Characterising the social interaction style of autism in young adult males with fragile X syndrome

BACKGROUND

The characterisation of autism in fragile X syndrome (FXS) has been a source of controversy due to the complexity of disentangling autism traits from common features of the FXS phenotype. Autism in FXS is significantly underdiagnosed in the community, which may be partly due to insufficient clinical description of the social interaction profile of autism within the FXS phenotype. In this study, we applied a classic framework for characterising social interaction styles in autism to a sample of young adult males with FXS and co-occurring autism to enhance understanding of how the social challenges associated with autism manifest within FXS.

METHODS

Participants were 41 males (M age = 18 years) with FXS and co-occurring autism. Interaction samples were coded for expression of predominately 'active' (characterised by a desire to make social approaches) or 'passive' (characterised by lack of initiation of social approach towards others) interaction profiles. Differences in the expression of phenotypic features of FXS, including anxiety, attention-deficit/hyperactivity disorder, cognitive, adaptive and language impairments and autism symptom severity, were examined across those with passive and active interaction styles.

RESULTS

Approximately half of the sample was classified as active and half as passive, demonstrating diversity in the social phenotype of autism associated with FXS. The two subtypes did not differ in autism severity, anxiety or attention-deficit/hyperactivity disorder symptoms or in cognitive, adaptive or language abilities.

CONCLUSIONS

This study enhances understanding of FXS-associated autism by documenting phenotypic variability in the social interaction profile in this group, with active and passive social interaction styles represented. The two social interaction styles were not associated with differential expression of common phenotypic features of FXS, suggesting similar support needs.

Phenotyping Down syndrome: discovery and predictive modelling with electronic medical records

BACKGROUND

Individuals with Down syndrome (DS) have a heightened risk for various co-occurring health conditions, including congenital heart disease (CHD). In this two-part study, electronic medical records (EMRs) were leveraged to examine co-occurring health conditions among individuals with DS (Study 1) and to investigate health conditions linked to surgical intervention among DS cases with CHD (Study 2).

METHODS

De-identified EMRs were acquired from Vanderbilt University Medical Center and facilitated creating a cohort of N = 2282 DS cases (55% females), along with comparison groups for each study. In Study 1, DS cases were one-by-two sex and age matched with samples of case-controls and of individuals with other intellectual and developmental difficulties (IDDs). The phenome-disease association study (PheDAS) strategy was employed to reveal co-occurring health conditions in DS versus comparison groups, which were then ranked for how often they are discussed in relation to DS using the PubMed database and Novelty Finding Index. In Study 2, a subset of DS individuals with CHD [N = 1098 (48%)] were identified to create longitudinal data for N = 204 cases with surgical intervention (19%) versus 204 case-controls. Data were included in predictive models and assessed which model-based health conditions, when more prevalent, would increase the likelihood of surgical intervention.

RESULTS

In Study 1, relative to case-controls and those with other IDDs, co-occurring health conditions among individuals with DS were confirmed to include heart failure, pulmonary heart disease, atrioventricular block, heart transplant/surgery and primary pulmonary hypertension (circulatory); hypothyroidism (endocrine/metabolic); and speech and language disorder and Alzheimer's disease (neurological/mental). Findings also revealed more versus less prevalent co-occurring health conditions in individuals with DS when comparing with those with other IDDs. Findings with high Novelty Finding Index were abnormal electrocardiogram, non-rheumatic aortic valve disorders and heart failure (circulatory); acid-base balance disorder (endocrine/metabolism); and abnormal blood chemistry (symptoms). In Study 2, the predictive models revealed that among individuals with DS and CHD, presence of health conditions such as congestive heart failure (circulatory), valvular heart disease and cardiac shunt (congenital), and pleural effusion and pulmonary collapse (respiratory) were associated with increased likelihood of surgical intervention.

CONCLUSIONS

Research efforts using EMRs and rigorous statistical methods could shed light on the complexity in health profile among individuals with DS and other IDDs and motivate precision-care development.

Adaptive behaviour deficits in individuals with 3q29 deletion syndrome

BACKGROUND

3q29 deletion syndrome (3q29del) is associated with a significantly increased risk for neurodevelopmental and neuropsychiatric phenotypes. Mild to moderate intellectual disability (ID) is common in this population, and previous work by our team identified substantial deficits in adaptive behaviour. However, the full profile of adaptive function in 3q29del has not been described nor has it been compared with other genomic syndromes associated with elevated risk for neurodevelopmental and neuropsychiatric phenotypes.

METHODS

Individuals with 3q29del (n = 32, 62.5% male) were evaluated using the Vineland Adaptive Behaviour Scales, Third Edition, Comprehensive Parent/Caregiver Form (Vineland-3). We explored the relationship between adaptive behaviour and cognitive function, executive function, and neurodevelopmental and neuropsychiatric comorbidities in our 3q29del study sample, and we compared subjects with 3q29del with published data on fragile X syndrome, 22q11.2 deletion syndrome and 16p11.2 deletion and duplication syndromes.

RESULTS

Individuals with 3q29del had global deficits in adaptive behaviour that were not driven by specific weaknesses in any given domain. Individual neurodevelopmental and neuropsychiatric diagnoses had a small effect on adaptive behaviour, and the cumulative number of comorbid diagnoses was significantly negatively associated with Vineland-3 performance. Both cognitive ability and executive function were significantly associated with adaptive behaviour, and executive function was a better predictor of Vineland-3 performance than cognitive ability. Finally, the severity of adaptive behaviour deficits in 3q29del was distinct from previously published data on comparable genomic disorders.

CONCLUSIONS

Individuals with 3q29del have significant deficits in adaptive behaviour, affecting all domains assessed by the Vineland-3. Executive function is a better predictor of adaptive behaviour than cognitive ability in this population and suggests that interventions targeting executive function may be an effective therapeutic strategy.

Brief report comparing the Scale of Emotional Development - Short (SED-S) with other scales for emotional development

BACKGROUND

Different instruments were devised for assessing emotional development (ED) level in persons with an intellectual disability (ID), that is, the Scale of Emotional Development - Short (SED-S), the Scheme for Appraisal of Emotional Development (SAED), the Scale for Emotional Development - Second Revision (SED-R2 ) and the Schaal voor Emotionele Ontwikkeling - Lukas (SEO-Lukas). The aim of this study was to compare the level of emotional functioning as assessed with the SED-S with the SAED, SED-R2 and SEO-Lukas.

METHODS

Emotional development was measured in adults with ID with the SED-S (N = 186) and the SAED (n = 85), the SED-R2 (n = 50) and the SEO-Lukas (n = 51). Correlation analysis and Cohen's kappas were calculated between the SED-S and the three respective scales. Internal consistencies (Cronbach's alpha) of the four scales were determined.

RESULTS

The SED-S results correlated most with the SEO-Lukas (γ = 1; кω = 0.936) followed by the SAED (γ = 0.809; кω = 0.343) and least by the SED-R2 (γ = 0.665; кω = 0.182). The stage of ED assessed with the SED-S was lower than the ED results measured with the SAED, but higher than with the SED-R2 and most similar to the SEO-Lukas. Cronbach's alphas were high, ranging from 0.853 to 0.975.

CONCLUSIONS

Given the respective differences between the scales, the SED-S may equalise the results as compared with previous versions.

Methylglyoxal in the Brain: From Glycolytic Metabolite to Signalling Molecule

Advances in molecular biology technology have piqued tremendous interest in glycometabolism and bioenergetics in homeostasis and neural development linked to ageing and age-related diseases. Methylglyoxal (MGO) is a by-product of glycolysis, and it can covalently modify proteins, nucleic acids, and lipids, leading to cell growth inhibition and, eventually, cell death. MGO can alter intracellular calcium homeostasis, which is a major cell-permeant precursor to advanced glycation end-products (AGEs). As side-products or signalling molecules, MGO is involved in several pathologies, including neurodevelopmental disorders, ageing, and neurodegenerative diseases. In this review, we demonstrate that MGO (the metabolic side-product of glycolysis), the GLO system, and their analogous relationship with behavioural phenotypes, epigenetics, ageing, pain, and CNS degeneration. Furthermore, we summarise several therapeutic approaches that target MGO and the glyoxalase (GLO) system in neurodegenerative diseases.

Behavioural phenomena in persons with an intellectual developmental disorder according to the level of emotional development

BACKGROUND

Challenging behaviours in people with an intellectual developmental disorder (IDD) are complex and often difficult to understand. The developmental perspective may provide additional insights into the specific behavioural patterns and underlying motives in different emotional reference ages.

METHODS

The behaviours of 185 adults with IDD who were admitted to psychiatry were systematically assessed with the Aberrant Behaviour Checklist (ABC) and the Modified Overt Aggression Scale (MOAS). The association of the different behaviours with various emotional reference age groups as assessed with the Scale of Emotional Development - Short (SED-S) was analysed to deduce behavioural patterns typical for a certain level of functioning.

RESULTS

Overall, the severity of challenging behaviours decreases in higher emotional reference age groups. Physical aggression was most prevalent in persons in the second phase of emotional development (7-18 months reference age). In SED-S-1 (reference age 0-6 months), the persons appeared to be searching for physical comfort and showed high scores in social withdrawal, stereotypies and aggression towards the self. Persons functioning in SED-S-2 (reference age 7-18 months) scored highest in irritability and physical aggression (searching for security), while those in SED-S-3 (19-36 months) exhibited the searching for autonomy type characterised by defiant and socially inappropriate behaviours. Persons with an emotional reference age of 4-7 years (SED-S-4) showed inappropriate speech, verbal self-regulation and depressive-like behavioural aspects (searching for identity).

CONCLUSIONS

The behavioural phenomena exhibited in a certain emotional reference age may support the clinician to differentiate behavioural problems from psychopathological symptoms to yield the proper diagnosis.

Executive functions and adaptive behaviour in individuals with Down syndrome

BACKGROUND

Previous research has explored executive functions (EFs) and adaptive behaviour in children and adolescents with Down syndrome (DS), but there is a paucity of research on the relationship between the two in this population. This study aims to shed light on the profile of EFs and adaptive behaviour in DS, exploring the differences by age and investigating the relationship between these two domains.

METHOD

Parents/caregivers of 100 individuals with DS from 3 to 16 years old participated in the study. The sample was divided into preschoolers (3-6.11 years old) and school-age children (7-16 years old). Parents/caregivers completed either the Preschool Version of the Behaviour Rating Inventory of Executive Function (for children 2-6.11 years old) or the Second Edition of the same Inventory (for individuals 7 + years old). Adaptive behaviour was assessed with the Vineland Adaptive Behaviour Scale - Interview, Second Edition.

RESULTS

Findings suggest that individuals with DS have overall difficulties, but also patterns of strength and weakness in their EFs and adaptive behaviour. The preschool-age and school-age children's EF profiles differed slightly. While both age groups showed Emotional Control as a relative strength and Working Memory as a weakness, the school-age group revealed further weaknesses in Shift and Plan/Organise. As concerns adaptive behaviour, the profiles were similar in the two age groups, with Socialisation as a strength, and Communication and Daily Living Skills as weaknesses, but with a tendency for preschoolers to obtain intermediate scores for the latter. When the relationship between EFs and adaptive behaviour was explored, Working Memory predicted Communication in the younger group, while in the older group the predictors varied, depending on the adaptive domains: Working Memory was a predictor of Communication, Inhibit of Daily Living Skills, and Inhibit and Shift of Socialisation.

CONCLUSION

As well as elucidating the EF profiles and adaptive behaviour in individuals with DS by age, this study points to the role of EFs in adaptive functioning, providing important information for targeted interventions.

Empowering Families Through Technology: A Mobile-Health Project to Reduce the TAND Identification and Treatment Gap (TANDem)

INTRODUCTION

Tuberous Sclerosis Complex (TSC) is a multi-system genetic disorder with various TSC-Associated Neuropsychiatric Disorders (TAND) that significantly impact the mental health and wellbeing of individuals with TSC and their caregivers. TAND represents the number one concern to families worldwide, yet is highly under-identified and under-treated. The clinician-administered TAND-Checklist (Lifetime version, TAND-L) has improved identification of TAND in clinical settings. However, many individuals with TSC and their caregivers still have difficulty accessing suitable support for diagnosis and evidence-informed interventions. The TANDem study is a community-based participatory research project with a broad range of TSC stakeholders aimed at reducing the TAND identification and treatment gap.

OBJECTIVES

Participatory research identified three priority next steps: 1) development and validation of a self-report, quantified version of the TAND Checklist (TAND-SQ) and building the TAND-SQ into a smartphone application, 2) generation of consensus clinical recommendations for the identification and treatment of TAND, to be incorporated as a TAND toolkit on the app, and 3) establishment of a global TAND consortium through networking, capacity-building and public engagement activities.

METHODS

TANDem is a four-year project, and includes 24 consortium members from 10 countries representing all World Health Organization regions. Collaborators represent five stakeholder groups (family representatives, technology experts, clinical experts, non-profit organisations and researchers). Here we outline the project study protocol in detail, describing the scientific rationale, the project aims and objectives, the methods involved in participant recruitment, multi-site and multi-phase data collection, data analysis, ethical considerations including informed consent, data protection, privacy and confidentiality considerations related to the European Union General Data Protection Regulation and the USA Health Insurance Portability and Accountability Act. The expected outcomes and potential impact on the TSC community, implementation and dissemination of results, as well as future scale-up and scale-out plans are also discussed.

CONCLUSIONS

The TANDem project has the potential to transform the global TSC community by empowering families living with TSC through an easily accessible digital solution to allow them to document their own TAND needs linked to an evidence-informed toolkit to enhance personalised healthcare, and by providing healthcare professionals with consensus clinical recommendations to prevent, identify and manage TAND manifestations.

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

BACKGROUND

There is limited research into the nature and aetiology of temper outbursts in people with intellectual disabilities. In this study, we describe the phenomenology and environmental context of temper outbursts in Lowe syndrome, a rare genetic syndrome in which outbursts are purportedly frequent.

METHOD

A temper outburst interview (TOI) was conducted with caregivers of seventeen individuals with Lowe syndrome to generate an account of the behavioural sequence, common antecedents and consequences of temper outbursts, and to enable comparisons with similar work on Prader-Willi syndrome.

RESULTS

Outbursts in Lowe syndrome were frequently triggered by thwarted goal-directed behaviour and were associated with high levels of physical aggression and property destruction.

CONCLUSIONS

Form and sequence of outbursts showed similarities to Prader-Willi syndrome and to behaviours reported in literature on typically developing children. The results highlight the importance of considering shared aetiology as well as syndrome-specific pathways in the development of outbursts.

Correlates of early cognition in infants with Down syndrome

BACKGROUND

While delays in cognitive development are detectable during early development in Down syndrome, the neuropsychological and biomedical underpinnings of cognitive skill acquisition in this population remain poorly understood.

METHOD

To explore this issue, 38 infants with Down syndrome [mean chronological age = 9.65 months; SD = 3.64] completed the Bayley Scales of Infant Development-III and a set of laboratory tasks that measured sustained attention (duration of visual attention during a 1-min object exploration task), attention shifting (mean latency to shift attention on an alternating object presentation task) and visual short-term memory (dishabituation to a novel object on a change preference task).

RESULTS

Latency to shift attention was negatively associated with Bayley Cognitive Scale raw scores, even when controlling for the effects of chronological age, r (33) = -.41, P = .02. In addition, prematurity status was associated with latency to shift attention.

CONCLUSIONS

Early attention shifting may be an important factor that facilitates overall cognitive skill acquisition in infants with Down syndrome, and premature birth may be a risk factor for difficulties on this dimension.

Early gesture use in fragile X syndrome

BACKGROUND

Emerging evidence suggests that children with fragile X syndrome (FXS) exhibit abnormal gesture use early in development, although few studies have investigated the emergence of gesture use in this population or the impact of autism spectrum disorder (ASD) features on these behaviours. The present study examined the longitudinal development of gesture use in infants with FXS relative to low-risk controls and infant siblings of children with ASD (high-risk siblings), with the goal of establishing potentially unique patterns of gesture development in infants with FXS and understanding the relative impact of ASD symptom severity on these patterns.

METHOD

Participants included 86 male infants (39 FXS, 27 high-risk siblings and 20 low-risk infants) assessed at 9, 12 and 24 months of age. Multilevel modelling was used to assess differences in number of gestures used and rates of gesture use across groups, as well as the relative impact of ASD symptom severity and nonverbal skills on these patterns.

RESULTS

Infants with FXS used fewer gestures than high-risk siblings and low-risk infants, with this difference being primarily accounted for by the effect of low nonverbal abilities in the FXS group. Furthermore, although higher ASD symptom severity was associated with the use of fewer gestures in both the FXS and high-risk sibling groups, a significant amount of variance was shared between ASD symptom severity and nonverbal skills in FXS, but not in high-risk siblings.

CONCLUSIONS

This study presents the first longitudinal analysis of early gesture development in FXS by using a multigroup design, clarifying the relative roles of cognitive deficits and ASD symptom severity in the development of gesture use in FXS. These findings offer novel evidence that early gesture use in FXS may reflect broader features of the FXS phenotype rather than predicting later social-communicative deficits characteristic of comorbid ASD.

Experimental evidence that density mediates negative frequency-dependent selection on aggression

Aggression can be beneficial in competitive environments if aggressive individuals are more likely to access resources than non-aggressive individuals. However, variation in aggressive behaviour persists within populations, suggesting that high levels of aggression might not always be favoured. The goal of this study was to experimentally assess the effects of population density and phenotypic frequency on selection on aggression in a competitive environment. We compared survival of two strains of Drosophila melanogaster that differ in aggression across three density treatments and five frequency treatments (single strain groups, equal numbers of each strain and strains mixed at 3:1 and 1:3 ratios) during a period of limited resources. While there was no difference in survival across single-strain treatments, survival was strongly density dependent, with declining survival as density increased. Furthermore, at medium and high densities, there was evidence of negative frequency-dependent selection, where rare strains experienced greater survival than common strains. However, there was no evidence of negative frequency-dependent selection at low density. Our results indicate that the benefits of aggression during periods of limited resources can depend on the interaction between the phenotypic composition of populations and population density, both of which are mechanisms that could maintain variation in aggressive behaviours within natural populations.

The effects of early positive parenting and developmental delay status on child emotion dysregulation

BACKGROUND

Emotion regulation has been identified as a robust predictor of adaptive functioning across a variety of domains (Aldao et al. ). Furthermore, research examining early predictors of competence and deficits in ER suggests that factors internal to the individual (e.g. neuroregulatory reactivity, behavioural traits and cognitive ability) and external to the individual (e.g. caregiving styles and explicit ER training) contribute to the development of ER (Calkins ). Many studies have focused on internal sources or external sources; however, few have studied them simultaneously within one model, especially in studies examining children with developmental delays (DD). Here, we addressed this specific research gap and examined the contributions of one internal factor and one external factor on emotion dysregulation outcomes in middle childhood. Specifically, our current study used structural equation modelling (SEM) to examine prospective, predictive relationships between DD status, positive parenting at age 4 years and child emotion dysregulation at age 7 years.

METHOD

Participants were 151 families in the Collaborative Family Study, a longitudinal study of young children with and without DD. A positive parenting factor was composed of sensitivity and scaffolding scores from mother-child interactions at home and in the research centre at child age 4 years. A child dysregulation factor was composed of a dysregulation code from mother-child interactions and a parent-report measure of ER and lability/negativity at age 7 years. Finally, we tested the hypothesis that positive parenting would mediate the relationship between DD and child dysregulation.

RESULTS

Mothers of children with DD exhibited fewer sensitive and scaffolding behaviours compared with mothers of typically developing children, and children with DD were more dysregulated on all measures of ER. SEM revealed that both DD status and early positive parenting predicted emotion dysregulation in middle childhood. Furthermore, findings provided support for our hypothesis that early positive parenting mediated the relationship between DD and dysregulation.

CONCLUSIONS

This work enhances our understanding of the development of ER across childhood and how endogenous child factors (DD status) and exogenous family factors (positive parenting) affect this process. Our findings provide clear implications for early intervention programmes for children with DD. Because of the predictive relationships between (a) developmental status and ER and (b) parenting and ER, the results imply that sensitive parenting behaviours should be specifically targeted in parent interventions for children with DD.

Problem behaviour in adolescent boys with fragile X syndrome: relative prevalence, frequency and severity

BACKGROUND

A large proportion of boys with fragile X syndrome (FXS), the most common known inherited form of intellectual disability (ID), exhibit problem behaviours (e.g. aggression, self-injury, property destruction and stereotypy) that can negatively impact the health and safety of others as well as the individual concerned. However, data are limited concerning the relative prevalence, frequency and severity of problem behaviours exhibited by boys with FXS compared with those by boys with mixed-aetiology ID who also exhibit problem behaviours.

METHOD

As part of a larger study on problem behaviour, we obtained survey data on 85 adolescent boys with FXS and 155 age-matched boys with mixed-aetiology ID who exhibited at least one form of problem behaviour.

RESULTS

For boys with FXS, stereotypy was reported to be more prevalent (χ²  = 4.52, P = 0.012), self-injury was reported to more frequent (U = 2525, P = 0.010) and aggression was reported to be less severe (U = 4176, P = 0.029) than for boys with mixed-aetiology ID. Ratings of aggression and property destruction were highly correlated in each group in terms of both frequency and severity (r = 0.60 to 0.71). Examination of the data by age indicated that the relative frequency of self-injury decreased with age in boys with FXS (χ²  = 8.29, P = 0.040).

CONCLUSIONS

Taken together, these results refine and extend previous studies concerning the specificity of the behavioural phenotype in FXS and indicate that specific forms of problem behaviour shown by boys with FXS appear to differ from those exhibited by boys with mixed-aetiology ID in terms of prevalence, frequency and severity. Studies employing more objective measures of frequency and severity, including direct observations, are needed to confirm these findings.

Boys with fragile X syndrome: investigating temperament in early childhood

BACKGROUND

Fragile X syndrome (FXS) is an x-linked genetic disorder that represents the most common hereditary cause of Intellectual Disability (ID). Very specific behavioural features (e.g. attention deficit hyperactivity disorder and stereotyped behaviour) are associated with FXS in adolescents and adults, yet research on temperament and behavioural characteristics in young children with FXS has been more limited and less conclusive.

METHOD

This study investigated temperament differences in young boys (3-7 years old) with FXS (N = 26) recruited from a national FXS centre and controls (N = 26) matched on age, gender and race.

RESULTS

Compared with controls, boys with FXS exhibited less overall surgency/extraversion and effortful control. Boys with FXS also displayed significantly greater activity and shyness and less attentional focusing, inhibitory control, soothability and high intensity pleasure (tendency to enjoy intense/complex activities), relative to comparison children. A significant interaction between age and diagnosis (FXS or control) was observed for negative affectivity only.

CONCLUSIONS

Attention difficulties commonly found in adolescents and adults with FXS appear to also be characteristic of young boys with FXS, as reflected by lower effortful control. Age-related findings concerning negative affectivity may be particularly significant, leading to improved intervention/preventative efforts.

Social cognitive training in adolescents with chromosome 22q11.2 deletion syndrome: feasibility and preliminary effects of the intervention

BACKGROUND

Children with chromosome 22q11.2 deletion syndrome (22q11DS) often have deficits in social cognition and social skills that contribute to poor adaptive functioning. These deficits may be of relevance to the later occurrence of serious psychiatric illnesses such as schizophrenia. Yet, there are no evidence-based interventions to improve social cognitive functioning in children with 22q11DS.

METHODS

Using a customised social cognitive curriculum, we conducted a pilot small-group-based social cognitive training (SCT) programme in 13 adolescents with 22q11DS, relative to a control group of nine age- and gender-matched adolescents with 22q11DS.

RESULTS

We found the SCT programme to be feasible, with high rates of compliance and satisfaction on the part of the participants and their families. Our preliminary analyses indicated that the intervention group showed significant improvements in an overall social cognitive composite index.

CONCLUSIONS

SCT in a small-group format for adolescents with 22q11DS is feasible and results in gains in social cognition. A larger randomised controlled trial would permit assessment of efficacy of this promising novel intervention.

Relationship dimensions of the 'Down syndrome advantage'

BACKGROUND

Some researchers have proposed an 'advantage' for parents of children with Down syndrome over parents of children with other intellectual disabilities, especially in relation to experiencing less parenting stress. Others have maintained that these differences are an artefact of demographic and related differences. This study extends the investigation of possible differences in dimensions of parenting stress and also examines whether differences exist in maternal and child contingent responsiveness during mother-child interaction in these two groups.

METHOD

Mothers of children with Down syndrome (n = 43) and undifferentiated developmental disabilities (n = 54) completed measures of children's adaptive functioning and behaviour problems, parenting stress and maternal social support. Observers rated the contingent interactions between mothers and children using the Nursing Child Assessment Teaching Scale.

RESULTS

Once mother's age, education and social support as well as child adaptive functioning and behaviour problems were considered, neither parent nor child related parenting stress demonstrated an advantage for parents of children with Down syndrome. However, a 'Down syndrome advantage' was apparent for both maternal and child contingent responsiveness after accounting for maternal demographic and contextual variables and child attributes.

CONCLUSIONS

Children with Down syndrome and their mothers have more positive interactions than children with other developmental disabilities, both in terms of the responsiveness of mothers and of child responses contingent on maternal behaviour. These findings suggest that both children with Down syndrome themselves and their mothers are contributing to a Down syndrome advantage.

Temper outbursts in Prader-Willi syndrome: causes, behavioural and emotional sequence and responses by carers

BACKGROUND

Temper outbursts are common in Prader-Willi syndrome but rarely described in detail. This study investigated the phenomenology of temper outbursts in terms of antecedents, sequence of behaviours and emotions and intervention strategies used.

METHOD

A semi-structured interview about temper outbursts was conducted with the main carers of seven children (9.5 to 16.7 years) and seven adults (24.7 to 47.10 years) with Prader-Willi syndrome (10 male, 4 female). Reliability and validity of the interview results was established.

RESULTS

Various setting events increased and reduced the likelihood of temper outbursts. The most common antecedent was a change to routine or expectation. There were marked similarities in the sequence of behaviours and emotions during temper outbursts, with anger rising quickly followed by expressions of remorse and distress at the end of an outburst.

DISCUSSION

The sequence of behaviours and emotions within outbursts was similar to that described in temper tantrums in typical development. Cognitive and emotional processes are likely to be important in the understanding of temper outbursts with implications for early intervention.

Determinants of adult functional outcome in adolescents receiving special educational assistance

BACKGROUND

This study investigates the role of IQ, autistic traits and challenging behaviours in affecting adult outcomes among adolescents who receive special educational assistance.

METHODS

A total of 58 participants were recruited from an ongoing longitudinal study. All received assessments of IQ, behavioural patterns (using the Childhood Behaviour Checklist - CBCL) and autistic traits (using the Social Communication Questionnaire - SCQ) during adolescence and were followed up 6 years later (at a mean age of 22 years) using the World Health Organization Disability Assessment Schedule II (WHO-DAS II) to assess functional outcome.

RESULTS

A significant positive relationship was found between CBCL score and WHO-DAS II score (β = 0.511, P = 0.001). IQ score showed a negative relationship with total WHO-DAS II score (β = -0.247, P = 0.04). SCQ score was not found to significantly influence total WHO-DAS II score (β = -0.028, P = 0.84).

CONCLUSIONS

Although the role of global intellectual ability is important, these results stress the highly predictive value of adolescent behaviours on functional outcomes in adult life among young adults receiving special educational assistance.

From mTOR to cognition: molecular and cellular mechanisms of cognitive impairments in tuberous sclerosis

BACKGROUND

Tuberous sclerosis (TSC) is a multi-system disorder caused by heterozygous mutations in the TSC1 or TSC2 gene and is often associated with neuropsychiatric symptoms, including intellectual disability, specific neuropsychological deficits, autism, other behavioural disorders and epilepsy.

METHOD

Here, we review evidence from animal models of TSC for the role of specific molecular and cellular processes in the pathogenesis of cognitive, developmental and epilepsy-related manifestations seen in the disorder.

RESULTS

Recent evidence shows that, in animal models, disinhibited mTOR (mammalian target of rapamycin) signalling substantially contributes to neuropsychiatric phenotypes, including cognitive deficits and seizures. We discuss potential pathogenetic mechanisms involved in the cognitive phenotypes of TSC and present implications regarding mTOR inhibitor-based treatments for TSC-related neuropsychiatric features.

CONCLUSIONS

Results suggest that reversing the underlying molecular deficits of TSC with rapamycin or other mTOR inhibitors could result in clinically significant improvements of cognitive function and neurological symptoms, even if treatments are started in adulthood.

Preschool children with intellectual disability: syndrome specificity, behaviour problems, and maternal well-being

BACKGROUND

Children with intellectual disability (ID) are at heightened risk for behaviour problems and diagnosed mental disorder. Likewise, mothers of children with ID are more stressed than mothers of typically developing children. Research on behavioural phenotypes suggests that different syndromes of ID may be associated with distinct child behavioural risks and maternal well-being risks. In the present study, maternal reports of child behaviour problems and maternal well-being were examined for syndrome-specific differences.

METHODS

The present authors studied the early manifestation and continuity of syndrome-specific behaviour problems in 215 preschool children belonging to 5 groups (typically developing, undifferentiated developmental delays, Down syndrome, autism, cerebral palsy) as well as the relation of syndrome group to maternal well-being.

RESULTS

At age 3, children with autism and cerebral palsy showed the highest levels of behaviour problems, and children with Down syndrome and typically developing children showed the lowest levels. Mothers of children with autism reported more parenting stress than all other groups. These syndrome-specific patterns of behaviour and maternal stress were stable across ages 3, 4 and 5 years, except for relative increases in behaviour problems and maternal stress in the Down syndrome and cerebral palsy groups. Child syndrome contributed to maternal stress even after accounting for differences in behaviour problems and cognitive level.

CONCLUSIONS

These results, although based on small syndrome groups, suggest that phenotypic expressions of behaviour problems are manifested as early as age 3. These behavioural differences were paralleled by differences in maternal stress, such that mothers of children with autism are at elevated risk for high stress. In addition, there appear to be other unexamined characteristics of these syndromes, beyond behaviour problems, which also contribute to maternal stress.