement methods for children with AS. Eye-tracking was successfully used to assess visual orienting functions in the current study and (with some practical adaptations) can potentially be used to assess other outcomes as well. BOD POD was successfully used to examine body composition.

TRIAL REGISTRATION

Registered d.d. 23-04-2020 under number 'NL8550' in the Dutch Trial Register: https://onderzoekmetmensen.nl/en/trial/23075.

Social attention and social-emotional modulation of attention in Angelman syndrome: an eye-tracking study

Individuals with Angelman syndrome (AS) present with severe intellectual disability alongside a social phenotype characterised by social communication difficulties and an increased drive for social engagement. As the social phenotype in this condition is poorly understood, we examined patterns of social attention and social modulation of attention in AS. Twenty-four individuals with AS and twenty-one young children with similar mental age were shown videos featuring unfamiliar actors who performed simple actions across two conditions: a playful condition, in which the actor showed positive facial emotions, and a neutral condition, in which the actor showed a neutral facial expression. During the passive observation of the videos, participants' proportion of time spent watching the two areas of interest (faces and actions) was examined using eye-tracking technology. We found that the playful condition elicited increased proportion of fixations duration to the actor's face compared to the neutral condition similarly across groups. Additionally, the proportion of fixations duration to the action area was similar across groups in the two conditions. However, children with AS looked towards the actor's face for a shorter duration compared to the comparison group across conditions. This pattern of similarities and differences provides novel insight on the complex social phenotype of children with AS.

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.

Investigation of age-related facial variation among Angelman syndrome patients

Angelman syndrome (AS) is one of the common genetic disorders that could emerge either from a 15q11-q13 deletion or paternal uniparental disomy (UPD) or imprinting or UBE3A mutations. AS comes with various behavioral and phenotypic variability, but the acquisition of subjects for experiment and automating the landmarking process to characterize facial morphology for Angelman syndrome variation investigation are common challenges. By automatically detecting and annotating subject faces, we collected 83 landmarks and 10 anthropometric linear distances were measured from 17 selected anatomical landmarks to account for shape variability. Statistical analyses were performed on the extracted data to investigate facial variation in each age group. There is a correspondence in the results achieved by relative warp (RW) of the principal component (PC) and the thin-plate spline (TPS) interpolation. The group is highly discriminated and the pattern of shape variability is higher in children than other groups when judged by the anthropometric measurement and principal component.

Sleep disorders in rare genetic syndromes: a meta-analysis of prevalence and profile

Background

Sleep disorders are common in people with intellectual disability (ID) and autism, with growing evidence of diverse sleep profiles across ID associated genetic syndromes. Documenting the prevalence and profile of specific sleep disorders in syndromes will quantify syndrome-driven ‘risk’, inform prognosis and enhance understanding of aetiology of sleep disorders.

Method

Following PRISMA guidelines for meta-analysis, we searched Ovid PsycINFO, Ovid MEDLINE, Ovid Embase, Web of Science and PubMed Central with use of syndrome-specific keywords and 60 sleep-related search terms. We screened and extracted papers that reported sleep disorder prevalence data for five or more individuals within a genetic syndrome, and applied quality criteria to produce a quality-effects prevalence model of six types of sleep disorder across nineteen syndromes. Relative risk estimates were calculated for the prevalence of each sleep disorder in each syndrome.

Results

Two hundred and seventy three papers were identified, generating 463 prevalence estimates for Angelman, CHARGE, Cornelia de Lange, Down, fragile X, Prader–Willi, Rett, Smith–Magenis and Williams syndromes, mucopolysaccharidoses (MPS disorders), neurofibromatosis and tuberous sclerosis complex. Prevalence estimates were higher in genetic syndromes than published equivalents for typically developing individuals, with few exceptions. Between-syndrome differences for some disorders were evident; sleep-disordered breathing was most prevalent in MPS disorders (72–77%), while excessive daytime sleepiness was highest in Smith–Magenis syndrome (60%). Conversely, insomnia, which was reported at a higher rate than TD estimates in all syndromes except fragile X, was not associated with specific genetic risk. This suggests insomnia could emerge because of the individual’s environment or associated developmental delay, rather than any specific genetic syndromes.

Limitations

Due to the broad scope of the meta-analysis, only syndromes previously identified as reporting preliminary sleep research were included. Other syndromes may also experience elevated prevalence rates of specific types of sleep disorder. Only English language papers were included.

Conclusions

Differing prevalence rates between types of sleep disorder suggest differing causal mechanisms, such as cranio-facial morphology in Down and Prader–Willi syndromes and the build-up of mucopolysaccharides in MPS disorders. Priorities for clinical assessment and intervention for sleep disorders are discussed.

Imitation in Angelman syndrome: the role of social engagement

Individuals with Angelman syndrome (AS) are characterized by severe cognitive impairments alongside an enhanced drive for social engagement. As knowledge on imitation skills in this population is limited, we conducted the first controlled study of imitation in AS. We examined how 23 individuals with AS and 21 typically developing young children with similar mental age imitated novel actions in response to socially or non-socially engaging models, and in response to video-recorded versus live demonstrations of novel actions. Individuals with AS imitated as frequently and as accurately as typical young children in response to live demonstrations; but they imitated less frequently and less accurately in response to video-recorded demonstrations. Further, imitation was modulated by whether the demonstrator was socially engaging or emotionally neutral in the AS group, while this modulation was not present in the comparison group. Individuals with higher mental age imitated more frequently and more accurately across groups. Imitation performance in AS appears to be more modulated by the social context compared to typical infants and young children with similar mental age, possibly reflecting an enhanced drive for social engagement. A socially engaging instructional style might facilitate imitative learning in this population.

Parent perceptions, beliefs, and fears around genetic treatments and cures for children with Angelman syndrome

Genetic therapies have shown recent promise in alleviating some of the cognitive issues associated with some genetic disorders; however, these therapies may come with significant health and socio-ethical concerns, particularly when they involve child participants. Little is known about what parents of children with genetic disorders think about genetic therapies, or about their knowledge of how genetic-based therapy might treat their child's symptoms. Forty-two parents of children with Angelman syndrome (AS) and 27 parents of a mixed etiology comparison group completed an online survey reporting on their perceptions of, and priorities for, genetic therapy. Almost all parents of children with AS (95%) and the comparison group (89%) agreed that treatments aiming to reduce symptoms associated with their child's syndrome were positive. However, significantly more parents of children with AS (95%) than the comparison group (56%) felt that genetic treatment trials aiming to "cure" their child should be a research priority. AS parent priorities for the focus of clinical trials were neurology/seizures, communication skills, and motor skills/mobility. For the comparison group, the priorities were IQ, immune response, and expressive speech. Parents of both groups did not want treatments to change their child's personality or their happiness. Global assumptions cannot be made about targets for therapy between syndromes, about parental understanding of genetics, or about research evidence across syndromes. This study highlights the need for true family and patient engagement in all stages of the research design and treatment evaluation.

Profiles of atypical sensory processing in Angelman, Cornelia de Lange and Fragile X syndromes

BACKGROUND

There is growing evidence to suggest that children with neurodevelopmental disorders may evidence differences in their sensory processing. The aim of this study was to compare sensory processing patterns in three genetic syndromes associated with sensory difference.

METHODS

Sensory processing in Angelman syndrome (n = 91), Cornelia de Lange syndrome (n = 28) and Fragile X syndrome (n = 40) was examined using the informant report measure the Sensory Experiences Questionnaire (SEQ).

RESULTS

All three groups were associated with a heightened prevalence of unusual sensory processing in comparison with normative data, evidenced in over 80% of all participants. Cross-syndrome comparisons highlighted syndrome-specific sensory processing profiles, with heightened hypo responsivity in Cornelia de Lange syndrome and sensory seeking in Angelman syndrome.

CONCLUSIONS

The results have important implications for the understanding of sensory processing in genetic syndromes and the development of tailored behavioural interventions.

Angelman syndrome in adolescence and adulthood: A retrospective chart review of 53 cases

Angelman syndrome is a neurogenetic disorder with varying clinical presentations and symptoms as the individual ages. The goal of this study was to characterize changes over time in the natural history of this syndrome in a large population. We reviewed the medical records of the 53 patients who were born prior to 2000 and seen at the Angelman Syndrome Clinic at Massachusetts General Hospital to assess neurological, sleep, behavioral, gastrointestinal, orthopedic, and ophthalmologic functioning. The average age of this cohort was 24 years. Active seizures were present in 35%, nonepileptic myoclonus in 42%, and clinically significant tremors in 55%. Anxiety was present in 57%, increasing to 71% in those ages 26-43 years. In terms of sleep, 56% reported 8 hr of sleep or more, although 43% reported frequent nocturnal awakenings. Gastrointestinal issues remain problematic with 81% having constipation and 53% gastroesophageal reflux. The majority lived in a parent's home and remained independently mobile, though scoliosis was reportedly present in 30%, and 20% had reported low bone density/osteoporosis. The results of this study suggest that the prevalence of active seizures may decrease in adulthood but that the prevalence of movement disorders such as tremor and nonepileptic myoclonus may increase. Anxiety increases significantly as individuals age while defiant behaviors appear to decrease. Sleep dysfunction typically improves as compared to childhood but remains a significant issue for many adults. Other areas that require monitoring into adulthood include gastrointestinal dysfunction, and orthopedic/mobility issues, such as reported scoliosis and bone density, and ophthalmologic disorders.

Overview of Social Cognitive Dysfunctions in Rare Developmental Syndromes With Psychiatric Phenotype

Rare neurodevelopmental syndromes often present social cognitive deficits that may underlie difficulties in social interactions and increase the risk of psychosis or autism spectrum disorders. However, little is known regarding the specificities of social cognitive impairment across syndromes while it remains a major challenge for the care. Our review provides an overview of social cognitive dysfunctions in rare diseases associated with psychiatric symptoms (with a prevalence estimated between 1 in 1,200 and 1 in 25,000 live births: 22q11.2 deletion syndrome, Angelman syndrome, Fragile X syndrome, Klinefelter syndrome, Prader-Willi syndrome, Rett syndrome, Smith-Magenis syndrome, Turner syndrome, and Williams syndrome) and shed some light on the specific mechanisms that may underlie these skills in each clinical presentation. We first detail the different processes included in the generic expression "social cognition" before summarizing the genotype, psychiatric phenotype, and non-social cognitive profile in each syndrome. Then, we offer a systematic review of the social cognitive abilities and the disturbed mechanisms they are likely associated with. We followed the PRISMA process, including the definition of the relevant search terms, the selection of studies based on clear inclusion, and exclusion criteria and the quality appraisal of papers. We finally provide insights that may have considerable influence on the development of adapted therapeutic interventions such as social cognitive training (SCT) therapies specifically designed to target the psychiatric phenotype. The results of this review suggest that social cognition impairments share some similarities across syndromes. We propose that social cognitive impairments are strongly involved in behavioral symptoms regardless of the overall cognitive level measured by intelligence quotient. Better understanding the mechanisms underlying impaired social cognition may lead to adapt therapeutic interventions. The studies targeting social cognition processes offer new thoughts about the development of specific cognitive training programs, as they highlight the importance of connecting neurocognitive and SCT techniques.

Unmet clinical needs and burden in Angelman syndrome: a review of the literature

Background

Angelman syndrome (AS) is a rare disorder with a relatively well-defined phenotype. Despite this, very little is known regarding the unmet clinical needs and burden of this condition, especially with regard to some of the most prevalent clinical features—movement disorders, communication impairments, behavior, and sleep.

Main text

A targeted literature review using electronic medical databases (e.g., PubMed) was conducted to identify recent studies focused on specific areas of the AS phenotype (motor, communication, behavior, sleep) as well as epidemiology, diagnostic processes, treatment, and burden. 142 articles were reviewed and summarized. Findings suggest significant impairment across the life span in all areas of function. While some issues may resolve as individuals get older (e.g., hyperactivity), others become worse (e.g., movement disorders, aggression, anxiety). There are no treatments focused on the underlying etiology, and the symptom-based therapies currently prescribed do not have much, if any, empirical support.

Conclusions

The lack of standardized treatment protocols or approved therapies, combined with the severity of the condition, results in high unmet clinical needs in the areas of motor functioning, communication, behavior, and sleep for individuals with AS and their families.

Hypersociability in the Angelman syndrome mouse model

Deletions and reciprocal triplications of the human chromosomal 15q11-13 region cause two distinct neurodevelopmental disorders. Maternally-derived deletions or inactivating mutations of UBE3A, a 15q11-13 gene expressed exclusively from the maternal allele in neurons, cause Angelman syndrome, characterized by intellectual disability, motor deficits, seizures, and a characteristic increased social smiling, laughing, and eye contact. Conversely, maternally-derived triplications of 15q11-13 cause a behavioral disorder on the autism spectrum with clinical features that include decreased sociability that we recently reconstituted in mice with Ube3a alone. Based on the unique sociability features reported in Angelman syndrome and the repressed sociability observed when Ube3a gene dosage is increased, we hypothesized that mice with neuronal UBE3A loss that models Angelman syndrome would display evidence of hypersocial behavior. We report that mice with maternally-inherited Ube3a gene deletion (Ube3a^mKO) have a prolonged preference for, and interaction with, social stimuli in the three chamber social approach task. By contrast, interactions with a novel object are reduced. Further, ultrasonic vocalizations and physical contacts are increased in male and female Ube3a^mKO mice paired with an unfamiliar genotype-matched female. Single housing wild type mice increased these same social behavior parameters to levels observed in Ube3a^mKO mice where this effect was partially occluded. These results indicate sociability is repressed by social experience and the endogenous levels of UBE3A protein and suggest some social behavioral features observed in Angelman syndrome may reflect an increased social motivation.

Angelman syndrome in adulthood

Angelman syndrome (AS) is a neurogenetic disorder. The goal of this study was to investigate the primary health issues affecting adults with AS and to further characterize the natural history and genotype-phenotype correlations. Standardized phone interviews with caregivers for 110 adolescents and adults with AS were conducted. The impact of age, sex, and genotype on specific outcomes in neurology, orthopedics, internal medicine, and psychiatry were investigated. The mean age of individuals with AS was 24 years (range 16-50y). Active seizures were present in 41% of individuals, and 72% had sleep dysfunction. Significant constipation was present in 85%, and 32% were overweight or obese, with obesity disproportionately affecting women. Scoliosis affected 50% with a mean age at diagnosis of 12 years, and 24% of those diagnosed with scoliosis required surgery, an intervention disproportionately affecting men. Sixty-eight percent were able to walk independently, and 13% were able to speak 5 or more words. Self-injurious behavior was exhibited in 52% of individuals. The results of this study indicate that epilepsy severity may assume a bimodal age distribution: seizures are typically most severe in early childhood but may recur in adulthood. While late-adolescent and adult sleep patterns were improved when compared to the degree of sleep dysfunction present during infancy and childhood, the prevalence of poor sleep in adults remained quite high. Primary areas of clinical management identified include the following: seizures, sleep, aspiration risk, GERD, constipation, dental care, vision, obesity, scoliosis, bone density, mobility, communication, behavior, and anxiety.

Communication Modality Sampling for a Toddler With Angelman Syndrome

Purpose

Vocal, gestural, and graphic communication modes were implemented concurrently with a toddler with Angelman syndrome to identify the most efficiently learned communication mode to emphasize in an initial augmentative communication system.

Method

Symbols representing preferred objects were introduced in vocal, gestural, and graphic communication modes using an alternating treatment single-subject experimental design. Conventionally accepted prompting strategies were used to teach symbols in each communication mode. Because the learner did not vocally imitate, vocal mode intervention focused on increasing vocal frequency as an initial step.

Results

When graphic and gestural mode performances were compared, the learner most accurately produced requests in graphic mode (percentage of nonoverlapping data = 96). Given the lack of success in prompting vocal productions, a comparison between vocal and the other two communication modes was not made.

Conclusion

A growing body of evidence suggests that concurrent modality sampling is a promising low-inference, data-driven procedure that can be used to inform selection of a communication mode(s) for initial emphasis with young children. Concurrent modality sampling can guide clinical decisions regarding the allocation of treatment resources to promote success in building an initial communicative repertoire.

Discrimination training reduces high rate social approach behaviors in Angelman syndrome: proof of principle

This proof of principle study was designed to evaluate whether excessively high rates of social approach behaviors in children with Angelman syndrome (AS) can be modified using a multiple schedule design. Four children with AS were exposed to a multiple schedule arrangement, in which social reinforcement and extinction, cued using a novel stimulus, were alternated. Twenty-five to 35 discrimination training sessions were conducted and levels of approach behaviors were measured before and after the discrimination training for two children. All four participants evidenced discrimination between conditions of reinforcement and extinction after 16-20 teaching sessions as indicated by lower rates of social approach behaviors in the presence of the S(Δ) for extinction. Reversal effects for the two children for whom this design was implemented were evident. The results demonstrate that after repeated training, the use of a novel stimulus can serve as a cue for children with AS to discriminate adult availability. This is a potentially effective component of a broader intervention strategy but highlights the need for sustained teaching procedures within this population.

Neurologic manifestations of Angelman syndrome

Angelman syndrome is a neurogenetic disorder characterized by the loss or reduction of the ubiquitin-protein ligase E3A enzyme. Angelman syndrome results from a deletion or mutation of the maternally inherited 15q11.2-13.1 region, paternal uniparental disomy of chromosome 15, or an imprinting error. Epilepsy is common and may present with multiple seizure types, including nonconvulsive status epilepticus. Seizures are often intractable and typically require broad-spectrum antiepileptic medications. Dietary therapy has also proved successful in Angelman syndrome. Electroencephalographic patterns include notched δ and rhythmic θ activity and epileptiform discharges. Sleep disorders are also common, often characterized by abnormal sleep-wake cycles. Movement disorders are nearly universal in Angelman syndrome, most frequently presenting with ataxia and tremor. Neurocognitive impairment is always present to varying degrees, and expressive speech is typically severely affected. Individuals with Angelman syndrome often manifest psychiatric comorbidities including hyperactivity, anxiety, and challenging behaviors such as aggression and self-injury. We focus on a comprehensive whole-child approach to the diagnosis and long-term clinical care of individuals with Angelman syndrome.