Autistic Spectrum Disorders in Velo-cardio Facial Syndrome (22q11.2 Deletion)

The extent to which the phenotype of children comorbid for velocardiofacial syndrome (VCFS) and autism spectrum disorders (ASD) differs from that of VCFS-only has not been studied. The sample consisted of 41 children (20 females) with VCFS, ranging in age from 6.5 years to 15.8 years. Eight children with VCFS met formal DSM-IV diagnostic criteria for autism based upon the ADI-R. These eight plus an additional nine participants met diagnostic criteria for an autistic spectrum disorder (VCFS + ASD). Ninety-four percent of the children with VCFS + ASD had a co-occurring psychiatric disorder while 60% of children with VCFS had a psychiatric disorder. Children with VCFS + ASD had larger right amygdala volumes. All other neuroanatomic regions of interest were statistically similar between the two groups.     

The dimensional structure of psychopathology in 22q11.2 Deletion Syndrome

Background22q11.2 Deletion Syndrome (22q11.2DS) is one of the strongest known genetic risk factors for developing schizophrenia. Individuals with 22q11.2DS have high rates of neurodevelopmental disorders in childhood, while in adulthood ∼25% develop schizophrenia. Similar to the general population, high rates of comorbidity are common in 22q11.2DS. Employing a dimensional approach where psychopathology is examined at the symptom-level as complementary to diagnostic categories in a population at such high genetic risk for schizophrenia can help gain a better understanding of how psychopathology is structured as well as its genetic underpinnings. This is the first study to examine the dimensional structure of a wide spectrum of psychopathology in the context of a homogeneous genetic etiology like 22q11.2DS.MethodsWe evaluated 331 individuals with 22q11.2DS, mean age (SD) = 16.9(8.7); 51% males, who underwent prospective comprehensive phenotyping. We sought to replicate previous findings by examining a bi-factor model that derives a general factor of psychopathology in addition to more specific dimensions of psychopathology (i.e., internalizing, externalizing and thought disorder).ResultsPsychopathology in 22q11.2DS was divided into one ‘general psychopathology’ factor and four specific dimensions (i.e., ‘anxiety’, ‘mood’, ‘ADHD’ and ‘psychosis’). The ‘psychosis’ symptoms loaded strongly on the ‘general psychopathology’ factor.ConclusionsThe similarity of the symptom structure of psychopathology between 22q11.2DS and community and clinical populations without the deletion indicate that 22q11.2DS can provide a model to explore alternative approaches to our current nosology. Our findings add to a growing literature indicating the need to reorganize current diagnostic classification systems.     

Epilepsy and Other Neuropsychiatric Manifestations in Children and Adolescents with 22q11.2 Deletion Syndrome

MethodsWe retrospectively analyzed the medical records of 145 child and adolescent patients (72 males and 73 females) with genetically diagnosed 22q11.2DS. The clinical data included seizures, growth chart, psychological reports, development characteristics, school performance, other clinical manifestations, and laboratory findings.ResultsOf the 145 patients with 22q11.2DS, 22 (15.2%) had epileptic seizures, 15 (10.3%) had developmental delay, and 5 (3.4%) had a psychiatric illness. Twelve patients with epilepsy were classified as genetic epilepsy whereas the remaining were classified as structural, including three with malformations of cortical development. Patients with epilepsy were more likely to display developmental delay (odds ratio=3.98; 95% confidence interval=1.5-10.5; p=0.005), and developmental delay was more common in patients with structural epilepsy than in those with genetic epilepsy.ConclusionsPatients with 22q11.2DS have a high risk of epilepsy, which in these cases is closely related to other NP manifestations. This implies that this specific genetic locus is critically linked to neurodevelopment and epileptogenesis.     

Psychotic Features as the First Manifestation of 22q11.2 Deletion Syndrome

The 22q11.2 deletion is a genetic disorder which is characterized by abnormalities in cardiac functioning, facial structure, neurobehavioral development, T cell functioning, and velopharyngeal insufficiencies. In the presented case study, 22q11.2 deletion was found in a patient who has psychotic symptoms only. A 25-year-old woman with a history of hypoparathyroidism and hypothyroidism presented with auditory hallucinations and persecutory delusions. After three months of treatment with antipsychotic medications, the patient was readmitted with generalized tonic-clonic seizures. The following week, the patient went into sepsis. A fluorescent in situ hybridization (FISH) analysis revealed the presence of a 22q11.2 microdeletion. This case study suggests that psychotic symptoms can develop prior to the typical symptoms of a 22q11.2 deletion. As such, psychiatrists should test for genetic abnormalities in patients with schizophrenia when these patients present with seizures and immunodeficiencies.     

Increased basal ganglia volumes in velo-cardio-facial syndrome (deletion 22q11.2).

BACKGROUND: This study evaluated differences in caudate volumes in subjects with velo-cardio-facial syndrome due to a 22q11.2 (22qDS) deletion. Because psychosis is observed in 30% of adult subjects with 22qDS, this neurogenetic disorder could represent a putative model for a genetically mediated subtype of schizophrenia.METHODS: Caudate volumes were measured on high-resolution magnetic resonance images in 30 children and adolescents with 22qDS and 30 gender- and age-matched normal comparison subjects.RESULTS: Caudate head volumes were increased in the 22qDS group independent of neuroleptic medications. Subjects with 22qDS also displayed an abnormal pattern of asymmetry in the anterior caudate, with left side greater than right.CONCLUSIONS: Alterations in the basal ganglia circuitry have been implicated in learning, cognitive, and behavioral problems in children and therefore could be involved in the expression of the neurobehavioral phenotype expressed by subjects with 22qDS. Abnormal caudate volume is a neurodevelopmental feature shared with schizophrenia, further establishing 22qDS as a potential neurodevelopmental model for this disorder.     

Reduced NoGo-anteriorisation during continuous performance test in deletion syndrome 22q11.2

Deletion syndrome 22q11.2 (DS22q11.2) is a high-risk factor for psychiatric disorders. Alterations in brain morphology and function including the anterior cingulate cortex (ACC) are suggested to underlie the increased psychiatric disposition. We assessed response-inhibition in patients with DS22q11.2 (n = 13) and healthy controls (n = 13) matched for age, sex, and handedness by means of a Go-NoGo-Task during recording of a multi-channel electroencephalography (EEG). Analysis of event-related potentials (P300) resulted in an aberrant topographical pattern and NoGo-anteriorisation (NGA) as a parameter of medial prefrontal function was significantly reduced in patients with DS22q11.2 compared to controls. Differences in IQ between groups did not account for the findings. Source localization analysis (LORETA) revealed diminished left temporal brain activation during the Go-condition, but no altered ACC activation in DS22q11 during the NoGo-condition. Despite recent reports of structural alterations of the ACC in DS22q11.2 our findings suggest that response-inhibition mediated by the ACC is not impaired in DS22q11.2.     

Core neuropsychological characteristics of children and adolescents with 22q11.2 deletion

Background The 22q11.2 deletion syndrome (22qDS) confers high risk for intellectual disability and neuropsychological/academic impairment, although a minority of patients show average intelligence. Intellectual heterogeneity and the high prevalence of psychiatric diagnoses in earlier studies may have obscured the prototypical neuropsychological profile in 22qDS. Methods We examined intelligence, memory, reading and mathematical processes in 31 children/adolescents with 22qDS, selected for educational underachievement and an absence of psychiatric diagnoses, using standardised, psychometrically matched instruments that specify how typical a score is for a given intelligence quotient (IQ). Results Corroborating earlier findings, verbal IQ was significantly superior to performance IQ; verbal memory and basic reading were relative strengths; and visual/spatial memory was a relative weakness. All four findings transcended performance characteristics that are typical of low‐IQ individuals. Rote learning yielded the highest score; reading comprehension, numerical operations and mathematical reasoning were among the lowest‐performed academic domains. Albeit in the expected direction, performance in the respective components could not be clearly differentiated from what is IQ‐appropriate. Conclusions A superiority of verbal intelligence over non‐verbal intelligence, relative strengths in verbal memory and basic reading, and a relative weakness in visual/spatial memory are likely to be core characteristics of children/adolescents with 22qDS, transcending performance features that are typical of individuals with low IQ.     

Impaired multiple object tracking in children with chromosome 22q11.2 deletion syndrome

Background

Williams syndrome (WS) is a rare genetic disorder caused by the deletion of approximately 25 genes at 7q11.23 that involves mild to moderate intellectual disability (ID). When using functional magnetic resonance imaging (fMRI) to compare individuals with ID to typically developing individuals, there is a possibility that differences in IQ contribute to between-group differences in BOLD signal. If IQ is correlated with BOLD signal, then group-level analyses should adjust for IQ, or else IQ should be matched between groups. If, however, IQ is not correlated with BOLD signal, no such adjustment or criteria for matching (and exclusion) based on IQ is necessary.

Methods

In this study, we aimed to test this hypothesis systematically using four extant fMRI datasets in WS. Participants included 29 adult subjects with WS (17 men) demonstrating a wide range of standardized IQ scores (composite IQ mean = 67, SD = 17.2). We extracted average BOLD activation for both cognitive and task-specific anatomically defined regions of interest (ROIs) in each individual and correlated BOLD with composite IQ scores, verbal IQ scores and non-verbal IQ scores in Spearman rank correlation tests.

Results

Of the 312 correlations performed, only six correlations (2%) in four ROIs reached statistical significance at a P value < 0.01, but none survived correction for multiple testing. All six correlations were positive. Therefore, none supports the hypothesis that IQ is negatively correlated with BOLD response.

Conclusions

These data suggest that the inclusion of subjects with below normal IQ does not introduce a confounding factor, at least for some types of fMRI studies with low cognitive load. By including subjects who are representative of IQ range for the targeted disorder, findings are more likely to generalize to that population.     

Parental report on socio-communicative behaviours in children with 22q11.2 deletion syndrome

Background Children with 22q11.2 deletion syndrome (22q11.2DS) are reported to have socio-communicative impairments. Although many of these children are diagnosed with intellectual disability (ID) and/or autism spectrum disorder (ASD), these populations are seldom used as control groups. Hence, information regarding syndrome-specific socio-communicative challenges is lacking.

Method Parental concerns regarding everyday communication were investigated by means of the Children’s Communication Checklist-2-NL (Geurts, 2007). Twenty children with 22q11.2DS (chronological age: 6 years–13 years 3 months) were compared to 21 children with idiopathic ID and 23 children with idiopathic ID and comorbid ASD. All groups were matched for fluid intelligence (Gf), chronological age, and core language scores.

Results Neglect or inadequate use of context information was more prevalent in children with 22q11.2DS than in children with idiopathic ID. Nonverbal communication seemed less impaired than in children with idiopathic ID + ASD.

Conclusion Pragmatic language skills and developmental trajectories in children with 22q11.2DS merit further investigation.     

Early developmental concerns in 22q11.2 deletion and duplication carriers

Background22q11.2 deletions (22qDEL) and duplications (22qDUP) are among the most common copy number variants (CNVs) associated with neurodevelopmental disorders (NDDs). Little is known about the earliest developmental features of 22q11.2 CNVs and whether developmental delays are detected in early childhood. This study primarily aimed to assess general development and social communication in 22q11.2 CNV carriers age 5 and under.MethodParticipants included parents of children age 5 and under with a reported genetic diagnosis of 22qDEL (N = 63) or 22qDUP (N = 30). In addition to questions addressing clinical and intervention information, two standardized parent questionnaires—the Ages & Stages Questionnaires, Third Edition (ASQ-3) and the Communication and Symbolic Behavior Scales Developmental Profile Infant/Toddler Checklist (ITC)—screened for developmental and social communication delays, respectively.ResultsDevelopmental delay and speech and/or language delay were the most commonly reported NDD diagnoses among young 22q11.2 CNV carriers, with prevalences at 19% and 17%, respectively. In the vast majority (91%) of 22q11.2 CNV carriers, parents reported concerns in at least one developmental domain, with 71% reporting global developmental concerns. 70% of parents of 22q11.2 CNV carriers age 2 and under also reported social communication concerns.ConclusionsThe high prevalence of reported developmental concerns in both CNV groups reinforces the need for close monitoring of early neurodevelopment in 22q11.2 CNV carriers with regard to both developmental delays and autism risk.     

Atypical developmental trajectory of functionally significant cortical areas in children with chromosome 22q11.2 deletion syndrome

Chromosome 22q11.2 deletion syndrome (22q11.2DS) is a neurogenetic disorder associated with neurocognitive impairments. This article focuses on the cortical gyrification changes that are associated with the genetic disorder in 6-15-year-old children with 22q11.2DS, when compared with a group of age-matched typically developing (TD) children. Local gyrification index (lGI; Schaer et al. [2008]: IEEE Trans Med Imaging 27:161-170) was used to characterize the cortical gyrification at each vertex of the pial surface. Vertex-wise statistical analysis of lGI differences between the two groups revealed cortical areas of significant reduction in cortical gyrification in children with 22q11.2DS, which were mainly distributed along the medial aspect of each hemisphere. To gain further insight into the developmental trajectory of the cortical gyrification, we examined age as a factor in lGI changes over the 6-15 years of development, within and across the two groups of children. Our primary results pertaining to the developmental trajectory of cortical gyrification revealed cortical regions where the change in lGI over the 6-15 years of age was significantly modulated by diagnosis, implying an atypical development of cortical gyrification in children with 22q11.2DS, when compared with the TD children. Significantly, these cortical areas included parietal structures that are associated, in typical individuals, with visuospatial, attentional, and numerical cognition tasks in which children with 22q11.2DS show impairments.     

Atypical development of the executive attention network in children with chromosome 22q11.2 deletion syndrome

Impairment in the executive control of attention has been found in youth with chromosome 22q11.2 deletion syndrome (22q11.2DS). However, how this impairment is modified by other factors, particularly age, is unknown. Forty-six typically developing and 53 children with 22q11.2DS were tested with the attention networks task (ANT) in this cross-sectional study. We used logarithmic transform and linear modeling to assess age effects on the executive index of the ANT. Mixed modeling accounted for between subject variability, age, handedness, catecholamine-O-transferase (COMT; codon 158) genotype, and gender on performance for all experimental conditions (cue × flanker) and their two-level interactions. Children with 22q11.2DS showed a relative, age-dependent executive index impairment but not orienting or alerting network index impairments. In factorial analysis, age was a major predictor of overall performance. There was a significant effect of the 22q11.2DS on overall performance. Of note, children with 22q11.2DS are specifically vulnerable to incongruent flanker interference, especially at younger ages. We did not find an overall effect of COMT genotype or handedness. Children with 22q11.2DS demonstrated age-related impairment in the executive control of attention. Future investigation will likely reveal that there are different developmental trajectories of executive attentional function likely related to the development of schizophrenia in 22q11.2DS.     

Cognitive phenotype and psychiatric disorder in 22q11.2 deletion syndrome: A review

The behavioural phenotype of 22q11.2 deletion syndrome syndrome (22q11DS), one of the most common human multiple anomaly syndromes, frequently includes intellectual disability (ID) together with high risk of diagnosis of psychotic disorders including schizophrenia. Candidate cognitive endophenotypes include problems with retrieval of contextual information from memory and in executive control and focussing of attention. 22q11DS may offer a model of the relationship between ID and risk of psychiatric disorder. This paper reviews research on the relationship between the cognitive phenotype and the development of psychiatric disorders in 22q11DS.Aspects of cognitive function including verbal I.Q., visual memory, and executive function, are associated with mental health outcome in people with 22q11DS. This relationship may result from a common neurobiological basis for the cognitive difficulties and psychiatric disorders. Some of the cognitive difficulties experienced by people with 22q11DS, especially in attention, memory retrieval, and face processing, may, however, in themselves constitute risk factors for development of hallucinations and paranoid delusions.Future research into factors leading to psychiatric disorder in people with 22q11DS should include assessment of social and psychological factors including life events, symptoms associated with trauma, attachment, and self-esteem, which together with cognitive risk factors may mediate mental health outcome.     

Ictus emeticus presenting as an unusual seizure type in chromosome 22q11.2 deletion syndrome

We present a case study of a patient with chromosome 22q11.2 deletion syndrome presenting with ictus emeticus, together with a review of the relevant literature. The patient developed generalized tonic‐clonic seizures at 3 months old, and seizures eventually remitted after calcium therapy. He then experienced vigorous vomiting that occurred during sleep, with glassy eyes and legs flexion. Video‐EEG recordings exhibited a switch in background activity from organized reactivity during normal sleep to left lateralized temporal delta activity, which was bilaterally synchronized during an emetic attack. The ictal vomiting ceased following management with oxcarbazepine, high‐dose phenobarbital, and a ketogenic diet. The unique seizure type and rare ictal EEG findings are the first reported in a child with chromosome 22q11.2 deletion syndrome. This case highlights that ictus emeticus without detectable epileptic discharge on EEG is one potential epileptic presentation in this genetic syndrome. [Published with video sequence on www.epilepticdisorders.com ]