II. Hypersociability in Williams Syndrome

Towards a genetics of semantics? False memories and semantic memory organization in Williams syndrome

Williams syndrome (WS) is a rare genetic neurodevelopmental disorder caused by microdeletion of a critical region on chromosome 7q11.23. At the cognitive level, it is usually characterized by moderate intellectual disability and deficits in visuospatial skills, while showing relative strengths in verbal skills and nonverbal reasoning. Despite their apparent good performance with verbal skills, previous studies have suggested that the structure of semantic memory may be altered in people diagnosed with WS. In this study, we explored the organization of semantic memory in WS through the Deese-Roediger-McDermott (DRM) paradigm, a task in which participants are induced to produce false memories through semantic associations. 24 participants with WS and 24 controls matched for gender and verbal mental age participated in the study. Results showed that the WS group, compared to the control group, had less false memories of critical lures, and made associations with words less related to the items studied. Taken together, these results suggest that semantic memory organization may be atypical in WS. We discuss how certain genes usually associated with the WS cognitive phenotype, GTF2I and GTF2IRD1, might modulate the development of brain areas responsible for semantic processing, ultimately producing atypical associations between words in the semantic networks of the mental lexicon.

Behaviour and Psychopathology in Preschool Children with William Syndrome and the Effects of Age, Sex and Cognition

The current study compared the prevalence of cognitive and psychopathological impairments among 24 preschool children with Williams syndrome (WS) (aged 2.20 to 5.97 years) and 53 controls without WS and screened for developmental or psychological diagnoses (aged 2.21 to 5.89 years) matched on chronological age and sex distribution. Associations between sex, chronological age, early development and psychopathology were also investigated. The Child Behavior Checklist-Preschool Version (CBCL) and the Mullen Scales of Early Learning were administered. Higher reported rates of Attention Problems, Emotional Reactivity, Somatic Complaints, Withdrawal, Affective Problems and Total Problems were found in preschool children with WS. There were no significant group differences in prevalence rates of all other CBCL domains. Attention Problems were the most prevalent psychopathology in preschool children with WS (33% falling in the clinically significant range), followed by Affective Problems (29% in clinically significant range), then Anxiety Problems (17%) or Attention Deficit/Hyperactivity Problems (17%). Among children without WS, the highest prevalence rates of psychopathology were for Attention Problems (4% falling in the clinically significant range), Aggressive Behaviour (4%), Sleep Problems (4%) and Oppositional Defiant Problems (4%). There were no significant associations between sex or chronological age and CBCL-reported psychopathology for either group. In addition, there were no significant relationships between CBCL ratings and verbal ability, nonverbal ability or overall developmental level in either group. Findings highlight variations in the pattern of psychopathology among preschool children with WS compared to those without WS, which needs to be considered in clinical management and future research.

Developmental process of the understanding of linguistic register in children: A comparison of typically developing children, autistic children, and children with Williams syndrome

Although the developmental process of linguistic register-the appropriate manner of speech as determined by the listener and social situation-has been gradually clarified in typically developing (TD) children, research on the mechanism and developmental process of register acquisition in atypically developing children are insufficient. This study compared the developmental process of understanding linguistic register among TD children, autistic children, and those with Williams syndrome (WS), and examined the contributions of social cognition and motivation to the acquisition of linguistic register. Two experiments were designed to assess the recognition of which linguistic register to use when communicating with different listeners and of the listener's feelings according to the speakers' use of register. The results revealed that the process of understanding register-listener associations was nearly identical among all groups of children and their understanding improved with age. Conversely, their understanding of the effect of register selection on the listener's feelings varied. Importantly, as TD children mature, they become aware that adult listeners may feel negatively when spoken to in an inappropriate register, whereas autistic children and those with WS do not exhibit the same awareness. Thus, our results suggest that atypical social cognition and motivation do not disturb the understanding of register-listener associations. However, social cognition and motivation play important roles in understanding the effect of register selection on the listener's feelings. These findings provide a significant contribution to clarifying the mechanism of linguistic register acquisition.

Comparison of the Social Responsiveness Scale-2 among Individuals with Autism Spectrum Disorder and Williams Syndrome in Japan

This study examined the similarities/differences between the social phenotypes of Williams syndrome (WS) and autism spectrum disorder (ASD). As cultural norms may affect symptom evaluation, this study administered the Social Responsiveness Scale-2 to Japanese individuals with WS (n = 78, 4.4-44.0 years) and ASD (n = 75, 4.7-55.4 years). The scores for Social Motivation and Social Communication were significantly more severe in the ASD than WS group. Overall, the similarities and differences between the social phenotypes of the syndromes were consistent with the findings of a recent study conducted in the UK, except for the social awareness subscale score. This highlights the importance of cross-cultural investigations of WS and ASD.

Why do individuals with Williams syndrome or Down syndrome fail the Weather Prediction Task?

Williams syndrome (WS) and Down syndrome (DS) are two neurodevelopmental disorders with distinct genetic origins characterized by mild to moderate intellectual disability. Individuals with WS or DS exhibit impaired hippocampus-dependent place learning and enhanced striatum-dependent spatial response learning. Here, we used the Weather Prediction Task (WPT), which can be solved using hippocampus- or striatum-dependent learning strategies, to determine whether individuals with WS or DS exhibit similar profiles outside the spatial domain. Only 10% of individuals with WS or DS solved the WPT. We further assessed whether a concurrent memory task could promote reliance on procedural learning to solve the WPT in individuals with WS but found that the concurrent task did not improve performance. To understand how the probabilistic cue-outcome associations influences WPT performance, and whether individuals with WS or DS can ignore distractors, we assessed performance using a visual learning task with differing reward contingencies, and a modified WPT with unpredictive cues. Both probabilistic feedback and distractors negatively impacted the performance of individuals with WS or DS. These findings are consistent with deficits in hippocampus-dependent learning and executive functions, and reveal the importance of congruent feedback and the minimization of distractors to optimize learning in these two populations.

Serine racemase deletion alters adolescent social behavior and whole-brain cFos activation

Background

Neurodevelopmental disorders (NDDs) can cause debilitating impairments in social cognition and aberrant functional connectivity in large-scale brain networks, leading to social isolation and diminished everyday functioning. To facilitate the treatment of social impairments, animal models of NDDs that link N- methyl-D-aspartate receptor (NMDAR) hypofunction to social deficits in adulthood have been used. However, understanding the etiology of social impairments in NDDs requires investigating social changes during sensitive windows during development.

Methods

We examine social behavior during adolescence using a translational mouse model of NMDAR hypofunction (SR-/-) caused by knocking out serine racemase (SR), the enzyme needed to make D-serine, a key NMDAR coagonist. Species-typical social interactions are maintained through brain-wide neural activation patterns; therefore, we employed whole-brain cFos activity mapping to examine network-level connectivity changes caused by SR deletion.

Results

In adolescent SR-/- mice, we observed disinhibited social behavior toward a novel conspecific and rapid social habituation toward familiar social partners. SR-/- mice also spent more time in the open arm of the elevated plus maze which classically points to an anxiolytic behavioral phenotype. These behavioral findings point to a generalized reduction in anxiety-like behavior in both social and non-social contexts in SR-/- mice; importantly, these findings were not associated with diminished working memory. Inter-regional patterns of cFos activation revealed greater connectivity and network density in SR-/- mice compared to controls.

Discussion

These results suggest that NMDAR hypofunction - a potential biomarker for NDDs - can lead to generalized behavioral disinhibition in adolescence, potentially arising from disrupted communication between and within salience and default mode networks.

Contrasting neurofunctional correlates of face- and visuospatial-processing in children and adolescents with Williams syndrome: convergent results from four fMRI paradigms

Understanding neurogenetic mechanisms underlying neuropsychiatric disorders such as schizophrenia and autism is complicated by their inherent clinical and genetic heterogeneity. Williams syndrome (WS), a rare neurodevelopmental condition in which both the genetic alteration (hemideletion of ~ twenty-six 7q11.23 genes) and the cognitive/behavioral profile are well-defined, offers an invaluable opportunity to delineate gene-brain-behavior relationships. People with WS are characterized by increased social drive, including particular interest in faces, together with hallmark difficulty in visuospatial processing. Prior work, primarily in adults with WS, has searched for neural correlates of these characteristics, with reports of altered fusiform gyrus function while viewing socioemotional stimuli such as faces, along with hypoactivation of the intraparietal sulcus during visuospatial processing. Here, we investigated neural function in children and adolescents with WS by using four separate fMRI paradigms, two that probe each of these two cognitive/behavioral domains. During the two visuospatial tasks, but not during the two face processing tasks, we found bilateral intraparietal sulcus hypoactivation in WS. In contrast, during both face processing tasks, but not during the visuospatial tasks, we found fusiform hyperactivation. These data not only demonstrate that previous findings in adults with WS are also present in childhood and adolescence, but also provide a clear example that genetic mechanisms can bias neural circuit function, thereby affecting behavioral traits.

Specificity of Early Childhood Hyperphagia Profiles in Neurogenetic Conditions

Hyperphagia is highly penetrant in Prader-Willi syndrome (PWS) and has increasingly been reported in other neurogenetic conditions (NGC). The Hyperphagia Questionnaire (HQ) was completed by caregivers of 4-8-year-olds with PWS (n = 17), Angelman syndrome (AS; n = 22), Williams syndrome (WS; n = 25), or low-risk controls (LRC; n = 35). All NGC groups were significantly elevated in HQ Total and Behavior scores compared to LRC. Only AS and WS were significantly elevated in the Drive domain, and only PWS in the Severity domain. After controlling for externalizing behavior, HQ Total scores were higher for PWS relative to other groups. Hyperphagic symptoms may not differentiate PWS from other NGCs in early childhood. However, hyperphagic phenotypes may be most severe in PWS. Further investigation of these profiles may inform etiology and syndrome-specific treatments.

Using a community engaged research approach to develop the social skills training program for adults with Williams syndrome

This article describes the development of a distance-delivered social skills training program for adults with Williams syndrome (SSTP-WS) through a community engaged approach. Throughout six phases of development, the research team received input from adults with Williams syndrome, caregivers, service providers, educators, and researchers on (a) the need for a training program and topics to be addressed (Phase 1), (b) an initial draft of the SSTP-WS (Phase 3), (c) the intervention pilot study (Phase 5), and (d) feedback to provide context for the results of the study (Phase 6). The development of the SSTP-WS resulted in an intervention aligned with the Williams syndrome community's values and needs that supports the unique cognitive and behavioral phenotypes and social characteristics of this low incidence disability population.

Evaluating the challenges and needs of parents caring for children with Williams syndrome: A preliminary study from Poland

BACKGROUND

Although physical, cognitive and behavioural manifestations of Williams syndrome (WS) affect every dimension of caregivers lives, no studies on the parental experiences of caring for a WS child have to date been carried out in Poland.

METHODS

In order to identify the challenges and needs of Polish carers of WS children a survey was conducted with 32 family caregivers who were supported by the Polish Williams Syndrome Association.

RESULTS

While caregivers were mostly challenged by their WS child's behaviours, health problems and mood swings, many parents experienced fatigue, intimacy problems with the partner and deterioration of mental health. They were also burdened by the lack of time for themselves and work restrictions resulting from caregiving responsibilities. Even though parents positively assessed quality of medical care for WS children, still many expressed their dissatisfaction both with the way the healthcare system for WS children works in Poland and complained about the doctors' lack of knowledge about WS, access to specialist care and lack of support from government and social institutions. Although many parents stressed positive impact of rising WS child, more than half experienced role captivity or role overload and felt not being understood by others. They also experienced variety of distressing emotions, including impatience, emotional lability, helplessness, anxiety and depression.

CONCLUSIONS

Although many WS parents stressed the affirmative aspect of raising WS child this research shows that the burden of caring for such a child goes far beyond clinical aspects and seriously affects every aspect of parents' lives, including their mental health, daily lives, family, their professional and social lives. Because apart from the daily challenges related to caring for a WS child, parents' dealings with the healthcare system and support services represent major problems there is a the need for a bio-psychosocial approach to WS that should include not only WS children, but also their caregivers. WHAT THIS PAPER ADDS?: 1. It analyses the challenges and needs of parents caring for children with Williams syndrome; 2. It provides evidence that the impact of caring for WS children goes far beyond clinical aspects and seriously affects every aspect of parents' lives, including their mental health, daily lives, family, their professional and social lives; 3. It also shows that, apart from the daily challenges related to caring for a WS child, parents' dealings with the healthcare system and support services represent major problems. 4. Thereby, it highlights the importance of incorporating a bio-psychosocial approach to WS that should include not only WS children, but also their caregivers.

Comparison of the Sensory Profile Among Autistic Individuals and Individuals with Williams Syndrome

PURPOSE

With the current study, we aimed to reveal the similarities and differences in sensory profiles between Williams syndrome (WS) and autism spectrum disorder.

METHODS

Using the sensory profile questionnaire completed by the caregivers, we analyzed the WS (n = 60, 3.4-19.8 years) and autistic (n = 39, 4.2-14.0 years) groups.

RESULTS

The Severity Analysis revealed a significant group difference in Sensory Sensitivity but not in Low Registration, Sensation Seeking, and Sensation Avoiding subscales. Age can modulate the subscale scores differently across groups. For Sensation Seeking, the scores of both groups decreased with development. However, the scores of Sensory Sensitivity decreased with age in the autistic group but not in the WS group. Sensation Avoiding scores increased with development in the WS group but not in the autistic group. No significant developmental changes were observed in Low Registration.

CONCLUSION

This study highlights the cross-syndrome similarities and differences in sensory profiles and developmental changes in autistic individuals and individuals with WS.

Intensive Care Unit Analgosedation After Cardiac Surgery in Children with Williams Syndrome : a Matched Case-Control Study

OBJECTIVE

Cardiovascular abnormalities are common in patients with Williams syndrome and frequently require surgical intervention necessitating analgesia and sedation in a population with a unique neuropsychiatric profile, potentially increasing the risk of adverse cardiac events during the perioperative period. Despite this risk, the overall postoperative analgosedative requirements in patients with WS in the cardiac intensive care unit have not yet been investigated. Our primary aim was to examine the analgosedative requirement in patients with WS after cardiac surgery compared to a control group. Our secondary aim was to compare the frequency of major ACE and mortality between the two groups.

DESIGN

Matched case-control study.

SETTING

Pediatric CICU at a Tertiary Children's Hospital.

PATIENTS

Patients with WS and age-matched controls who underwent cardiac surgery and were admitted to the CICU after cardiac surgery between July 2014 and January 2021.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Postoperative outcomes and total doses of analgosedative medications were collected in the first six days after surgery for the study groups. Median age was 29.8 (12.4-70.8) months for WS and 23.5 (11.2-42.3) months for controls. Across all study intervals (48 h and first 6 postoperative days), there were no differences between groups in total doses of morphine equivalents (5.0 mg/kg vs 5.6 mg/kg, p = 0.7 and 8.2 mg/kg vs 10.0 mg/kg, p = 0.7), midazolam equivalents (1.8 mg/kg vs 1.5 mg/kg, p = 0.4 and 3.4 mg/kg vs 3.8 mg/kg, p = 0.4), or dexmedetomidine (20.5 mcg/kg vs 24.4 mcg/kg, p = 0.5 and 42.3 mcg/kg vs 39.1 mcg/kg, p = 0.3). There was no difference in frequency of major ACE or mortality.

CONCLUSIONS

Patients with WS received similar analgosedative medication doses compared with controls. There was no significant difference in the frequency of major ACE (including cardiac arrest, extracorporeal membrane oxygenation, and surgical re-intervention) or mortality between the two groups, though these findings must be interpreted with caution. Further investigation is necessary to elucidate the adequacy of pain/sedation control, factors that might affect analgosedative needs in this unique population, and the impact on clinical outcomes.

Early Communicative Development in Williams Syndrome: A Longitudinal Case Study

Individuals with Williams Syndrome (WS) have a specific and atypical neuropsychological profile, where language is above what is expected for their mental age, although it shows a late onset. There exists only one longitudinal study in infants younger than 20 months old with WS about early language precursors (joint attention, referential and instrumental behaviors, pointing gesture, verbal tags). The aim of this investigation is to evaluate these precursors in a baby with WS (8 to 18 months). Seven sessions of systematic observation were performed (six at baby's home, one at the Early Childhood Assistance center). The Battelle Developmental Inventory was used to evaluate the baby's development in two occasions (12 and 18 months). The results show an atypical development, and he is 5-6 months under what is expected for his chronological age. Attention towards objects prevails over preference for faces, but this one tends to increase. The pointing gesture does not emerge at the end of the observation period and therefore follows the first words that appear. The implications for the comprehension of the early linguistic profile in WS are discussed, as well as the implications for specific intervention strategies in the context of early childhood care.

No transfer of arousal from other's eyes in Williams syndrome

Typically developing humans automatically synchronize their arousal levels, resulting in pupillary contagion, or spontaneous adaptation of pupil size to that of others. This phenomenon emerges in infancy and is believed to facilitate social interaction. Williams syndrome (WS) is a genetic condition characterized by a hyper-social personality and social interaction challenges. Pupillary contagion was examined in individuals with WS (n = 44), age-parallel-matched typically developing children and adults (n = 65), and infants (n = 79). Bayesian statistics were used. As a group, people with WS did not show pupillary contagion (Bayes factors supporting the null: 25-50) whereas control groups did. This suggests a very early emerging atypical developmental trajectory. In WS, higher pupillary contagion was associated with lower autistic symptoms of social communication. Diminished synchronization of arousal may explain why individuals with WS have social challenges, whereas synchronization of arousal is not a necessary correlate of high social motivation.

Emotion Priming in People with Williams Syndrome

Emotion categories configure the basic semantic knowledge of the human cognitive structure. Previous studies with people with Williams syndrome (WS) investigated their ability to process basic emotions and the dimensions of emotional valences. However, little is known about the categorization of emotions from the subordinate perspective of lexical words in people with WS. In this study, emotion priming was used as the research paradigm. Three types of emotional valence were used as stimuli: positive, neutral, and negative. Each emotional valence was used as a prime matched to a target in one of these same three types of emotional valence. All participants were asked to judge whether the prime and the target were matched in their emotional valence. People with WS (n = 14, 11M/3F, CA = 10.49, and MA = 6.57) showed priming patterns for emotion valences like those of the typically developing controls. When positive primes were presented, accuracy was higher for positive and negative targets than neutral targets. When neutral primes were presented, accuracy was highest for negative targets. When negative primes were presented, accuracy was the lowest for negative targets. All participants showed high priming accuracy for positive emotions; however, they confused neutral with positive targets. A negative priming effect was observed when negative primes preceded negative targets. Considering previous findings that people with WS show developmental delays in the basic emotions of anger and surprise, this study concludes that people with WS responded least accurately to the classification of emotional valence. The findings regarding the categorization of emotions in people with WS not only advance our understanding of their emotion knowledge and socioemotional cognition but also confirm the superficial enrichment of lexical semantics with weak conceptual change in people with WS. This weakness may result in impaired contextual integration in people with WS.

Social feedback enhances learning in Williams syndrome

Williams syndrome (WS) is a rare genetic condition characterized by high social interest and approach motivation as well as intellectual disability and anxiety. Despite the fact that social stimuli are believed to have an increased intrinsic reward value in WS, it is not known whether this translates to learning and decision making. Genes homozygously deleted in WS are linked to sociability in the general population, making it a potential model condition for understanding the social brain. Probabilistic reinforcement learning was studied with either social or non-social rewards for correct choices. Social feedback improved learning in individuals with Williams syndrome but not in typically developing controls or individuals with other intellectual disabilities. Computational modeling indicated that these effects on social feedback were mediated by a shift towards higher weight given to rewards relative to punishments and increased choice consistency. We conclude that reward learning in WS is characterized by high volatility and a tendency to learn how to avoid punishment rather than how to gain rewards. Social feedback can partly normalize this pattern and promote adaptive reward learning.

Autism spectrum disorder symptom expression in individuals with 3q29 deletion syndrome

BACKGROUND

The 1.6 Mb 3q29 deletion is associated with neurodevelopmental and neuropsychiatric phenotypes, including a 19-fold increased risk for autism spectrum disorder (ASD). Previous work by our team identified elevated social disability in this population via parent-report questionnaires. However, clinical features of ASD in this population have not been explored in detail.

METHODS

Thirty-one individuals with 3q29 deletion syndrome (3q29del, 61.3% male) were evaluated using two gold-standard clinical ASD evaluations: the Autism Diagnostic Observation Schedule, Second Edition (ADOS-2), and the Autism Diagnostic Interview, Revised (ADI-R). Four matched comparators for each subject were ascertained from the National Database for Autism Research. Item-level scores on the ADOS-2 and ADI-R were compared between subjects with 3q29del and matched comparators.

RESULTS

Subjects with 3q29del and no ASD (3q29del-ASD) had greater evidence of social disability compared to typically developing (TD) comparison subjects across the ADOS-2. Subjects with 3q29del and ASD (3q29del + ASD) were largely indistinguishable from non-syndromic ASD (nsASD) subjects on the ADOS-2. 3q29del + ASD performed significantly better on social communication on the ADI-R than nsASD (3q29 + ASD mean = 11.36; nsASD mean = 15.70; p = 0.01), and this was driven by reduced deficits in nonverbal communication (3q29 + ASD mean = 1.73; nsASD mean = 3.63; p = 0.03). 3q29del + ASD reported significantly later age at the first two-word phrase compared to nsASD (3q29del + ASD mean = 43.89 months; nsASD mean = 37.86 months; p = 0.01). However, speech delay was not related to improved nonverbal communication in 3q29del + ASD.

LIMITATIONS

There were not enough TD comparators with ADI-R data in NDAR to include in the present analysis. Additionally, our relatively small sample size made it difficult to assess race and ethnicity effects.

CONCLUSIONS

3q29del is associated with significant social disability, irrespective of ASD diagnosis. 3q29del + ASD have similar levels of social disability to nsASD, while 3q29del-ASD have significantly increased social disability compared to TD individuals. However, social communication is reasonably well preserved in 3q29del + ASD relative to nsASD. It is critical that verbal ability and social disability be examined separately in this population to ensure equal access to ASD and social skills evaluations and services.

An exploratory study on emotion regulation strategy use in individuals with Williams syndrome, autism spectrum disorder and intellectual disability

Background

Individuals with neurodevelopmental disorders often have atypical emotion profiles, but little is known about how they regulate their emotions. While several studies have examined emotion regulation strategy use in autism spectrum disorder (ASD), only a few have included individuals with intellectual disability (ID) or focused on specific syndromes such as Williams syndrome (WS).

Methods

A parent-reported survey launched during the first months of the COVID-19 pandemic allowed to exploratorily study emotion regulation strategy use and its link to anxiety in individuals with ASD with (N=785) and without ID (N=596), WS (N=261), and Intellectual Disability not otherwise specified (N=649).

Results

Using multilevel analyses, besides revealing specific group differences in emotion regulation strategy use, a variety of strategies (e.g., rumination, avoiding information, repetitive behaviors) were found to be linked to elevated levels of anxiety, while focusing on the positive was linked to lower anxiety levels in all groups. Moreover, only autistic people without ID used humor more frequently while experiencing lower anxiety levels.

Conclusion

This study sheds light on an underexplored area of emotion regulation strategy use in different neurodevelopmental disorders. It also paves the way to further examine emotion regulation in more rigorous ways to better understand emotion regulation in different neurodevelopmental disorders as well as the impact on outcome measures such as anxiety. This exploratory study may help to develop and validate adequate measures to study a broad array of ER strategies used by individuals with neurodevelopmental disorders.

Neuroanatomical correlates of social approach in Williams Syndrome and down syndrome

Individuals with Williams Syndrome (WS) or Downs Syndrome (DS) are often described as hypersociable, friendly and overly trusting of others. This hypersociability is a major concern for parents/caregivers due to the associated increased risk of exploitation and victimisation. Two brain regions - the amygdala and the orbitofrontal cortex (OFC) - have been implicated in driving this hypersociability in WS, and in the general population and have associations with emotional evaluation, threat detection and social motivation. However, there has been little neuroimaging research on this topic, especially in DS, to date. The aim of the present study was to investigate the potential neuroanatomical and neuropsychological correlates of hypersociability in WS and DS. Twelve individuals with WS (M = 22 years of age) and eleven individuals with DS (M = 26 years of age) completed a neuropsychological battery of executive functioning and social measures, including informant ratings on an ecologically measure of social approach. Clinical groups and twelve typically developing controls (M = 23 years) underwent a magnetic resonance imaging scan to investigate volumetric differences in the OFC and the amygdala. As expected, WS individuals displayed the highest overall social approach, especially in relation to need to approach strangers and drive to interact with strangers, as well as inappropriate/overfriendly behaviours. Both groups rated similarly in terms of social trust and unconditional positive regard. Emotion recognition abilities were similar across groups, with the DS group displaying some difficulties with negative emotions (especially anger). Inhibition and flexibility were similarly impaired across WS and DS. Compared to neurotypical controls, the DS group showed increased amygdala volumes bilaterally, while the WS group showed an enlarged right medial OFC. Approach ratings were significantly correlated with left amygdala and medial and left lateral OFC volumes in WS, and with these same regions bilaterally in DS. Results provide potential biological explanations for the hypersociability seen in WS and DS. Future research should focus on other potential neural correlates, as well as potential genetic and hormonal contributions to approach.

Investigating basic emotion knowledge of people with Williams syndrome

BACKGROUND

Emotional recognition is a key aspect of mentalizing other people's minds. People with Williams syndrome (WS) are reported to be hypersocial and empathetic; however, few studies have investigated their emotion processing ability.

AIMS

This study aimed to examine emotion knowledge in people with WS and to further understand their emotion-related mentalizing ability.

METHODS AND PROCEDURES

Six basic emotions (happiness, sadness, anger, fear, disgust, and surprise) were tested by narrating scenarios targeting specific emotions. Participants with WS (n = 16, 8F/8 M, CA = 8.46, MA = 5.27) listened to each scenario and pointed to an emoticon displayed on a card. Correct percentages of each target emotion and replacement by other emotions were analyzed. Comparison groups comprised mental age-matched controls (n = 16, 8F/8 M, CA = 5.26) and chronological age-matched controls (n = 16, 8 F/8 M, CA = 8.31), sixth graders (n = 20, 10F/10M, CA = 12.04), and college students (n = 20, 10F/10M, CA = 20.03). All were Chinese-speaking participants with right handedness.

OUTCOMES AND RESULTS

People with WS were delayed compared to the mental age-matched group but differed from the chronological age-matched group in emotion processing. The 6th graders showed different patterns from college students, suggesting that development of emotion processing takes time.

CONCLUSIONS AND IMPLICATIONS

These findings suggest (1) a gap in the maturation of emotion knowledge between people with WS and typically developing controls, (2) a nonequivalent chronological emotion-related mentalizing ability in people with WS, and (3) developmental changes in emotion processing from childhood to adulthood.

Auditory affective processing, musicality, and the development of misophonic reactions

Misophonia can be characterized both as a condition and as a negative affective experience. Misophonia is described as feeling irritation or disgust in response to hearing certain sounds, such as eating, drinking, gulping, and breathing. Although the earliest misophonic experiences are often described as occurring during childhood, relatively little is known about the developmental pathways that lead to individual variation in these experiences. This literature review discusses evidence of misophonic reactions during childhood and explores the possibility that early heightened sensitivities to both positive and negative sounds, such as to music, might indicate a vulnerability for misophonia and misophonic reactions. We will review when misophonia may develop, how it is distinguished from other auditory conditions (e.g., hyperacusis, phonophobia, or tinnitus), and how it relates to developmental disorders (e.g., autism spectrum disorder or Williams syndrome). Finally, we explore the possibility that children with heightened musicality could be more likely to experience misophonic reactions and develop misophonia.

The Quality of Everyday Eye Contact in Williams Syndrome: Insights From Cross-Syndrome Comparisons

Past research shows that individuals with Williams syndrome (WS) have heightened and prolonged eye contact. Using parent report measures, we examined not only the presence of eye contact but also its qualitative features. Study 1 included individuals with WS (n = 22, ages 6.0-36.3). Study 2 included children with different neurodevelopmental (ND) conditions (WS, autism spectrum condition, fragile X syndrome, attention-deficit/hyperactivity disorder) and children with neurotypical development (NT; n = 262, ages 4.0-17.11). Unusual eye contact features, including staring, were found in approximately half of the WS samples. However, other features such as brief glances were frequently found in WS and in all ND conditions, but not NT. Future research in ND conditions should focus on qualitative as well as quantitative features of eye contact.

Williams-Beuren Syndrome Related Methyltransferase WBSCR27: From Structure to Possible Function

Williams-Beuren syndrome (WBS) is a genetic disorder associated with the hemizygous deletion of several genes in chromosome 7, encoding 26 proteins. Malfunction of these proteins induce multisystemic failure in an organism. While biological functions of most proteins are more or less established, the one of methyltransferase WBSCR27 remains elusive. To find the substrate of methylation catalyzed by WBSCR27 we constructed mouse cell lines with a Wbscr27 gene knockout and studied the obtained cells using several molecular biology and mass spectrometry techniques. We attempted to pinpoint the methylation target among the RNAs and proteins, but in all cases neither a direct substrate has been identified nor the protein partners have been detected. To reveal the nature of the putative methylation substrate we determined the solution structure and studied the conformational dynamic properties of WBSCR27 in apo state and in complex with S-adenosyl-L-homocysteine (SAH). The protein core was found to form a canonical Rossman fold common for Class I methyltransferases. N-terminus of the protein and the β6–β7 loop were disordered in apo-form, but binding of SAH induced the transition of these fragments to a well-formed substrate binding site. Analyzing the structure of this binding site allows us to suggest potential substrates of WBSCR27 methylation to be probed in further research.

A Distance-Delivered Social Skills Program for Young Adults with Williams Syndrome: Evaluating Feasibility and Preliminary Efficacy

Adults with Williams syndrome (WS) display hypersocial behaviors and experience social skills deficits. To improve social outcomes, we evaluated the feasibility, acceptability, and preliminary efficacy of an 8-week distance-delivered social skills program for adults with WS. Sessions were offered twice a week for 90 min. Twenty-four adults with WS were assigned to an intervention or waitlist control group. Outcomes were assessed through interviews and surveys with adults with WS, parents, and facilitators. The intervention was rated as acceptable and feasible by all. Parents rated adults with WS as displaying significant improvements in social skills; yet ratings by adults with WS did not change. Adults also displayed increased social skills knowledge following participation. Implications for practice and future research are discussed.

A Comparison of Adaptive Functioning Between Children With Duplication 7 Syndrome and Williams-Beuren Syndrome: A Pilot Investigation

Interstitial deletions of 7q11.23 cause the well-known Williams-Beuren Syndrome (WBS), while duplication of the same region leads to duplication 7 syndrome (Dup7). Children with WBS share a distinct neurobehavioral phenotype including mild to severe intellectual disability, severely impaired visual spatial abilities, relatively preserved verbal expressive skills, anxiety problems, enhanced social motivation (i.e., hypersociable behaviors) and socio-communicative problems. Children with Dup7 syndrome exhibit some "inverted" features when compared to those of individuals with WBS, such as reduced social motivation and impairment of expressive language. Direct comparison of WBS and Dup7 represents a unique opportunity for the neurobehavioral characterization of the 7q11.23 section. However, most of the available data come from qualitative analysis between different studies. To the best of our knowledge, there are no studies directly comparing features of two matched samples of individuals with WBS and Dup7 syndromes. In this pilot study, we compare the adaptive functioning - measured with the Vineland Adaptive Behavior Scales, Second Edition - of two relatively small samples of children with molecularly confirmed diagnosis of WBS and Dup7 matched for IQ and chronological age, with a particular attention to socialization domain and expressive subdomain. Contrary to our assumption, we have not found any significant difference on socialization domain and expressive subdomains. This pilot investigation suggests that, when matched for chronological age and cognitive level, children with WBS and Dup7 share more similarities than expected. The inverted features that emerge in clinical settings on expressive language and social motivation seem not to differently interfere with the daily abilities to communicate and socialize with meaningful others during daily lives. Differences highlighted by previous undirected comparisons could be due to general and non-specific factors such as cognitive level, which is more severely impaired in individuals with WBS than Dup7. Implications for assessment and treatment are discussed.

Williams syndrome: reduced orienting to other's eyes in a hypersocial phenotype

Williams syndrome (WS) is a rare genetic condition associated with high sociability, intellectual disability, and social cognitive challenges. Attention to others’ eyes is crucial for social understanding. Orienting to, and from other’s eyes was studied in WS (n = 37, mean age = 23, age range 9–53). The WS group was compared to a typically developing comparison participants (n = 167) in stratified age groups from infancy to adulthood. Typically developing children and adults were quicker and more likely to orient to eyes than the mouth. This bias was absent in WS. The WS group had reduced peak saccadic velocities, indicating hypo-arousal. The current study indicates reduced orienting to others’ eyes in WS, which may affect social interaction skills.

Anxiety and Spatial Navigation in Williams Syndrome and Down Syndrome

Individuals with Down Syndrome (DS) and individuals with Williams syndrome (WS) present with poor navigation and elevated anxiety. The aim of this study was to determine the relationship between these two characteristics. Parent report questionnaires measured navigation abilities and anxiety in WS (N = 55) and DS (N = 42) as follows. Anxiety: Spence Children's Anxiety Scale and a novel measure of navigation anxiety. Navigation: Santa Barbara Sense of Direction Scale (SBSOD) and a novel measure of navigation competence. Most individuals were not permitted to travel independently. A relationship between navigation anxiety and SBSOD scores (but not navigation competence) was observed for both groups.

Pragmatic Profiles of Adults with Fragile X Syndrome and Williams Syndrome

Linguistic phenotypes of individuals with Fragile X (FXS) and Williams (WS) syndromes exhibit various degrees of pragmatic impairment, involving difficulties in social communication and in adapting to conversational principles. The goal of the present study was to explore syndrome-specific pragmatic profiles of adults with FXS and WS based on the assessment of the observance of Gricean maxims of conversation. The participants were 12 Spanish-speaking adults (6 FXS/6 WS), without a diagnosis of ASD, whose extensive naturalistic conversations (71,859 words) were transcribed and coded with the CHILDES/TALKBANK tools and the PREP-CORP pragmatic protocol. Violations of the maxims of conversation were analyzed, and indexes of cooperation and conversational response were obtained. Both groups showed reduced verbal production and repetitive dysfluencies; prominent features in the FXS profile were higher proportion of non-contingent language, perseverations of topic and form, and impulsive conversational responses; in the WS profile, salient characteristics were higher proportion of tangential utterances, reformulations, and conversational responses reflecting overly literal interpretation. Pragmatic profiles of violation of conversational maxims reflect specific communication skills impaired in adults with FXS and WS and raise the need for assessment and intervention methods that specifically address their social communication abilities.

Amygdala connectivity and implications for social cognition and disorders

The amygdala is a hub of subcortical region that is crucial in a wide array of affective and motivation-related behaviors. While early research contributed significantly to our understanding of this region's extensive connections to other subcortical and cortical regions, recent methodological advances have enabled researchers to better understand the details of these circuits and their behavioral contributions. Much of this work has focused specifically on investigating the role of amygdala circuits in social cognition. In this chapter, we review both long-standing knowledge and novel research on the amygdala's structure, function, and involvement in social cognition. We focus specifically on the amygdala's circuits with the medial prefrontal cortex, the orbitofrontal cortex, and the hippocampus, as these regions share extensive anatomic and functional connections with the amygdala. Furthermore, we discuss how dysfunction in the amygdala may contribute to social deficits in clinical disorders including autism spectrum disorder, social anxiety disorder, and Williams syndrome. We conclude that social functions mediated by the amygdala are orchestrated through multiple intricate interactions between the amygdala and its interconnected brain regions, endorsing the importance of understanding the amygdala from network perspectives.

Parents' perspective on the social traits observed in school-age children with autism and children with Williams syndrome

Individuals with autism spectrum disorders and those with Williams syndrome often have impairments in social behaviors. These two neurodevelopmental disorders are often reputed to be on the opposite ends of the social spectrum, with autistic individuals being socially avoidant and those with Williams syndrome highly social. Most research on children with autism and Williams syndrome has focused on preschool and younger school-age children. The current study assessed school-age children between the ages of 7-14 years with high-functioning autism, Williams syndrome, and neurotypical developing peers. Parents completed the Salk Institute Sociability Questionnaire and the Social Responsiveness Scale, to provide unique insights into social functioning and tap into different behavioral areas, social approach behaviors, and social responsiveness. This study provides additional evidence that young children with autism and Williams syndrome continue to show divergent social-behavioral tendencies at school-age, despite controlling for age and intellect. Results of this study better elucidate disparities as well as commonalities across school-age children with neurodevelopmental disorders and their typically developing peers, providing insight into everyday social functioning.

Cognitive profile of young children with Williams syndrome

BACKGROUND

There is very little research on the cognitive profile of young children with Williams syndrome (WS).

METHOD

The present study utilised the Differential Ability Scales - Second Edition to examine the early cognitive abilities of 22 young children with WS (aged 3.98 to 7.70 years, 10 male and 12 female participants).

RESULTS

Overall, IQ ranged from 38 (severely impaired) to 81.00 (low average). Consistent with Mervis et al. who looked at an older sample, over half (59.08%) of our young WS sample showed a significant and abnormal weakness in spatial ability relative to verbal ability. Moreover, 81.82% showed a significant and clinically unusual weakness in spatial ability relative to nonverbal reasoning ability. At the subtest level, only 4.55% of our sample showed a significant strength in naming vocabulary compared with verbal comprehension, while 13.64% showed a significant weakness in naming vocabulary relative to verbal comprehension.

CONCLUSIONS

The results of the present study show cognitive heterogeneity, consistent with the literature on older children and adults with WS. There were variable levels of intellect and variable patterns of cognitive strength and weakness across both index and subtest scores. Findings highlight the need for individual assessment and management of young children with WS but also indicate that for the majority of WS individuals spatial skills are indeed an area of significant and abnormal weakness and should be a focus for early intervention.

Sharing Experiences in Infancy: From Primary Intersubjectivity to Shared Intentionality

We contrast two theses that make different assumptions about the developmental onset of human-unique sociality. The primary intersubjectivity thesis (PIT) argues that humans relate to each other in distinct ways from the beginning of life, as is shown by newborns' participation in face-to-face encounters or "primary intersubjectivity." According to this thesis, humans' innate relational capacity is the seedbed from which all subsequent social-emotional and social-cognitive developments continuously emerge. The shared intentionality thesis (SIT) states that human-unique forms of interaction develop at 9-12 months of age, when infants put their heads together with others in acts of object-focused joint attention and simple collaborative activities. According to this thesis, human-unique cognition emerges rapidly with the advent of mind-reading capacities that evolved specifically for the purpose of coordination. In this paper, we first contrast the two theses and then sketch the outlines of an account that unifies their strengths. This unified account endorses the PIT's recognition of the fundamental importance of primary intersubjectivity. Any act of sharing experiences is founded on the communicative capacity that is already displayed by young infants in primary intersubjectivity. At the same time, we question the PIT's interpretation that dyadic encounters have the triadic structure of joint attention. Lastly, we draw on empirical work on the development of joint attention, imitation, and social referencing that serves as evidence that primary intersubjectivity continuously unfolds into the capacity for triadic joint attention.

Survey of the Home Music Environment of Children with Various Developmental Profiles

Families with young children with and without developmental disabilities often create a musically rich home environment. Parent-child music engagement, like singing play songs, is associated with positive outcomes for children, parents, and their relationship. However, little is known about if the home music environment differs across diagnostic groups and if parent-child music engagement relates to parent-child affective attachment across families of diagnostically diverse children. Using an online questionnaire, the current study examined the home music environment of 340 families with young children with typical and atypical development. A variety of musical activities were common in all diagnostic groups. Diagnostic groups differed in active musical engagement, potentially relating to the differing phenotypes of various developmental disabilities. Parent-child music engagement was associated with parent-child affective attachment, even when controlling for relevant variables. Promoting musical engagement at home and through parent-child therapy may be an accessible way to support parent-child relationships.

"Intolerance of uncertainty" mediates the relationship between social profile and anxiety in both Williams syndrome and autism

Anxiety is the most significant mental health concern for both Williams syndrome (WS) and autism. Whilst WS and autism are characterized by some syndrome-specific social differences, less is known about cross-syndrome profiles of anxiety symptoms. Previous research has shown that Intolerance of Uncertainty (IU) is a core mechanism of anxiety maintenance for clinically anxious populations and for autistic children, adolescents, and adults. The only published study in this area for WS has shown some similar patterns-with an added emphasis on the role of sensory sensitivities-in a sample of older teens and adults (mean age = 24), with the authors highlighting the need for younger samples to consider developmental influences. Here we report a cross-syndrome, cross-sectional mediation analyses of children diagnosed with WS or autism, including data from parent surveys of 90 children with WS (n = 48) or autism (n = 42). Group differences showed higher trait levels on all measures for the autism group. Importantly, the relationship between social profile and anxiety was fully mediated by IU level for both groups. This suggests possible similar core mechanisms underlying anxiety in these conditions, and the possibility of generalized intervention approaches especially related to managing distress related to uncertainty in multiple contexts. LAY SUMMARY: Autism and Williams Syndrome share some similarities in social profile and also in anxiety traits, but there are also some key differences as well. Comparing them side-by-side at the same time improved identification of ways to reduce feelings of anxiety. We found that the intolerance of uncertainty affected the relationship between social profile and anxiety in the same way for young children diagnosed with autism or Williams syndrome, meaning that intervention approaches could be similar for both.

Sleep-related learning in Williams Syndrome and Down's Syndrome

This chapter addresses sleep research challenges for the study of neurodevelopmental disorders drawing upon two disorders such as Down Syndrome and Williams syndrome. General sleep problems are outlined here, however particular consideration is given to the syndrome-specific issues or challenges that may be crucial to advancing our understanding of sleep-related cognitive and behavioral issues.

Sleep's role in memory consolidation: What can we learn from atypical development?

Research conducted over the last century has suggested a role for sleep in the processes guiding healthy cognition and development, including memory consolidation. Children with intellectual and developmental disabilities (IDDs) tend to have higher rates of sleep disturbances, which could relate to behavior issues, developmental delays, and learning difficulties. While several studies examine whether sleep exacerbates daytime difficulties and attention deficits in children with IDDs, this chapter focuses on the current state of knowledge regarding sleep and memory consolidation in typically developing (TD) groups and those at risk for learning difficulties. In particular, this chapter summarizes the current literature on sleep-dependent learning across developmental disabilities, including Down syndrome, Williams syndrome, Autism Spectrum Disorder, and Learning Disabilities (Attention-Deficit/Hyperactivity Disorder and Dyslexia). We also highlight the gaps in the current literature and identify challenges in studying sleep-dependent memory in children with different IDDs. This burgeoning new field highlights the importance of considering the role of sleep in memory retention across long delays when evaluating children's memory processes. Further, an understanding of typical and atypical development can mutually inform recent theories of sleep's role in memory.

Online and Face-to-Face Performance on Two Cognitive Tasks in Children With Williams Syndrome

There has been an increase in cognitive assessment via the Internet, especially since the coronavirus disease 2019 surged the need for remote psychological assessment. This is the first study to investigate the appropriability of conducting cognitive assessments online with children with a neurodevelopmental condition and intellectual disability, namely, Williams syndrome. This study compared Raven’s Colored Progressive Matrices (RCPM) and British Picture Vocabulary Scale (BPVS) scores from two different groups of children with WS age 10–11 years who were assessed online (n = 14) or face-to-face (RCPM n = 12; BPVS n = 24). Bayesian t-tests showed that children’s RCPM scores were similar across testing conditions, but suggested BPVS scores were higher for participants assessed online. The differences between task protocols are discussed in line with these findings, as well as the implications for neurodevelopmental research.

Developmental Perspectives on the Study of Persons with Intellectual Disability

Developmental approaches provide inclusive, universal, and methodologically rigorous frameworks for studying persons with intellectual disability (ID). This is an exceptionally heterogeneous group with regard to etiology, genotype, and phenotype that simply shares the traditional diagnostic criteria, typically a score of two standard deviations below the population mean of 100 on standardized IQ tests and deficits in adaptive behavior. We trace the foundational, conceptual, and methodological roots of developmental approaches and highlight ways that these and more recent iterations continue to be central to advances in the increasingly nuanced study of persons with ID. This work is premised on the consideration of specific etiological groupings and subgroupings across and between different domains of functioning within the context of familial and complex environments throughout the life span. We highlight the potential contributions of advances in behavioral methodologies, genomics, and neuroscience when considered within universal and hierarchic frameworks based on development.

Face first impression of trustworthiness in Williams Syndrome: Dissociating automatic vs decision based perception

Humans make rapid decisions of trustworthiness based on facial appearance. Williams Syndrome (WS) is a genetic disorder associated with hypersociability toward strangers, suggesting a disruption in trust assessment. We recorded eye-movements in neurotypically-developed (TD) participants (N = 21) and in patients with WS (N = 22) as we presented pairs of computer-generated faces, pre-rated as trustworthy or untrustworthy. In a spontaneous visual preference task, TD participants gazed significantly longer at trustworthy faces while patients with WS showed no preferences for either face-type. Next, in a decision task, participants selected the face that they judged consistent with one of three social descriptions relating to high levels of trust. Both groups gazed longer at trustworthy faces and made correct matches with the corresponding social descriptions. Improvements by patients with WS in the decision task were contingent on outcomes measured on the emotional NEPSY scale. We conclude that while spontaneous representation of trustworthiness is impaired in WS, top-down mechanisms of trust recognition appear partially preserved.

Autism and Williams syndrome: truly mirror conditions in the socio-cognitive domain?

Autism Spectrum Disorders (ASD) and Williams Syndrome (WS) are frequently characterized as mirror conditions in the socio-cognitive domain, with ASD entailing restrictive social interests and with WS exhibiting hypersociability. In this review paper, we examine in detail the strong points and deficits of people with ASD or WS in the socio-cognitive domain and show that both conditions also share some common features. Moreover, we explore the neurobiological basis of the social profile of ASD and WS and found a similar mixture of common affected areas and condition-specific impaired regions. We discuss these findings under the hypothesis of a continuum of the socio-cognitive abilities in humans.

Cognitive abilities in Williams syndrome

The current study utilized a comprehensive neuropsychological test battery to investigate cognitive abilities in a sample of 49 WS individuals (25 male) aged 6-39 years. Age effects were also investigated by splitting the sample into child and adult groups. Cognitive heterogeneity was found on the Woodcock Johnson III Tests of Cognitive Abilities, Australian Adaptation (WJ-III COG) (Woodcock, McGrew, & Mather, 2001), with cognitive abilities ranging from profoundly impaired to superior and individualized profiles of strength and weakness varying considerably. Overall, findings supported previous research showing strengths in auditory processing and phonemic awareness. The weakest performance, on average, was in processing speed, attention, delayed associative learning and executive functioning capabilities. Visual-spatial functioning was not a weakness overall, neither was nonverbal reasoning. Chronological age did not relate significantly to cognitive abilities. Findings highlight the need for individual assessment and management of WS individuals.

Sensory processing profiles and autistic symptoms as predictive factors in autism spectrum disorder and Williams syndrome

BACKGROUND

Unusual sensory responses were included in the diagnostic criteria for autism spectrum disorder (ASD), yet they are also common among individuals with other neurodevelopmental disorders, including Williams syndrome (WS). Cross-syndrome comparisons of sensory atypicalities and the evaluation of their syndrome specificity however have rarely been undertaken. We aimed to (1) examine and compare the sensory profiles in ASD and WS groups and (2) investigate whether autistic symptoms, including sensory processing scores, can predict a group membership.

METHODS

Parents of 26 children with ASD and intellectual disability, 30 parents of children with ASD (no intellectual disability) and 26 with WS aged between 4 and 16 years were recruited. Parents completed the Sensory Profile to provide information about their children's sensory experiences and the Social Responsiveness Scale - Second Edition (SRS-2) to assess the degree of social impairment in their children.

RESULTS

No significant differences were found in sensory processing scores between the three groups. Binary logistic regression analyses were undertaken with sensory quadrants and SRS-2 total score as factors. Models significantly predicted group membership, with Low Registration, Sensory Sensitivity and SRS-2 total score being significant predictors.

CONCLUSIONS

The findings suggest that high rates of sensory atypicalities are a common neurodevelopmental characteristic that do not reliably distinguish between WS and ASD groups. Low Registration and Sensory Sensitivity-related behaviours might, however, be more specific to ASD. Further work is needed to explore what behaviours within sensory profiles can discriminate between neurodevelopmental disorders and should be included in diagnostic classifications.

The Profiles and Correlates of Psychopathology in Adolescents and Adults with Williams, Fragile X and Prader-Willi Syndromes

Psychopathology is prevalent in Williams (WS), fragile X (FXS) and Prader–Willi (PWS) syndromes. However, little is known about the potential correlates of psychopathology in these groups. A questionnaire study was completed by 111 caregivers of individuals with WS (n = 35); FXS (n = 50) and PWS (n = 26). Mean age was 26 years (range 12–57 years); 74 (67%) were male. Multiple regression analyses indicated that higher rates of health problems and sensory impairments predicted higher psychopathology in WS (p < .0001). In PWS, poorer adaptive ability predicted higher overall psychiatric disturbance (p = .001), generalised anxiety (p = .006) and hyperactivity (p = .003). There were no significant predictors in FXS. This study highlights dissociations in the potential risk markers of psychopathology between genetic syndromes. Implications for intervention are discussed.

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.

An Examination of Social Skills, Friendship Quality, and Loneliness for Adults with Williams Syndrome

Individuals with Williams Syndrome (WS) are hypersocial, overfriendly, and experience social skills deficits that may adversely impact their social outcomes. This study examined the relation between social skills, friendship quality, and feelings of loneliness for adults with WS as reported by 114 parent-adult with WS dyads. Results indicate that although most friends do not live close-by, adults with WS have good quality friendships and do not report high feelings of loneliness. Positive friendship qualities were found to partially mediate the relationship between social skills impairments and social feelings of loneliness. Findings indicate that although adults with WS experience social skills deficits and struggle to maintain friendships in their immediate community, they still report positive friendship qualities and low feelings of loneliness.

Serotonergic innervation of the amygdala is increased in autism spectrum disorder and decreased in Williams syndrome

BACKGROUND

Williams syndrome (WS) and autism spectrum disorder (ASD) are neurodevelopmental disorders that demonstrate overlapping genetic associations, dichotomous sociobehavioral phenotypes, and dichotomous pathological differences in neuronal distribution in key social brain areas, including the prefrontal cortex and the amygdala. The serotonergic system is critical to many processes underlying neurodevelopment and is additionally an important neuromodulator associated with behavioral variation. The amygdala is heavily innervated by serotonergic projections, suggesting that the serotonergic system is a significant mediator of neuronal activity. Disruptions to the serotonergic system, and atypical structure and function of the amygdala, are implicated in both WS and ASD.

METHODS

We quantified the serotonergic axon density in the four major subdivisions of the amygdala in the postmortem brains of individuals diagnosed with ASD and WS and neurotypical (NT) brains.

RESULTS

We found opposing directions of change in serotonergic innervation in the two disorders, with ASD displaying an increase in serotonergic axons compared to NT and WS displaying a decrease. Significant differences (p < 0.05) were observed between WS and ASD data sets across multiple amygdala nuclei.

LIMITATIONS

This study is limited by the availability of human postmortem tissue. Small sample size is an unavoidable limitation of most postmortem human brain research and particularly postmortem research in rare disorders.

CONCLUSIONS

Differential alterations to serotonergic innervation of the amygdala may contribute to differences in sociobehavioral phenotype in WS and ASD. These findings will inform future work identifying targets for future therapeutics in these and other disorders characterized by atypical social behavior.

Genetic factors contributing to autism spectrum disorder in Williams-Beuren syndrome

BACKGROUND

The hallmark of the neurobehavioural phenotype of Williams-Beuren syndrome (WBS) is increased sociability and relatively preserved language skills, often described as opposite to autism spectrum disorders (ASD). However, the prevalence of ASD in WBS is 6-10 times higher than in the general population. We have investigated the genetic factors that could contribute to the ASD phenotype in individuals with WBS.

METHODS

We studied four males and four females with WBS and a confirmed diagnosis of ASD by the Autism Diagnostic Interview-Revised. We performed a detailed molecular characterisation of the deletion and searched for genomic variants using exome sequencing.

RESULTS

A de novo deletion of 1.55 Mb (6 cases) or 1.83 Mb (2 cases) at 7q11.23 was detected, being in 7/8 patients of paternal origin. No common breakpoint, deletion mechanism or size was found. Two cases were hemizygous for the rare T allele at rs12539160 in MLXIPL, previously associated with ASD. Inherited rare variants in ASD-related or functionally constrained genes and a de novo nonsense mutation in the UBR5 gene were identified in six cases, with higher burden in females compared with males (p=0.016).

CONCLUSIONS

The increased susceptibility to ASD in patients with WBS might be due to additive effects of the common WBS deletion, inherited and de novo rare sequence variants in ASD-related genes elsewhere in the genome, with higher burden of deleterious mutations required for females, and possible hypomorphic variants in the hemizygous allele or cis-acting mechanisms on imprinting.