Autism, ADHD, mental retardation and behavior problems in 100 individuals with 22q11 deletion syndrome

Neuropsychological Profile of 25 Brazilian Patients with 22q11.2 Deletion Syndrome: Effects of Clinical and Socioeconomic Variables

The 22q11.2 deletion syndrome (22q11.2DS) is associated with a heterogeneous neurocognitive phenotype, which includes psychiatric disorders. However, few studies have investigated the influence of socioeconomic variables on intellectual variability. The aim of this study was to investigate the cognitive profile of 25 patients, aged 7 to 32 years, with a typical ≈3 Mb 22q11.2 deletion, considering intellectual, adaptive, and neuropsychological functioning. Univariate linear regression analysis explored the influence of socioeconomic variables on intellectual quotient (IQ) and global adaptive behavior. Associations with relevant clinical conditions such as seizures, recurrent infections, and heart diseases were also considered. Results showed IQ scores ranging from 42 to 104. Communication, executive functions, attention, and visuoconstructive skills were the most impaired in the sample. The study found effects of access to quality education, family socioeconomic status (SES), and caregiver education level on IQ. Conversely, age at diagnosis and language delay were associated with outcomes in adaptive behavior. This characterization may be useful for better understanding the influence of social-environmental factors on the development of patients with 22q11.2 deletion syndrome, as well as for intervention processes aimed at improving their quality of life.

Longitudinal Development of Thalamocortical Functional Connectivity in 22q11.2 Deletion Syndrome

BACKGROUND

The 22q11.2 deletion syndrome (22qDel) is a genetic copy number variant that strongly increases risk for schizophrenia and other neurodevelopmental disorders. Disrupted functional connectivity between the thalamus and the somatomotor/frontoparietal cortex has been implicated in cross-sectional studies of 22qDel, idiopathic schizophrenia, and youths at clinical high risk for psychosis. Here, we used a novel functional atlas approach to investigate longitudinal age-related changes in network-specific thalamocortical functional connectivity (TCC) in participants with 22qDel and typically developing (TD) control participants.

METHODS

TCC was calculated for 9 functional networks derived from resting-state functional magnetic resonance imaging scans collected from 65 participants with 22qDel (63.1% female) and 69 demographically matched TD control participants (49.3% female) ages 6 to 23 years. Analyses included 86 longitudinal follow-up scans. Nonlinear age trajectories were characterized with generalized additive mixed models.

RESULTS

In participants with 22qDel, TCC in the frontoparietal network increased until approximately age 13, while somatomotor TCC and cingulo-opercular TCC decreased from age 6 to 23. In contrast, no significant relationships between TCC and age were found in TD control participants. Somatomotor connectivity was significantly higher in participants with 22qDel than in TD control participants in childhood, but lower in late adolescence. Frontoparietal TCC showed the opposite pattern.

CONCLUSIONS

22qDel is associated with aberrant development of functional network connectivity between the thalamus and cortex. Younger individuals with 22qDel have lower frontoparietal connectivity and higher somatomotor connectivity than control individuals, but this phenotype may normalize or partially reverse by early adulthood. Altered maturation of this circuitry may underlie elevated neuropsychiatric disease risk in this syndrome.

The impact of maternal immune activation on GABAergic interneuron development: A systematic review of rodent studies and their translational implications

Mothers exposed to infections during pregnancy disproportionally birth children who develop autism and schizophrenia, disorders associated with altered GABAergic function. The maternal immune activation (MIA) model recapitulates this risk factor, with many studies also reporting disruptions to GABAergic interneuron expression, protein, cellular density and function. However, it is unclear if there are species, sex, age, region, or GABAergic subtype specific vulnerabilities to MIA. Furthermore, to fully comprehend the impact of MIA on the GABAergic system a synthesised account of molecular, cellular, electrophysiological and behavioural findings was required. To this end we conducted a systematic review of GABAergic interneuron changes in the MIA model, focusing on the prefrontal cortex and hippocampus. We reviewed 102 articles that revealed robust changes in a number of GABAergic markers that present as gestationally-specific, region-specific and sometimes sex-specific. Disruptions to GABAergic markers coincided with distinct behavioural phenotypes, including memory, sensorimotor gating, anxiety, and sociability. Findings suggest the MIA model is a valid tool for testing novel therapeutics designed to recover GABAergic function and associated behaviour.

Catecholaminergic and cholinergic neuromodulation in autism spectrum disorder: A comparison to attention-deficit hyperactivity disorder

Autism spectrum disorder (ASD) is a heterogeneous neurodevelopmental disorder characterized by social impairments and restricted, repetitive behaviors. Treatment of ASD is notoriously difficult and might benefit from identification of underlying mechanisms that overlap with those disturbed in other developmental disorders, for which treatment options are more obvious. One example of the latter is attention-deficit hyperactivity disorder (ADHD), given the efficacy of especially stimulants in treatment of ADHD. Deficiencies in catecholaminergic systems [dopamine (DA), norepinephrine (NE)] in ADHD are obvious targets for stimulant treatment. Recent findings suggest that dysfunction in catecholaminergic systems may also be a factor in at least a subgroup of ASD. In this review we scrutinize the evidence for catecholaminergic mechanisms underlying ASD symptoms, and also include in this analysis a third classic ascending arousing system, the acetylcholinergic (ACh) network. We complement this with a comprehensive review of DA-, NE-, and ACh-targeted interventions in ASD, and an exploratory search for potential treatment-response predictors (biomarkers) in ASD, genetically or otherwise. Based on this review and analysis we propose that (1) stimulant treatment may be a viable option for an ASD subcategory, possibly defined by genetic subtyping; (2) cerebellar dysfunction is pronounced for a relatively small ADHD subgroup but much more common in ASD and in both cases may point toward NE- or ACh-directed intervention; (3) deficiency of the cortical salience network is sizable in subgroups of both disorders, and biomarkers such as eye blink rate and pupillometric data may predict the efficacy of targeting this underlying deficiency via DA, NE, or ACh in both ASD and ADHD.

A genetics-first approach to understanding autism and schizophrenia spectrum disorders: the 22q11.2 deletion syndrome

Recently, increasing numbers of rare pathogenic genetic variants have been identified that are associated with variably elevated risks of a range of neurodevelopmental outcomes, notably including Autism Spectrum Disorders (ASD), Schizophrenia Spectrum Disorders (SSD), and Intellectual Disability (ID). This review is organized along three main questions: First, how can we unify the exclusively descriptive basis of our current psychiatric diagnostic classification system with the recognition of an identifiable, highly penetrant genetic risk factor in an increasing proportion of patients with ASD or SSD? Second, what can be learned from studies of individuals with ASD or SSD who share a common genetic basis? And third, what accounts for the observed variable penetrance and pleiotropy of neuropsychiatric phenotypes in individuals with the same pathogenic variant? In this review, we focus on findings of clinical and preclinical studies of the 22q11.2 deletion syndrome (22q11DS). This particular variant is not only one of the most common among the increasing list of known rare pathogenic variants, but also one that benefits from a relatively long research history. Consequently, 22q11DS is an appealing model as it allows us to: (1) elucidate specific genotype-phenotype associations, (2) prospectively study behaviorally defined classifications, such as ASD or SSD, in the context of a known, well-characterized genetic basis, and (3) elucidate mechanisms underpinning variable penetrance and pleiotropy, phenomena with far-reaching ramifications for research and clinical practice. We discuss how findings from animal and in vitro studies relate to observations in human studies and can help elucidate factors, including genetic, environmental, and stochastic, that impact the expression of neuropsychiatric phenotypes in 22q11DS, and how this may inform mechanisms underlying neurodevelopmental expression in the general population. We conclude with research priorities for the field, which may pave the way for novel therapeutics.

Higher scores on autonomic symptom scales in pediatric patients with neurodevelopmental disorders of known genetic etiology

INTRODUCTION

Features of underlying autonomic dysfunction, including sleep disturbances, gastrointestinal problems, and atypical heart rate, have been reported in neurodevelopmental conditions, including autism spectrum disorder (ASD). The current cross-sectional, between-groups study aimed to quantify symptoms of autonomic dysfunction in a neurodevelopmental pediatric cohort characterized by clinical diagnoses as well as genetic etiology.

METHOD

The Pediatric Autonomic Symptom Scales (PASS) questionnaire was used to assess autonomic features across a group of patients with clinical neurodevelopmental diagnoses (NPD; N = 90) and genetic etiologies. Patients were subdivided based on either having a clinical ASD diagnosis (NPD-ASD; n = 37) or other non-ASD neurodevelopmental diagnoses, such as intellectual disability without ASD, speech and language disorders, and/or attention deficit hyperactivity disorder (NPD-OTHER; n = 53). Analyses focused on characterizing differences between the NPD group compared to previously published reference samples, as well as differences between the two NPD subgroups (NPD-ASD and NPD-OTHER).

RESULTS

Our results indicate higher PASS scores in our NPD cohort relative to children with and without ASD from a previously published cohort. However, we did not identify significant group differences between our NPD-ASD and NPD-OTHER subgroups. Furthermore, we find a significant relationship between quantitative ASD traits and symptoms of autonomic function.

CONCLUSION

This work demonstrates the utility of capturing quantitative estimates of autonomic trait dimensions that may be significantly linked with psychosocial impairments and other core clinical features of ASD.

Parent-Reported Social-Communicative Skills of Children with 22q11.2 Copy Number Variants and Siblings

22q11.2 deletion (22q11.2DS) and 22q11.2 duplication (22q11.2Dup) confer risk for neurodevelopmental difficulties, but the characterization of speech-language and social skills in 22q11.2Dup is still limited. Therefore, this study aims to delineate social-communicative skills in school-aged children with 22q11.2Dup (n = 19) compared to their non-carrier siblings (n = 11) and age-matched children with 22q11.2DS (n = 19). Parents completed two standardized questionnaires: the Children's Communication Checklist (CCC-2), screening speech, language, and social skills, and the Social Responsiveness Scales (SRS-2), assessing deficits in social behavior. Parents report that both children with 22q11.2Dup and 22q11.2DS show more social-communicative deficits than the general population; children with 22q11.2Dup seem to take an intermediate position between their siblings and children with 22q11.2DS. Compared to 22q11.2DS, they demonstrate less frequent and less severe problems, and more heterogeneous social-communicative profiles, with fewer restricted interests and repetitive behaviors. In siblings of 22q11Dup, milder social-communicative difficulties and equally heterogeneous profiles are reported, which might indicate that-in addition to the duplication-other factors such as the broader genetic context play a role in social-communicative outcomes.

Longitudinal trajectories of cortical development in 22q11.2 copy number variants and typically developing controls

Probing naturally-occurring, reciprocal genomic copy number variations (CNVs) may help us understand mechanisms that underlie deviations from typical brain development. Cross-sectional studies have identified prominent reductions in cortical surface area (SA) and increased cortical thickness (CT) in 22q11.2 deletion carriers (22qDel), with the opposite pattern in duplication carriers (22qDup), but the longitudinal trajectories of these anomalies-and their relationship to clinical symptomatology-are unknown. Here, we examined neuroanatomic changes within a longitudinal cohort of 261 22q11.2 CNV carriers and demographically-matched typically developing (TD) controls (84 22qDel, 34 22qDup, and 143 TD; mean age 18.35, ±10.67 years; 50.47% female). A total of 431 magnetic resonance imaging scans (164 22qDel, 59 22qDup, and 208 TD control scans; mean interscan interval = 20.27 months) were examined. Longitudinal FreeSurfer analysis pipelines were used to parcellate the cortex and calculate average CT and SA for each region. First, general additive mixed models (GAMMs) were used to identify regions with between-group differences in developmental trajectories. Secondly, we investigated whether these trajectories were associated with clinical outcomes. Developmental trajectories of CT were more protracted in 22qDel relative to TD and 22qDup. 22qDup failed to show normative age-related SA decreases. 22qDel individuals with psychosis spectrum symptoms showed two distinct periods of altered CT trajectories relative to 22qDel without psychotic symptoms. In contrast, 22q11.2 CNV carriers with autism spectrum diagnoses showed early alterations in SA trajectories. Collectively, these results provide new insights into altered neurodevelopment in 22q11.2 CNV carriers, which may shed light on neural mechanisms underlying distinct clinical outcomes.

Synaptic Plasticity Dysfunctions in the Pathophysiology of 22q11 Deletion Syndrome: Is There a Role for Astrocytes?

The 22q11 deletion syndrome (DS) is the most common microdeletion syndrome in humans and gives a high probability of developing psychiatric disorders. Synaptic and neuronal malfunctions appear to be at the core of the symptoms presented by patients. In fact, it has long been suggested that the behavioural and cognitive impairments observed in 22q11DS are probably due to alterations in the mechanisms regulating synaptic function and plasticity. Often, synaptic changes are related to structural and functional changes observed in patients with cognitive dysfunctions, therefore suggesting that synaptic plasticity has a crucial role in the pathophysiology of the syndrome. Most interestingly, among the genes deleted in 22q11DS, six encode for mitochondrial proteins that, in mouse models, are highly expressed just after birth, when active synaptogenesis occurs, therefore indicating that mitochondrial processes are strictly related to synapse formation and maintenance of a correct synaptic signalling. Because correct synaptic functioning, not only requires correct neuronal function and metabolism, but also needs the active contribution of astrocytes, we summarize in this review recent studies showing the involvement of synaptic plasticity in the pathophysiology of 22q11DS and we discuss the relevance of mitochondria in these processes and the possible involvement of astrocytes.

Evaluation and Maintenance of Behavioral Interventions for 22q11.2 Deletion Syndrome

22q11.2-deletion syndrome is a genetic disorder caused by a small deletion of chromosome 22. This deletion often results in developmental delays, learning disabilities, medical conditions, and comorbid psychiatric conditions. Patients with 22q11.2DS may present with a variety of behavioral phenotypes including obsessiveness and rigidity, poor social skills, and anxiety. In some cases, the phenotype can consist of destructive and inappropriate behavior including harming self and others. Behavioral difficulties are reported as one of the most challenging aspects of 22q11.2-deletion syndrome for families of patients, however, few studies have examined behavioral interventions as a possible therapeutic treatment for this population. Using principles derived from operant-behavioral psychology, we conducted functional assessments to determine the environmental correlates of destructive and inappropriate behaviors in two adult men with 22q11.2-deletion syndrome. Subsequently, behavioral interventions based on differential reinforcement were incorporated into each participant's natural environment to eliminate these behaviors. Significant reductions in destructive and inappropriate behavior were observed with both participants and therapeutic gains were maintained at follow-up. We discuss the role of behavioral interventions in combination with appropriate psychotropic medication when addressing challenging behaviors in this population.

OUP accepted manuscript

Multiple pieces of evidence support the prenatal predisposition of autism spectrum disorder (ASD). Nevertheless, robust data about abnormalities in foetuses later developing into children diagnosed with ASD are lacking. Prenatal ultrasound is an excellent tool to study abnormal foetal development as it is frequently used to monitor foetal growth and identify foetal anomalies throughout pregnancy. We conducted a retrospective case-sibling-control study of children diagnosed with ASD (cases); their own typically developing, closest-in-age siblings (TDS); and typically developing children from the general population (TDP), matched by year of birth, sex and ethnicity to investigate the association between ultrasonography foetal anomalies and ASD. The case group was drawn from all children diagnosed with ASD enrolled at the National Autism Research Center of Israel. Foetal ultrasound data from the foetal anatomy survey were obtained from prenatal ultrasound clinics of Clalit Health Services in southern Israel. The study comprised 659 children: 229 ASD, 201 TDS and 229 TDP. Ultrasonography foetal anomalies were found in 29.3% of ASD cases versus only 15.9% and 9.6% in the TDS and TDP groups [adjusted odds ratio (aOR) = 2.23, 95% confidence interval (CI) = 1.32-3.78, and aOR = 3.50, 95%CI = 2.07-5.91, respectively]. Multiple co-occurring ultrasonography foetal anomalies were significantly more prevalent among ASD cases. Ultrasonography foetal anomalies in the urinary system, heart, and head and brain were the most significantly associated with ASD diagnosis (aORUrinary = 2.08, 95%CI = 0.96-4.50 and aORUrinary = 2.90, 95%CI = 1.41-5.95; aORHeart = 3.72, 95%CI = 1.50-9.24 and aORHeart = 8.67, 95%CI = 2.62-28.63; and aORHead&Brain = 1.96, 95%CI = 0.72-5.30 and aORHead&Brain = 4.67, 95%CI = 1.34-16.24; versus TDS and TDP, respectively). ASD females had significantly more ultrasonography foetal anomalies than ASD males (43.1% versus 25.3%, P = 0.013) and a higher prevalence of multiple co-occurring ultrasonography foetal anomalies (15.7% versus 4.5%, P = 0.011). No sex differences were seen among TDS and TDP controls. ASD foetuses were characterized by a narrower head and a relatively wider ocular-distance versus TDP foetuses (ORBPD = 0.81, 95%CI = 0.70-0.94, and aOROcular distance = 1.29, 95%CI = 1.06-1.57). Ultrasonography foetal anomalies were associated with more severe ASD symptoms. Our findings shed important light on the multiorgan foetal anomalies associated with ASD.

Parents' perspectives, experiences, and need for support when communicating with their children about the psychiatric manifestations of 22q11.2 deletion syndrome (22q11DS)

OBJECTIVE

To develop a theoretical model to explain how parents think about the process of communicating with their affected child about the psychiatric manifestations of 22q11DS.

METHODS

Semi-structured interviews were conducted with parents of children with 22q11DS, who had all received psychiatric genetic counseling. Interviews were recorded, transcribed verbatim, and analyzed concurrently with data collection, using interpretive description. Identified themes were used to inductively develop a model of how parents think about communicating with their child about psychiatric risk in 22q11DS.

RESULTS

From interviews with 10 parents, we developed a model representing the communication of psychiatric risk in 22q11DS as a process where various dynamic contextual factors (e.g., perception of risk, desire to normalize) act as either motivators or barriers to communication. Parents described challenges with the content, process, and outcome of these conversations. Parents wanted hands on, practical, personalized, and ongoing support from health professionals around communication about these issues.

CONCLUSION

This model may help equip genetics professionals to support parents to communicate effectively with their children in order to improve health outcomes and family adaptation to 22q11DS.

PRACTICE IMPLICATIONS

Our findings may apply not only to 22q11DS, but also to other genetic conditions where psychiatric manifestations occur.

Heterotopia in Individuals with 22q11.2 Deletion Syndrome

BACKGROUND AND PURPOSE

MR imaging studies and neuropathologic findings in individuals with 22q11.2 deletion syndrome show anomalous early brain development. We aimed to retrospectively evaluate cerebral abnormalities, focusing on gray matter heterotopia, and to correlate these with subjects' neuropsychiatric impairments.

MATERIALS AND METHODS

Three raters assessed gray matter heterotopia and other morphologic brain abnormalities on 3D T1WI and T2*WI in 75 individuals with 22q11.2 deletion syndrome (27 females, 15.5 [SD, 7.4] years of age) and 53 controls (24 females, 12.6 [SD, 4.7] years of age). We examined the association among the groups' most frequent morphologic findings, general cognitive performance, and comorbid neuropsychiatric conditions.

RESULTS

Heterotopia in the white matter were the most frequent finding in individuals with 22q11.2 deletion syndrome (n = 29; controls, n = 0; between-group difference, P < .001), followed by cavum septi pellucidi and/or vergae (n = 20; controls, n = 0; P < .001), periventricular cysts (n = 10; controls, n = 0; P = .007), periventricular nodular heterotopia (n = 10; controls, n = 0; P = .007), and polymicrogyria (n = 3; controls, n = 0; P = .3). However, individuals with these morphologic brain abnormalities did not differ significantly from those without them in terms of general cognitive functioning and psychiatric comorbidities.

CONCLUSIONS

Taken together, our findings, periventricular nodular heterotopia or heterotopia in the white matter (possibly related to interrupted Arc cells migration), persistent cavum septi pellucidi and/or vergae, and formation of periventricular cysts, give clues to the brain development disorder induced by the 22q11.2 deletion syndrome. There was no evidence that these morphologic findings were associated with differences in psychiatric or cognitive presentation of the 22q11.2 deletion syndrome.

Neuropsychological and ASD phenotypes in rare genetic syndromes: A critical review of the literature

OBJECTIVE

Autism spectrum disorder (ASD) is a complex neurodevelopmental condition characterized by core deficits in social communication and restricted and repetitive behaviors and interests. Recent advances in clinical genetics have improved our understanding of genetic syndromes associated with ASD, which has helped clarify distinct etiologies of ASD and document syndrome-specific profiles of neurocognitive strengths and weaknesses. Pediatric neuropsychologists have the potential to be impactful members of the care team for children with genetic syndromes and their families.

METHOD

We provide a critical review of the current literature related to the neuropsychological profiles of children with four genetic syndromes associated with ASD, including Tuberous Sclerosis Complex (TSC), fragile X syndrome (FXS), 22q11.2 deletion syndrome, and Angelman syndrome. Recommendations for assessment, intervention, and future directions are provided.

RESULTS

There is vast heterogeneity in terms of the cognitive, language, and developmental abilities of these populations. The within- and across-syndrome variability characteristic of genetic syndromes should be carefully considered during clinical evaluations, including possible measurement limitations, presence of intellectual disability, and important qualitative differences in the ASD-phenotypes across groups.

CONCLUSIONS

Individuals with genetic disorders pose challenging diagnostic and assessment questions. Pediatric neuropsychologists with expertise in neurodevelopmental processes are well suited to address these questions and identify profiles of neurocognitive strengths and weaknesses, tailor individualized recommendations, and provide diagnostic clarification.

The Importance of Understanding Individual Differences of Emotion Regulation Abilities in 22q11.2 Deletion Syndrome

Chromosome 22q11.2 deletion syndrome (22q11DS) is characterised by a complex behavioural phenotype including anxiety, attention-deficit/hyperactivity disorder and psychosis. In the current study, we aimed at improving our understanding of the heterogeneity of behavioural characteristics in a group of 129 young people (aged 4-22) with a confirmed 22q11.2 microdeletion and 116 age and gender matched typically developing controls. Half the participants with 22q11DS had behaviour characterised by emotion dysregulation. A cluster analyses, of the participants with 22q11DS, revealed four groups characterised by intact emotion regulation; predominantly internalizing problems; both internalizing and externalizing problems; and predominantly externalizing difficulties. Importantly, it was found that young people with 22q11DS whose emotion dysregulation was characterised by externalizing problems had the poorest levels of functioning. As our understanding of 22q11DS improves, it is becoming increasingly clear that we need a better understanding of how individual differences and psychosocial factors contribute to, and interact with one another, to result in the observable individual differences in the 22q11DS behavioural phenotype.

Reflections of parents of children with 22q11.2 Deletion Syndrome on the experience of receiving psychiatric genetic counseling: 'Awareness to Act'

Individuals with 22q11.2 deletion syndrome (22qDS) have a 25%-41% risk for a psychotic disorder. Although early intervention for psychiatric conditions leads to the best long-term outcomes, healthcare providers often provide inadequate information about these issues and psychiatric services are underused by this population. We conducted semi-structured interviews with parents of children with 22qDS a month after they received psychiatric genetic counseling (pGC), to evaluate outcomes and perceived value of pGC with respect to parents' needs. Using grounded theory, we generated a theoretical framework of the process of building parental awareness of psychiatric risks associated with 22qDS and protective and management strategies for mental health (MH). Parents described how after their child's diagnosis with 22qDS, a variety of barriers stalled their building awareness of psychiatric risk and protective/management strategies: dealing with the immediate symptoms of 22qDS; child's young age; parental fear and stigma; and missing MH guidance. These barriers led them to carry the burden of worrying over missing emerging psychiatric symptoms and the stress over advocating for their child's MH. Parents indicated pGC was beneficial in that led them to achieve an 'awareness to act,' feeling confident in being alert and equipped to protect and/or manage their child's MH.

A cross-comparison of cognitive ability across 8 genomic disorders

Genomic disorders result from rearrangement of the human genome. Most genomic disorders are caused by copy number variants (CNV), deletions or duplications of several hundred kilobases. Many CNV loci are associated with autism, schizophrenia, and most commonly, intellectual disability (ID). However, there is little comparison of cognitive ability measures across these CNV disorders. This study aims to understand whether existing data can be leveraged for a cross-comparison of cognitive ability among multiple CNV. We found there is a lack of harmonization among assessment instruments and little standardization for reporting summary data across studies. Despite these limitations, we identified a differential impact of CNV loci on cognitive ability. Our data suggest that future cross-comparisons of CNV disorders will reveal meaningful differences across the phenotypic spectrum, especially if standardized phenotypic assessment is achieved.

Social cognition in 22q11.2 deletion syndrome and idiopathic developmental neuropsychiatric disorders

BACKGROUND

22q11.2 deletion syndrome (22q11DS) is a common recurrent neurogenetic condition associated with elevated risk for developmental neuropsychiatric disorders and intellectual disability. Children and adults with 22q11DS often exhibit marked social impairment as well as neurocognitive deficits, and have elevated rates of both autism spectrum disorder (ASD) and psychosis. However, the relationship between the basic processes of social cognition and cognitive ability has not been well studied in 22q11DS. Here, we examined differences in social cognition in 22q11DS, relative to multiple groups of idiopathic neuropsychiatric disorders, and typically developing healthy controls (HC). Additionally, we examined differences in intellectual functioning and its relationship to social cognitive abilities. Finally, we examined the relationship between social cognitive abilities and real-world social behavior.

METHODS

We examined social cognition and intellectual functioning in 273 participants (mean age = 17.74 ± 5.18% female = 44.3%): 50 with 22q11DS, 49 youth with first episode psychosis (FEP), 48 at clinical high-risk (CHR) for psychosis, 24 participants with ASD, and 102 HC. Social cognition was assessed using The Awareness of Social Inference Test (TASIT), while reciprocal social behavior was assessed via parent/caregiver ratings on the Social Responsiveness Scale (SRS). Participants were also administered the Wechsler Abbreviated Scale of Intelligence, 2nd edition (WASI-II) to assess intellectual functioning.

RESULTS

The 22q11DS group exhibited significantly lower social cognitive abilities compared to CHR, FEP, and HC groups after controlling for intellectual functioning, but not in comparison to the ASD group. Significant positive correlations were found between social cognition, as measured by the TASIT and IQ across groups. In contrast, no significant relationships were found between TASIT and real-world social behavior (SRS) for any group.

CONCLUSIONS

Our findings indicate social cognitive deficits are more prominent in 22q11DS than idiopathic neuropsychiatric conditions across the age range, even after adjusting for global intellectual function. These results contribute to our understanding of the intellectual and social vulnerabilities of 22q11DS in comparison to idiopathic neuropsychiatric disorders. Our findings of robust associations between intellectual ability and social cognition emphasizes the importance of accounting for neurocognitive deficits in social skills interventions and tailoring these existing treatment models for 22q11DS and other populations with intellectual impairment.

Psychological Adjustment of Children and Adolescents with 22q11.2 Deletion Syndrome and Their Mothers' Stress and Coping-A Longitudinal Study

At present, there is a lack of longitudinal studies on the psychological adjustment of both children and adolescents with 22q11.2 deletion syndrome (22q11.2DS) and their primary caregivers. To fill this gap, we performed a four-year follow-up study. Mothers filled out the Child Behavior Checklist 4–18, the Social Orientation of Parents with Handicapped Children questionnaire to assess maternal stress and coping strategies, and the Freiburger Personality Inventory-Revised—subscales strain and life satisfaction. Fifty-five subjects with 22q11.2DS (26 males and 29 females; age: M = 10.79 years, SD = 3.56 years) and their biological mothers (age: M = 40.84 years, SD = 4.68 years) were included in this study. Significantly higher levels of behavior problems than in the general population and an increase in these problems, especially internalizing ones, over time could be found. In contrast, maternal stress did not change significantly over time, but mothers demonstrated increased levels of strain and reduced life satisfaction at T2. Thus, careful monitoring as well as early and adequate interventions, if indicated, should be offered to families with a child with 22q11.2DS, not only for somatic complaints but also for problems with psychological adjustment.

Genotypic and phenotypic variability of 22q11.2 microdeletions – an institutional experience

<abstract> <p>Patients with chromosome 22q11.2 deletion syndromes classically present with variable cardiac defects, parathyroid and thyroid gland hypoplasia, immunodeficiency and velopharyngeal insufficiency, developmental delay, intellectual disability, cognitive impairment, and psychiatric disorders. New technologies including chromosome microarray have identified smaller deletions in the 22q11.2 region. An increasing number of studies have reported patients presenting with various features harboring smaller 22q11.2 deletions, suggesting a need to better elucidate 22q11.2 deletions and their phenotypic contributions so that clinicians may better guide prognosis for families. We identified 16 pediatric patients at our institution harboring various 22q11.2 deletions detected by chromosomal microarray and report their clinical presentations. Findings include various neurodevelopmental delays with the most common one being attention deficit hyperactivity disorder (ADHD), one reported case of infant lethality, four cases of preterm birth, one case with dual diagnoses of 22q11.2 microdeletion and Down syndrome. We examined potential genotypic contributions of the deleted regions.</p> </abstract>

Modular, Circuit-Based Interventions Rescue Hippocampal-Dependent Social and Spatial Memory in a 22q11.2 Deletion Syndrome Mouse Model

BACKGROUND

22q11.2 deletion syndrome (22qDS) manifests with myriad symptoms, including multiple neuropsychiatric disorders. Complications associated with the polygenic haploinsufficiency make 22qDS symptoms particularly difficult to manage with traditional therapeutic approaches. However, the varying mechanistic consequences often culminate to generate inappropriate regulation of neuronal circuit activity. We explored whether managing this aberrant activity in adults could be a therapeutically beneficial strategy.

METHODS

To assess and dissect hippocampal circuit function, we performed functional imaging in acute slices and targeted eloquent circuits (specific subcircuits tied to specific behavioral tasks) to provide relevant behavioral outputs. For example, the ventral and dorsal CA1 regions critically support social and spatial discrimination, respectively. We focally introduced chemogenetic constructs in 34 control and 24 22qDS model mice via adeno-associated viral vectors, driven by excitatory neuron-specific promoter elements, to manipulate circuit recruitment in an on-demand fashion.

RESULTS

22qDS model mice exhibited CA1 excitatory ensemble hyperexcitability and concomitant behavioral deficits in both social and spatial memory. Remarkably, acute chemogenetic inhibition of pyramidal cells successfully corrected memory deficits and did so in a regionally specific manner: ventrally targeted constructs rescued only social behavior, while those expressed dorsally selectively affected spatial memory. Additionally, manipulating activity in control mice could recapitulate the memory deficits in a regionally specific manner.

CONCLUSIONS

These data suggest that retuning activity dysregulation can rescue function in disease-altered circuits, even in the face of a polygenetic haploinsufficiency with a strong developmental component. Targeting circuit excitability in a focal, modular manner may prove to be an effective therapeutic for treatment-resistant symptoms of mental illness.

Neuroimaging Phenotypes Associated With Risk and Resilience for Psychosis and Autism Spectrum Disorders in 22q11.2 Microdeletion Syndrome

Identification of biological risk factors that contribute to the development of complex neuropsychiatric disorders such as psychosis and autism spectrum disorder (ASD) is key for early intervention and detection. Furthermore, parsing the biological heterogeneity associated with these neuropsychiatric syndromes will help us understand the neural mechanisms underlying psychiatric symptom development. The 22q11.2 microdeletion syndrome (22q11DS) is caused by a recurrent genetic mutation that carries significantly increased risk for developing psychosis and/or ASD. In this review, I provide an brief introduction to 22q11DS and discuss common phenotyping strategies that are used to assess psychosis and ASD in this population. I then summarize neuroimaging phenotypes associated with psychosis and ASD in 22q11.DS. Next, I discuss challenges within the field and provide practical suggestions to overcome these obstacles. Finally, I discuss future directions for moving 22q11DS risk and resilience research forward.

Relationship between parent-reported gastrointestinal symptoms, sleep problems, autism spectrum disorder symptoms, and behavior problems in children and adolescents with 22q11.2 deletion syndrome

BACKGROUND

22q11.2 deletion syndrome (22q) is a chromosome disorder, where a segment of chromosome 22, located at q11.2, is missing. This study aims to investigate the relationship between a number of parent-reported comorbid conditions including gastrointestinal symptoms, sleep problems, autism spectrum disorder (ASD) symptoms and behavior problems in children and adolescents with 22q deletion syndrome.

METHOD

The Gastrointestinal Symptom Inventory, Children's Sleep Habits Questionnaire, Behavior Problem Inventory-Short Form and the Social Communication Questionnaire were completed by parents of 149 children and adolescents aged 3-18 years with a diagnosis of 22q.

RESULTS

A series of correlations and hierarchical multiple regressions were conducted to examine the relationships between GI symptoms, sleep problems and behavior problems in children and adolescents with 22q deletion syndrome. A significant moderate relationship was found between GI symptoms and sleep problems. Gender and ASD symptoms predicted GI symptoms. Significant small relationships were found between GI symptoms and self-injurious behavior. Significant small to moderate relationships were found between sleep problems and self-injurious behavior, aggressive/destructive behavior, and sterotyped behavior. Sleep problems predicted challenging behavior.

CONCLUSIONS

This research demonstrated the importance of studying the relationship between comorbidities, including gastrointestinal symptoms, sleep problems, and behavior problems and how they shape the phenotype of 22q deletion syndrome.

Layers II/III of Prefrontal Cortex in Df(h22q11)/+ Mouse Model of the 22q11.2 Deletion Display Loss of Parvalbumin Interneurons and Modulation of Neuronal Morphology and Excitability

The 22q11.2 deletion has been identified as a risk factor for multiple neurodevelopmental disorders. Behavioral and cognitive impairments are common among carriers of the 22q11.2 deletion. Parvalbumin expressing (PV⁺) interneurons provide perisomatic inhibition of excitatory neuronal circuits through GABA_A receptors, and a deficit of PV⁺ inhibitory circuits may underlie a multitude of the behavioral and functional deficits in the 22q11.2 deletion syndrome. We investigated putative deficits of PV⁺ inhibitory circuits and the associated molecular, morphological, and functional alterations in the prefrontal cortex (PFC) of the Df(h22q11)/+ mouse model of the 22q11.2 hemizygous deletion. We detected a significant decrease in the number of PV⁺ interneurons in layers II/III of PFC in Df(h22q11)/+ mice together with a reduction in the mRNA and protein levels of GABA_A (α3), a PV⁺ putative postsynaptic receptor subunit. Pyramidal neurons from the same layers further experienced morphological reorganizations of spines and dendrites. Accordingly, a decrease in the levels of the postsynaptic density protein 95 (PSD95) and a higher neuronal activity in response to the GABA_A antagonist bicuculline were measured in these layers in PFC of Df(h22q11)/+ mice compared with their wild-type littermates. Our study shows that a hemizygotic deletion of the 22q11.2 locus leads to deficit in the GABAergic control of network activity and involves molecular and morphological changes in both the inhibitory and excitatory synapses of parvalbumin interneurons and pyramidal neurons specifically in layers II/III PFC.

Schizophrenia-related microdeletion causes defective ciliary motility and brain ventricle enlargement via microRNA-dependent mechanisms in mice

Progressive ventricular enlargement, a key feature of several neurologic and psychiatric diseases, is mediated by unknown mechanisms. Here, using murine models of 22q11-deletion syndrome (22q11DS), which is associated with schizophrenia in humans, we found progressive enlargement of lateral and third ventricles and deceleration of ciliary beating on ependymal cells lining the ventricular walls. The cilia-beating deficit observed in brain slices and in vivo is caused by elevated levels of dopamine receptors (Drd1), which are expressed in motile cilia. Haploinsufficiency of the microRNA-processing gene Dgcr8 results in Drd1 elevation, which is brought about by a reduction in Drd1-targeting microRNAs miR-382-3p and miR-674-3p. Replenishing either microRNA in 22q11DS mice normalizes ciliary beating and ventricular size. Knocking down the microRNAs or deleting their seed sites on Drd1 mimicked the cilia-beating and ventricular deficits. These results suggest that the Dgcr8-miR-382-3p/miR-674-3p-Drd1 mechanism contributes to deceleration of ciliary motility and age-dependent ventricular enlargement in 22q11DS.

Comprehensive analysis of a novel mouse model of the 22q11.2 deletion syndrome: a model with the most common 3.0-Mb deletion at the human 22q11.2 locus

The 22q11.2 deletion syndrome (22q11.2DS) is associated with an increased risk for psychiatric disorders. Although most of the 22q11.2DS patients have a 3.0-Mb deletion, existing mouse models only mimic a minor mutation of 22q11.2DS, a 1.5-Mb deletion. The role of the genes existing outside the 1.5-Mb deletion in psychiatric symptoms of 22q11.2DS is unclear. In this study, we generated a mouse model that reproduced the 3.0-Mb deletion of the 22q11.2DS (Del(3.0 Mb)/ +) using the CRISPR/Cas9 system. Ethological and physiological phenotypes of adult male mutants were comprehensively evaluated by visual-evoked potentials, circadian behavioral rhythm, and a series of behavioral tests, such as measurement of locomotor activity, prepulse inhibition, fear-conditioning memory, and visual discrimination learning. As a result, Del(3.0 Mb)/ + mice showed reduction of auditory prepulse inhibition and attenuated cue-dependent fear memory, which is consistent with the phenotypes of existing 22q11.2DS models. In addition, Del(3.0 Mb)/ + mice displayed an impaired early visual processing that is commonly seen in patients with schizophrenia. Meanwhile, unlike the existing models, Del(3.0 Mb)/ + mice exhibited hypoactivity over several behavioral tests, possibly reflecting the fatigability of 22q11.2DS patients. Lastly, Del(3.0 Mb)/ + mice displayed a faster adaptation to experimental jet lag as compared with wild-type mice. Our results support the validity of Del(3.0 Mb)/ + mice as a schizophrenia animal model and suggest that our mouse model is a useful resource to understand pathogenic mechanisms of schizophrenia and other psychiatric disorders associated with 22q11.2DS.

Interrelationship Between Cognitive Control, Anxiety, and Restricted and Repetitive Behaviors in Children with 22q11.2 Deletion Syndrome

Restricted and repetitive behaviors (RRB) are common in individuals with 22q11.2 microdeletion syndrome (22q11.2DS), yet the underlying mechanisms of these behaviors remain poorly characterized. In the present pilot investigation, we aimed to further our understanding of RRB in 22q11.2DS by exploring their relationship with cognitive control and anxiety as well as with sex, chronological age, and full-scale IQ. Parents of 38 children with 22q11.2DS (17 females; Mage = 11.15 years, SD = 2.46) completed the Social Communication Questionnaire as a measure of RRB and social and communication (SC) problems and the Behavioral Assessment System for Children-2 as a measure of anxiety and cognitive control. Higher RRB scores were significantly associated with higher anxiety levels (r = 0.44, P = 0.006), more impairments in cognitive control (r = 0.56, P < 0.001), and higher SC scores (r = 0.43, P = 0.011). In the first step of the hierarchical regression model, anxiety accounted for 24.5% of variance (F = 10.05, P = 0.003); cognitive control accounted for an additional 18.1% of variance (Fchange = 11.15, P < 0.001) in the second step; SC score accounted for only 0.8% of additional variance in the third step (Fchange = 0.40, P = 0.53). The final model explained 43.4% of variance (F = 7.42, P = 0.001), with cognitive control as a unique independent predictor of RRB score (t = 2.52, P = 0.01). The current study provides the first exploration of the cognitive control-anxiety-RRB link in individuals with 22q11.2DS and points to cognitive control as a potentially viable target for treatments aimed at reducing RRB. Autism Res 2019, 12: 1737-1744. © 2019 International Society for Autism Research, Wiley Periodicals, Inc. LAY SUMMARY: People with 22q11.2 deletion syndrome show high levels of repetitive behaviors, however, the previous research has not explored why people with this syndrome exhibit high rates of repetitive behaviors. Understanding the reasons for the high levels of repetitive behaviors is important given that these behaviors can be highly impairing. Our study found that repetitive behaviors were associated with impaired ability to self-regulate and high levels of anxiety. These findings need to be further replicated; however, they are important as they suggest potentially promising ways of reducing these behaviors.

Congenital Heart Disease and Autism: A Case-Control Study

OBJECTIVES

There has long been an association between congenital heart disease (CHD) and general neurodevelopmental delays. However, the association between CHD and autism spectrum disorders (AuSDs) is less well understood. Using administrative data, we sought to determine the association between CHD and AuSD and identify specific CHD lesions with higher odds of developing AuSD.

METHODS

We performed a 1:3 case-control study of children enrolled in the US Military Health System from 2001 to 2013. Children with International Classification of Disease, Ninth Revision, Clinical Modification codes for AuSD were identified as cases and matched with controls on the basis of date of birth, sex, and enrollment time frame. Each child's records were reviewed for CHD lesions and associated procedures. Conditional logistic regression determined odds ratios (ORs) and 95% confidence intervals (CIs) for comparative associations.

RESULTS

There were 8760 cases with AuSD and 26 280 controls included in the study. After adjustment for genetic syndrome, maternal age, gestational diabetes, short gestation, newborn epilepsy, birth asphyxia, and low birth weight, there were increased odds of AuSD in patients with CHD (OR 1.32; 95% CI 1.10-1.59). Specific lesions with significant OR included atrial septal defects (n = 82; OR 1.72; 95% CI 1.07-2.74) and ventricular septal defects (n = 193; OR 1.65; 95% CI 1.21-2.25).

CONCLUSIONS

Children with CHD have increased odds of developing AuSD. Specific lesions associated with increased risk include atrial septal defects and ventricular septal defects. These findings will be useful for counseling parents of children with CHD.

Autism needs to be considered in children with Down Syndrome

AIM

To analyse levels and profiles of autism symptoms in children with Down Syndrome (DS) with and without diagnosed autism spectrum disorder (ASD) and to specifically study the groups with severe Intellectual Disability (ID).

METHODS

From a population-based cohort of 60 children with DS (age 5-17 years) with 41 participating children, scores obtained from the Autism Diagnostic Observation Schedule (ADOS) Module-1 algorithm were compared between those with and without diagnosed ASD. Children with DS and ASD were also compared to a cohort of children with idiopathic ASD, presented in the ADOS manual.

RESULTS

Children with DS and ASD had significantly higher ADOS scores in all domains compared to those without ASD. When the groups with DS, with and without ASD, were restricted to those with severe ID, the difference remained. When the children with DS and ASD and the idiopathic autism group were compared, the ADOS profiles were similar.

CONCLUSION

A considerable proportion of children with DS has ASD, but there is also a group of children with DS and severe ID without autism. There is a need to increase awareness of the high prevalence of autism in children with DS to ensure that appropriate measures and care are provided.

22q11 microdeletion syndrome and ultra-high risk for psychosis: The role of neurological soft signs as an independent marker of vulnerability for psychosis

AIM

22q11 microdeletion syndrome has an increased risk for psychosis, similar to subjects at ultra-high risk for psychosis. Neurological soft signs are considered an endophenotype of psychotic disorders and a marker of vulnerability to Schizophrenia, consisting of overflow movements, dysrhythmia and speed of timed activities. To date, there are no studies that have evaluated the presence of the neurological soft signs in subjects with 22q11 microdeletion syndrome and there are a few studies that have analysed this issue in subjects at ultra-high risk.

METHODS

We sought to measure neurological soft signs in these two conditions, compared to healthy controls and to analyse the possible correlation between neurological soft signs and positive/negative symptoms both in 22q11 microdeletion syndrome and ultra-high-risk groups. 54 drug-naive patients (29 with 22q11 microdeletion syndrome and 25 at ultra-high risk for psychosis) and 25 healthy controls were evaluated for neurological soft signs.

RESULTS

Both clinical groups showed a greater number of neurological soft signs compared to healthy control, although the two clinical groups did not differ for the number of neurological soft signs. Positive correlation between speed of timed activities and negative symptoms was found in subjects at ultra-high risk.

CONCLUSION

Neurological soft signs could represent a marker of atypical neurodevelopment in the two populations examined. Since we did not found a strong correlation between neurological soft signs and positive/negative symptoms, we suggest that neurological soft signs could be indicators of vulnerability to psychosis independent from the psychopathology.

Neuropsychiatric phenotypes and a distinct constellation of ASD features in 3q29 deletion syndrome: results from the 3q29 registry

Background

The 1.6 Mb 3q29 deletion is associated with neurodevelopmental and psychiatric phenotypes, including increased risk for autism spectrum disorder (ASD) and a 20 to 40-fold increased risk for schizophrenia. However, the phenotypic spectrum of the deletion, particularly with respect to ASD, remains poorly described.

Methods

We ascertained individuals with 3q29 deletion syndrome (3q29Del, “cases,” n = 93, 58.1% male) and typically developing controls (n = 64, 51.6% male) through the 3q29 registry (https://3q29deletion.patientcrossroads.org). Self-report of neuropsychiatric illness was evaluated for 93 cases. Subsets of participants were evaluated with the Social Responsiveness Scale (SRS, n = 48 cases, 56 controls), Social Communication Questionnaire (n = 33 cases, 46 controls), Autism Spectrum Screening Questionnaire (n = 24 cases, 35 controls), and Achenbach Behavior Checklists (n = 48 cases, 57 controls).

Results

3q29Del cases report a higher prevalence of autism diagnoses versus the general population (29.0% vs. 1.47%, p < 2.2E− 16). Notably, 3q29 deletion confers a greater influence on risk for ASD in females (OR = 41.8, p = 4.78E− 05) than in males (OR = 24.6, p = 6.06E− 09); this is aligned with the reduced male:female bias from 4:1 in the general population to 2:1 in our study sample. Although 71% of cases do not report a diagnosis of ASD, there is evidence of significant social disability (3q29Del SRS T-score = 71.8, control SRS T-score = 45.9, p = 2.16E− 13). Cases also report increased frequency of generalized anxiety disorder compared to controls (28.0% vs. 6.2%, p = 0.001), which is mirrored by elevated mean scores on the Achenbach diagnostic and statistical manual-oriented sub-scales (p < 0.001). Finally, cases show a distinct constellation of ASD features on the SRS as compared to idiopathic ASD, with substantially elevated Restricted Interests and Repetitive Behaviors, but only mild impairment in Social Motivation.

Conclusions

Our sample of 3q29Del is significantly enriched for ASD diagnosis, especially among females, and features of autism may be present even when an ASD diagnosis is not reported. Further, the constellation of ASD features in this population is distinct from idiopathic ASD, with substantially less impaired social motivation. Our study implies that ASD evaluation should be the standard of care for individuals with 3q29Del. From a research perspective, the distinct ASD subtype present in 3q29Del is an ideal entry point for expanding understanding of ASD.

Electronic supplementary material

The online version of this article (10.1186/s13229-019-0281-5) contains supplementary material, which is available to authorized users.

Both rare and common genetic variants contribute to autism in the Faroe Islands

The number of genes associated with autism is increasing, but few studies have been performed on epidemiological cohorts and in isolated populations. Here, we investigated 357 individuals from the Faroe Islands including 36 individuals with autism, 136 of their relatives and 185 non-autism controls. Data from SNP array and whole exome sequencing revealed that individuals with autism had a higher burden of rare exonic copy-number variants altering autism associated genes (deletions (p = 0.0352) or duplications (p = 0.0352)), higher inbreeding status (p = 0.023) and a higher load of rare homozygous deleterious variants (p = 0.011) compared to controls. Our analysis supports the role of several genes/loci associated with autism (e.g., NRXN1, ADNP, 22q11 deletion) and identified new truncating (e.g., GRIK2, ROBO1, NINL, and IMMP2L) or recessive deleterious variants (e.g., KIRREL3 and CNTNAP2) affecting autism-associated genes. It also revealed three genes involved in synaptic plasticity, RIMS4, KALRN, and PLA2G4A, carrying de novo deleterious variants in individuals with autism without intellectual disability. In summary, our analysis provides a better understanding of the genetic architecture of autism in isolated populations by highlighting the role of both common and rare gene variants and pointing at new autism-risk genes. It also indicates that more knowledge about how multiple genetic hits affect neuronal function will be necessary to fully understand the genetic architecture of autism.

Intellectual performance profi le of a sample of children and adolescents from Brazil with 22q11.2 Deletion Syndrome (22q11.2DS) based on the Wechsler Scale

Abstract The 22q11.2 Deletion Syndrome (22q11.2DS), the most common human chromosome microdeletion syndrome, is associated with a very heterogeneous neurocognitive phenotype. One of the main characteristics of the syndrome spectrum is the intellectual variability, which encompasses average performance and intellectual disability and discrepancies between Verbal Intelligence Quotient and Performance Verbal Intelligence Quotient, with greater impairment in nonverbal tasks. The present study aimed at investigating the intellectual performance aspects of a 21children and adolescents sample from Brazil who had been diagnosed with 22q11.2DS, based on the Wechsler Intelligence Scale for Children - 4th edition. The samples were reviewed considering the differences between indices. The results revealed an Full Scale Intelligence Quotient predominant in the borderline range (42 to 104) and a significant discrepancy between the indices of Verbal Comprehension and Perceptual Reasoning in 42% of the sample. With regard to the performance in the subtests alone, a better performance was found in Similarities, whereas block design, matrix reasoning, digit span and letter-number sequencing subtests were the most challenging. These findings indicate that a comprehensive assessment of intellectual performance aspects covering the different measures of the Wechsler Intelligence Scale may contribute to a broader understanding of the neurocognitive phenotype associated with 22q11.2DS.

Psychiatric disorders and autism in young children with 22q11.2 deletion syndrome compared to children with idiopathic autism

BACKGROUND

The 22q11.2 deletion syndrome (22q11DS) is a neurogenetic condition characterized by high rates of psychiatric disorders. To our knowledge, this is the first study to assess psychiatric disorders in young children with 22q11DS using a structured psychiatric diagnostic interview, and one of few studies to use the complete gold standard diagnostic evaluation to examine the prevalence of autism spectrum disorder (ASD) in young children with 22q11DS and compare it to a matched control group with iASD.

METHODS

We identified the psychiatric disorders and autistic phenotype of young children with 22q11DS (age 3-8 years) and compared them with those of age and sex-matched children with idiopathic autism (iASD). We used the gold standard psychiatric and ASD assessments including the Autism Diagnostic Interview-Revised (ADI-R), the Autism Diagnostic Observation Schedule (ADOS) and a clinical examination by a child psychiatrist.

RESULTS

Eighty-four percent of the children with 22q11DS had at least one psychiatric disorder, including anxiety disorders and ADHD, and 16% met strict criteria for ASD. Children with 22q11DS and ASD symptoms had less severe overall ASD symptoms than those with iASD. Children with 22q11DS, regardless of ASD diagnosis, were characterized by repetitive restricted behaviors.

CONCLUSIONS

Our results highlight the need to screen for psychiatric disorders in 22q11DS and treat them already in preschool years.

Abnormalities in gray matter microstructure in young adults with 22q11.2 deletion syndrome

BACKGROUND

22q11.2 Deletion Syndrome (22q11DS) is a genetic, neurodevelopmental disorder characterized by a chromosomal deletion and a distinct cognitive profile. Although abnormalities in the macrostructure of the cortex have been identified in individuals with 22q11DS, it is not known if there are additional microstructural changes in gray matter regions in this syndrome, and/or if such microstructural changes are associated with cognitive functioning.

METHODS

This study employed a novel diffusion MRI measure, the Heterogeneity of Fractional Anisotropy (HFA), to examine variability in the microstructural organization of the cortex in healthy young adults (N = 30) and those with 22q11DS (N = 56). Diffusion MRI, structural MRI, clinical and cognitive data were acquired.

RESULTS

Compared to controls, individuals with 22q11DS evinced increased HFA in cortical association (p = .003, d = 0.86) and paralimbic (p < .0001, d = 1.2) brain areas, whereas no significant differences were found between the two groups in primary cortical brain areas. Additionally, increased HFA of the right paralimbic area was associated with poorer performance on tests of response inhibition, i.e., the Stroop Test (rho = -0.37 p = .005) and the Gordon Diagnostic System Vigilance Commission (rho = -0.41 p = .002) in the 22q11DS group. No significant correlations were found between HFA and cognitive abilities in the healthy control group.

CONCLUSIONS

These findings suggest that cortical microstructural disorganization may be a neural correlate of response inhibition in individuals with 22q11DS. Given that the migration pattern of neural crest cells is disrupted at the time of early brain development in 22q11DS, we hypothesize that these neural alterations may be neurodevelopmental in origin, and reflect cortical dysfunction associated with cognitive deficits.

Understanding the pediatric psychiatric phenotype of 22q11.2 deletion syndrome

The purpose of this article is to provide an overview of current insights into the neurodevelopmental and psychiatric manifestations of 22q11.2 deletion syndrome (22q11DS) in children and adolescents. The pediatric neuropsychiatric expression of 22q11DS is characterized by high variability, both interindividual and intraindividual (different expressions over the lifespan). Besides varying levels of intellectual disability, the prevalence of autism spectrum disorders, attention deficit disorders, anxiety disorders, and psychotic disorders in young individuals with 22q11DS is significantly higher than in the general population, or in individuals with idiopathic intellectual disability. Possible explanations for this observed phenotypic variability will be discussed, including genetic pleiotropy, gene-environment interactions, the age-dependency of phenotypes, but also the impact of assessment and ascertainment bias as well as the limitations of our current diagnostic classification system. The implications inferred by these observations aforementioned bear direct relevance to both scientists and clinicians. Observations regarding the neuropsychiatric manifestations in individuals with 22q11DS exemplify the need for a dimensional approach to neuropsychiatric assessment, in addition to our current categorical diagnostic classification system. The potential usefulness of 22q11DS as a genetic model to study the early phases of schizophrenia as well as the phenomenon of neuropsychiatric pleiotropy observed in many CNV's will be delineated. From a clinical perspective, the importance of regular neuropsychiatric evaluations with attention to symptoms not always captured in diagnostic categories and of maintaining equilibrium between individual difficulties and competencies and environmental demands will be discussed.

Exploratory study on cognitive abilities and social responsiveness in children with 22q11.2 deletion syndrome (22q11DS) and children with idiopathic intellectual disability (IID)

BACKGROUND

Development of cognitive skills and social responsiveness are areas of concern in children with 22q11.2 deletion syndrome (22q11DS). It remains unclear if the cognitive and social profiles and trajectories are syndrome-specific or similar to those of children with idiopathic intellectual disabilities (IID) with or without comorbid autism spectrum disorder (ASD).

AIMS AND METHODS

In this exploratory study, we examined and compared five broad cognitive abilities (BCAs) and the social responsiveness in primary school-aged children with 22q11DS (age 6-13, n = 21) and IQ-matched peers with IID (n = 21). The relative strengths and weaknesses of both groups were re-evaluated after 19 to 30 months.

OUTCOMES AND RESULTS

Four different cognitive trajectories (i.e. absolute progress, stability, growing into deficit, and absolute decline) were demonstrated in both groups. Most children showed combined types of trajectories across BCAs resulting in a complex changing cognitive profile. In the 22q11DS group, social responsiveness problems increased, whereas no significant change was observed in the IID group.

CONCLUSIONS AND IMPLICATIONS

Results reflect similar cognitive and social responsiveness profiles and trajectories across groups with children with 22q11DS being more at risk for growing into a social deficit. We recommend repeated monitoring of social skills development to adapt the environmental demands to the child's individual social capacities.

Atypical language characteristics and trajectories in children with 22q11.2 deletion syndrome

BACKGROUND

22q11.2 deletion syndrome (22q11.2DS) is a genetic condition associated with a highly variable phenotypic expression. During childhood speech and language deficits are commonly observed. Findings of cross-sectional studies suggest syndrome-specific and changing language profiles, but a longitudinal approach to identify developmental changes is still lacking to date.

AIMS

The present study aimed to delineate language characteristics and trajectories by comparing the performance of Dutch-speaking school-aged children with 22q11.2DS (n = 18) to those of peers with idiopathic intellectual disability (IID, n  = 19) and to those of children with IID and comorbid autism spectrum disorder (IID + ASD, n = 23). The literature shows contradictory findings regarding language comprehension difficulties in children with 22q11.2DS, we focused on the receptive-expressive language discrepancy. Given their relative strength for verbal short-term memory (VSTM) tasks, a fine-grained error categorization was included to elucidate a possible influence of VSTM on the expressive language outcomes. Finally, we suggested that the inability of children with 22q11.2DS to use contextual information could interfere with morphosyntactic measures.

METHODS

All groups (22q11.2DS, IID, and IID + ASD) were matched for nonverbal fluid reasoning (Gf) using the Analogies and Categories subtests of the Snijders-Oomen Nonverbal Intelligence Test or the Matrix Reasoning and Picture Concepts subtests of the Wechsler Preschool and Primary Scale of Intelligence. Several structural language skills were measured using the Clinical Evaluation of Language Fundamentals and Peabody Picture Vocabulary Test. The same instruments were re-administered after 18 to 24 months. A fine-grained error analysis of the Formulating and Recalling Sentences subtests, both measuring expressive syntax, explored factors contributing to expressive language deficits.

RESULTS

In children with 22q11.2DS the relative advantage of receptive over expressive language had decreased compared to children with IID. For children with 22q11.2DS, complex sentence comprehension remained very challenging over time. Expressive language skills seemed less limited compared to children with IID, and were accompanied by less VSTM difficulties. In children with 22q11.2DS and children with IID + ASD, variable patterns of strengths and weaknesses were demonstrated, resulting in subtle differences between these groups. Error analyses indicated disregard of content-contextual cues and use of vague and elliptic language as being typical for children with 22q11.2DS.

CONCLUSIONS

We recommend that in children with 22q11.2DS the impact of the receptive language impairment should be comprehensively examined and followed-up since it can have a negative effect on their social communication skills, adaptive functioning and academic achievement. Error analysis underscores that multiple measures should be used to evaluate the child's expressive language ability. Further research should focus on developmental trajectories of social communication skills and on the use of intervention strategies to improve language comprehension and pragmatics in school-aged children with 22q11.2DS.

Adult ADHD and Comorbid Somatic Disease: A Systematic Literature Review

OBJECTIVE

To systematically review, synthesize, and appraise available evidence, connecting adult ADHD with somatic disease.

METHOD

Embase, Psychinfo, and Medline databases were searched for studies published from 1994 to 2015 addressing adult ADHD and somatic comorbidity. Somatic conditions were classified according to International Classification of Diseases (ICD-10) codes. Levels of evidence were graded as inconclusive, tentative, or well documented.

RESULTS

Most of the 126 studies included in the qualitative synthesis were small and of modest quality. Obesity, sleep disorders, and asthma were well-documented comorbidities in adult ADHD. Tentative evidence was found for an association between adult ADHD and migraine and celiac disease. In a large health registry study, cardiovascular disease was not associated with adult ADHD.

CONCLUSION

There are few large systematic studies using standardized diagnostic criteria evaluating adult ADHD and somatic comorbidities. Significant associations are found between adult ADHD and several somatic diseases, and these are important to consider when assessing and treating either adult ADHD or the somatic diseases.

Developmental excitatory-to-inhibitory GABA-polarity switch is disrupted in 22q11.2 deletion syndrome: a potential target for clinical therapeutics

Individuals with 22q11.2 microdeletion syndrome (22q11.2 DS) show cognitive and behavioral dysfunctions, developmental delays in childhood and risk of developing schizophrenia and autism. Despite extensive previous studies in adult animal models, a possible embryonic root of this syndrome has not been determined. Here, in neurons from a 22q11.2 DS mouse model (Lgdel^+/−), we found embryonic-premature alterations in the neuronal chloride cotransporters indicated by dysregulated NKCC1 and KCC2 protein expression levels. We demonstrate with large-scale spiking activity recordings a concurrent deregulation of the spontaneous network activity and homeostatic network plasticity. Additionally, Lgdel^+/− networks at early development show abnormal neuritogenesis and void of synchronized spontaneous activity. Furthermore, parallel experiments on Dgcr8^+/− mouse cultures reveal a significant, yet not exclusive contribution of the dgcr8 gene to our phenotypes of Lgdel^+/− networks. Finally, we show that application of bumetanide, an inhibitor of NKCC1, significantly decreases the hyper-excitable action of GABA_A receptor signaling and restores network homeostatic plasticity in Lgdel^+/− networks. Overall, by exploiting an on-a-chip 22q11.2 DS model, our results suggest a delayed GABA-switch in Lgdel^+/− neurons, which may contribute to a delayed embryonic development. Prospectively, acting on the GABA-polarity switch offers a potential target for 22q11.2 DS therapeutic intervention.

Working Memory Impairments in Chromosome 22q11.2 Deletion Syndrome: The Roles of Anxiety and Stress Physiology

Stress and anxiety have a negative impact on working memory systems by competing for executive resources and attention. Broad memory deficits, anxiety, and elevated stress have been reported in individuals with chromosome 22q11.2 deletion syndrome (22q11.2DS). We investigated anxiety and physiological stress reactivity in relation to visuospatial working memory impairments in 20 children with 22q11.2DS and 32 typically developing (TD) children ages 7 to 16. Children with 22q11.2DS demonstrated poorer working memory, reduced post-stress respiratory sinus arrhythmia recovery, and overall increased levels of cortisol in comparison to TD children. Anxiety, but not physiological stress responsivity, mediated the relationship between 22q11.2DS diagnosis and visuospatial working memory impairment. Findings indicate that anxiety exacerbates impaired working memory in children with 22q11.2DS.

Epigenetics of Autism Spectrum Disorder

Autism spectrum disorder (ASD), one of the most common childhood neurodevelopmental disorders (NDDs), is diagnosed in 1 of every 68 children. ASD is incredibly heterogeneous both clinically and aetiologically. The etiopathogenesis of ASD is known to be complex, including genetic, environmental and epigenetic factors. Normal epigenetic marks modifiable by both genetics and environmental exposures can result in epigenetic alterations that disrupt the regulation of gene expression, negatively impacting biological pathways important for brain development. In this chapter we aim to summarize some of the important literature that supports a role for epigenetics in the underlying molecular mechanism of ASD. We provide evidence from work in genetics, from environmental exposures and finally from more recent studies aimed at directly determining ASD-specific epigenetic patterns, focusing mainly on DNA methylation (DNAm). Finally, we briefly discuss some of the implications of current research on potential epigenetic targets for therapeutics and novel avenues for future work.

Attention and motor deficits index non-specific background liabilities that predict autism recurrence in siblings

Background

Recent research has demonstrated that subclinical autistic traits of parents amplify the effects of deleterious mutations in the causation of autism spectrum disorder (ASD) in their offspring. Here, we examined the extent to which two neurodevelopmental traits that are non-specific to ASD—inattention/hyperactivity and motor coordination—might contribute to ASD recurrence in siblings of ASD probands.

Methods

Data from a quantitative trait study of 114 ASD probands and their brothers, 26% of whom also had ASD, were analyzed. Autistic trait severity was ascertained using the Social Responsiveness Scale-2, attention/hyperactivity problems using the Achenbach System of Empirically Based Assessment, and motor coordination (in a subset of participants) using the Developmental Coordination Disorder Questionnaire.

Results

Among siblings (affected and unaffected), both categorical recurrence of ASD (Nagelkerke R² = 0.53) and quantitative ASD trait burden (R² = 0.55) were predicted by sibling ADHD and motor coordination impairment scores, even though these traits, on average, were not elevated among the unaffected siblings.

Conclusions

These findings in a clinical family cohort confirm observations from general population studies that inattention/hyperactivity and motor impairment—axes of behavioral development that are non-specific to ASD, and often appreciable before ASD is typically diagnosed—jointly account for over 50% of the variation in autistic impairment of siblings, whether ascertained quantitatively or categorically. This finding within a sibling design suggests that background ASD susceptibilities that are inherited but non-specific (“BASINS”) may contribute to additive genetic liability in the same manner that ASD-specific susceptibilities (such as parental subclinical ASD traits and deleterious mutations) engender ASD risk.

Electronic supplementary material

The online version of this article (doi:10.1186/s11689-017-9212-y) contains supplementary material, which is available to authorized users.

Differential DNA methylation at birth associated with mental disorder in individuals with 22q11.2 deletion syndrome

Individuals with 22q11.2 deletion syndrome (DS) have an increased risk of comorbid mental disorders including schizophrenia, attention deficit hyperactivity disorder, depression, as well as intellectual disability. Although most 22q11.2 deletion carriers have the long 3-Mb form of the hemizygous deletion, there remains a large variation in the development and progression of psychiatric disorders, which suggests that alternative factors contribute to the pathogenesis. In this study we investigated whether neonatal DNA methylation signatures in individuals with the 22q11.2 deletion associate with mental disorder later in life. DNA methylation was measured genome-wide from neonatal dried blood spots in a cohort of 164 individuals with 22q11.2DS, including 48 individuals diagnosed with a psychiatric disorder. Among several CpG sites with P-value<10-6, we identified cg23546855 (P-value=2.15 × 10-7) mapping to STK32C to be associated with a later psychiatric diagnosis. Pathway analysis of the top findings resulted in the identification of several Gene Ontology pathways to be significantly enriched (P-value<0.05 after Benjamini-Hochberg correction); among them are the following: neurogenesis, neuron development, neuron projection development, astrocyte development, axonogenesis and axon guidance. In addition, we identified differentially methylated CpG sites in LRP2BP (P-value=5.37 × 10-8) to be associated with intellectual disability (F70-79), in TOP1 (P-value=1.86 × 10-7) with behavioral disorders (F90-98), in NOSIP (P-value=5.12 × 10-8) with disorders of psychological development (F80-89) and in SEMA4B (P-value=4.02 × 10-7) with schizophrenia spectrum disorders (F20-29). In conclusion, our study suggests an association of DNA methylation differences at birth with development of mental disorder later in life in 22q11.2DS individuals.

Mapping 22q11.2 Gene Dosage Effects on Brain Morphometry

Reciprocal chromosomal rearrangements at the 22q11.2 locus are associated with elevated risk of neurodevelopmental disorders. The 22q11.2 deletion confers the highest known genetic risk for schizophrenia, but a duplication in the same region is strongly associated with autism and is less common in schizophrenia cases than in the general population. Here we conducted the first study of 22q11.2 gene dosage effects on brain structure in a sample of 143 human subjects: 66 with 22q11.2 deletions (22q-del; 32 males), 21 with 22q11.2 duplications (22q-dup; 14 males), and 56 age- and sex-matched controls (31 males). 22q11.2 gene dosage varied positively with intracranial volume, gray and white matter volume, and cortical surface area (deletion < control < duplication). In contrast, gene dosage varied negatively with mean cortical thickness (deletion > control > duplication). Widespread differences were observed for cortical surface area with more localized effects on cortical thickness. These diametric patterns extended into subcortical regions: 22q-dup carriers had a significantly larger right hippocampus, on average, but lower right caudate and corpus callosum volume, relative to 22q-del carriers. Novel subcortical shape analysis revealed greater radial distance (thickness) of the right amygdala and left thalamus, and localized increases and decreases in subregions of the caudate, putamen, and hippocampus in 22q-dup relative to 22q-del carriers. This study provides the first evidence that 22q11.2 is a genomic region associated with gene-dose-dependent brain phenotypes. Pervasive effects on cortical surface area imply that this copy number variant affects brain structure early in the course of development.SIGNIFICANCE STATEMENT Probing naturally occurring reciprocal copy number variation in the genome may help us understand mechanisms underlying deviations from typical brain and cognitive development. The 22q11.2 genomic region is particularly susceptible to chromosomal rearrangements and contains many genes crucial for neuronal development and migration. Not surprisingly, reciprocal genomic imbalances at this locus confer some of the highest known genetic risks for developmental neuropsychiatric disorders. Here we provide the first evidence that brain morphology differs meaningfully as a function of reciprocal genomic variation at the 22q11.2 locus. Cortical thickness and surface area were affected in opposite directions with more widespread effects of gene dosage on cortical surface area.