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Single-cell analysis of dup15q syndrome reveals developmental and postnatal molecular changes in autism.

Duplication 15q (dup15q) syndrome is a leading genetic cause of autism spectrum disorder, offering a key model for studying autism-related mechanisms. Using single-cell and single-nucleus RNA sequencing of cortical organoids from dup15q patient-derived iPSCs and post-mortem brain samples, we identify increased glycolysis, disrupted layer-specific marker expression, and aberrant morphology in deep-layer neurons during fetal-stage organoid development. In adolescent-adult postmortem brains, upper-layer neurons exhibit heightened transcriptional burden related to synaptic signaling, a pattern shared with idiopathic autism. Using spatial transcriptomics, we confirm these cell-type-specific disruptions in brain tissue. By gene co-expression network analysis, we reveal disease-associated modules that are well preserved between postmortem and organoid samples, suggesting metabolic dysregulation that may lead to altered neuron projection, synaptic dysfunction, and neuron hyperexcitability in dup15q syndrome.

Humans↗

Language dysfunction in epileptic conditions.

Epilepsy may disrupt brain functions necessary for language development by its associated intellectual disabilities or directly as a consequence of the seizure disorder. Additionally, in recent years, there has been increasing recognition of the association of epileptiform electroencephalogram (EEG) abnormalities with language disorders and autism spectrum disorders. Any process that impairs language function has long-term consequences for academic, social, and occupational adjustments in children and adolescents with epilepsy. Furthermore, impairments in specific language abilities can impact memory and learning abilities. This article reviews interictal language function in children and adults with epilepsy; epilepsy surgery and language outcome; and language disorders associated with abnormal EEGs. The relationship between epilepsy and language function is complicated as the neuroanatomic circuits common to both overlap. We demonstrate how magnetoencephalography (MEG) offers the ability to analyze the relationship of language, EEG abnormalities, and epilepsy.

Adolescent↗

Exploring the cerebellum with a new tool: neonatal Borna disease virus (BDV) infection of the rat's brain.

Cerebellar pathology has been associated with a number of developmental behavioral disorders, including autism spectrum disorders. Despite the fact that perinatal virus infections have been implicated in neurodevelopmental damage, few animal models have been developed to study the pathogenesis involved. One of the most interesting in vivo models of virus-induced cerebellar damage is the neonatal Borna disease virus (BDV) infection of the rat brain. The present review describes molecular, cellular, neuroanatomical, neurochemical and behavioral features of the BDV model and also provides a basis for a new understanding of the pathogenic mechanisms of cerebellar malformation and associated behavioral deficits.

Animals↗

Sudden infant death syndrome, child sexual abuse, and child development.

Since the introduction of the Back to Sleep Campaigns, there has been a dramatic reduction in sudden infant death syndrome in this country. Steven Blatt and Victoria Meguid review the literature surrounding sleep position. Investigators have continued efforts to find other modifiable risk factors of sudden infant death syndrome. A prospective study of more than 33,000 neonates found a link between a prolonged QT electrocardiogram interval and sudden infant death syndrome. Also discussed are investigations seeking to explain the relationship between smoking and sudden infant death syndrome. Ann Botash, Florence Jean-Louis and Mongkae Ploy Siripornsawan review the latest thinking on genital warts and their relation to specific viral etiologies and child sexual abuse. Other symptoms and signs of sexual abuse are the focus of a number of articles that can help the practitioner care for these unfortunate children. Catherine Church reviews medication options for children diagnosed with pervasive developmental disorders or autism spectrum disorders. Finally, in this article, risperidone, fluoxetine and naltrexone are reviewed.

Autistic Disorder↗

Principles and practices of neurodevelopmental assessment in children: lessons learned from the Centers for Children's Environmental Health and Disease Prevention Research.

Principles and practices of pediatric neurotoxicology are reviewed here with the purpose of guiding the design and execution of the planned National Children's Study. The developing human central nervous system is the target organ most vulnerable to environmental chemicals. An investigation of the effects of environmental exposures on child development is a complex endeavor that requires consideration of numerous critical factors pertinent to a study's concept, design, and execution. These include the timing of neurodevelopmental assessment, matters of biologic plausibility, site, child and population factors, data quality assurance and control, the selection of appropriate domains and measures of neurobehavior, and data safety and monitoring. Here we summarize instruments for the assessment of the neonate, infant, and child that are being employed in the Centers for Children's Environmental Health and Disease Prevention Research, sponsored by the National Institute of Environmental Health Sciences and the U.S. Environmental Protection Agency, discuss neural and neurobiologic measures of development, and consider the promises of gene-environment studies. The vulnerability of the human central nervous system to environmental chemicals has been well established, but the contribution these exposures may make to problems such as attention deficit disorder, conduct problems, pervasive developmental disorder, or autism spectrum disorder remain uncertain. Large-scale studies such as the National Children's Study may provide some important clues. The human neurodevelopmental phenotype will be most clearly represented in models that include environmental chemical exposures, the social milieu, and complex human genetic characteristics that we are just beginning to understand.

Central Nervous System↗

Association of Genetic Liability to Psychiatric Disorders with Peripheral Metabolic Dysregulation.

IMPORTANCE: Individuals with psychiatric disorders face elevated cardiometabolic risk which is linked to increased mortality. The extent to which this reflects shared pathogenesis or the downstream effects of illness and treatment remains poorly understood. OBJECTIVE: To characterize the direct pleiotropic effects of psychiatric genetic liability on circulating metabolites and aggregate cardiometabolic risk, independent of psychiatric diagnosis and psychotropic medication use. DESIGN SETTING AND PARTICIPANTS: Cross-sectional analysis of Mass General Brigham Biobank participants with metabolomic profiling, genomic data, and linked electronic health records. EXPOSURES: Genetic liability to nine psychiatric disorders quantified using polygenic risk scores (PRS): attention deficit/hyperactivity disorder (ADHD), anorexia nervosa (ANO), anxiety disorder (ANX), autism spectrum disorder (ASD), bipolar disorder (BD), major depressive disorder (MDD), PTSD, schizophrenia (SCZ), and substance use disorder (SUD). MAIN OUTCOMES AND MEASURES: 249 circulating metabolites and four metabolomic risk scores (MRS) for type 2 diabetes, myocardial infarction, ischemic stroke, and vascular dementia. PRS-metabolite associations were estimated using nested models adjusting for lifetime psychiatric diagnosis and psychotropic medication use. RESULTS: Across 25,290 participants, we identified 604 significant PRS-metabolite associations (Bonferroni p< 1.36 x 10-4), of which 89% persisted after adjustment for lifetime diagnosis and medication use, suggesting that the direct genetic effects on metabolism are largely independent of illness or treatment. PRS for MDD, PTSD, and ADHD showed the most extensive dysregulation, with a transdiagnostic pattern of elevated lipids and systemic inflammation, specifically triglycerides (&#x3b2; = 0.04 to 0.05, all p< 4.4 x10-13) and glycoprotein acetyls (&#x3b2; = 0.05, all p< 2.2 x10-16). Notably, PRS for SCZ and BD showed minimal metabolite dysregulation despite having the strongest association with their target diagnoses. PRS for MDD, PTSD, ADHD, and SUD were associated with increased MRS across cardiometabolic conditions (&#x3b2; = 0.03 to 0.08, all p< 2.1 x10-4). Sensitivity analyses controlling for BMI or excluding participants without any psychiatric history (N: 21,305 and 11,150, respectively) showed a similar pattern. CONCLUSIONS AND RELEVANCE: Psychiatric genetic liability is associated with systemic metabolic dysregulation independent of illness onset or treatment, supporting a partially pleiotropic basis for psychiatric-cardiometabolic comorbidity.

Journal Article↗

Predicting language outcome in infants with autism and pervasive developmental disorder.

BACKGROUND: To examine longitudinal associations between diagnosis, joint attention, play and imitation abilities and language outcome in infants with autism and pervasive developmental disorder. METHODS AND PROCEDURES: Experimental measures of joint attention, play and imitation were conducted with a sample of infants with autism spectrum disorder at age 20 months. Language outcome was assessed at age 42 months. A within-group longitudinal correlational design was adopted. OUTCOMES AND RESULTS: Language at 42 months was higher for children with a diagnosis of pervasive developmental disorder than for children with a diagnosis of autism. Language at follow-up was also positively associated with performance on experimental measures of joint attention and imitation, but not with performance on experimental measures of play and 'goal detection' at 20 months, nor with a non-verbal intelligence quotient, although these associations were not examined independent of diagnosis. However, floor effects on the measure of play at 20 months and the small sample size limit the conclusions that can be drawn. CONCLUSIONS: Individual differences in infant social-communication abilities as well as diagnosis may predict language outcome in preschoolers with autism spectrum disorders. Attention should be directed at assessing these skills in 2- and 3-year-old children referred for a diagnosis of autism spectrum disorder. Imitation and joint attention abilities may be important targets for early intervention.

Attention↗

The phenotypic manifestations of interstitial duplications of proximal 15q with special reference to the autistic spectrum disorders.

This study investigated the phenotypic manifestations of interstitial duplications of chromosome 15 that involve the Prader-Willi/Angelman syndrome critical region (PWACR). Twenty-one affected individuals from six families were evaluated in detail, using standardized and semi-standardized measures of intelligence, psychopathology, and physical anomalies. Special attention was placed on determining the prevalence of autism spectrum disorders as well as the relationship between the parental origin of the duplication and the phenotypic effects. Assessments of the affected individuals were compared with evaluations of the unaffected relatives from the same families. Results indicated that duplications in the region were associated with variable degrees of intellectual impairments and motor coordination problems. Four of the subjects received a diagnosis of pervasive developmental disorder. Three of these cases were probands and only one met criteria for classic autism. There was very little evidence of the duplication cosegregating with autism spectrum disorder diagnosis. Paternally inherited duplications were significantly less likely to give rise to phenotypic effects. The findings indicate that duplications in the PWACR give rise to developmental delay but not necessarily autism spectrum disorders. They also suggest that phenotypic expression is dependent on the parental origin of the duplication and implicate maternally active genes in the pathogenesis of the developmental impairments. Further research will be required to clarify the range and basis of the phenotypic manifestations.

Adult↗

Abnormally high plasma levels of vitamin B6 in children with autism not taking supplements compared to controls not taking supplements.

BACKGROUND: There have been many studies of the effect of high-dose supplementation of vitamin B6 on children and adults with autism, with all but one reporting benefits. OBJECTIVE: The aim of this study was to investigate the biochemical basis for vitamin B6 therapy by measuring the level of total vitamin B6 in the plasma of unsupplemented children with autism spectrum disorder compared to unsupplemented control subjects. PARTICIPANTS: Children with autism spectrum disorders (n = 35, age 3-9 years) and unrelated typical children (n = 11, age 6-9 years), all from Arizona, were studied. (This includes the data from 24 children with autism from our previous study.) METHODOLOGY: A microbiologic assay was used to measure the level of total vitamin B6 (including phosphorylated and unphosphorylated forms), in a blinded fashion. RESULTS: Children with autism had a 75% higher level of total vitamin B6 than the controls (medians of 56 versus 32 ng/mL, respectively, p = 0.00002). Most of the autistic children (77%) had levels that were more than 2 standard deviations above the median value of the controls. The autistic girls (n = 5) also had elevated levels (mean of 54.6 ng/mL, median of 60 ng/mL). DISCUSSION: These results are consistent with previous studies that found that: (1) pyridoxal kinase had a very low activity in children with autism and (2) pyridoxal 5 phosphate (PLP) levels are unusually low in children with autism. Thus, it appears that the low conversion of pyridoxal and pyridoxine to PLP results in low levels of PLP, which is the active cofactor for 113 known enzymatic reactions, including the formation of many key neurotransmitters. CONCLUSIONS: Total vitamin B6 is abnormally high in autism, consistent with previous reports of an impaired pyridoxal kinase for the conversion of pyridoxine and pyridoxal to PLP. This may explain the many published studies of benefits of high-dose vitamin B6 supplementation in some children and adults with autism.

Autistic Disorder↗

Psychiatric disorders in individuals with pervasive developmental disorder.

Pervasive developmental disorders (PDD) refer to the group of heterogeneous conditions that make up a continuum or spectrum of autistic disorders and share a core triad of impairments consisting of qualitative disturbances in social interaction and verbal and nonverbal communication and imagination. It has long been believed that the prevalence of autism was 2-4 per 10,000 children. However, studies using broader definitions of autistic disorder have suggested that the prevalence of autism spectrum disorder may be as high as 90 per 10,000 and that a greater proportion of individuals with PDD have intellectual levels above 70. Clinicians and researchers have commented on the apparent increase in prevalence of the disorder and have offered a number of explanations, including better recognition and diagnosis of the autism spectrum of disorders and a real increase in the disturbance. It is being increasingly recognized that individuals with PDD are at risk for a wide array of psychiatric disturbances, including affective disorder, anxiety disorders, schizophrenia-like psychosis, aggression, antisocial behavior, and Tourette's disorder (TD). Evidence indicates that PDD is significantly related to the comorbid psychiatric disorders and TD. Because PDD is not rare, individuals with autism spectrum disorder may represent significant subgroups of severely emotionally disturbed patients referred for psychiatric treatment. Because of lack of awareness that the clinical manifestations of PDD are heterogeneous and often mild and that comorbid psychiatric disturbances may obscure the symptoms of the developmental disorder, the diagnosis of PDD may be missed. Implications for practicing clinicians are discussed.

Journal Article↗

Why bother about clumsiness? The implications of having developmental coordination disorder (DCD).

Developmental coordination disorder (DCD) is a common motor problem affecting--even in rather severe form--several percent of school age children. In the past, DCD has usually been called 'clumsy child syndrome' or 'non-cerebral-palsy motor-perception dysfunction'. This disorder is more common in boys than in girls and is very often associated with psychopathology, particularly with attention-deficit/hyperactivity disorder (ADHD) and autism spectrum disorders/ autistic-type problems. Conversely, children with ADHD and autism spectrum problems, particularly those given a diagnosis of Asperger syndrome, have a very high rate of comorbid DCD. Psychiatrists appear to be unaware of this type of comorbidity in their young patients. Neurologists, on the other hand, usually pay little attention to the striking behavioral and emotional problems shown by so many of their 'clumsy' patients. A need exists for a much clearer focus on DCD-in child psychiatry and in child neurology-both in research and in clinical practice.

Asperger Syndrome↗

Neuroimaging in disorders of social and emotional functioning: what is the question?

Social and emotional processing uses neural systems involving structures ranging from the brain stem to the associational cortex. Neuroimaging research has attempted to identify abnormalities in components of these systems that would underlie the behavioral abnormalities seen in disorders of social and emotional processing, notably autism spectrum disorders, the focus of this review. However, the findings have been variable. The most replicated anatomic finding (a tendency toward large brains) is not modular, and metabolic imaging and functional imaging (although showing substantial atypicality in activation) are not consistent regarding specific anatomic sites. Moreover, autism spectrum disorder demonstrates substantial heterogeneity on multiple levels. Here evidence is marshaled from a review of neuroimaging data to support the claim that abnormalities in social and emotional processing on the autism spectrum are a consequence of systems disruptions in which the behaviors are a final common pathway and the focal findings can be variable, downstream of other pathogenetic mechanisms, and downstream of more pervasive abnormalities.

Adolescent↗

Repetitive behaviour in children with high functioning autism and obsessive compulsive disorder.

Children with Autism Spectrum Disorders (ASD) and children with Obsessive Compulsive Disorder (OCD) were compared on a range of repetitive behaviours. Parents reported similar levels of sameness behaviour and repetitive movements in the clinical groups, although children with OCD engaged in more repetitive behaviour focussed around routines and rituals. Children with OCD reported more compulsions and obsessions than children with ASD; both groups reported more compulsions and obsessions than a typically developing comparison group. Types of compulsions and obsessions tended to be less sophisticated in children with ASD than those with OCD. Sameness behaviour was more prevalent in younger children with OCD, but for children with ASD, age was not significantly related to sameness behaviour, repetitive movements, compulsions, or obsessions.

Autistic Disorder↗

Asperger syndrome in children.

PURPOSE: To review Asperger syndrome characteristics, assessment tools, interventions, outcomes, and the role of the nurse practitioner in diagnosing and caring for children with Asperger syndrome. DATA SOURCES: Review of published literature on and diagnostic criteria of the condition. CONCLUSIONS: Asperger syndrome is a pervasive developmental disorder or an autism spectrum disorder that is thought to have an incidence higher than that of autism. Asperger syndrome is different from autism, with a lack of delayed language as the most distinct difference between Asperger syndrome and autism. IMPLICATIONS FOR PRACTICE: Because of the importance of early diagnosis of Asperger syndrome for outcome improvement, screening at all well-child visits from infancy on is of utmost importance to primary care pediatric nurse practitioners. With early diagnosis, timely intervention is possible, which is proven to show improvement in outcomes.

Asperger Syndrome↗

Epigenetic overlap in autism-spectrum neurodevelopmental disorders: MECP2 deficiency causes reduced expression of UBE3A and GABRB3.

Autism is a common neurodevelopmental disorder of complex genetic etiology. Rett syndrome, an X-linked dominant disorder caused by MECP2 mutations, and Angelman syndrome, an imprinted disorder caused by maternal 15q11-q13 or UBE3A deficiency, have phenotypic and genetic overlap with autism. MECP2 encodes methyl-CpG-binding protein 2 that acts as a transcriptional repressor for methylated gene constructs but is surprisingly not required for maintaining imprinted gene expression. Here, we test the hypothesis that MECP2 deficiency may affect the level of expression of UBE3A and neighboring autism candidate gene GABRB3 without necessarily affecting imprinted expression. Multiple quantitative methods were used including automated quantitation of immunofluorescence and in situ hybridization by laser scanning cytometry on tissue microarrays, immunoblot and TaqMan PCR. The results demonstrated significant defects in UBE3A/E6AP expression in two different Mecp2 deficient mouse strains and human Rett, Angelman and autism brains compared with controls. Although no difference was observed in the allelic expression of several imprinted transcripts in Mecp2-null brain, Ube3a sense expression was significantly reduced, consistent with the decrease in protein. A non-imprinted gene from 15q11-q13, GABRB3, encoding the beta3 subunit of the GABAA receptor, also showed significantly reduced expression in multiple Rett, Angelman and autism brain samples, and Mecp2 deficient mice by quantitative immunoblot. These results suggest an overlapping pathway of gene dysregulation within 15q11-q13 in Rett, Angelman and autism and implicate MeCP2 in the regulation of UBE3A and GABRB3 expressions in the postnatal mammalian brain.

Angelman Syndrome↗

[Epidemiological research in autism: an integrative view].

INTRODUCTION: Sixty years after the first descriptions of Autism, the same diagnostic criteria based on clinical observation used then are still valid today. Two years ago, the Instituto de Salud Carlos III set up the Grupo de Estudio en los Trastornos del Espectro Autista (Autism Spectrum Disorders Study Group) with the aim of evaluating the current state of research in autism spectrum disorders (ASD) in Spain. This group established collaborative links with different associations and set up a way of working that was more coordinated and closer to the real day-to-day situation experienced by the families involved. AIMS AND DEVELOPMENT: The aim of this review is to update certain areas of knowledge concerning the distribution of the factors that determine ASD, that is to say, about the epidemiology of these disorders. At the same time, it intends to arouse a greater degree of interest among professionals who are more directly involved in the study of pervasive developmental disorders. The latest diagnostic tools offer a higher degree of certainty in the complicated process of evaluating a case with symptoms of autism. Nevertheless, given the effectiveness of early attention and how it affects the prognosis, population-based ASD screening programmes must be implemented. These would have to include the use of Modified Check List for Autism in Toddlers (M-CHAT)-type questionnaires, followed by several levels of diagnosis, in order to reduce the number of false positives while at the same time increasing the true positives.

Autistic Disorder↗

Cortical sound processing in children with autism disorder: an MEG investigation.

Previous work investigating frequency encoding mechanisms in human auditory cortex has provided evidence that latency of the auditory evoked M100 is strongly proportional to frequency, with low frequency (100-200 Hz) tones associated with approximately 30 ms longer latencies than mid-range frequency (1-2 kHz) tones. Motivated by pervasive speech and auditory perception deficits observed in autism spectrum disorder, we evaluated M100 frequency dependence in children with autism disorder and typically developing controls. Results indicate that for control children, the dynamic range of frequency modulation was similar to previous reports for healthy adults. Children with autism had a much reduced range of modulation in right hemisphere sites. Findings indicate that frequency encoding mechanisms may follow a differential maturational path in autism spectrum disorder.

Acoustic Stimulation↗

Brief report: early social communication behaviors in the younger siblings of children with autism.

The early social and communicative development of very young siblings of children with autism spectrum disorder (ASD) is the focus of the current study. Three groups of children were included: (1) young children diagnosed with ASD, (2) younger siblings in families with a somewhat older child with ASD, and (3) young typically developing children. All children participated in a videotaped, structured interactional procedure called the Early Social Communication Scales (ESCS; [Mundy & Hogan, 1996, A Preliminary Manual for the Abridged Early Social Communication Scales (ESCS) Unpublished manual, University of Miami]). Very young siblings were compared to young children with a diagnosed autism spectrum disorder and to a group of young typically developing children. Results indicated that, on three of four of the ESCS subscales, the social communicative behaviors of the younger siblings differed from those of the typically developing children but not from the behaviors displayed by the ASD group. Genetic vulnerability for ASD among siblings and characteristics of family interaction may explain the level of impairment observed in the very young siblings of children with autism spectrum disorders.

Age Factors↗