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

Behavioral profiles and social relationships in Wiedemann-Steiner syndrome: parent reports on 25 cases

BACKGROUND

Wiedemann-Steiner syndrome (WSS) is a rare, variable neurodevelopmental condition associated with developmental delay, intellectual disability and congenital abnormalities. There are few investigations into behavioral characteristics. Importantly, parental perspectives are particularly lacking. This study investigated commonalities in the behavioral characteristics through the perspectives of parents' lived experiences.

METHOD

We conducted in-depth interviews with 25 parents of children with WSS in the United States and United Kingdom, tapping lived experience and specific examples of behavior, relationships and communication. Responses were analysed using reflexive thematic analysis.

RESULTS

We report three main themes: intense sociability (confirming questionnaire-based research), intense relationships and executive dysregulation (novel findings). We also found previously unreported sensory sensitivities and cognitive patterns of uneven memory and poor comprehension.

CONCLUSIONS

These data direct from parent experience reveal novel commonalities in behavior and relationships in this group. Findings should inform clinical assessment and diagnosis, new research questions and choice of patient-focused outcome measures for clinical interventions. The findings also contribute to improved practice in providing care and support for people with WSS and their families and to guidelines for more tailored education and improved healthcare.

Comparison of autism domains across thirty rare variant genotypes

BACKGROUND

A number of Neurodevelopmental risk Copy Number Variants (ND-CNVs) and Single Gene Variants (SGVs) are strongly linked to elevated likelihood of autism. However, few studies have examined the impact on autism phenotypes across a wide range of rare variant genotypes.

METHODS

This study compared Social Communication Questionnaire (SCQ) scores (total and subdomains: social, communication, repetitive behaviour) in 1314 young people with one of thirty rare variant genotypes (15 ND-CNVs; n = 1005, 9.2 ± 3.5 years and 15 SGVs; n = 309, 8.3 ± 4.0 years). Comparisons were also conducted with young people without known genetic conditions (controls; n = 460, 10.6 ± 3.4 years) and with idiopathic autism (n = 480, 8.6 ± 3.2 years).

FINDINGS

The prevalence of indicative autism (SCQ ≥ 22) was higher in those with a rare variant genotype compared to controls (32% vs 2%; OR = 43.1, CI = 6.6-282.2, p < 0.001) and in those with SGVs compared to ND-CNVs (53% vs 25%; OR = 4.00, CI = 2.2-7.3, p = 0.002). The prevalence of indicative autism varied considerably across the 30 rare variant genotypes (range 10-85%). SGVs were associated with greater impairment in total, social, communication and repetitive behaviour subdomains than ND-CNVs. However, genotype explained limited variation in these scores (η2 between 11.8 and 21.4%), indicating more convergence than divergence in autism phenotype across rare variant genotypes. Comparisons with young people with idiopathic autism indicated no differences compared to those with ND-CNVs, whereas those with SGVs showed greater communication and less repetitive behaviour.

INTERPRETATION

The likelihood of autism was higher across all rare variant genotypes, with individuals with SGVs showing higher prevalence and greater impairment compared to those with ND-CNVs. Despite subdomain-specific patterns, there was no strong evidence for specific genotype-phenotype associations. This suggests that rare variant genotypes alone may have limited predictive value for autism phenotypes and that other factors like polygenic risk and the environment are likely to play a role. Further research is needed in order to understand these influences, improve risk prediction and inform genetic counselling and interventions.

FUNDING

This work was funded by the Tackling Multimorbidity at Scale Strategic Priorities Fund programme (MR/W014416/1) (van den Bree) delivered by the Medical Research Council and the National Institute for Health Research in partnership with the Economic and Social Research Council and in collaboration with the Engineering and Physical Sciences Research Council. NIMH U01 MH119738-01 (van den Bree), IMAGINE study (Medical Research Council UK: MR/T033045/1; MR/N022572/1; and MR/L011166/1) (van den Bree) and Medical Research Council UK Centre Grant (MR/L010305/1) (Owen). SJRAC is funded by a Medical Research Foundation Fellowship (MRF-058-0015-F-CHAW). We would also like to acknowledge NIH 1R01MH110701-01A1 (PI Mulle), U01MH119736 (CEB), R21MH116473 (CEB), and R01MH085953 (CEB), and the Simons Foundation (SFARI Explorer Award to CEB).

Synapse and primary cilia dysfunctions in Autism Spectrum Disorders. Avenues to normalize these functions

AIM

An update on the plasticity of the brain networks involved in autism (autism spectrum disorders [ASD]), and the increasing role of their synapses and primary non-motile cilia.

METHODS

Data from PubMed and Google on this subject, published until February 2024, were analyzed.

RESULTS

Structural and functional brain characteristics and genetic particularities involving synapses and cilia that modify neuronal circuits are observed in ASD, such as reduced pruning of dendrites, minicolumnar pathology, or persistence of connections usually doomed to disappear. Proteins involved in synapse functions (such as neuroligins and neurexins), in the postsynaptic architectural scaffolding (such as Shank proteins) or in cilia functions (such as IFT-independent kinesins) are often abnormal. There is an increase in glutaminergic transmission and a decrease in GABA inhibition. ASD may occur in genetic ciliopathies. The means of modulating these specificities, when deemed useful, are described.

INTERPRETATION

The wide range of clinical manifestations of ASD is strongly associated with abnormalities in the morphology, functions, and plasticity of brain networks, involving their synapses and non-motile cilia. Their modulation offers important research perspectives on treatments when needed, especially since brain plasticity persists much later than previously thought. Improved early detection of ASD and additional studies on synapses and primary cilia are needed.

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.

Autism Spectrum Disorder Symptom Profiles in Fragile X Syndrome, Angelman Syndrome, Tuberous Sclerosis Complex and Neurofibromatosis Type 1

Studying Autism Spectrum Disorder (ASD) heterogeneity in biologically homogeneous samples may increase our knowledge of ASD etiology. Fragile X syndrome (FXS), Angelman syndrome (AS), Tuberous Sclerosis Complex (TSC), and Neurofibromatosis type 1 (NF1) are monogenic disorders with high a prevalence of ASD symptomatology. This study aimed to identify ASD symptom profiles in a large group of children and adolescents (0;9-28 years) with FXS, AS, TSC, and NF1. Data on ASD symptomatology (Autism Diagnostic Observation Scale (ADOS-2) & Social Responsiveness Scale (SRS-2)) were collected from children and adolescents with FXS (n = 54), AS (n = 93), TSC (n = 112), and NF1 (n = 278). To identify groups of individuals with similar ASD profiles, we performed two latent profile analyses. We identified a four-profile model based on the ADOS-2, with a (1) 'Non-spectrum symptom profile', (2) 'Social Affect symptom profile', (3)'Restricted/Repetitive Behaviors symptom profile', and (4)'ASD symptom profile'. We also identified a four-profile model based on the SRS, with a (1)'Non-clinical symptom profile', (2)'Mild symptom profile', (3)'Moderate symptom profile', and (4)'Severe symptom profile'. Although each syndrome group exhibited varying degrees of severity, they also displayed heterogeneity in the profiles in which they were classified. We found distinct ASD symptom profiles in a population consisting of children and adolescents with FXS, AS, TSC, and NF1. Our study highlights the importance of a personalized approach to the identification and management of ASD symptoms in rare genetic syndromes. Future studies should aim to include more domains of functioning and investigate the stability of latent profiles over time.

Differential item functioning in the autism behavior checklist in children with autism spectrum disorder based on a machine learning approach

Aim

Our study utilized the Rasch analysis to examine the psychometric properties of the Autism Behavior Checklist (ABC) in children with autism spectrum disorder (ASD).

Methods

A total of 3,319 children (44.77 ± 23.52 months) were included. The Rasch model (RM) was utilized to test the reliability and validity of the ABC. The GPCMlasso model was used to test the differential item functioning (DIF).

Result

The response pattern of this sample showed acceptable fitness to the RM. The analysis supported the unidimensionality assumption of the ABC. Disordered category functions and DIF were found in all items in the ABC. The participants responded to the ABC items differently depending not only on autistic traits but also on age groups, gender, and symptom classifications.

Conclusion

The Rasch analysis produces reliable evidence to support that the ABC can precisely depict clinical ASD symptoms. Differences in population characteristics may cause unnecessary assessment bias and lead to overestimated or underestimated symptom severity. Hence, special consideration for population characteristics is needed in making an ASD diagnosis.

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.

Identification of Smith-Magenis syndrome cases through an experimental evaluation of machine learning methods

This research work introduces a novel, nonintrusive method for the automatic identification of Smith-Magenis syndrome, traditionally studied through genetic markers. The method utilizes cepstral peak prominence and various machine learning techniques, relying on a single metric computed by the research group. The performance of these techniques is evaluated across two case studies, each employing a unique data preprocessing approach. A proprietary data "windowing" technique is also developed to derive a more representative dataset. To address class imbalance in the dataset, the synthetic minority oversampling technique (SMOTE) is applied for data augmentation. The application of these preprocessing techniques has yielded promising results from a limited initial dataset. The study concludes that the k-nearest neighbors and linear discriminant analysis perform best, and that cepstral peak prominence is a promising measure for identifying Smith-Magenis syndrome.

The use of eye-tracking technology as a tool to evaluate social cognition in people with an intellectual disability: a systematic review and meta-analysis

BACKGROUND

Relatively little is known about social cognition in people with intellectual disability (ID), and how this may support understanding of co-occurring autism. A limitation of previous research is that traditional social-cognitive tasks place a demand on domain-general cognition and language abilities. These tasks are not suitable for people with ID and lack the sensitivity to detect subtle social-cognitive processes. In autism research, eye-tracking technology has offered an effective method of evaluating social cognition-indicating associations between visual social attention and autism characteristics. The present systematic review synthesised research which has used eye-tracking technology to study social cognition in ID. A meta-analysis was used to explore whether visual attention on socially salient regions (SSRs) of stimuli during these tasks correlated with degree of autism characteristics presented on clinical assessment tools.

METHOD

Searches were conducted using four databases, research mailing lists, and citation tracking. Following in-depth screening and exclusion of studies with low methodological quality, 49 articles were included in the review. A correlational meta-analysis was run on Pearson's r values obtained from twelve studies, reporting the relationship between visual attention on SSRs and autism characteristics.

RESULTS AND CONCLUSIONS

Eye-tracking technology was used to measure different social-cognitive abilities across a range of syndromic and non-syndromic ID groups. Restricted scan paths and eye-region avoidance appeared to impact people's ability to make explicit inferences about mental states and social cues. Readiness to attend to social stimuli also varied depending on social content and degree of familiarity. A meta-analysis using a random effects model revealed a significant negative correlation (r = -.28, [95% CI -.47, -.08]) between visual attention on SSRs and autism characteristics across ID groups. Together, these findings highlight how eye-tracking can be used as an accessible tool to measure more subtle social-cognitive processes, which appear to reflect variability in observable behaviour. Further research is needed to be able to explore additional covariates (e.g. ID severity, ADHD, anxiety) which may be related to visual attention on SSRs, to different degrees within syndromic and non-syndromic ID groups, in order to determine the specificity of the association with autism characteristics.

Behavioural and physiological indicators of anxiety reflect shared and distinct profiles across individuals with neurogenetic syndromes

Anxiety is heightened in individuals with intellectual disability, particularly in those with specific neurogenetic syndromes. Assessment of anxiety for these individuals is hampered by a lack of appropriate measures that cater for communication impairment, differences in presentation, and overlapping features with co-occurring conditions. Here, we adopt a multi-method approach to identify fine-grained behavioural and physiological (via salivary cortisol) responses to anxiety presses in people with fragile X (FXS; n = 27; Mage = 20.11 years; range 6.32 - 47.04 years) and Cornelia de Lange syndromes (CdLS; n = 27; Mage = 18.42 years; range 4.28 - 41.08 years), two neurogenetic groups at high risk for anxiety, compared to neurotypical children (NT; n = 21; Mage = 5.97 years; range 4.34 - 7.30 years). Results indicate that physical avoidance of feared stimuli and proximity seeking to a familiar adult are prominent behavioural indicators of anxiety/stress in FXS and CdLS. Heightened pervasive physiological arousal was identified in these groups via salivary cortisol. An association between autistic characteristics and anxiety was evident in the FXS group but not in the CdLS group pointing to syndrome-specific nuances in the association between anxiety and autism. This study furthers understanding of the behavioural and physiological presentation of anxiety in individuals with intellectual disability and progresses theoretical developments regarding the development and maintenance of anxiety at the intersection of autism.

Heterogeneity of Autism Characteristics in Genetic Syndromes: Key Considerations for Assessment and Support

Purpose of Review

Elevated prevalence of autism characteristics is reported in genetic syndromes associated with intellectual disability. This review summarises recent evidence on the behavioural heterogeneity of autism in the following syndromes: Fragile X, Cornelia de Lange, Williams, Prader-Willi, Angelman, Down, Smith-Magenis, and tuberous sclerosis complex. Key considerations for assessment and support are discussed.

Recent Findings

The profile and developmental trajectory of autism-related behaviour in these syndromes indicate some degree of syndrome specificity which may interact with broader behavioural phenotypes (e.g. hypersociability), intellectual disability, and mental health (e.g. anxiety). Genetic subtype and co-occurring epilepsy within syndromes contribute to increased significance of autism characteristics. Autism-related strengths and challenges are likely to be overlooked or misunderstood using existing screening/diagnostic tools and criteria, which lack sensitivity and specificity within these populations.

Summary

Autism characteristics are highly heterogeneous across genetic syndromes and often distinguishable from non-syndromic autism. Autism diagnostic assessment practices in this population should be tailored to specific syndromes. Service provisions must begin to prioritise needs-led support.