Delineating the profile of autism spectrum disorder characteristics in Cornelia de Lange and Fragile X syndromes

Profiling Autism and Attention Deficit Hyperactivity Disorder Traits in Children with SYNGAP1-Related Intellectual Disability

SYNGAP1-related ID is a genetic condition characterised by global developmental delay and epilepsy. Individuals with SYNGAP1-related ID also commonly show differences in attention and social communication/interaction and frequently receive additional diagnoses of Autism Spectrum Disorder (ASD) or Attention Deficit Hyperactivity Disorder (ADHD). We thus set out to quantify ASD and ADHD symptoms in children with this syndrome. To assess ASD and ADHD, parents and caregivers of a child with SYNGAP1-related ID (N = 34) or a typically developing control (N = 21) completed the Social Responsiveness Scale-2, the Social Communication Questionnaire with a subset of these also completing the Conners-3. We found that those with SYNGAP1-related ID demonstrated higher levels of autistic traits on both the SRS and SCQ than typically developing controls. On the SRS, those with SYNGAP1-related ID scored highest for restricted repetitive behaviours, and were least impaired in social awareness. On the Conners-3, those with SYNGAP1-related ID also showed a high prevalence of ADHD traits, with scores demonstrating difficulties with peer relations but relatively low occurrence of symptoms for DSM-5 conduct disorder and DSM-5 oppositional defiant disorder. Hierarchical clustering analysis highlighted distinct SYNGAP1-related ID subgroups for both ASD and ADHD traits. These findings provide further characterisation of the SYNGAP1-related ID behavioural phenotype, guiding diagnosis, assessment and potential interventions.

Behaviours that Challenge in SATB2-associated Syndrome: Correlates of Self-injury, Aggression and Property Destruction

SATB2-associated syndrome (SAS) is a genetic syndrome characterised by intellectual disability, severe speech delay, and palatal and dental problems. Behaviours that challenge (BtC) are reported frequently; however, there is limited research on specific forms of BtC and the correlates of these behaviours. The current study explores correlates of well-defined BtC, self-injury, aggression, and property destruction, in SAS. Eighty-one parents/caregivers of individuals with SAS (53.1% male, Mage 10.12 years) completed questionnaire measures of health, behavioural, emotional, and autism characteristics. Individuals with SAS were grouped based on caregiver responses to the presence or absence of self-injury, aggression, and property destruction on the Challenging Behaviour Questionnaire. Rates of self-injury, aggression and property destruction were 42%, 77% and 49%, respectively. Between-group comparisons were conducted to compare characteristics between behaviour groups. Significantly differing characteristics were entered into separate hierarchical logistic regressions for each form of BtC. Behavioural comparisons indicated variation in the characteristics associated with each behaviour. All hierarchical logistic regression models were significant (p < .001): self-injury (χ2(5) = 38.46, R2 = 0.571), aggression (χ2(4) = 25.12, R2 = 0.414), property destruction (χ2(4) = 23.70, R2 = 0.346), explaining between 34.6% and 57.1% of the variance in behaviour presence. This is the first study to identify correlates of self-injury, aggression, and property destruction in SAS. Variability in the characteristics associated with each behaviour highlights the importance of specificity when examining BtC. Understanding correlates of specific forms of BtC has important implications for informing SAS-associated pathways to behavioural outcomes and the implementation of tailored behavioural interventions.

Visual attention patterns during a gaze following task in neurogenetic syndromes associated with unique profiles of autistic traits: Fragile X and Cornelia de Lange syndromes

BACKGROUND

Gaze following difficulties are considered an early marker of autism, thought likely to cumulatively impact the development of social cognition, language and social skills. Subtle differences in gaze following abilities may contribute to the diverse range social and communicative autistic characteristics observed across people with genetic syndromes, such as Cornelia de Lange (CdLS) and fragile X (FXS) syndromes.

AIMS

To compare profiles of 1) visual attention to the eye region at critical points of the attention direction process, 2) whether children follow the gaze cue to the object, and 3) participant looking time to the target object following the gaze cue between groups and conditions.

MATERIALS AND METHODS

Children with CdLS (N = 11) and FXS (N = 8) and autistic (N = 22) and neurotypical (N = 15) children took part in a passive viewing paradigm adapted from Senju and Csibra (2008), in which videos of a central cue (ball/cartoon face/human face) directed attention towards one of two objects. Visual attention patterns were recorded via eye tracking technology.

RESULTS

Neurotypical children were used as a reference group against which the autistic, CdLS and FXS groups were compared. Although autistic children looked at the eye region for significantly less time, they looked at the target object as frequently and for a similar duration as neurotypical children. Children with FXS looked at the target as frequently as neurotypical children but looked at it for comparatively less time. Both neurotypical children and children with CdLS frequently looked at the eye region, but children with CdLS were less likely to look at the target than neurotypical children.

CONCLUSIONS

Findings provide preliminary evidence of unique patterns of visual attention and gaze following strategies in children with CdLS, children with FXS and autistic children. These unique gaze following patterns may underpin the distinct profiles of social and communication autistic traits observed between these groups.

Profiles of autism characteristics in thirteen genetic syndromes: a machine learning approach

BACKGROUND

Phenotypic studies have identified distinct patterns of autistic characteristics in genetic syndromes associated with intellectual disability (ID), leading to diagnostic uncertainty and compromised access to autism-related support. Previous research has tended to include small samples and diverse measures, which limits the generalisability of findings. In this study, we generated detailed profiles of autistic characteristics in a large sample of > 1500 individuals with rare genetic syndromes.

METHODS

Profiles of autistic characteristics based on the Social Communication Questionnaire (SCQ) scores were generated for thirteen genetic syndrome groups (Angelman n = 154, Cri du Chat n = 75, Cornelia de Lange n = 199, fragile X n = 297, Prader-Willi n = 278, Lowe n = 89, Smith-Magenis n = 54, Down n = 135, Sotos n = 40, Rubinstein-Taybi n = 102, 1p36 deletion n = 41, tuberous sclerosis complex n = 83 and Phelan-McDermid n = 35 syndromes). It was hypothesised that each syndrome group would evidence a degree of specificity in autistic characteristics. To test this hypothesis, a classification algorithm via support vector machine (SVM) learning was applied to scores from over 1500 individuals diagnosed with one of the thirteen genetic syndromes and autistic individuals who did not have a known genetic syndrome (ASD; n = 254). Self-help skills were included as an additional predictor.

RESULTS

Genetic syndromes were associated with different but overlapping autism-related profiles, indicated by the substantial accuracy of the entire, multiclass SVM model (55% correctly classified individuals). Syndrome groups such as Angelman, fragile X, Prader-Willi, Rubinstein-Taybi and Cornelia de Lange showed greater phenotypic specificity than groups such as Cri du Chat, Lowe, Smith-Magenis, tuberous sclerosis complex, Sotos and Phelan-McDermid. The inclusion of the ASD reference group and self-help skills did not change the model accuracy.

LIMITATIONS

The key limitations of our study include a cross-sectional design, reliance on a screening tool which focuses primarily on social communication skills and imbalanced sample size across syndrome groups.

CONCLUSIONS

These findings replicate and extend previous work, demonstrating syndrome-specific profiles of autistic characteristics in people with genetic syndromes compared to autistic individuals without a genetic syndrome. This work calls for greater precision of assessment of autistic characteristics in individuals with genetic syndromes associated with ID.

Examining Phenotypic Differences in Gaze Avoidance Between Autism Spectrum Disorder and Fragile X Syndrome

We examined potential phenotypic differences in eye gaze avoidance exhibited by boys with autism spectrum disorder (ASD) and boys with fragile X syndrome (FXS). In Study 1, the Eye Contact Avoidance Scale (ECAS) was administered to caregivers of boys aged 7-18 years with FXS (n = 148), ASD (n = 168), and mixed developmental disabilities (MDD; n = 128). In Study 2, subsets of boys with FXS (n = 31) and boys with ASD (n = 25) received a brief behavioral treatment probe to improve eye contact. Results showed that boys with FXS obtained significantly higher scores on the ECAS compared to boys with ASD and MDD. Exposure to the brief behavioral treatment probe resulted in significant decreases in scores for boys with FXS, but not for boys with ASD.

Divergent presentation of anxiety in high-risk groups within the intellectual disability population

Background

Anxiety symptomatology is common in individuals with intellectual disability (ID). Symptomatology includes both traditional Diagnostic and Statistical Manual of Mental Disorders, 5th Edition (DSM-5) anxiety disorders and autism spectrum disorder (ASD)-related anxiety traits. Some genetic disorders such as Cornelia de Lange (CdLS) and fragile X syndromes (FXS) are at very high risk of anxiety and afford the opportunity to examine prevalence, profiles and associated person characteristics. However, prevalence and associated characteristics of anxiety in these high-risk groups remain poorly described and understood. The aim of the current study was to examine the prevalence and profile of DSM-5 and ASD-related anxiety symptomatology in individuals with CdLS and FXS and associated behavioural and cognitive characteristics.

Methods

Questionnaires and interviews assessing DSM-5 and ASD-related anxiety were conducted with caregivers of individuals with CdLS (n = 49) and FXS (n = 36).

Results

DSM-5 anxiety symptomatology was present in both groups with high co-morbidity across anxiety diagnoses. ASD-related anxiety was also prevalent with specific difficulties related to intolerance of uncertainty identified in both groups. Symptomatology was persistent over the lifespan for both groups. Anxiety type was partially associated with repetitive behaviour but not measures of overall ASD phenomenology in CdLS.

Conclusions

DSM-5 and ASD-related anxiety are common in these high-risk syndromes associated with ID. Prospective syndrome specific presentations and associations, which may implicate specific underlying mechanisms, are discussed. Clinicians should be aware of the risk and difficulties involved in assessment of anxiety in individuals with ID, including atypical types, to ensure these individuals do not “miss” diagnoses and support in general clinical practice.

Prevalence of anxiety symptomatology and diagnosis in syndromic intellectual disability: A systematic review and meta-analysis

Individuals with syndromic intellectual disability are at increased risk of experiencing anxiety. Comparing prevalence estimates of anxiety will allow the identification of at-risk groups and inform causal pathways of anxiety. No known study has explored estimates of anxiety symptomatology and diagnosis, including specific anxiety profiles, across groups whilst accounting for methodological quality of studies. This systematic review and meta-analysis aimed to fill this gap. Prior to review completion, methodology and analysis plans were registered and documented in a protocol (CRD42019123561). Data from 83 papers, involving a pooled sample of 13,708 across eight syndromes were synthesised using a random effects model. Anxiety prevalence ranged from 9 % (95 % CI: 4-14) in Down syndrome to 73% in Rett syndrome (95 % CI: 70-77). Anxiety prevalence across syndromic intellectual disability was higher than for intellectual disability of mixed aetiology and general population estimates. Substantial variability between syndromes identified groups at higher risk than others. The identification of high-risk groups is crucial for early intervention, allowing us to refine models of risk and identify divergent profiles.

Executive function, repetitive behaviour and restricted interests in neurodevelopmental disorders

BACKGROUND

Individuals with genetic syndromes show unique profiles of repetitive behaviours and restricted interests (RRBs). The executive dysfunction account of RRBs suggests that in autistic (AUT) individuals executive function impairments underpin RRBs, but not communication and social interaction autistic characteristics.

AIMS

To 1) describe profiles of behavioural manifestations of executive function (EF behaviours) and 2) explore the relationship between EF behaviours and autistic traits across individuals with Cornelia de Lange (CdLS), fragile X (FXS) and Rubinstein-Taybi syndromes (RTS), and AUT individuals.

METHOD

Carers completed the Behavior Rating Inventory of Executive Function - Preschool Version and the Social Communication Questionnaire. Data reporting on 25 individuals with CdLS (Mage = 18.60, SD = 8.94), 25 with FXS (Mage = 18.48, SD = 8.80), 25 with RTS (Mage = 18.60, SD = 8.65) and 25 AUT individuals (Mage = 18.52, SD = 8.65) matched on chronological age and adaptive ability were included in analyses.

RESULTS

All groups showed impairments across EF behaviours compared to two-to-three-year-old typically developing normative samples with no differences between groups. Different EF behaviours predicted RRBs in the syndrome groups with no associations found in the AUT group.

CONCLUSIONS

Syndrome related differences should be considered when developing targeted interventions that focus on EF behaviours and/or RRBs in these groups.

Behavioral markers of social anxiety in Cornelia de Lange Syndrome: A brief systematic review

BACKGROUND

There is evidence that social impairments in Cornelia de Lange Syndrome (CdLS) differ from those observed in idiopathic autism as they are characterized mainly by social anxiety. However, the knowledge of the fundamental features of social anxiety symptoms in this target population is limited. This brief systematic review aims to investigate the relationship between social anxiety and CdLS through multiple cross-sectional comparisons.

METHODS

PRISMA-P guidelines were followed, and the literature research was conducted in Pubmed, EBSCOhost, Google Scholar, and ScienceDirect using "Cornelia de Lange Syndrome" or "CdLS" and "social anxiety" as search terms.

RESULTS

Six articles met the eligibility criteria. Results show that heightened levels of social anxiety in CdLS individuals occur before and after the social engagement and are mediated by both the nature of the social demand and the familiarity of the examiner they interact with.

LIMITATIONS

The interpretation of results is limited by the wide heterogeneity of patients' age and sample size across the reviewed studies, and by the absence of a unique observational procedure to detect behaviors indicative of social anxiety in syndromic individuals.

CONCLUSIONS

These findings have considerable clinical implications for intervention planning which might be generalized to all people with intellectual disability linked to a genetic syndrome.

Behavior Problems and Social Competence in Fragile X Syndrome: A Systematic Review

Fragile X syndrome (FXS) causes intellectual disability and is the known leading cause of autism. Common problems in FXS include behavior and social problems. Along with syndromic characteristics and autism comorbidity, environmental factors might influence these difficulties. This systematic review focuses on the last 20 years of studies concerning behavior and social problems in FXS, considering environmental and personal variables that might influence both problems. Three databases were reviewed, leading to fifty-one studies meeting the inclusion criteria. Attention deficit hyperactivity disorder (ADHD) problems remain the greatest behavior problems, with behavioral problems and social competence being stable during the 20 years. Some developmental trajectories might have changed due to higher methodological control, such as aggressive behavior and attention problems. The socialization trajectory from childhood to adolescence remains unclear. Comorbidity with autism in individuals with FXS increased behavior problems and worsened social competence profiles. At the same time, comparisons between individuals with comorbid FXS and autism and individuals with autism might help define the comorbid phenotype. Environmental factors and parental characteristics influenced behavior problems and social competence. Higher methodological control is needed in studies including autism symptomatology and parental characteristics. More studies comparing autism in FXS with idiopathic autism are needed to discern differences between conditions.

Behavioural and psychological features of PTEN mutations: a systematic review of the literature and meta-analysis of the prevalence of autism spectrum disorder characteristics

BACKGROUND

Phosphatase and tensin homologue (PTEN) is a cancer suppressor gene. Constitutional mutations affecting this gene are associated with several conditions, collectively termed PTEN hamartoma tumour syndromes (PHTS). In addition to hamartomas, PTEN aberrations have been associated with a range of non-tumoural phenotypes such as macrocephaly, and research indicates possibly increased rates of developmental delay and autism spectrum disorder (ASD) for people with germline mutations affecting PTEN.

METHOD

A systematic review of literature reporting behavioural and psychological variables for people with constitutional PTEN mutations/PHTS was conducted using four databases. Following in-depth screening, 25 articles met the inclusion criteria and were used in the review. Fourteen papers reported the proportion of people with PTEN mutations/PTHS meeting criteria for or having characteristics of ASD and were thus used in a pooled prevalence meta-analysis.

RESULTS

Meta-analysis using a random effects model estimated pooled prevalence of ASD characteristics at 25% (95% CI 16-33%), although this should be interpreted cautiously due to possible biases in existing literature. Intellectual disability and developmental delay (global, motor and speech and language) were also reported frequently. Emotional difficulties and impaired cognitive functioning in specific domains were noted but assessed/reported less frequently. Methods of assessment of psychological/behavioural factors varied widely (with retrospective examination of medical records common).

CONCLUSIONS

Existing research suggests approximately 25% of people with constitutional PTEN mutations may meet criteria for or have characteristics of ASD. Studies have also begun to establish a range of possible cognitive impairments in affected individuals, especially when ASD is also reported. However, further large-scale studies are needed to elucidate psychological/behavioural corollaries of this mutation, and how they may relate to physiological/physical characteristics.

The development of early social cognitive skills in neurogenetic syndromes associated with autism: Cornelia de Lange, fragile X and Rubinstein-Taybi syndromes

BACKGROUND

Cornelia de Lange (CdLS), Fragile X (FXS) and Rubinstein-Taybi syndromes (RTS) evidence unique profiles of autistic characteristics. To delineate these profiles further, the development of early social cognitive abilities in children with CdLS, FXS and RTS was compared to that observed in typically developing (TD) and autistic (AUT) children.

METHODS

Children with CdLS (N = 22), FXS (N = 19) and RTS (N = 18), completed the Early Social Cognition Scale (ESCogS). Extant data from AUT (N = 19) and TD (N = 86) children were used for comparison.

RESULTS

Similar to AUT children, children with CdLS, FXS and RTS showed an overall delay in passing ESCogS tasks. Children with CdLS showed a similar degree of delay to AUT children and greater delay than children with FXS and RTS. The CdLS, FXS and RTS groups did not pass tasks in the same sequence observed in TD and AUT children. Children with CdLS (p = 0.04), FXS (p = 0.02) and RTS (p = 0.04) performed better on tasks requiring understanding simple intentions in others significantly more than tasks requiring joint attention skills.

CONCLUSIONS

An underlying mechanism other than general cognitive delay may be disrupting early social cognitive development in children with CdLS, FXS and RTS. Factors that may disrupt early social cognitive development within these syndromes are discussed.

Behavioral Inflexibility Across Two Neurogenetic Conditions: Down Syndrome and Fragile X Syndrome

Behavioral inflexibility (BI) has been highlighted to occur across genetic and neurodevelopmental disorders. This study characterized BI in two common neurogenetic conditions: Fragile X syndrome (FXS) and Down syndrome (DS). Caregivers of children with FXS (N = 56; with ASD = 28; FXS only = 28) and DS (N = 146) completed the Behavioral Inflexibility Scale (BIS) via an online survey. Total BIS scores were higher in FXS+ASD than both FXS only and DS (p <.001). Most endorsed items were similar across the three groups, but scores were higher in the FXS+ASD group. In all groups, BI associated with other clinical variables (receptive behaviors, anxiety, social communication). The current data suggest that BI is variable across neurogenetic conditions and higher in individuals with comorbid ASD.

The prevalence and profile of autism in Sturge-Weber syndrome

A systematic retrospective case note review was undertaken to investigate autism diagnostic factors in 124 individuals with Sturge-Weber syndrome (SWS). Social Responsiveness Scale questionnaires were then analysed to explore the severity and profile of autism characteristics in 70 participants. Thirty-two to forty percent of participants had a clinical diagnosis of autism and half of those without a diagnosis showed significant social communication difficulties. Children had a relative strength in social awareness and social motivation, which are typically much reduced in people with autism. This finding may explain why, to date, the diagnosis has often been overlooked in this population. The research therefore suggests that children with Sturge-Weber should be screened to identify social communications difficulties and provided with timely support.

Distinct patterns of repetition suppression in Fragile X syndrome, down syndrome, tuberous sclerosis complex and mutations in SYNGAP1

Sensory processing is the gateway to information processing and more complex processes such as learning. Alterations in sensory processing is a common phenotype of many genetic syndromes associated with intellectual disability (ID). It is currently unknown whether sensory processing alterations converge or diverge on brain responses between syndromes. Here, we compare for the first time four genetic conditions with ID using the same basic sensory learning paradigm. One hundred and five participants, aged between 3 and 30 years old, composing four clinical ID groups and one control group, were recruited: Fragile X syndrome (FXS; n = 14), tuberous sclerosis complex (TSC; n = 9), Down syndrome (DS; n = 19), SYNGAP1 mutations (n = 8) and Neurotypical controls (NT; n = 55)). All groups included female and male participants. Brain responses were recorded using electroencephalography (EEG) during an audio-visual task that involved three repetitions of the pronunciation of the phoneme /a/. Event Related Potentials (ERP) were used to: 1) compare peak-to-peak amplitudes between groups, 2) evaluate the presence of repetition suppression within each group and 3) compare the relative repetition suppression between groups. Our results revealed larger overall amplitudes in FXS. A repetition suppression (RS) pattern was found in the NT group, FXS and DS, suggesting spared repetition suppression in a multimodal task in these two ID syndromes. Interestingly, FXS presented a stronger RS on one peak-to-peak value in comparison with the NT. The results of our study reveal the distinctiveness of ERP and RS brain responses in ID syndromes. Further studies should be conducted to understand the molecular mechanisms involved in these patterns of responses.

An Observational Study of Social Interaction Skills and Behaviors in Cornelia de Lange, Fragile X and Rubinstein-Taybi Syndromes

We directly assessed the broader aspects of sociability (social enjoyment, social motivation, social interaction skills and social discomfort) in individuals with Cornelia de Lange (CdLS), fragile X (FXS) and Rubinstein-Taybi syndromes (RTS), and their association with autism characteristics and chronological age in these groups. Individuals with FXS (p < 0.01) and RTS (p < 0.01) showed poorer quality of eye contact compared to individuals with CdLS. Individuals with FXS showed less person and more object attention than individuals with CdLS (p < 0.01). Associations between sociability and autism characteristics and chronological age differed between groups, which may indicate divergence in the development and aetiology of different components of sociability across these groups. Findings indicate that individuals with CdLS, FXS and RTS show unique profiles of sociability.

A Behavioural Assessment of Social Anxiety and Social Motivation in Fragile X, Cornelia de Lange and Rubinstein-Taybi Syndromes

Unique socio-behavioural phenotypes are reported for individuals with different neurodevelopmental disorders. Here, the effects of adult familiarity and nature of interaction on social anxiety and social motivation were investigated in individuals with fragile X (FXS; n = 20), Cornelia de Lange (CdLS; n = 20) and Rubinstein-Taybi (RTS; n = 20) syndromes, compared to individuals with Down syndrome (DS; n = 20). The Social Anxiety and Motivation Rating Scale was employed whilst participants completed four social tasks, each administered separately by a familiar adult, and also by an unfamiliar adult. Compared to participants with DS, those with FXS and RTS exhibited high levels of social anxiety but similar levels of social motivation. Participants with CdLS showed heightened social anxiety and reduced social motivation only during interactions with an unfamiliar adult when active participation was voluntary.

Behavioural and psychological characteristics in Pitt-Hopkins syndrome: a comparison with Angelman and Cornelia de Lange syndromes

Background

Pitt-Hopkins syndrome (PTHS) is a genetic neurodevelopmental disorder associated with intellectual disability. Although the genetic mechanisms underlying the disorder have been identified, description of its behavioural phenotype is in its infancy. In this study, reported behavioural and psychological characteristics of individuals with PTHS were investigated in comparison with the reported behaviour of age-matched individuals with Angelman syndrome (AS) and Cornelia de Lange syndrome (CdLS).

Methods

Questionnaire data were collected from parents/caregivers of individuals with PTHS (n = 24), assessing behaviours associated with autism spectrum disorder (ASD), sociability, mood, repetitive behaviour, sensory processing, challenging behaviours and overactivity and impulsivity. For most measures, data were compared to data for people with AS (n = 24) and CdLS (n = 24) individually matched by adaptive ability, age and sex.

Results

Individuals with PTHS evidenced significantly higher levels of difficulties with social communication and reciprocal social interaction than individuals with AS, with 21 of 22 participants with PTHS meeting criteria indicative of ASD on a screening instrument. Individuals with PTHS were reported to be less sociable with familiar and unfamiliar people than individuals with AS, but more sociable with unfamiliar people than individuals with CdLS. Data also suggested areas of atypicality in sensory experiences. Challenging behaviours were reported frequently in PTHS, with self-injury (70.8%) occurring at significantly higher rates than in AS (41.7%) and aggression (54.2%) occurring at significantly higher rates than in CdLS (25%). Individuals with PTHS also evidenced lower reported mood than individuals with AS.

Conclusions

Behaviours which may be characteristic of PTHS include those associated with ASD, including deficits in social communication and reciprocal social interaction. High rates of aggression and self-injurious behaviour compared to other genetic syndrome groups are of potential clinical significance and warrant further investigation. An atypical sensory profile may also be evident in PTHS. The specific aetiology of and relationships between different behavioural and psychological atypicalities in PTHS, and effective clinical management of these, present potential topics for future research.

Lifespan trajectory of affect in Cornelia de Lange syndrome: towards a neurobiological hypothesis

Background

Depressive symptomology and low affect are comparatively common in individuals with genetic disorders such as Cornelia de Lange syndrome. However, lifespan trajectories and associated person characteristics have not been examined. In this study, the trajectories for affect and associated behavioural characteristics were investigated in individuals with Cornelia de Lange syndrome with individuals with fragile X syndrome (FXS) comparable for chronological age and total number of behavioural indicators of ASD included for the purpose of contrast.

Methods

A 7-year longitudinal study of affect (mood, interest and pleasure) was conducted in individuals with CdLS (n = 44) and FXS (n = 95). The trajectories of low affect were explored, as well as associations between Time 1 behavioural characteristics and affect at Time 1 and Time 3 (7 years later).

Results

The CdLS group were lower in mood than the FXS group overall (p < .001). Interest and pleasure scores showed a significant decline over the lifespan for individuals with CdLS (p < .001) but not the FXS group. Lower level of ability at Time 1 was associated with lower mood at Time 1 and Time 3 in the FXS group only. Higher levels of ASD symptomology at Time 1 were associated with low mood and interest and pleasure in both syndrome groups at Time 1 and Time 3. Greater insistence on sameness at Time 1 was associated with lower mood at Time 1 in the FXS group and lower interest and pleasure at Time 1 and Time 3 in the CdLS group.

Conclusions

Low affect in specific genetic syndromes may be associated with differing lifespan trajectories and behavioural profiles. Specifically, individuals with CdLS appear at risk for experiencing declines in levels of interest and pleasure whereas individuals with FXS show no significant change in the level of affect with age.

Movement Disorders and Syndromic Autism: A Systematic Review

Movement disorders are reported in idiopathic autism but the extent to which comparable movement disorders are found in syndromic/co-morbid autism is unknown. A systematic search of Medline, Embase, PsychINFO and CINAHL on the prevalence of specific movement disorder in syndromic autism associated with specific genetic syndromes identified 16 papers, all relating to Angelman syndrome or Rett syndrome. Prevalence rates of 72.7-100% and 25.0-27.3% were reported for ataxia and tremor, respectively, in Angelman syndrome. In Rett syndrome, prevalence rates of 43.6-50% were reported for ataxia and 27.3-48.3% for tremor with additional reports of dystonia, rigidity and pyramidal signs. However, reliable assessment measures were rarely used and recruitment was often not described in sufficient detail.

A clinical update on tuberous sclerosis complex-associated neuropsychiatric disorders (TAND)

Tuberous sclerosis complex (TSC) is associated with a wide range of behavioral, psychiatric, intellectual, academic, neuropsychological, and psychosocial difficulties, which are often underdiagnosed and undertreated. Here, we present a clinical update on TSC-associated neuropsychiatric disorders, abbreviated as "TAND," to guide screening, diagnosis, and treatment in practice. The review is aimed at clinical geneticists, genetic counselors, pediatricians, and all generalists involved in the assessment and treatment of children, adolescents and adults with TSC, and related disorders. The review starts with a summary of the construct and levels of TAND, before presenting up-to-date information about each level of investigation. The review concludes with a synopsis of current and future TAND research.

Diverse Profiles of Anxiety Related Disorders in Fragile X, Cornelia de Lange and Rubinstein-Taybi Syndromes

Anxiety disorders are heightened in specific genetic syndromes in comparison to intellectual disability of heterogeneous aetiology. In this study, we described and contrasted anxiety symptomatology in fragile X (FXS), Cornelia de Lange (CdLS) and Rubinstein-Taybi syndromes (RTS), and compared the symptomatology to normative data for typically-developing children and children diagnosed with an anxiety disorder. Scores did not differ between children diagnosed with an anxiety disorder and (a) participants with FXS on social phobia, panic/agoraphobia, physical injury fears, and obsessive-compulsive subscales (b) participants with CdLS on separation anxiety, generalized anxiety, panic/agoraphobia, physical injury fears and obsessive-compulsive subscales, and (c) participants with RTS on panic/agoraphobia and obsessive-compulsive subscales. The results highlight divergent profiles of anxiety symptomatology between these groups.

Prospective study of autism phenomenology and the behavioural phenotype of Phelan-McDermid syndrome: comparison to fragile X syndrome, Down syndrome and idiopathic autism spectrum disorder

Background

The limited behavioural phenotype literature on Phelan–McDermid syndrome (PMS) indicates atypically high levels of activity, impulsivity and autism spectrum disorder (ASD) behaviours. Divergent profiles of ASD in PMS are also reported, with some studies demonstrating similarities to idiopathic ASD and others indicating an uneven profile of social and communication impairments and repetitive behaviours. An evaluation of the behavioural phenotype of PMS and the prevalence and phenomenology of ASD is warranted, particularly given the causal involvement of the SHANK3 gene in the aetiology of PMS.

Methods

Carers of individuals with PMS (N = 30; mean age = 10.55, SD = 7.08) completed questionnaires relating to impulsivity, overactivity, mood, interest and pleasure, repetitive behaviour and ASD phenomenology. These data were compared to data from matched samples of individuals with fragile X and Down syndromes and idiopathic ASD. In order to evaluate the profile of ASD phenomenology in PMS, two comparisons were made: first, including the total sample with PMS, and second, including only those who met the threshold indicative of autism on an ASD screening measure.

Results

The results revealed lower mood in individuals with PMS, but no differences in impulsivity and overactivity. Compulsive and routine-driven repetitive behaviours were less common in the total sample with PMS; however, motor-based stereotyped behaviours were more common. ASD phenomenology was highly prevalent, with 87% of the sample meeting the cutoff score for ASD and 57% meeting the cutoff for autism. The profile of ASD phenomenology in the total sample with PMS differed from those with idiopathic ASD across impairments in communication and social interaction and repetitive behaviour. However, the profile of those who met the threshold for autism was commensurate to those with idiopathic ASD.

Conclusions

ASD phenomenology is common within PMS. Whilst the total sample may display an atypical profile of ASD behaviour, the profile in those who met the threshold for autism was very similar to those with idiopathic ASD. These results are discussed in relation to the wider behavioural phenotype and the emerging evidence of an autism endophenotype in PMS.

Executive functioning in Cornelia de Lange syndrome: domain asynchrony and age-related performance

BACKGROUND

The aim of this study was to examine executive functioning in adolescents and adults with Cornelia de Lange syndrome (CdLS) to identify a syndrome and age-related profile of cognitive impairment.

METHODS

Participants were 24 individuals with CdLS aged 13-42 years (M = 22; SD = 8.98), and a comparable contrast group of 21 individuals with Down syndrome (DS) aged 15-33 years (M = 24; SD = 5.82). Measures were selected to test verbal and visual fluency, inhibition, perseverance/flexibility, and working memory and comprised both questionnaire and performance tests.

RESULTS

Individuals with CdLS showed significantly greater impairment on tasks requiring flexibility and inhibition (rule switch) and on forwards span capacity. These impairments were also reported in the parent/carer-rated questionnaire measures. Backwards Digit Span was significantly negatively correlated with chronological age in CdLS, indicating increased deficits with age. This was not identified in individuals with DS.

CONCLUSIONS

The relative deficits in executive functioning task performance are important in understanding the behavioural phenotype of CdLS. Prospective longitudinal follow-up is required to examine further the changes in executive functioning with age and if these map onto observed changes in behaviour in CdLS. Links with recent research indicating heightened responses to oxidative stress in CdLS may also be important.

Updated report on tools to measure outcomes of clinical trials in fragile X syndrome

OBJECTIVE

Fragile X syndrome (FXS) has been the neurodevelopmental disorder with the most active translation of preclinical breakthroughs into clinical trials. This process has led to a critical assessment of outcome measures, which resulted in a comprehensive review published in 2013. Nevertheless, the disappointing outcome of several recent phase III drug trials in FXS, and parallel efforts at evaluating behavioral endpoints for trials in autism spectrum disorder (ASD), has emphasized the need for re-assessing outcome measures and revising recommendations for FXS.

METHODS

After performing an extensive database search (PubMed, Food and Drug Administration (FDA)/National Institutes of Health (NIH)'s www.ClinicalTrials.gov, etc.) to determine progress since 2013, members of the Working Groups who published the 2013 Report evaluated the available outcome measures for FXS and related neurodevelopmental disorders using the COSMIN grading system of levels of evidence. The latter has also been applied to a British survey of endpoints for ASD. In addition, we also generated an informal classification of outcome measures for use in FXS intervention studies as instruments appropriate to detect shorter- or longer-term changes.

RESULTS

To date, a total of 22 double-blind controlled clinical trials in FXS have been identified through www.ClinicalTrials.gov and an extensive literature search. The vast majority of these FDA/NIH-registered clinical trials has been completed between 2008 and 2015 and has targeted the core excitatory/inhibitory imbalance present in FXS and other neurodevelopmental disorders. Limited data exist on reliability and validity for most tools used to measure cognitive, behavioral, and other problems in FXS in these trials and other studies. Overall, evidence for most tools supports a moderate tool quality grading. Data on sensitivity to treatment, currently under evaluation, could improve ratings for some cognitive and behavioral tools. Some progress has also been made at identifying promising biomarkers, mainly on blood-based and neurophysiological measures.

CONCLUSION

Despite the tangible progress in implementing clinical trials in FXS, the increasing data on measurement properties of endpoints, and the ongoing process of new tool development, the vast majority of outcome measures are at the moderate quality level with limited information on reliability, validity, and sensitivity to treatment. This situation is not unique to FXS, since reviews of endpoints for ASD have arrived at similar conclusions. These findings, in conjunction with the predominance of parent-based measures particularly in the behavioral domain, indicate that endpoint development in FXS needs to continue with an emphasis on more objective measures (observational, direct testing, biomarkers) that reflect meaningful improvements in quality of life. A major continuous challenge is the development of measurement tools concurrently with testing drug safety and efficacy in clinical trials.

Assistive technology to promote occupation and reduce mouthing by three boys with fragile X syndrome

OBJECTIVES

To extend the use of assistive technology (AT) for promoting a new adaptive response and to reduce hand mouthing, by three boys with fragile X syndrome. To monitor the effects of the intervention program on the positive mood. To carry out a three month follow-up phases. To conduct a social validation assessment involving 30 parents of children who presented multiple disabilities as raters.

METHODS

The study was implemented according to an ABAB experimental design, where A represented baseline phases (technology available but inactive) and B represented intervention phases (the technology ensured 7 s of positive stimulation).

RESULTS

All participants improved and consolidated their performance. Parents involved in the social validation assessment rated positively the use of such technology.

CONCLUSION

AT-based program was useful, affordable, and effective for enhancing constructive engagement, self-determination, and for improving quality of life by children with fragile X syndrome and severe to profound developmental disabilities.

Profiles of children with Down syndrome who meet screening criteria for autism spectrum disorder (ASD): a comparison with children diagnosed with ASD attending specialist schools

BACKGROUND

Recent research suggests that around 16% to 18% of children with Down syndrome (DS) also meet diagnostic criteria for autism spectrum disorder (ASD). However, there are indications that profiles of autism symptoms in this group may vary from those typically described in children with ASD.

METHOD

Rates of autism symptoms and emotional and behavioural problems among children with DS who screened positive for ASD on the Social Communication Questionnaire (SCQ) (n = 183) were compared with a group of children with clinical diagnoses of ASD (n = 189) attending specialist schools in the UK. Groups were matched for age and approximate language level (use of phrase speech).

RESULTS

Profiles of autistic symptoms in the two groups were generally similar, but children with DS meeting ASD cut-off on the SCQ tended to show fewer problems in reciprocal social interaction than those in the ASD group. They also showed slightly lower rates of emotional and peer-related problems. The results mostly confirm findings from a previous study in which the original validation sample for the SCQ was used as a comparison group.

CONCLUSION

Findings suggest that children with DS who meet screening criteria for ASD show similar profiles of communication and repetitive behaviours to those typically described in autism. However, they tend to have relatively milder social difficulties. It is important that clinicians are aware of this difference if children with DS and ASD are to be correctly diagnosed and eligible for specialist intervention and education services.

Targeted next generation sequencing of a panel of autism-related genes identifies an EHMT1 mutation in a Kleefstra syndrome patient with autism and normal intellectual performance

Autism spectrum disorder (ASD) is a complex neurodevelopmental disorder with unknown genetic and environmental causation in most of the affected individuals. On the other hand, there are a growing number of ASD-associated syndromes, where the exact genetic origin can be revealed. Here we report a method, which included the targeted next generation sequencing (NGS) and filtering of 101 ASD associated genes, followed by database search. Next, RNA sequencing was used to study the region of interest at the transcriptional level. Using this workflow, we identified a de novo mutation in the euchromatic histone-lysine N-methyltransferase 1 gene (EHMT1) of an autistic patient with dysmorphisms. Sequencing of EHMT1 transcripts showed that the premature termination codon (Trp1138Ter) created by a single nucleotide change elicited nonsense-mediated mRNA decay, which led to haploinsufficiency already at the transcriptional level. Database and literature search provided evidence that this mutation caused Kleefstra syndrome (KS), which was confirmed by the presence of the disorder-specific phenotype in the patient. We provide a proof of principle that the implemented method is capable to elucidate the genetic etiology of individuals with syndromic autism. The novel mutation detected in the EHMT1 gene is responsible for KS's symptoms. In addition, further genetic factors might be involved in the ASD pathogenesis of the patient including a missense DPP6 mutation (Arg322Cys), which segregated with the autistic phenotype within the family.

Visual preference for social stimuli in individuals with autism or neurodevelopmental disorders: an eye-tracking study

BACKGROUND

Recent research has identified differences in relative attention to competing social versus non-social video stimuli in individuals with autism spectrum disorder (ASD). Whether attentional allocation is influenced by the potential threat of stimuli has yet to be investigated. This is manipulated in the current study by the extent to which the stimuli are moving towards or moving past the viewer. Furthermore, little is known about whether such differences exist across other neurodevelopmental disorders. This study aims to determine if adolescents with ASD demonstrate differences in attentional allocation to competing pairs of social and non-social video stimuli, where the actor or object either moves towards or moves past the viewer, in comparison to individuals without ASD, and to determine if individuals with three genetic syndromes associated with differing social phenotypes demonstrate differences in attentional allocation to the same stimuli.

METHODS

In study 1, adolescents with ASD and control participants were presented with social and non-social video stimuli in two formats (moving towards or moving past the viewer) whilst their eye movements were recorded. This paradigm was then employed with groups of individuals with fragile X, Cornelia de Lange, and Rubinstein-Taybi syndromes who were matched with one another on chronological age, global adaptive behaviour, and verbal adaptive behaviour (study 2).

RESULTS

Adolescents with ASD demonstrated reduced looking-time to social versus non-social videos only when stimuli were moving towards them. Individuals in the three genetic syndrome groups showed similar looking-time but differences in fixation latency for social stimuli moving towards them. Across both studies, we observed within- and between-group differences in attention to social stimuli that were moving towards versus moving past the viewer.

CONCLUSIONS

Taken together, these results provide strong evidence to suggest differential visual attention to competing social versus non-social video stimuli in populations with clinically relevant, genetically mediated differences in socio-behavioural phenotypes.

Looping Genomes: Diagnostic Change and the Genetic Makeup of the Autism Population

This article builds on Hacking's framework of "dynamic nominalism" to show how knowledge about biological etiology can interact with the "kinds of people" delineated by diagnostic categories in ways that "loop" or modify both over time. The authors use historical materials to show how "geneticization" played a crucial role in binding together autism as a biosocial community and how evidence from genetics research later made an important contribution to the diagnostic expansion of autism. In the second part of the article, the authors draw on quantitative and qualitative analyses of autism rates over time in several rare conditions that are delineated strictly according to genomic mutations in order to demonstrate that these changes in diagnostic practice helped to both increase autism's prevalence and create its enormous genetic heterogeneity. Thus, a looping process that began with geneticization and involved the social effects of genetics research itself transformed the autism population and its genetic makeup.

Social-emotional instability in individuals with Rett syndrome: parents' experiences with second stage behaviour

BACKGROUND

While the medical profession often terms behaviours in individuals with Rett syndrome (RTT) in the second stage as 'autistic-like', parents disagree with this description. The present study focuses on a comparison of parents' experiences with the social-emotional behaviour of the child with RTT in the second and subsequent stages.

METHOD

In collaboration with the Dutch Rett Syndrome Organization, 51 parents of children with RTT in the Netherlands took part in the present study. Parents completed an online questionnaire to clarify their experiences of the social-emotional behaviour of their children during and after the second stage of RTT. Both quantitative and qualitative analysis techniques have been used.

RESULTS

The results of the paired-samples t-test show that parents see significantly less social-emotional behaviour in the children during the second stage of RTT than in the subsequent stages. Parents reported that their children did not seek as much interaction. From the parents' descriptions, it would seem that the children are willing but unable to interact with their environment.

CONCLUSIONS

Like previous research, our study leads to doubts about the appropriateness of the label 'autistic-like' for the behaviour of individuals in the second stage of RTT. While behaviours of individuals with autism and individuals with RTT may resemble each other, quality and intentions may differ. Still, future studies are needed for further clarification.

The relationship between autistic symptomatology and independent living skills in adolescents and young adults with fragile X syndrome

Few studies have examined the relationship between autistic symptomatology and competence in independent living skills in adolescents and young adults with fragile X syndrome (FXS). In this study, 70 individuals with FXS, aged 15-25 years, and 35 matched controls were administered direct measures of independent living skills and autistic symptomatology. Results showed that higher levels of autistic symptomatology were associated with lower levels of competence in independent living skills in individuals with FXS, but not in controls. These data indicated that the relationship between autistic symptomatology and independent living skills was syndrome-specific. Early intervention strategies that address autistic symptomatology are sorely needed to improve functional outcomes in this population.

Prevalence of autism spectrum disorder phenomenology in genetic disorders: a systematic review and meta-analysis

BACKGROUND

Autism spectrum disorder (ASD) phenomenology is reported to be more common in individuals with some genetic syndromes than in the general population; however, no meta-analysis has provided prevalence data within and between syndromes. In this systematic review and meta-analysis, we aimed to synthesise data from a wide range of papers to provide accurate estimates about ASD phenomenology in genetic and metabolic syndromes.

METHODS

We identified syndromes reported as most likely to be associated with ASD. We searched Ovid PsycINFO, Ovid MEDLINE, Ovid Embase, and PubMed Central for English-language papers published from database creation up to early 2014 with use of syndrome-specific keywords and a set of ASD keywords. We screened and extracted papers that had ASD prevalence data for ten or more people within a genetic syndrome. With use of a prespecified set of reliable criteria, we applied quality weighting to papers and estimated a quality-effects prevalence of ASD phenomenology for each syndrome. We then calculated relative risks to compare ASD between all syndromes and also calculated odds ratios to compare prevalence with the general population taking the current estimate of one in 68 people.

RESULTS

We identified 168 papers reporting the prevalence of ASD phenomenology and found widely varying methods and quality of data. Quality-weighted effect prevalence estimates of ASD phenomenology were established for Rett's syndrome (female individuals only 61%), Cohen's syndrome (54%), Cornelia de Lange syndrome (43%), tuberous sclerosis complex (36%), Angelman's syndrome (34%), CHARGE syndrome (30%), fragile X syndrome (male individuals only 30%; mixed sex 22%), neurofibromatosis type 1 (18%), Down's syndrome (16%), Noonan's syndrome (15%), Williams' syndrome (12%), and 22q11.2 deletion syndrome (11%). Relative risks and the odds ratio compared with the general population were highest for Rett's syndrome and Cohen's syndrome. In all syndromes, odds ratios showed ASD phenomenology to be significantly more likely than in the general population.

INTERPRETATION

ASD phenomenology varied between syndromes, but was consistently more likely than in the general population. Further research is needed in these populations, including how ASD in genetic and metabolic syndromes differs from idiopathic autism and what that can tell us about the mechanisms underlying ASD.

FUNDING

Cerebra.

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.

Implicit Discrimination of Basic Facial Expressions of Positive/Negative Emotion in Fragile X Syndrome and Autism Spectrum Disorder

Fragile X syndrome (FXS) and autism spectrum disorders (ASD) are characterized by impaired social functioning. We examined the spontaneous discrimination of happy and disgusted facial expressions, from neutral faces, in individuals with FXS (n  =  13, Mage  =  19.70) and ASD (n  =  15, Mage  =  11.00) matched on adaptive behavior and verbal abilities measured by the Vineland Adaptive Behavior Scale. Eye gaze to the eyes and mouth of neutral faces was also measured. Results suggest individuals with FXS and ASD distinguish facial expressions spontaneously in the same way. Individuals with FXS looked significantly less at the eye region of neutral faces than individuals with ASD. These results provide insight into similarities and differences in face processing in two neurodevelopmental disorders noted for their similarities in social behavior.

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.

Autism traits in children and adolescents with Cornelia de Lange syndrome

Cornelia de Lange syndrome (CdLS) is a cohesinopathy causing delayed growth and limb deficits. Individuals with CdLS have mild to profound intellectual disability and autistic features. This study characterizes the behavioral phenotype of children with CdLS, focusing on autistic features, maladaptive behaviors, and impact of age. Children with CdLS (5-18 years) were administered normed instruments to characterize autism features (Childhood Autism Rating Scale, CARS), maladaptive behaviors (Aberrant Behavior Checklist), and adaptive skills (Vineland Adaptive Behaviors Scales). CdLS features and severity were rated with Diagnostic Criteria for CdLS. Forty-one children with CdLS (23 females, 18 males) were classified as having "no autism" (n = 7; 17.1%), "mild autism" (n = 17; 41.4%), and "severe autism" (n = 17; 41.4%), using CARS scores. Characteristic items were abnormal emotional response, stereotypies, odd object use, rigidity, lack of verbal communication, and low intellectual functioning. Verbal communication deficits and repetitive behaviors were higher compared to sensory, social cognition, and behavior abnormalities (P ≤ 0.0001). Maladaptive behaviors associated with autism traits were stereotypies (P = 0.003), hyperactivity (P = 0.01), and lethargy (P = 0.03). Activities of daily living were significantly affected; socialization adaptive skills were a relative strength. However, with advancing age, both socialization (P < 0.0001) and communication (P = 0.001) domains declined significantly. CdLS is characterized by autistic features, notably excessive repetitive behaviors and expressive language deficits. While other adaptive skills are impacted, socialization adaptive skills are less affected. Advancing age can worsen communication and socialization deficits relative to neurotypical peers.

Social behavior and characteristics of autism spectrum disorder in Angelman, Cornelia de Lange, and Cri du Chat syndromes

We evaluated autism spectrum disorder (ASD) characteristics and social behavior in Angelman (AS; n  =  19; mean age  = 10.35 years), Cornelia de Lange (CdLS; n  =  15; mean age  = 12.40 years), and Cri du Chat (CdCS, also known as 5 p-syndrome; n  =  19; mean age  =  8.80 years) syndromes. The proportion of individuals meeting the ASD cutoff on the Social Communication Questionnaire was significantly higher in the AS and CdLS groups than in the CdCS group (p < .01). The groups demonstrated divergent social behavior profiles during social conditions in which adult availability, adult familiarity, and social demand were manipulated. Social enjoyment was significantly heightened in AS, whereas social approaches were heightened in individuals with CdCS. Social motivation, social communication, and enjoyment were significantly lower in CdLS. The findings highlight the importance of detailed observation when evaluating ASD and social behavior in genetic syndromes.