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1.
Front Immunol ; 15: 1347139, 2024.
Article En | MEDLINE | ID: mdl-38726016

Background: Autism spectrum disorder (ASD) is a disease characterized by social disorder. Recently, the population affected by ASD has gradually increased around the world. There are great difficulties in diagnosis and treatment at present. Methods: The ASD datasets were obtained from the Gene Expression Omnibus database and the immune-relevant genes were downloaded from a previously published compilation. Subsequently, we used WGCNA to screen the modules related to the ASD and immune. We also choose the best combination and screen out the core genes from Consensus Machine Learning Driven Signatures (CMLS). Subsequently, we evaluated the genetic correlation between immune cells and ASD used GNOVA. And pleiotropic regions identified by PLACO and CPASSOC between ASD and immune cells. FUMA was used to identify pleiotropic regions, and expression trait loci (EQTL) analysis was used to determine their expression in different tissues and cells. Finally, we use qPCR to detect the gene expression level of the core gene. Results: We found a close relationship between neutrophils and ASD, and subsequently, CMLS identified a total of 47 potential candidate genes. Secondly, GNOVA showed a significant genetic correlation between neutrophils and ASD, and PLACO and CPASSOC identified a total of 14 pleiotropic regions. We annotated the 14 regions mentioned above and identified a total of 6 potential candidate genes. Through EQTL, we found that the CFLAR gene has a specific expression pattern in neutrophils, suggesting that it may serve as a potential biomarker for ASD and is closely related to its pathogenesis. Conclusions: In conclusion, our study yields unprecedented insights into the molecular and genetic heterogeneity of ASD through a comprehensive bioinformatics analysis. These valuable findings hold significant implications for tailoring personalized ASD therapies.


Autism Spectrum Disorder , Computational Biology , Genetic Predisposition to Disease , Quantitative Trait Loci , Humans , Autism Spectrum Disorder/genetics , Autism Spectrum Disorder/immunology , Computational Biology/methods , Gene Expression Profiling , Gene Regulatory Networks , Machine Learning , Databases, Genetic , Immunogenetics , Neutrophils/immunology , Neutrophils/metabolism , Transcriptome
2.
Front Immunol ; 15: 1370276, 2024.
Article En | MEDLINE | ID: mdl-38742104

Background: Extensive observational studies have reported an association between inflammatory factors and autism spectrum disorder (ASD), but their causal relationships remain unclear. This study aims to offer deeper insight into causal relationships between circulating inflammatory factors and ASD. Methods: Two-sample bidirectional Mendelian randomization (MR) analysis method was used in this study. The genetic variation of 91 circulating inflammatory factors was obtained from the genome-wide association study (GWAS) database of European ancestry. The germline GWAS summary data for ASD were also obtained (18,381 ASD cases and 27,969 controls). Single nucleotide polymorphisms robustly associated with the 91 inflammatory factors were used as instrumental variables. The random-effects inverse-variance weighted method was used as the primary analysis, and the Bonferroni correction for multiple comparisons was applied. Sensitivity tests were carried out to assess the validity of the causal relationship. Results: The forward MR analysis results suggest that levels of sulfotransferase 1A1, natural killer cell receptor 2B4, T-cell surface glycoprotein CD5, Fms-related tyrosine kinase 3 ligand, and tumor necrosis factor-related apoptosis-inducing ligand are positively associated with the occurrence of ASD, while levels of interleukin-7, interleukin-2 receptor subunit beta, and interleukin-2 are inversely associated with the occurrence of ASD. In addition, matrix metalloproteinase-10, caspase 8, tumor necrosis factor-related activation-induced cytokine, and C-C motif chemokine 19 were considered downstream consequences of ASD. Conclusion: This MR study identified additional inflammatory factors in patients with ASD relative to previous studies, and raised a possibility of ASD-caused immune abnormalities. These identified inflammatory factors may be potential biomarkers of immunologic dysfunction in ASD.


Autism Spectrum Disorder , Genome-Wide Association Study , Mendelian Randomization Analysis , Polymorphism, Single Nucleotide , Humans , Autism Spectrum Disorder/genetics , Autism Spectrum Disorder/blood , Autism Spectrum Disorder/immunology , Genetic Predisposition to Disease , White People/genetics , Biomarkers/blood , Inflammation/genetics , Inflammation/blood , Inflammation Mediators/blood , Inflammation Mediators/metabolism , Male , Female , Cytokines/blood , Cytokines/genetics , Europe
3.
Adv Exp Med Biol ; 1447: 11-19, 2024.
Article En | MEDLINE | ID: mdl-38724780

Multiple risk factors have been associated with the development of atopic dermatitis (AD). Recent advances in understanding the role of genetics in this disease have been made, with discovery of the filaggrin (FLG) gene as the most notable so far. In addition to FLG gene mutations as a risk factor for AD, a positive family history of atopic or allergic disease in either parent has been shown to confer a greater risk of developing AD. Atopic dermatitis usually presents early in life and is thought to represent the initial step in the "atopic march," which is characterized by the development of other atopic diseases later in life such as asthma, allergic rhinitis, and/or rhinoconjunctivitis, food allergies, and hay fever. Other comorbid diseases that have been associated with AD include increase risk of viral and bacterial skin infections, neuropsychiatric diseases such as attention-deficit hyperactivity disorders (ADHD), and autistic spectrum disorder (ASD). Patients with AD have also been found to have worse sleep quality overall compared to patients without AD. In this chapter, we will discuss the risk factors associated with development of atopic dermatitis as well as the most commonly reported comorbidities in patients with this disease.


Comorbidity , Dermatitis, Atopic , Filaggrin Proteins , Dermatitis, Atopic/genetics , Dermatitis, Atopic/epidemiology , Humans , Risk Factors , Attention Deficit Disorder with Hyperactivity/genetics , Attention Deficit Disorder with Hyperactivity/epidemiology , Attention Deficit Disorder with Hyperactivity/etiology , Genetic Predisposition to Disease , Mutation , Autism Spectrum Disorder/genetics , Autism Spectrum Disorder/epidemiology , Autism Spectrum Disorder/etiology , Intermediate Filament Proteins/genetics
4.
Neuromolecular Med ; 26(1): 20, 2024 May 14.
Article En | MEDLINE | ID: mdl-38744725

The salient features of autism spectrum disorder (ASD) encompass persistent difficulties in social communication, as well as the presence of restricted and repetitive facets of behavior, hobbies, or pursuits, which are often accompanied with cognitive limitations. Over the past few decades, a sizable number of studies have been conducted to enhance our understanding of the pathophysiology of ASD. Preclinical rat models have proven to be extremely valuable in simulating and analyzing the roles of a wide range of established environmental and genetic factors. Recent research has also demonstrated the significant involvement of the endocannabinoid system (ECS) in the pathogenesis of several neuropsychiatric diseases, including ASD. In fact, the ECS has the potential to regulate a multitude of metabolic and cellular pathways associated with autism, including the immune system. Moreover, the ECS has emerged as a promising target for intervention with high predictive validity. Particularly noteworthy are resent preclinical studies in rodents, which describe the onset of ASD-like symptoms after various genetic or pharmacological interventions targeting the ECS, providing encouraging evidence for further exploration in this area.


Autism Spectrum Disorder , Disease Models, Animal , Endocannabinoids , Endocannabinoids/physiology , Endocannabinoids/metabolism , Autism Spectrum Disorder/drug therapy , Autism Spectrum Disorder/genetics , Autism Spectrum Disorder/metabolism , Animals , Humans , Rats , Receptors, Cannabinoid/physiology , Mice , Child
5.
Cereb Cortex ; 34(13): 30-39, 2024 May 02.
Article En | MEDLINE | ID: mdl-38696599

The amygdala undergoes a period of overgrowth in the first year of life, resulting in enlarged volume by 12 months in infants later diagnosed with ASD. The overgrowth of the amygdala may have functional consequences during infancy. We investigated whether amygdala connectivity differs in 12-month-olds at high likelihood (HL) for ASD (defined by having an older sibling with autism), compared to those at low likelihood (LL). We examined seed-based connectivity of left and right amygdalae, hypothesizing that the HL and LL groups would differ in amygdala connectivity, especially with the visual cortex, based on our prior reports demonstrating that components of visual circuitry develop atypically and are linked to genetic liability for autism. We found that HL infants exhibited weaker connectivity between the right amygdala and the left visual cortex, as well as between the left amygdala and the right anterior cingulate, with evidence that these patterns occur in distinct subgroups of the HL sample. Amygdala connectivity strength with the visual cortex was related to motor and communication abilities among HL infants. Findings indicate that aberrant functional connectivity between the amygdala and visual regions is apparent in infants with genetic liability for ASD and may have implications for early differences in adaptive behaviors.


Amygdala , Magnetic Resonance Imaging , Visual Cortex , Humans , Amygdala/diagnostic imaging , Amygdala/physiopathology , Male , Female , Infant , Visual Cortex/diagnostic imaging , Visual Cortex/physiopathology , Visual Cortex/growth & development , Neural Pathways/physiopathology , Neural Pathways/diagnostic imaging , Autistic Disorder/genetics , Autistic Disorder/physiopathology , Autistic Disorder/diagnostic imaging , Autism Spectrum Disorder/genetics , Autism Spectrum Disorder/physiopathology , Autism Spectrum Disorder/diagnostic imaging , Genetic Predisposition to Disease/genetics
6.
Mol Biol Rep ; 51(1): 610, 2024 May 05.
Article En | MEDLINE | ID: mdl-38704762

Autism spectrum disorder is a neurodevelopmental condition marked by restricted interests and difficulty with social communication. ASD is characterized by heightened neuroinflammation and irregular neuronal connections. ASD is more frequent in male than female with male-female ratio of around 4:1. ASD affects 2.8% or 1 in 36 8-year-olds, based on the CDC's Morbidity and Mortality Weekly Report. Various factors like Environmental, Genetic, Epigenetic and Developmental factors are linked with genesis of ASD. Repetitive behaviors, Impaired communication skills, difficulty with social interaction are some of the clinical features of ASD. Current Pharmacotherapy of ASD limits to management of symptoms only, not cure. The stem cell therapy has a promising potential to be a breakthrough in treating ASD. Various types of stem cells have been successfully tested in children with ASD. AI has a potential to emerge as a tool for early detection of ASD. Robotics can assist the children with ASD to overcome the challenges associated with ASD.


Autism Spectrum Disorder , Humans , Autism Spectrum Disorder/genetics , Female , Male , Child
7.
Cereb Cortex ; 34(13): 161-171, 2024 May 02.
Article En | MEDLINE | ID: mdl-38696595

Autism spectrum disorder (ASD) is a developmental disorder with a rising prevalence and unknown etiology presenting with deficits in cognition and abnormal behavior. We hypothesized that the investigation of the synaptic component of prefrontal cortex may provide proteomic signatures that may identify the biological underpinnings of cognitive deficits in childhood ASD. Subcellular fractions of synaptosomes from prefrontal cortices of age-, brain area-, and postmortem-interval-matched samples from children and adults with idiopathic ASD vs. controls were subjected to HPLC-tandem mass spectrometry. Analysis of data revealed the enrichment of ASD risk genes that participate in slow maturation of the postsynaptic density (PSD) structure and function during early brain development. Proteomic analysis revealed down regulation of PSD-related proteins including AMPA and NMDA receptors, GRM3, DLG4, olfactomedins, Shank1-3, Homer1, CaMK2α, NRXN1, NLGN2, Drebrin1, ARHGAP32, and Dock9 in children with autism (FDR-adjusted P < 0.05). In contrast, PSD-related alterations were less severe or unchanged in adult individuals with ASD. Network analyses revealed glutamate receptor abnormalities. Overall, the proteomic data support the concept that idiopathic autism is a synaptopathy involving PSD-related ASD risk genes. Interruption in evolutionarily conserved slow maturation of the PSD complex in prefrontal cortex may lead to the development of ASD in a susceptible individual.


Dorsolateral Prefrontal Cortex , Proteomics , Humans , Child , Male , Female , Adult , Dorsolateral Prefrontal Cortex/metabolism , Child, Preschool , Autism Spectrum Disorder/metabolism , Autism Spectrum Disorder/genetics , Synapses/metabolism , Adolescent , Young Adult , Autistic Disorder/metabolism , Autistic Disorder/genetics , Nerve Tissue Proteins/metabolism , Nerve Tissue Proteins/genetics , Synaptosomes/metabolism , Prefrontal Cortex/metabolism , Post-Synaptic Density/metabolism
8.
Cereb Cortex ; 34(13): 94-103, 2024 May 02.
Article En | MEDLINE | ID: mdl-38696597

Autism (or autism spectrum disorder) was initially defined as a psychiatric disorder, with the likely cause maternal behavior (the very destructive "refrigerator mother" theory). It took several decades for research into brain mechanisms to become established. Both neuropathological and imaging studies found differences in the cerebellum in autism spectrum disorder, the most widely documented being a decreased density of Purkinje cells in the cerebellar cortex. The popular interpretation of these results is that cerebellar neuropathology is a critical cause of autism spectrum disorder. We challenge that view by arguing that if fewer Purkinje cells are critical for autism spectrum disorder, then any condition that causes the loss of Purkinje cells should also cause autism spectrum disorder. We will review data on damage to the cerebellum from cerebellar lesions, tumors, and several syndromes (Joubert syndrome, Fragile X, and tuberous sclerosis). Collectively, these studies raise the question of whether the cerebellum really has a role in autism spectrum disorder. Autism spectrum disorder is now recognized as a genetically caused developmental disorder. A better understanding of the genes that underlie the differences in brain development that result in autism spectrum disorder is likely to show that these genes affect the development of the cerebellum in parallel with the development of the structures that do underlie autism spectrum disorder.


Cerebellum , Humans , Cerebellum/pathology , Autism Spectrum Disorder/pathology , Autism Spectrum Disorder/genetics , Autism Spectrum Disorder/physiopathology , Autism Spectrum Disorder/diagnostic imaging , Animals , Autistic Disorder/pathology , Autistic Disorder/genetics , Autistic Disorder/physiopathology , Purkinje Cells/pathology
9.
Neuron ; 112(9): 1375-1378, 2024 May 01.
Article En | MEDLINE | ID: mdl-38697019

Animal models are instrumental to understanding the mechanisms underlying autism spectrum disorder, yet translating human behavioral phenotypes remains challenging. Wang et al. leverage a conserved sensorimotor reflex to elucidate synaptic deficits in Scn2a haploinsufficiency and pilot novel rescue strategies.


Autism Spectrum Disorder , Autism Spectrum Disorder/physiopathology , Autism Spectrum Disorder/genetics , Humans , Animals , Reflex/physiology , Disease Models, Animal
10.
Int J Mol Sci ; 25(9)2024 Apr 30.
Article En | MEDLINE | ID: mdl-38732157

Autism Spectrum Disorder (ASD) is an early onset neurodevelopmental disorder characterized by impaired social interaction and communication, and repetitive patterns of behavior. Family studies show that ASD is highly heritable, and hundreds of genes have previously been implicated in the disorder; however, the etiology is still not fully clear. Brain imaging and electroencephalography (EEG) are key techniques that study alterations in brain structure and function. Combined with genetic analysis, these techniques have the potential to help in the clarification of the neurobiological mechanisms contributing to ASD and help in defining novel therapeutic targets. To further understand what is known today regarding the impact of genetic variants in the brain alterations observed in individuals with ASD, a systematic review was carried out using Pubmed and EBSCO databases and following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. This review shows that specific genetic variants and altered patterns of gene expression in individuals with ASD may have an effect on brain circuits associated with face processing and social cognition, and contribute to excitation-inhibition imbalances and to anomalies in brain volumes.


Autism Spectrum Disorder , Brain , Neuroimaging , Humans , Autism Spectrum Disorder/genetics , Autism Spectrum Disorder/diagnostic imaging , Neuroimaging/methods , Brain/diagnostic imaging , Brain/pathology , Brain/metabolism , Electroencephalography , Genetic Predisposition to Disease
11.
Sci Adv ; 10(15): eadf7001, 2024 Apr 12.
Article En | MEDLINE | ID: mdl-38608030

Genes implicated in translation control have been associated with autism spectrum disorders (ASDs). However, some important genetic causes of autism, including the 16p11.2 microdeletion, bear no obvious connection to translation. Here, we use proteomics, genetics, and translation assays in cultured cells and mouse brain to reveal altered translation mediated by loss of the kinase TAOK2 in 16p11.2 deletion models. We show that TAOK2 associates with the translational machinery and functions as a translational brake by phosphorylating eukaryotic elongation factor 2 (eEF2). Previously, all signal-mediated regulation of translation elongation via eEF2 phosphorylation was believed to be mediated by a single kinase, eEF2K. However, we show that TAOK2 can directly phosphorylate eEF2 on the same regulatory site, but functions independently of eEF2K signaling. Collectively, our results reveal an eEF2K-independent signaling pathway for control of translation elongation and suggest altered translation as a molecular component in the etiology of some forms of ASD.


Autism Spectrum Disorder , Autistic Disorder , Ursidae , Animals , Mice , Autistic Disorder/genetics , Peptide Elongation Factor 2 , Phosphorylation , Autism Spectrum Disorder/genetics , Biological Assay
12.
Sci Rep ; 14(1): 8558, 2024 04 12.
Article En | MEDLINE | ID: mdl-38609494

Glutamate (Glu) is important for memory and learning. Hence, Glu imbalance is speculated to affect autism spectrum disorder (ASD) pathophysiology. The action of Glu is mediated through receptors and we analyzed four metabotropic Glu receptors (mGluR/GRM) in Indo-Caucasoid families with ASD probands and controls. The trait scores of the ASD probands were assessed using the Childhood Autism Rating Scale2-ST. Peripheral blood was collected, genomic DNA isolated, and GRM5 rs905646, GRM6 rs762724 & rs2067011, and GRM7 rs3792452 were analyzed by PCR/RFLP or Taqman assay. Expression of mGluRs was measured in the peripheral blood by qPCR. Significantly higher frequencies of rs2067011 'A' allele/ AA' genotype were detected in the probands. rs905646 'A 'exhibited significantly higher parental transmission. Genetic variants showed independent as well as interactive effects in the probands. Receptor expression was down-regulated in the probands, especially in the presence of rs905646 'AA', rs762724 'TT', rs2067011 'GG', and rs3792452 'CC'. Trait scores were higher in the presence of rs762724 'T' and rs2067011 'G'. Therefore, in the presence of risk genetic variants, down-regulated mGluR expression may increase autistic trait scores. Since our investigation was confined to the peripheral system, in-depth exploration involving peripheral as well as central nervous systems may validate our observation.


Autism Spectrum Disorder , Autistic Disorder , Receptors, Metabotropic Glutamate , Humans , Child , Autistic Disorder/genetics , Autism Spectrum Disorder/genetics , Gene Expression , Glutamic Acid , Receptors, Metabotropic Glutamate/genetics
13.
Mol Biol Rep ; 51(1): 577, 2024 Apr 25.
Article En | MEDLINE | ID: mdl-38664339

BACKGROUND: Chromosomal microarray analysis is an essential tool for copy number variants detection in patients with unexplained developmental delay/intellectual disability, autism spectrum disorders, and multiple congenital anomalies. The study aims to determine the clinical significance of chromosomal microarray analysis in this patient group. Another crucial aspect is the evaluation of copy number variants detected in terms of the diagnosis of patients. METHODS AND RESULTS: A Chromosomal microarray analysis was was conducted on a total of 1227 patients and phenotype-associated etiological diagnosis was established in 135 patients. Phenotype-associated copy number variants were detected in 11% of patients. Among these, 77 patients 77 (57%, 77/135) were diagnosed with well-recognized genetic syndromes and phenotype-associated copy number variants were found in 58 patients (42.9%, 58/135). The study was designed to collect data of patients in Kocaeli Derince Training and Research Hospital retrospectively. In our study, we examined 135 cases with clinically significant copy number variability among all patients. CONCLUSIONS: In this study, chromosomal microarray analysis revealed pathogenic de novo copy number variants with new clinical features. Chromosomal microarray analysis in the Turkish population has been reported in the largest patient cohort to date.


Abnormalities, Multiple , Autism Spectrum Disorder , DNA Copy Number Variations , Developmental Disabilities , Humans , Autism Spectrum Disorder/genetics , Autism Spectrum Disorder/diagnosis , Turkey/epidemiology , DNA Copy Number Variations/genetics , Female , Male , Child , Child, Preschool , Developmental Disabilities/genetics , Developmental Disabilities/diagnosis , Abnormalities, Multiple/genetics , Abnormalities, Multiple/diagnosis , Adolescent , Phenotype , Infant , Intellectual Disability/genetics , Intellectual Disability/diagnosis , Chromosome Aberrations , Microarray Analysis/methods , Retrospective Studies , Adult
14.
Sci Rep ; 14(1): 9230, 2024 04 22.
Article En | MEDLINE | ID: mdl-38649688

With its high rate of consanguineous marriages and diverse ethnic population, little is currently understood about the genetic architecture of autism spectrum disorder (ASD) in Pakistan. Pakistan has a highly ethnically diverse population, yet with a high proportion of endogamous marriages, and is therefore anticipated to be enriched for biallelic disease-relate variants. Here, we attempt to determine the underlying genetic abnormalities causing ASD in thirty-six small simplex or multiplex families from Pakistan. Microarray genotyping followed by homozygosity mapping, copy number variation analysis, and whole exome sequencing were used to identify candidate. Given the high levels of consanguineous marriages among these families, autosomal recessively inherited variants were prioritized, however de novo/dominant and X-linked variants were also identified. The selected variants were validated using Sanger sequencing. Here we report the identification of sixteen rare or novel coding variants in fifteen genes (ARAP1, CDKL5, CSMD2, EFCAB12, EIF3H, GML, NEDD4, PDZD4, POLR3G, SLC35A2, TMEM214, TMEM232, TRANK1, TTC19, and ZNF292) in affected members in eight of the families, including ten homozygous variants in four families (nine missense, one loss of function). Three heterozygous de novo mutations were also identified (in ARAP1, CSMD2, and NEDD4), and variants in known X-linked neurodevelopmental disorder genes CDKL5 and SLC35A2. The current study offers information on the genetic variability associated with ASD in Pakistan, and demonstrates a marked enrichment for biallelic variants over that reported in outbreeding populations. This information will be useful for improving approaches for studying ASD in populations where endogamy is commonly practiced.


Autism Spectrum Disorder , Exome Sequencing , Pedigree , Humans , Autism Spectrum Disorder/genetics , Pakistan , Male , Female , DNA Copy Number Variations/genetics , Genetic Predisposition to Disease , Child , Alleles , Consanguinity , Child, Preschool , Mutation , Homozygote
15.
ACS Chem Neurosci ; 15(8): 1635-1642, 2024 Apr 17.
Article En | MEDLINE | ID: mdl-38557009

CHD8 is a high penetrance, high confidence risk gene for autism spectrum disorder (ASD), a neurodevelopmental disorder that is substantially more prevalent among males than among females. Recent studies have demonstrated variable sex differences in the behaviors and synaptic phenotypes of mice carrying different heterozygous ASD-associated mutations in Chd8. We examined functional and structural cellular phenotypes linked to synaptic transmission in deep layer pyramidal neurons of the prefrontal cortex in male and female mice carrying a heterozygous, loss-of-function Chd8 mutation in the C57BL/6J strain across development from postnatal day 2 to adulthood. Notably, excitatory neurotransmission was decreased only in Chd8+/- males with no differences in Chd8+/- females, and the majority of alterations in inhibitory transmission were found in males. Similarly, analysis of cellular morphology showed male-specific effects of reduced Chd8 expression. Both functional and structural phenotypes were most prominent at postnatal days 14-20, a stage approximately corresponding to childhood. Our findings suggest that the effects of Chd8 mutation are predominantly seen in males and are maximal during childhood.


Prefrontal Cortex , Animals , Female , Humans , Male , Mice , Autism Spectrum Disorder/genetics , Haploinsufficiency , Mice, Inbred C57BL , Phenotype , Prefrontal Cortex/growth & development
16.
J Int Med Res ; 52(4): 3000605241245293, 2024 Apr.
Article En | MEDLINE | ID: mdl-38619175

In recent years, the incidence of autism spectrum disorder (ASD) has increased, but the etiology and pathogenesis remain unclear. In this narrative review, we review and systematically summarize the methods used to construct animal models to study ASD and the related behavioral studies based on recent literature. Utilization of various ASD animal models can complement research on the etiology, pathogenesis, and core behaviors of ASD, providing information and a foundation for further basic research and clinical treatment of ASD.


Autism Spectrum Disorder , Animals , Autism Spectrum Disorder/genetics , Models, Animal
17.
Proc Natl Acad Sci U S A ; 121(15): e2317769121, 2024 Apr 09.
Article En | MEDLINE | ID: mdl-38564633

Autism spectrum disorder (ASD) is a complex neurodevelopmental condition characterized by social and communication deficits and repetitive behaviors. The genetic heterogeneity of ASD presents a challenge to the development of an effective treatment targeting the underlying molecular defects. ASD gating charge mutations in the KCNQ/KV7 potassium channel cause gating pore currents (Igp) and impair action potential (AP) firing of dopaminergic neurons in brain slices. Here, we investigated ASD gating charge mutations of the voltage-gated SCN2A/NaV1.2 brain sodium channel, which ranked high among the ion channel genes with mutations in individuals with ASD. Our results show that ASD mutations in the gating charges R2 in Domain-II (R853Q), and R1 (R1626Q) and R2 (R1629H) in Domain-IV of NaV1.2 caused Igp in the resting state of ~0.1% of the amplitude of central pore current. The R1626Q mutant also caused significant changes in the voltage dependence of fast inactivation, and the R1629H mutant conducted proton-selective Igp. These potentially pathogenic Igp were exacerbated by the absence of the extracellular Mg2+ and Ca2+. In silico simulation of the effects of these mutations in a conductance-based single-compartment cortical neuron model suggests that the inward Igp reduces the time to peak for the first AP in a train, increases AP rates during a train of stimuli, and reduces the interstimulus interval between consecutive APs, consistent with increased neural excitability and altered input/output relationships. Understanding this common pathophysiological mechanism among different voltage-gated ion channels at the circuit level will give insights into the underlying mechanisms of ASD.


Autism Spectrum Disorder , Autistic Disorder , Voltage-Gated Sodium Channels , Humans , Autism Spectrum Disorder/genetics , Autistic Disorder/genetics , Brain , Mutation
18.
Methods Mol Biol ; 2794: 331-340, 2024.
Article En | MEDLINE | ID: mdl-38630242

Autism spectrum disorder (ASD) is a complex neurodevelopmental disorder characterized by social deficits and stereotyped, repetitive patterns of behaviors, limited interests, and cognitive impairment. Especially, social deficit has been considered a core feature of ASD. Because of the limitations of the experimental approach in humans, valid animal models are essential in an effort to identify novel therapeutics for social deficits in ASD. The genetic and environmental factors are clinically relevant to the pathophysiology of ASD. Epidemiological studies demonstrate environmental interventions such as prenatal exposure to valproic acid (VPA). Prenatal exposure to VPA represents a robust model of ASD exhibiting face, construct, and predictive validity. Here, we introduce protocols of the social interaction test and the three-chamber test for evaluating social deficits in mice prenatally exposed to VPA.


Autism Spectrum Disorder , Cognitive Dysfunction , Prenatal Exposure Delayed Effects , Humans , Female , Pregnancy , Animals , Mice , Autism Spectrum Disorder/genetics , Social Behavior , Models, Animal , Valproic Acid/therapeutic use
19.
J Neurodev Disord ; 16(1): 17, 2024 Apr 17.
Article En | MEDLINE | ID: mdl-38632549

Monogenic disorders account for a large proportion of population-attributable risk for neurodevelopmental disabilities. However, the data necessary to infer a causal relationship between a given genetic variant and a particular neurodevelopmental disorder is often lacking. Recognizing this scientific roadblock, 13 Intellectual and Developmental Disabilities Research Centers (IDDRCs) formed a consortium to create the Brain Gene Registry (BGR), a repository pairing clinical genetic data with phenotypic data from participants with variants in putative brain genes. Phenotypic profiles are assembled from the electronic health record (EHR) and a battery of remotely administered standardized assessments collectively referred to as the Rapid Neurobehavioral Assessment Protocol (RNAP), which include cognitive, neurologic, and neuropsychiatric assessments, as well as assessments for attention deficit hyperactivity disorder (ADHD) and autism spectrum disorder (ASD). Co-enrollment of BGR participants in the Clinical Genome Resource's (ClinGen's) GenomeConnect enables display of variant information in ClinVar. The BGR currently contains data on 479 participants who are 55% male, 6% Asian, 6% Black or African American, 76% white, and 12% Hispanic/Latine. Over 200 genes are represented in the BGR, with 12 or more participants harboring variants in each of these genes: CACNA1A, DNMT3A, SLC6A1, SETD5, and MYT1L. More than 30% of variants are de novo and 43% are classified as variants of uncertain significance (VUSs). Mean standard scores on cognitive or developmental screens are below average for the BGR cohort. EHR data reveal developmental delay as the earliest and most common diagnosis in this sample, followed by speech and language disorders, ASD, and ADHD. BGR data has already been used to accelerate gene-disease validity curation of 36 genes evaluated by ClinGen's BGR Intellectual Disability (ID)-Autism (ASD) Gene Curation Expert Panel. In summary, the BGR is a resource for use by stakeholders interested in advancing translational research for brain genes and continues to recruit participants with clinically reported variants to establish a rich and well-characterized national resource to promote research on neurodevelopmental disorders.


Autism Spectrum Disorder , Autistic Disorder , Intellectual Disability , Neurodevelopmental Disorders , Humans , Male , Female , Autism Spectrum Disorder/genetics , Brain , Registries , Methyltransferases
20.
Mol Autism ; 15(1): 12, 2024 Apr 03.
Article En | MEDLINE | ID: mdl-38566250

BACKGROUND: Glutamatergic synapse dysfunction is believed to underlie the development of Autism Spectrum Disorder (ASD) and Intellectual Disability (ID) in many individuals. However, identification of genetic markers that contribute to synaptic dysfunction in these individuals is notoriously difficult. Based on genomic analysis, structural modeling, and functional data, we recently established the involvement of the TRIO-RAC1 pathway in ASD and ID. Furthermore, we identified a pathological de novo missense mutation hotspot in TRIO's GEF1 domain. ASD/ID-related missense mutations within this domain compromise glutamatergic synapse function and likely contribute to the development of ASD/ID. The number of ASD/ID cases with mutations identified within TRIO's GEF1 domain is increasing. However, tools for accurately predicting whether such mutations are detrimental to protein function are lacking. METHODS: Here we deployed advanced protein structural modeling techniques to predict potential de novo pathogenic and benign mutations within TRIO's GEF1 domain. Mutant TRIO-9 constructs were generated and expressed in CA1 pyramidal neurons of organotypic cultured hippocampal slices. AMPA receptor-mediated postsynaptic currents were examined in these neurons using dual whole-cell patch clamp electrophysiology. We also validated these findings using orthogonal co-immunoprecipitation and fluorescence lifetime imaging (FLIM-FRET) experiments to assay TRIO mutant overexpression effects on TRIO-RAC1 binding and on RAC1 activity in HEK293/T cells. RESULTS: Missense mutations in TRIO's GEF1 domain that were predicted to disrupt TRIO-RAC1 binding or stability were tested experimentally and found to greatly impair TRIO-9's influence on glutamatergic synapse function. In contrast, missense mutations in TRIO's GEF1 domain that were predicted to have minimal effect on TRIO-RAC1 binding or stability did not impair TRIO-9's influence on glutamatergic synapse function in our experimental assays. In orthogonal assays, we find most of the mutations predicted to disrupt binding display loss of function but mutants predicted to disrupt stability do not reflect our results from neuronal electrophysiological data. LIMITATIONS: We present a method to predict missense mutations in TRIO's GEF1 domain that may compromise TRIO function and test for effects in a limited number of assays. Possible limitations arising from the model systems employed here can be addressed in future studies. Our method does not provide evidence for whether these mutations confer ASD/ID risk or the likelihood that such mutations will result in the development of ASD/ID. CONCLUSIONS: Here we show that a combination of structure-based computational predictions and experimental validation can be employed to reliably predict whether missense mutations in the human TRIO gene impede TRIO protein function and compromise TRIO's role in glutamatergic synapse regulation. With the growing accessibility of genome sequencing, the use of such tools in the accurate identification of pathological mutations will be instrumental in diagnostics of ASD/ID.


Autism Spectrum Disorder , Intellectual Disability , Humans , Autism Spectrum Disorder/genetics , Autism Spectrum Disorder/metabolism , HEK293 Cells , Intellectual Disability/genetics , Intellectual Disability/metabolism , Mutation , Mutation, Missense , Neurons/metabolism
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