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Autism spectrum disorder (ASD) is among the most common neurodevelopmental conditions in humans. While public awareness of the challenges faced by individuals with autism is steadily increasing, the underlying causes of abnormalities observed in ASD remains incompletely understood. The autism spectrum is notably broad, with symptoms that can manifest in various forms and degrees of severity. Core features of ASD, such as communication difficulties, impaired social interactions, and restricted patterns of behavior, interests, and activities, are often accompanied by other co‑occurring conditions, such as anxiety. ASD affects individuals regardless of gender, race, or ethnicity. Although we are currently unable to pinpoint a single definitive cause of autism, it is clear that genetics play a crucial role in its development. The first genes associated with an increased risk for ASD were discovered in rare monogenic disorders, such as fragile X syndrome (FXS), caused by mutations in the fragile X messenger ribonucleoprotein 1 (FMR1) gene, and macrocephaly, linked to mutations in the phosphatase and tensin homolog (PTEN) gene. This review aims to summarize the current knowledge of ASD in patients with mutations in the FMR1 and PTEN genes.

Deletion and duplication in the human 16p11.2 chromosomal region are closely linked to neurodevelopmental disorders, specifically autism spectrum disorder. Data from neuroimaging studies suggest white matter microstructure aberrations across these conditions. In 16p11.2 deletion and duplication carriers, potential gene dosage effects may impact white matter organisation, contributing to phenotypes including impaired cognition. However, the biological mechanisms underlying this white matter pathology remain unclear. To bridge this knowledge gap, we utilised mouse models of 16p11.2 deletion and duplication to explore changes in corpus callosum oligodendrocytes, myelination, axon caliber, and astrocytes. Immunofluorescence staining was employed to measure lineage and mature oligodendrocyte numbers, as well as myelin basic protein and glial fibrillary acidic protein fluorescence intensity. Transmission electron microscopy was utilised to evaluate axonal structural alterations related to myelin, such as myelinated axon percentage, diameter, myelin thickness, and g-ratio. Our findings reveal changes in the number of mature oligodendrocytes, myelination levels, axon diameter, and astrocytes in the corpus callosum of mice with 16p11.2 deletion and duplication. Deletion mice displayed a tendency toward reduced counts of mature oligodendrocytes and myelination levels, while duplication mice exhibited a notable increase. Axon diameter variations included a significant increase in axon diameter and myelin thickness in both deletion and duplication mice, but with irregular structure in duplication mice. Variances in astrocytes between genotypes showed significant early increases in development for both deletion and duplication mice compared to wild-type mice, with this rise sustained in duplication mice but significantly diminished in deletion mice at a later stage. Our research reveals changes in the biological mechanisms impacting white matter. Comparison of reciprocal trends in 16p11.2 deletion and duplication mice with wild-type mice suggests the possibility of gene dosage effects. Identification of these mechanisms offers an initial step in unveiling therapeutic targets for associated neurodevelopmental disorder phenotypes.

Hypoplastic left heart syndrome (HLHS) is a severe congenital heart disease associated with microcephaly and poor neurodevelopmental outcomes. Here we show that the Ohia HLHS mouse model, with mutations in Sap130, a chromatin modifier, and Pcdha9, a cell adhesion protein, also exhibits microcephaly associated with mitotic block and increased apoptosis leading to impaired cortical neurogenesis. Transcriptome profiling, DNA methylation, and Sap130 ChIPseq analyses all demonstrate dysregulation of genes associated with autism and cognitive impairment. This includes perturbation of REST transcriptional regulation of neurogenesis, disruption of CREB signaling regulating synaptic plasticity, and defects in neurovascular coupling mediating cerebral blood flow. Adult mice harboring either the Pcdha9 mutation, which show normal brain anatomy, or forebrain-specific Sap130 deletion via Emx1-Cre, which show microcephaly, both demonstrate learning and memory deficits and autism-like behavior. These findings provide mechanistic insights indicating the adverse neurodevelopment in HLHS may involve cell autonomous/nonautonomous defects and epigenetic dysregulation., Competing Interests: Competing interests: The authors declare no competing interests., (© 2025. The Author(s).)

Autism spectrum disorder (ASD) is characterized by difficulties in social interaction, communication challenges, and repetitive behaviors. Despite extensive research, the molecular mechanisms underlying these neurodevelopmental abnormalities remain elusive. We integrated microscale brain gene expression data with macroscale MRI data from 1829 participants, including individuals with ASD and typically developing controls, from the autism brain imaging data exchange I and II. Using fractal dimension as an index for quantifying cortical complexity, we identified significant regional alterations in ASD, within the left temporoparietal, left peripheral visual, right central visual, left somatomotor (including the insula), and left ventral attention networks. Partial least squares regression analysis revealed gene sets associated with these cortical complexity changes, enriched for biological functions related to synaptic transmission, synaptic plasticity, mitochondrial dysfunction, and chromatin organization. Cell-specific analyses, protein-protein interaction network analysis and gene temporal expression profiling further elucidated the dynamic molecular landscape associated with these alterations. These findings indicate that ASD-related alterations in cortical complexity are closely linked to specific genetic pathways. The combined analysis of neuroimaging and transcriptomic data enhances our understanding of how genetic factors contribute to brain structural changes in ASD., Competing Interests: Declarations. Competing interests: The authors declare no competing interests., (© 2024. The Author(s).)

Autism spectrum disorder (ASD) comprises alterations in brain anatomy and physiology that ultimately affect information processing and behavior. In most cases, autism is considered idiopathic, involving alterations in numerous genes whose functions are not extensively documented. We evaluated the C58/J mouse strain as an idiopathic model of ASD, emphasizing synaptic transmission as the basis of information processing. Through in silico analysis, we found that the C58/J strain carries single nucleotide polymorphisms (SNPs) compared to the C57BL/6J control strain related to synaptic structure and LTP induction. These SNPs have human orthologs previously associated with ASD. We then assessed chemical potentiation (cLTP) in synaptosomes, the electrophysiological properties of hippocampal CA3 cells, and the induction of LTP in ex-vivo slices. An increased proportion of synaptosomes expressing the GluA1 subunit of AMPA receptor and Nrx1β in the membrane was found in the C57BL/6J control strain, but not in C58/J mice, after cLTP induction. Additionally, several electrophysiological properties of CA3 pyramidal cells and hippocampal communication were altered. Behaviorally, C58/J mice exhibited hyperactivity and subtle memory changes. Our results demonstrate that an idiopathic model of ASD exhibits alterations in hippocampal physiology from the cellular to the circuitry and behavioral levels., Competing Interests: Declarations. Competing interests: The authors declare no competing interests. Ethical approval: All animal procedures were carried out following the ARRIVE Guidelines86 and were performed in agreement with local government rules (Official Mexican Standard NOM-062-ZOO-1999) and the local Institutional Animal Care and Research Advisory Committees (CICUAL, ID 10367) from the Universidad Nacional Autónoma de México (UNAM) and the protocols authorized by the internal ethics committee of CINVESTAV (CICUAL, Protocol number 0090-14), which mandate the minimization of suffering and the number of experimental animals used., (© 2024. The Author(s).)

Autism spectrum disorder (ASD) affects up to 1 in 59 children, and is one of the most common neurodevelopmental disorders. Recent genomic studies have highlighted the role of rare variants in ASD. This study aimed to identify genes affected by rare variants shared by siblings with ASD and validate the function of a candidate gene FRRS1L. By integrating the whole genome sequencing data of 866 multiplex families from the Hartwell Foundation's Autism Research and Technology Initiative and Autism Speaks MSSNG project, we identified rare variants shared by two or more siblings with ASD. Using shared rare variants (SRVs), we selected candidate genes for ASD. Gene prioritization by evolutionary features and expression alterations on autism identified FRRS1L in two families, including one with impaired social behaviors. One variant in this family was 6 bp away from human-specific trinucleotide fixation. Additionally, CRISPR/Cas9 experiments demonstrated downregulation by a family variant and upregulation by a fixed site. Population genetics further demonstrated that upregulation of this gene has been favored during human evolution. Various mouse behavioral tests showed that Frrs1l knockout specifically impairs social novelty recognition without altering other behavioral phenotypes. Furthermore, we constructed humanized mice by introducing human sequences into a mouse genome. These knockin mice showed improved abilities to retain social memory over time. The results of our population genetic and evolutionary analyses, behavior experiments, and genome editing propose a molecular mechanism that may confer a selective advantage through social memory enhancement and may cause autism-related social impairment when disrupted in humans. These findings highlight the role of FRRS1L, the AMPA receptor subunit, in social behavior and evolution., Competing Interests: Declarations. Ethics approval and consent to participate: All the procedures were performed in accordance with Animal Research: Reporting In Vivo Experiments (ARRIVE) guidelines and regulations, and were approved by the KAIST Institutional Animal Care and Use Committee. Competing interests: The authors declare no competing interests., (© 2024. The Author(s).)

E3 ubiquitin ligases have been linked to developmental diseases including autism, Angelman syndrome (UBE3A), and Johanson-Blizzard syndrome (JBS) (UBR1). Here, we report variants in the E3 ligase UBR5 in 29 individuals presenting with a neurodevelopmental syndrome that includes developmental delay, autism, intellectual disability, epilepsy, movement disorders, and/or genital anomalies. Their phenotype is distinct from JBS due to the absence of exocrine pancreatic insufficiency and the presence of autism, epilepsy, and, in some probands, a movement disorder. E3 ubiquitin ligases are responsible for transferring ubiquitin to substrate proteins to regulate a variety of cellular functions, including protein degradation, protein-protein interactions, and protein localization. Knocking out ubr-5 in C. elegans resulted in a lower movement score compared to the wild type, supporting a role for UBR5 in neurodevelopment. Using an in vitro autoubiquitination assay and confocal microscopy for the human protein, we found decreased ubiquitination activity and altered cellular localization in several variants found in our cohort compared to the wild type. In conclusion, we found that variants in UBR5 cause a neurodevelopmental syndrome that can be associated with a movement disorder, reinforcing the role of the UBR protein family in a neurodevelopmental disease that differs from previously described ubiquitin-ligase-related syndromes. We also provide evidence for the pathogenic potential loss of UBR5 function with functional experiments in C. elegans and in vitro ubiquitination assays., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2024 American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.)

Cortical layer 5 (L5) intratelencephalic (IT) and pyramidal tract (PT) neurons are embedded in distinct information processing pathways. Their morphology, connectivity, electrophysiological properties, and role in behavior have been extensively analyzed. However, the molecular composition of their synapses remains largely uncharacterized. Here, we dissect the protein composition of the excitatory postsynaptic compartment of mouse L5 neurons in intact somatosensory circuits, using an optimized proximity biotinylation workflow with high spatial accuracy. We find distinct synaptic signatures of L5 IT and PT neurons that are defined by proteins regulating synaptic organization and transmission, including cell-surface proteins (CSPs), neurotransmitter receptors and ion channels. In addition, we find a differential vulnerability to disease, with a marked enrichment of autism risk genes in the synaptic signature of L5 IT neurons compared to PT neurons. These results align with human studies and suggest that the excitatory postsynaptic compartment of L5 IT neurons is susceptible in autism. Our approach is versatile and can be broadly applied to other neuron types to create a protein-based, synaptic atlas of cortical circuits., Competing Interests: Competing interests: J.d.W. is scientific co-founder and served as scientific advisory board member of Augustine Tx. The remaining authors declare no competing interests., (© 2024. The Author(s).)

Rationale: Mutations in the synaptic protein MAM domain containing glycosylphosphatidylinositol anchor 2 (MDGA2) have been associated with autism spectrum disorder (ASD). Therefore, elucidating the regulatory mechanisms of MDGA2 can help develop effective treatments for ASD. Methods: Liquid chromatography-tandem mass spectrometry was carried out to identify proteins interacting with the extracellular domain of RPS23RG1 and with MDGA2, followed by co-immunoprecipitation assays to confirm protein-protein interactions. RPS23RG1 and SORT1 levels were downregulated by siRNAs to study their effects on MDGA2 degradation, with additional applications of immunoblotting and immunostaining assays. Lysosome isolation was performed to determine the lysosomal degradation of MDGA2 further. Rps23rg1 knockout mice and Mdga2 +/- mice were subjected to various behavioral tests to study their ASD-like phenotypes. AAVs expressing MDGA2 were delivered in Rps23rg1 knockout mice, and RPS23RG1-derived peptide was delivered in Mdga2 +/- mice to study their rescuing effects. Results: We found that both RPS23RG1 and SORT1 interacted with MDGA2. MDGA2 was primarily degraded through the SORT1-mediated lysosomal degradation pathway. RPS23RG1 competed with SORT1 for MDGA2 binding to inhibit MDGA2 degradation. Furthermore, we showed that Rps23rg1 knockout mice exhibited decreased MDGA2 levels and ASD-like behaviors, whereas restoration of MDGA2 levels attenuated social defects in Rps23rg1 KO mice. Moreover, we identified a crucial region of RPS23RG1 for MDGA2 interaction and found that a peptide derived from this region not only bound MDGA2 and promoted MDGA2 levels, but also rescued social defects in Mdga2 +/- mice. Conclusion: Our findings highlight a crucial role of RPS23RG1 in antagonizing SORT1-mediated lysosomal degradation of MDGA2 and suggest a potential for targeting the RPS23RG1-MDGA2 axis to treat ASD with MDGA2 deficiency., Competing Interests: Competing Interests: The authors have declared that no competing interest exists., (© The author(s).)

Autism Spectrum Disorders (ASDs) are reported as a group of neurodevelopmental disorders. The structural changes of brain regions including the hippocampus were widely reported in autistic patients and mouse models with dysfunction of ASD risk genes, but the underlying mechanisms are not fully understood. Here, we report that deletion of Trio, a high-susceptibility gene of ASDs, causes a postnatal dentate gyrus (DG) hypoplasia with a zigzagged suprapyramidal blade, and the Trio-deficient mice display autism-like behaviors. The impaired morphogenesis of DG is mainly caused by disturbing the postnatal distribution of postmitotic granule cells (GCs), which further results in a migration deficit of neural progenitors. Furthermore, we reveal that Trio plays different roles in various excitatory neural cells by spatial transcriptomic sequencing, especially the role of regulating the migration of postmitotic GCs. In summary, our findings provide evidence of cellular mechanisms that Trio is involved in postnatal DG morphogenesis., Competing Interests: Conflict of interest: The authors declare that they have no competing financial interests., (© 2024. The Author(s).)

The WAVE regulatory pentameric complex regulates actin remodeling. Two components of it (CYFIP2 and NCKAP1) are encoded by genes whose genetic mutations increase the risk for autism spectrum disorder (ASD) and related neurodevelopmental disorders. Here, we use a newly developed computational protocol and hotspot analysis to uncover the functional impact of these mutations at the interface of the correct isoforms of the two proteins into the complex. The mutations turn out to be located on the surfaces involving the largest number of hotspots of the complex. Most of them decrease the affinity of the proteins for the rest of the complex, but some have the opposite effect. The results are fully consistent with the available experimental data. The observed changes in the WAVE regulatory complex stability might impact on complex activation and ultimately play a role in the aberrant pathway of the complex, leading to the cell derangement associated with the disease., (© 2024 The Author(s). Protein Science published by Wiley Periodicals LLC on behalf of The Protein Society.)

Autism spectrum disorder (ASD) is a set of heterogeneous neurodevelopmental conditions, with a highly diverse genetic hereditary component, including altered neuronal circuits, that has an impact on communication skills and behaviours of the affected individuals. Beside the recognised role of neuronal alterations, perturbations of microglia and the associated neuroinflammatory processes have emerged as credible contributors to aetiology and physiopathology of ASD. Mutations in NRXN1, a member of the neurexin family of cell-surface receptors that bind neuroligin, have been associated to ASD. NRXN1 is known to be expressed by neurons where it facilitates synaptic contacts, but it has also been identified in glial cells including microglia. Asserting the impact of ASD-related genes on neuronal versus microglia functions has been challenging. Here, we present an ASD subject-derived induced pluripotent stem cells (iPSC)-based in vitro system to characterise the effects of the ASD-associated NRXN1 gene deletion on neurons and microglia, as well as on the ability of microglia to support neuronal circuit formation and function. Using this approach, we demonstrated that NRXN1 deletion, impacting on the expression of the alpha isoform (NRXN1α), in microglia leads to microglial alterations and release of IL6, a pro-inflammatory interleukin associated with ASD. Moreover, microglia bearing the NRXN1α-deletion, lost the ability to support the formation of functional neuronal networks. The use of recombinant IL6 protein on control microglia-neuron co-cultures or neutralizing antibody to IL6 on their NRXN1α-deficient counterparts, supported a direct contribution of IL6 to the observed neuronal phenotype. Altogether, our data suggest that, in addition to neurons, microglia are also negatively affected by NRXN1α-deletion, and this significantly contributes to the observed neuronal circuit aberrations., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: B.J. is co-founder of CERVO Therapeutics AB. S.C. and S.S. are co-founders of NorthernLight Diagnostics AB. The other authors declare no conflict of interest., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: Anxiety disorders, major psychiatric disorders (e.g., schizophrenia and major affective disorders), and neurodevelopmental disorders (e.g., autism and attention-deficit/hyperactivity disorder [ADHD]) may cluster together within families. However, whether the first-degree relatives (FDRs) of individuals with generalized anxiety disorder (GAD) are at an elevated risk of neurodevelopmental or major psychiatric disorders remains unknown., Methods: We identified 2,378,190 FDRs of patients with GAD and 9,512,760 birth year-matched and sex-matched controls from Taiwan's National Health Insurance Research Database. Neurodevelopmental disorders, including autism and ADHD, and major psychiatric disorders, including schizophrenia, bipolar disorder, major depressive disorder, obsessive-compulsive disorder, and GAD, were identified., Results: The FDRs-parents, offspring, and siblings-of individuals with GAD were more likely to be diagnosed as having schizophrenia (relative risk: 1.22), bipolar disorder (1.36), major depressive disorder (1.29), autism (1.20), ADHD (1.52), obsessive-compulsive disorder (1.21), and GAD (1.61) than are the FDRs of individuals without GAD., Conclusion: Our findings support the notion of a familial coaggregation between GAD, major psychiatric disorders, and neurodevelopmental disorders. Future studies should elucidate the definitive genetic etiology of this familial coaggregation., Competing Interests: Declaration of competing interest All authors declare no conflict of interest., (Copyright © 2024 Elsevier B.V. All rights reserved.)

CELF2 variants have been linked to neurodevelopmental disorders (NDD), including autism spectrum disorder (ASD). However, the molecular mechanisms remain unclear. We generated Celf2 Nestin-Cre knockout mice.Our findings revealed that Celf2 Nestin-Cre heterozygous knockout mice exhibited social impairment and anxiety, an autism-like behavior, though no manifestations of repetitive stereotyped behavior, learning cognitive impairment, or depression were observed. Immunofluorescence assay showed an underdeveloped cerebral cortex with significantly reduced cortical thickness, albeit without abnormal cell density. Further in vitro neuronal culture demonstrated a significant reduction in dendritic spine density and affected synaptic maturation in Celf2 deficient mice, with no notable abnormalities in total neurite and axon length. RNA-seq and RIP-seq analysis of the cerebral cortex revealed differentially expressed genes post Celf2 gene knockout compared with the control group. Enrichment analysis highlighted significant enrichment in dendrite and synapse-related biological processes and pathways. Our study delineated the behavioral and neurodevelopmental phenotypes of Celf2, suggesting its potential involvement in autism through the regulation of target genes associated with dendritic spines and synapse development. Further research is needed to elucidate the specific mechanisms involved., Competing Interests: Declarations. Ethics Approval: All mouse lines were maintained in the C57BL/6N background by regular backcrossing to the C57BL/6N line. Study protocols complied with all relevant ethical regulations and were approved by the IRB of Central South. Consent for Publication: Not applicable. Competing Interests: The authors declare no competing interests., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Dyslexia is a learning difficulty with neurodevelopmental origins, manifesting as reduced accuracy and speed in reading and spelling. It is substantially heritable and frequently co-occurs with other neurodevelopmental conditions, particularly attention deficit-hyperactivity disorder (ADHD). Here, we investigate the genetic structure underlying dyslexia and a range of psychiatric traits using results from genome-wide association studies of dyslexia, ADHD, autism, anorexia nervosa, anxiety, bipolar disorder, major depressive disorder, obsessive compulsive disorder, schizophrenia, and Tourette syndrome. Genomic Structural Equation Modelling (GenomicSEM) showed heightened support for a model consisting of five correlated latent genomic factors described as: F1) compulsive disorders (including obsessive-compulsive disorder, anorexia nervosa, Tourette syndrome), F2) psychotic disorders (including bipolar disorder, schizophrenia), F3) internalising disorders (including anxiety disorder, major depressive disorder), F4) neurodevelopmental traits (including autism, ADHD), and F5) attention and learning difficulties (including ADHD, dyslexia). ADHD loaded more strongly on the attention and learning difficulties latent factor (F5) than on the neurodevelopmental traits latent factor (F4). The attention and learning difficulties latent factor (F5) was positively correlated with internalising disorders (.40), neurodevelopmental traits (.25) and psychotic disorders (.17) latent factors, and negatively correlated with the compulsive disorders (-.16) latent factor. These factor correlations are mirrored in genetic correlations observed between the attention and learning difficulties latent factor and other cognitive, psychological and wellbeing traits. We further investigated genetic variants underlying both dyslexia and ADHD, which implicated 49 loci (40 not previously found in GWAS of the individual traits) mapping to 174 genes (121 not found in GWAS of individual traits) as potential pleiotropic variants. Our study confirms the increased genetic relation between dyslexia and ADHD versus other psychiatric traits and uncovers novel pleiotropic variants affecting both traits. In future, analyses including additional co-occurring traits such as dyscalculia and dyspraxia will allow a clearer definition of the attention and learning difficulties latent factor, yielding further insights into factor structure and pleiotropic effects., Competing Interests: Competing interests: PF and the 23andMe Research Team members are employed by and hold stock or stock options in 23andMe, Inc. All other authors declare no competing interests. Ethical approval: The study used secondary data, with all original studies stating relevant ethical approval. The secondary data analyses were approved under the Edinburgh Medical School Research Ethics Committee., (© 2024. The Author(s).)

Neuroligin-3 (Nlgn3) is an autism-associated cell-adhesion molecule that interacts with neurexins and is robustly expressed in both neurons and astrocytes. Neuronal Nlgn3 is an essential regulator of synaptic transmission but the function of astrocytic Nlgn3 is largely unknown. Given the high penetrance of Nlgn3 mutations in autism and the emerging role of astrocytes in neuropsychiatric disorders, we here asked whether astrocytic Nlgn3 might shape neural circuit properties in the cerebellum similar to neuronal Nlgn3. Imaging of tagged Nlgn3 protein produced by CRISPR/Cas9-mediated genome editing showed that Nlgn3 is enriched in the cell body but not the fine processes of cerebellar astrocytes (Bergmann glia). Astrocyte-specific knockout of Nlgn3 did not detectably alter the number of synapses, synaptic transmission, or astrocyte morphology in mouse cerebellum. However, spatial transcriptomic analyses revealed a significant shift in gene expression among multiple cerebellar cell types after the deletion of astrocytic Nlgn3. Hence, in contrast to neuronal Nlgn3, astrocytic Nlgn3 in the cerebellum is not involved in shaping synapses but may modulate gene expression in specific brain areas., Competing Interests: Competing interests: The authors declare no competing interests., (© 2024. The Author(s).)

Developmental delays have been associated with metabolic disturbances in children. Previous research in the childhood autism risk from genetics and the environment (CHARGE) case-control study identified neurodevelopment-related plasma metabolites in children, suggesting disturbances in the energy-related tricarboxylic acid (TCA) cycle and 1-carbon metabolism (1CM). Here, we investigated associations between children's neurodevelopmental outcomes and their mothers' plasma metabolite profiles in a subset of mother-child dyads from CHARGE, including those with autism spectrum disorder (ASD, n = 209), Down syndrome (DS, n = 76), idiopathic developmental delay (iDD, n = 64), and typically developed (TD, n = 185) controls. Multiple linear regression revealed associations between child neurodevelopmental outcomes and maternal plasma metabolites related to the TCA cycle, 1CM, and lipid metabolism. Despite profound metabolic disturbances in children with DS reported previously, few of these differences were observed in the mothers, which might reflect differences in gene dosage between children with DS and their euploid mothers. Notably differences in maternal metabolism related to ASD and iDD followed similar patterns of disturbance in previously reported metabolic signatures in children but were generally smaller in magnitude. Similar patterns of metabolic disturbances observed in mothers and their children with ASD or iDD could reflect shared genetic, mitochondrial, and/or environmental risk factors., Competing Interests: Declarations. Competing interests: The authors declare no competing interests., (© 2024. The Author(s).)

Autism spectrum disorder (ASD) is a complex neurodevelopmental disorder that is marked by impaired social interactions, and increased repetitive behaviors. There is evidence of genetic changes in ASD, and several of these altered genes are linked to the process of DNA repair. Therefore, individuals with ASD must have improved DNA repair efficiency to mitigate risks associated with ASD. Despite numerous milestones in ASD research, the disease remains incurable, with a high occurrence rate and substantial financial burdens. This motivates scientists to search for new drugs to manage the disease. Disruption of glucagon-like peptide-1 (GLP-1) signaling, a regulator in neuronal development and maintains homeostasis, has been associated with the pathogenesis and progression of several neurological disorders, such as ASD. Our study aimed to assess the impact of semaglutide, a new GLP-1 analog antidiabetic medication, on behavioral phenotypes and DNA repair efficiency in the BTBR autistic mouse model. Furthermore, we elucidated the underlying mechanism(s) responsible for the ameliorative effects of semaglutide against behavioral problems and DNA repair deficiency in BTBR mice. The current results demonstrate that repeated treatment with semaglutide efficiently decreased autism-like behaviors in BTBR mice without affecting motor performance. Semaglutide also mitigated spontaneous DNA damage and enhanced DNA repair efficiency in the BTBR mice as determined by comet assay. Moreover, administering semaglutide recovered oxidant-antioxidant balance in BTBR mice. Semaglutide restored the disrupted DNA damage/repair pathways in the BTBR mice by reducing Gadd45a expression and increasing Ogg1 and Xrcc1 expression at both the mRNA and protein levels. This suggests that semaglutide holds great potential as a novel therapeutic candidate for treating ASD traits., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Background: ASH1L (absent, small, or homeotic-like 1), a histone methyltransferase, has been identified as a high-risk gene for autism spectrum disorder (ASD). We previously showed that postnatal Ash1l severe deficiency in the prefrontal cortex (PFC) of male and female mice caused seizures. However, the synaptic mechanisms underlying autism-like social deficits and seizures need to be elucidated., Objective: The goal of this study is to characterize the behavioral deficits and reveal the synaptic mechanisms in an Ash1l haploinsufficiency mouse model using a targeted gene-trap knockout (gtKO) strategy., Method: A series of behavioral tests were used to examine behavioral deficits. Electrophysiological and chemogenetic approaches were used to examine and manipulate the excitability of pyramidal neurons in the PFC of Ash1l +/GT mice., Results: Ash1l +/GT mice displayed social deficits, increased self-grooming, and cognitive impairments. Epileptiform discharges were found on electroencephalograms (EEGs) of Ash1l +/GT mice, indicating absence-like seizures. Ash1l haploinsufficiency increased the susceptibility for convulsive seizures when Ash1l +/GT mice were challenged by pentylenetetrazole (PTZ, a competitive GABA A receptor antagonist). Whole-cell patch-clamp recordings showed that Ash1l haploinsufficiency increased the excitability of pyramidal neurons in the PFC by altering intrinsic neuronal properties, enhancing glutamatergic synaptic transmission, and diminishing GABAergic synaptic inhibition. Chemogenetic inhibition of pyramidal neurons in the PFC of Ash1l +/GT mice ameliorated autism-like social deficits and abolished absence-like seizures., Conclusions: We demonstrated that increased neural activity in the PFC contributed to the autism-like social deficits and absence-like seizures in Ash1l +/GT mice, which provides novel insights into the therapeutic strategies for patients with ASH1L -associated ASD and epilepsy.

Background: Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by limited interests, difficulties in social interactions, repetitive behaviors, and impairments in social communication. ASD tends to run in families, and twin studies suggest a strong genetic basis for the disorder. However, the definition of a genetic profile that indicates a risk for ASD remains unclear., Methods: This analysis includes an investigation (Autism Dataset 4 from the NIMH repository, n = 2890) and a replication (Autism Dataset 3 from the NIMH repository, n = 1233) of trio samples with GWAS data. In Phase 1, a molecular pathway analysis is conducted on the investigation sample to test for the enrichment of specific Gene Ontology (GO) terms associated with autism. In Phase 2, the identified pathways are tested for enrichment in the replication sample. Permutation tests are performed to reduce the risk of false-positive findings. Quality assessment is conducted using QQ-plots and λ values, with Plink and R utilized for the Transmission Disequilibrium Test (TDT) and permutation tests., Results: The GO term GO:0007417 was found to be enriched in both the investigation and replication samples. SNPs associated with this pathway were observed at a frequency higher than expected in the replication sample., Conclusions: The GO term GO:0007417 (development of the nervous system) was associated with autism in both trio samples. Variations in the genes TMPRSS4 , TRPC4 , and PCDH9 were consistently linked to autism across the two independent samples, highlighting the role of calcium signaling and cell adhesion molecules in the risk of autism-related disorders. The pathways and variations associated with autism are described in detail, which can contribute to the engineering of new pharmacological treatments for ASD.

The epidemiological evidence regarding prenatal PFAS exposure and its interaction with genetic factors on the autistic traits risk is unclear. This study included 1610 mother-child pairs from the Shanghai Birth Cohort (SBC). Ten PFAS were quantified in blood serum collected in the first trimester. Child autistic traits were evaluated at age 4 using a Chinese version of the social responsiveness scale-short form (SRS-SF). We calculated the polygenic risk score (PRS) to evaluate the cumulative genetic effects of autism. Additive interaction models were established to explore whether genetic susceptibility modified the effects of prenatal PFAS exposure. After adjusting for confounders, we found prenatal PFOA exposure was associated with an increased risk of autistic traits in children (OR, 3.05; 95 % CI, 1.14-7.58), and the increased risk associated with PFOA was mitigated among women who reported pre-pregnancy folic acid supplementation. Additionally, an increased risk of autistic traits was observed in children with higher levels of prenatal PFHxS exposure and a high PRS (p for interaction = 0.021). Our findings suggest prenatal PFAS exposure may increase the risk of autistic traits in children, especially in those with a high genetic risk. Further research is warranted to confirm this association and explore the underlying mechanisms., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier B.V.)

The cerebellum is heavily connected with other brain regions, sub-serving not only motor but also nonmotor functions. Genetic mutations leading to cerebellar dysfunction are associated with mental diseases, but cerebellar outputs have not been systematically studied in this context. Here, we present three dimensional distributions of 50,168 target neurons of cerebellar nuclei (CN) from wild-type mice and Nlgn3R451C mutant mice, a mouse model for autism. Our results derived from 36 target nuclei show that the projections from CN to thalamus, midbrain and brainstem are differentially affected by Nlgn3R451C mutation. Importantly, Nlgn3R451C mutation altered the innervation power of CN→zona incerta (ZI) pathway, and chemogenetic inhibition of a neuronal subpopulation in the ZI that receives inputs from the CN rescues social defects in Nlgn3R451C mice. Our study highlights potential role of cerebellar outputs in the pathogenesis of autism and provides potential new therapeutic strategy for this disease., (© The Author(s) 2024. Published by Oxford University Press on behalf of Higher Education Press.)

This study investigated the neurodevelopmental impact of pathogenic adenomatous polyposis coli (APC) gene variants in patients with familial adenomatous polyposis (FAP), a cancer predisposition syndrome. We hypothesized that certain pathogenic APC variants result in behavioral-cognitive challenges. We compared 66 FAP patients (cases) and 34 unaffected siblings (controls) to explore associations between APC variants and behavioral and cognitive challenges. Our findings indicate that FAP patients exhibited higher Social Responsiveness Scale (SRS) scores, suggesting a greater prevalence of autistic traits when compared to unaffected siblings (mean 53.8 vs. 47.4, Wilcoxon p = 0.018). The distribution of SRS scores in cases suggested a bimodal pattern, potentially linked to the location of the APC variant, with scores increasing from the 5' to 3' end of the gene (Pearson's r = 0.33, p = 0.022). While we observed a trend toward lower educational attainment in cases, this difference was not statistically significant. This study is the first to explore the connection between APC variant location and neurodevelopmental traits in FAP, expanding our understanding of the genotype-phenotype correlation. Our results emphasize the importance of clinical assessment for autistic traits in FAP patients, shedding light on the potential role of APC gene variants in these behavioral and cognitive challenges., (© 2024 The Author(s). American Journal of Medical Genetics Part B: Neuropsychiatric Genetics published by Wiley Periodicals LLC.)

Bisphenol AP (BPAP), an environmental endocrine disruptor, may cause neurodevelopmental disorders affecting human health. Studies have shown that BPAP impacts hormone synthesis and metabolism, causes social behavior abnormalities, and induces anxiety-like behavioral impairments in mice. However, evidence for the neurobehavioral effects of BPAP is still lacking. Here, we examined the toxic effects of BPAP on neurodevelopment using a Drosophila model. We assessed the role of BPAP exposure in autism-like behavior and explored the underlying mechanisms. Our findings indicated that BPAP exposure reduced pupation and eclosion rates and delayed growth in Drosophila. Furthermore, BPAP exposure caused autism-like behaviors, characterized by increased grooming times and aberrant social interactions, along with abnormalities in locomotor activity, as well as learning and memory ability. Mechanistically, we found that BPAP decreases the number of neuroblasts (NBs) and mature intermediate neural progenitors (INPs) in the 3rd larval brain, impairing axon guidance in the mushroom body of the adult Drosophila brain. Additionally, our transcriptome analysis revealed that BPAP exposure alters the expression of neurodevelopment-related genes (Nplp3, sand, lush, and orco) and affects the estrogen signaling pathway (Hsp70Ab, Hsp70Bc, Hsp70Ba, and Hsp70Bb). These changes potentially explain the BPAP-induced autism-like behavior in Drosophila., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Importance: In the neurotypical brain, regions develop in coordinated patterns, providing a fundamental scaffold for brain function and behavior. Whether altered patterns contribute to clinical profiles in neurodevelopmental conditions, including autism, remains unclear., Objectives: To examine if, in autism, brain regions develop differently in relation to each other and how these differences are associated with molecular/genomic mechanisms and symptomatology., Design, Setting, and Participants: This study was an analysis of one the largest deep-phenotyped, case-control, longitudinal (2 assessments separated by approximately 12-24 months) structural magnetic resonance imaging and cognitive-behavioral autism datasets (EU-AIMS Longitudinal European Autism Project [LEAP]; study dates, February 2014-November 2017) and an out-of-sample validation in the Brain Development Imaging Study (BrainMapASD) independent cohort. Analyses were performed during the 2022 to 2023 period. This multicenter study included autistic and neurotypical children, adolescents, and adults. Autistic participants were included if they had an existing autism diagnosis (DSM-IV/International Statistical Classification of Diseases and Related Health Problems, Tenth Revision or DSM-5 criteria). Autistic participants with co-occurring psychiatric conditions (except psychosis/bipolar disorder) and those taking regular medications were included., Exposures: Neuroanatomy of neurotypical and autistic participants., Main Outcomes and Measures: Intraindividual changes in surface area and cortical thickness over time, analyzed via surface-based morphometrics., Results: A total of 386 individuals in the LEAP cohort (6-31 years at first visit; 214 autistic individuals, mean [SD] age, 17.3 [5.4] years; 154 male [72.0%] and 172 neurotypical individuals, mean [SD] age, 16.35 [5.7] years; 108 male [62.8%]) and 146 individuals in the BrainMapASD cohort (11-18 years at first visit; 49 autistic individuals, mean [SD] age, 14.31 [2.4] years; 42 male [85.7%] and 97 neurotypical individuals, mean [SD] age, 14.10 [2.5] years; 58 male [59.8%]). Maturational between-group differences in cortical thickness and surface area were established that were mostly driven by sensorimotor regions (eg, across features, absolute loadings for early visual cortex ranged from 0.07 to 0.11, whereas absolute loadings for dorsolateral prefrontal cortex ranged from 0.005 to 0.06). Neurodevelopmental differences were transcriptomically enriched for genes expressed in several cell types and during various neurodevelopmental stages, and autism candidate genes (eg, downregulated genes in autism, including those regulating synaptic transmission; enrichment odds ratio =3.7; P =2.6 × -10). A more neurotypical, less autismlike maturational profile was associated with fewer social difficulties and more typical sensory processing (false discovery rate P <.05; Pearson r ≥0.17). Results were replicated in the independently collected BrainMapASD cohort., Conclusions and Relevance: Results of this case-control study suggest that the coordinated development of brain regions was altered in autism, involved a complex interplay of temporally sensitive molecular mechanisms, and may be associated with both lower-order (eg, sensory) and higher-order (eg, social) clinical features of autism. Thus, examining maturational patterns may provide an analytic framework to study the neurobiological origins of clinical profiles in neurodevelopmental/mental health conditions.

Autism spectrum disorder (ASD) is complex neurobehavioral condition influenced by several cellular and molecular mechanisms that are often concerned with synaptogenesis and synaptic activity. Based on the excitation/inhibition (E/I) imbalance theory, ASD could be the result of disruption in excitatory and inhibitory synaptic transmission across the brain. The prefrontal cortex (PFC) is the chief regulator of executive function and can be affected by altered neuronal excitation and inhibition in the course of ASD. The molecular mechanisms involved in E/I imbalance are subject to epigenetic regulation. In ASD, altered enrichment and spreading of histone H3 and H4 modifications such as the activation-linked H3K4me2/3, H3K9ac, and H3K27ac, and repression-linked H3K9me2, H3K27me3, and H4K20me2 in the PFC result in dysregulation of molecules mediating synaptic excitation (ARC, EGR1, mGluR2, mGluR3, GluN2A, and GluN2B) and synaptic inhibition (BSN, EphA7, SLC6A1). Histone modifications are a dynamic component of the epigenetic regulatory elements with a pronounced effect on patterns of gene expression with regards to any biological process. The excitation/inhibition imbalance associated with ASD is based on the excitatory and inhibitory synaptic activity in different regions of the brain, including the PFC, the ultimate outcome of which is highly influenced by transcriptional activity of relevant genes., (© 2024 Wiley Periodicals LLC.)

Genetic correlations have been reported between chronotype and both autism (AUT) and schizophrenia (SCZ), as well as between insomnia and attention-deficit/hyperactivity disorder (ADHD), bipolar disorder (BP), schizophrenia (SCZ) and major depression (MDD). Our study aimed to investigate these shared genetic variations using genome-wide and pathway-based polygenic score analyses. We computed polygenic scores using summary statistics from genome-wide association studies (GWAS) of ADHD (N = 225,534), AUT (N = 46,350), BP (N = 353,899), MDD (N = 500,199) and SCZ (N = 160,779). We tested their performance in predicting chronotype (N = 409,630) and insomnia (N = 239,918) status of UK Biobank participants. For pathway-based polygenic scores, we restricted genetic variation to SNPs that mapped to genes within 1377 Reactome pathways. Genome-wide polygenic scores for AUT, BP, MDD and SCZ were associated with an evening chronotype (p < 2.2 × 10 -16 , p = 4.8 × 10 -3 , p = 8.07 × 10 -4 and p < 2.2 × 10 -16 , respectively). Polygenic scores for ADHD, AUT, BP, MDD SCZ were associated with insomnia (p < 2.2 × 10 -16 , p = 2.93 × 10 -3 , p = 2.9 × 10 -7 , p < 2.2 × 10 -16 and p = 8.86 × 10 -3 , respectively). While pathway-based polygenic score analysis identified the KEAP1-NRF2 (p = 1.29 × 10 -8 ) and mRNA Splicing-Minor Pathways (p = 1.52 × 10 -8 ) as enriched for genetic variation overlapping between chronotype and BP, the majority of tested pathways yielded null findings, suggesting that specific shared genetic mechanisms between sleep-related phenotypes and neurodevelopmental/psychiatric conditions (NDPC) may be limited to a subset of pathways. Colocalisation analysis identified BP-associated SNPs in CUL3 and SF3B1 as being linked to changes in their expression. Our results strengthen evidence for shared genetic variation between NDPC and sleep-related phenotypes. We identify the KEAP1-NRF2 and mRNA Splicing-Minor Pathways as potentially mediating the disrupted circadian rhythm phenotype of BP., (© 2024 The Author(s). Genes, Brain and Behavior published by International Behavioural and Neural Genetics Society and John Wiley & Sons Ltd.)

Background: Mosaic Down syndrome is a triplication of chromosome 21 in some but not all cells. Little is known about the epidemiology of mosaic Down syndrome. We described prevalence of mosaic Down syndrome and the co-occurrence of common chronic conditions in 94,533 Medicaid enrolled adults with any Down syndrome enrolled from 2016 to 2019., Methods: We identified mosaic Down syndrome using the International Classification of Diseases and Related Health Problems, tenth edition code for mosaic Down syndrome and compared to those with nonmosaic Down syndrome codes. We identified chronic conditions using established algorithms and compared prevalence by mosaicism., Results: In total, 1966 (2.08%) had claims for mosaic Down syndrome. Mosaicism did not differ by sex or race/ethnicity with similar age distributions. Individuals with mosaicism were more likely to present with autism (13.9% vs. 9.6%) and attention deficit hyperactivity disorder (17.7% vs. 14.0%) compared to individuals without mosaicism. In total, 22.3% of those with mosaic Down syndrome and 21.5% of those without mosaicism had claims for Alzheimer's dementia (Prevalence difference: 0.8; 95% Confidence interval: -1.0, 2.8). The mosaic group had 1.19 times the hazard of Alzheimer's dementia compared to the nonmosaic group (95% CI: 1.0, 1.3)., Discussion: Mosaicism may be associated with a higher susceptibility to certain neurodevelopmental and neurodegenerative conditions, including Alzheimer's dementia. Our findings challenge previous assumptions about its protective effects in Down syndrome. Further research is necessary to explore these associations in greater depth., (© 2024 Wiley Periodicals LLC.)

Duplication of chromosome 15q11-13 has been reported to be one of the most frequent cytogenetic copy number variations in autism spectrum disorder (ASD), and a mouse model of paternal 15q11-13 duplication was generated, termed 15q dup mice. While previous studies have replicated some of the behavioral and brain structural phenotypes of ASD separately, the relationship between brain structure and behavior has rarely been examined. In this study, we performed behavioral experiments related to anxiety and social behaviors and magnetic resonance imaging (MRI) using the same set of 15q dup and wild-type mice. 15q dup mice showed increased anxiety and a tendency toward alterations in social behaviors, as reported previously, as well as variability in terms of sociability. MRI analysis revealed that a lower sociability index was correlated with a smaller gray matter volume in the right medial entorhinal cortex. These results may help to understand how variability in behavioral phenotypes of ASD arises even in individuals with the same genetic background and to determine the individual differences in neurodevelopmental trajectory correlated with specific brain structures that underlie these phenotypes., Competing Interests: Declaration of Competing Interest The authors declare no conflicts of interest., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Timothy syndrome type 1 (TS1), a malignant variant of Long QT Syndrome, is caused by L-type Ca2+ Channel (LTCC) inactivation defects secondary to the p.Gly406Arg mutation in the CACNA1C gene. Leveraging on the experimental in vitro data from our TS1 knock-in swine model and their wild-type (WT) littermates, we first developed a mathematical model of WT large white swine ventricular cardiomyocyte electrophysiology that reproduces a wide range of experimental data, including ionic current properties, action potential (AP) dynamics, and Ca 2 + handling. A sensitivity analysis tested robustness and facilitated comparison with the parent ORd human model. Introducing 22% of TS1-mutated LTCCs, the model faithfully reproduced key disease features, including marked AP prolongation, steeper rate-dependent adaptation of AP duration, Ca 2 + overload, and CaMKII-mediated decreased upstroke velocity. Translational relevance of the TS1 model was investigated by: dissecting the roles of primary and secondary contributors to TS1 phenotype; demonstrating the arrhythmogenic potential of TS1 vs. WT cells; and evaluating the model's capability to identify novel pharmacological targets which could modulate the cellular phenotype. In conclusion, we developed a mathematical large white swine ventricular myocyte model, demonstrating its utility in exploring arrhythmogenic mechanisms and therapeutic interventions in cardiac diseases, such as TS1., Competing Interests: Declarations. Competing interests: The authors declare that they have no competing interests., (© 2024. The Author(s).)

Background: MAGEL2 is an autism susceptibility gene whose deficiency has been associated with autism-related behaviors in animal models and in syndromic human autism spectrum disorders (ASDs) such as Schaaf-Yang syndrome, but has not been studied in the broader autism spectrum. Given the capabilities of long-read sequencing technologies, this pilot study used a targeted nanopore sequencing approach to simultaneously examine MAGEL2 DNA sequence and methylation in adults with high-functioning autism (HFA) compared to neurotypical controls (NC)., Methods: Using DNA extracted from peripheral blood, Cas9-targeted nanopore DNA sequencing was used to analyze MAGEL2, including its entire regulatory construct (chr15:23639316-23651466), for sequence variation and 5-methyl-cytosine (5mC) modification in a cohort of adults with HFA compared to sex- and age-matched NC. Given the known sex differences in ASD and MAGEL2 KO animal models, results were further analyzed by sex., Results: 20 adults with HFA (10 males, 10 females) and 20 NC were included. While there were no overall differences in MAGEL2 DNA sequence and 5mC modification between HFA and NC, we found a significant difference in MAGEL2 gene promoter methylation between males and females with HFA and NC of both sexes, with HFA males tending to show hypomethylation in a 300 bp long differentially methylated region (chr15:23647640-23647939) around the MAGEL2 transcription start site., Conclusions: In this pilot study utilizing nanopore Cas9 targeted DNA sequencing, significant sex-specific differences in MAGEL2 gene promoter methylation were identified in male adults with HFA in comparison to control groups, suggesting the potential for sex-specific epigenetic differences. However, further replication in larger cohorts is required to validate these findings., Competing Interests: Declarations. Ethics approval and consent to participate: This study was prospectively reviewed and approved by the ethics committee of Hannover Medical School, Germany, under approval number 3054-2016. All subjects gave written informed consent to participate in the study. The mental health professionals in charge of the study have determined that all participants are capable of providing informed consent for their involvement in the research presented in this manuscript. Consent for publication: Not applicable. Competing interests: The authors declare no competing interests., (© 2024. The Author(s).)

Background: Timothy syndrome (OMIM #601005) is a rare disease caused by variants in the gene CACNA1C. Initially, Timothy syndrome was characterized by a cardiac presentation of long QT syndrome and syndactyly of the fingers and/or toes, all associated with the CACNA1C variant, Gly406Arg. However, subsequent identification of diverse variants in CACNA1C has expanded the clinical spectrum, revealing various cardiac and extra-cardiac manifestations. It remains underexplored whether individuals with the canonical Gly406Arg variants in mutually exclusive exon 8A (Timothy syndrome 1) or exon 8 (Timothy syndrome 2) exhibit overlapping symptoms. Moreover, case reports have indicated that some CACNA1C variants may produce a cardiac-selective form of Timothy syndrome often referred to as non-syndromic long QT type 8 or cardiac-only Timothy syndrome, however few reports follow up on these patients to confirm the cardiac selectivity of the phenotype over time., Methods: A survey was administered to the parents of patients with Timothy syndrome, querying a broad range of symptoms and clinical features. Study participants were organized into 5 separate categories based on genotype and initial diagnosis, enabling comparison between groups of patients which have been described differentially in the literature., Results: Our findings reveal that Timothy syndrome patients commonly exhibit both cardiac and extra-cardiac features, with long QT syndrome, neurodevelopmental impairments, hypoglycemia, and respiratory issues being frequently reported. Notably, the incidence of these features was similar across all patient categories, including those diagnosed with non-syndromic long QT type 8, suggesting that the 'non-syndromic' classification may be incomplete., Conclusions: This study represents the first Natural History Study of Timothy syndrome, offering a comprehensive overview of the disease's clinical manifestations. We demonstrate that both cardiac and extra-cardiac features are prevalent across all patient groups, underscoring the syndromic nature of CACNA1C variants. While the critical role of long QT syndrome and cardiac arrhythmias in Timothy syndrome has been well recognized, our findings indicate that hypoglycemia and respiratory dysfunction also pose significant life-threatening risks, emphasizing the need for comprehensive therapeutic management of affected individuals., Competing Interests: Declarations. Ethics approval and consent to participate: Data within this study was collected after informed consent from the TS individual or parent/guardian completing the survey on their behalf. The study was approved by the Institutional Review Board of Genetic Alliance (Washington, DC, USA). Consent for publication: All participants provided consent consistent with the IRB approved by Genetic Alliance. Competing interests: The authors have no competing financial interests., (© 2024. The Author(s).)

Background: To explore the therapeutic role of arginine vasopressin (AVP) and its possible mechanisms in autism., Methods: Mid-trimester pregnant rats treated with valproate on embryonic day 12.5 and their offspring were selected as autism model. The autism rats were randomly assigned to autism group and AVP treatment group that given AVP by inhalation per day from postnatal days 21 to 42. The changes in social behavior and the hippocampus transcriptome were compared, and the hub genes were confirmed by quantitative real-time polymerase chain reaction (qPCR) and Mendelian randomization (MR)., Results: 403 genes were found to be differentially expressed in the autism model, with the majority of these genes being involved in oligodendrocyte development and myelination. Only 11 genes associated with myelination exhibited statistically significant alterations following AVP treatment when compared to the autism group. Gene set enrichment, expression patterns, and weighted gene co-expression network analysis (WGCNA) analysis consistently indicated that the biological processes of oligodendrocyte development and myelination were markedly enriched in the autism group and exhibited improvement following treatment. The variation trend of various nerve cells demonstrated a notable increase in the proportion of oligodendrocytes and oligodendrocyte precursor cells in the autism group, which subsequently exhibited a significant decline following treatment. Five hub genes ( MBP, PLIP, CNP, GFAP, and TAOK1 ) were verified by qPCR. Finally, MR studies have confirmed a causal relationship between hippocampal myelination-related gene expression and the risk of autism., Conclusions: AVP could markedly enhance social interaction abilities in the autism rat model, possibly due to the significantly improved hippocampus oligodendrocytes development and myelination., (© 2024 The Author(s). Published by IMR Press.)

Special AT-rich sequence-binding protein 2 (SATB2) is a master regulator of gene expression. Mutations of the SATB2 gene results in the SATB2-associated syndrome (SAS), a genetic disorder characterized by neurodevelopmental disabilities and autism-related phenotype. The importance of plasma as an indicator of SAS phenotypes is unknown. We aim to investigate if pathogenic variants in SATB2 are associated with alteration to relevant pathways in the plasma of SAS patients and identify key differentially regulated proteins which may serve as biomarkers to improve diagnostic and future pharmacological approaches. We used well-validated proteomic technologies to determine the proteomic profile of plasma from SAS patients compared to healthy control subjects. Bioinformatical analysis was performed to identify significant proteins and functionally enriched pathways. We identified differentially expressed proteins in the plasma of SAS patients that are significantly involved in metabolism-related pathways. Energy metabolism, glucose metabolism and vitamin metabolism pathways are significantly enriched in SAS patients as compared to healthy controls. Our study linked SATB2 mutations to the impairment of plasma proteins involved in different metabolic pathways in SAS patients., Competing Interests: Declarations Competing interests The authors declare no competing interests., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Autism is a developmental disability. Research demonstrated that children with autism benefit from early diagnosis and early intervention. Genetic factors are considered major contributors to the development of autism. Machine learning (ML), including deep learning (DL), has been evaluated in phenotype prediction, but this method has been limited in its application to autism. We developed a DL model, the Separate Translated Autism Research Neural Network (STAR-NN) model to predict autism status. The model was trained and tested using whole exome sequencing data from 43,203 individuals (16,809 individuals with autism and 26,394 non-autistic controls). Polygenic scores from common variants and the aggregated count of rare variants on genes were used as input. In STAR-NN, protein truncating variants, possibly damaging missense variants and mild effect missense variants on the same gene were separated at the input level and merged to one gene node. In this way, rare variants with different level of pathogenic effects were treated separately. We further validated the performance of STAR-NN using an independent dataset, including 13,827 individuals with autism and 14,052 non-autistic controls. STAR-NN achieved a modest ROC-AUC of 0.7319 on the testing dataset and 0.7302 on the independent dataset. STAR-NN outperformed other traditional ML models. Gene Ontology analysis on the selected gene features showed an enrichment for potentially informative pathways including calcium ion transport., Competing Interests: No competing interests., (Copyright: © 2024 Wu et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Autism spectrum disorders (ASD) are complex, polygenic and heterogenous neurodevelopmental conditions. The severity of autism-associated variants is influenced by environmental factors, particularly social experiences during the critical neurodevelopmental period. While early behavioral interventions have shown efficacy in some children with autism, pharmacological support for core features - impairments in social interaction and communication, and stereotyped or restricted behaviors - is currently lacking. In this study, we examined how the social environment influences both wild-type (WT) and Shank3 knockout (KO) mice, a model reflecting core autism-like traits. Our findings revealed that chronic social isolation enhanced social interaction and olfactory neuron responses in WT animals. Furthermore, it restored impairments in social novelty preference and olfactory function, as well as self-grooming in Shank3 KO mice. Conversely, an enriched social environment heightened social interest toward novel conspecifics in WT mice, but elicited the opposite effect in Shank3 KO mice. Notably, Shank3 KO mice displayed distinct social responses when exposed to WT or Shank3 KO mice. These results offer novel insights that could favor the implementation of behavioral interventions and inclusive classroom programs for children with ASD., (© 2024. The Author(s).)

Purpose: Individuals with proximal 16p11.2 copy number variants (CNVs), either deletions (16p11.2DS) or duplications (16p11.2Dup), are predisposed to neurodevelopmental difficulties and disorders, such as language disorders, intellectual disability, and autism spectrum disorder. The purpose of the current study was to characterize language profiles of school-age children with proximal 16p11.2 CNVs, in relation to the normative sample and unaffected siblings of children with 16p11.2DS., Method: Standardized language tests were conducted in 33 school-age children with BP4-BP5 16p11.2 CNVs and eight unaffected siblings of children with 16p11.2DS to evaluate language production and comprehension skills across various language domains. A standardized intelligence test was also administered, and parents completed a standardized questionnaire to assess autistic traits. Language profiles were compared across 16p11.2 CNVs and intrafamilial pairs. The influence of nonverbal intelligence and autistic traits on language outcomes was investigated., Results: No significant differences were found between children with 16p11.2DS and those with 16p11.2Dup, although both groups exhibited significantly poorer language skills compared to the normative sample and unaffected siblings of children with 16p11.2DS. Severe language deficits were identified in 70% of individuals with 16p11.2 CNVs across all language subdomains, with significantly better receptive vocabulary skills than overall receptive language abilities. In children with 16p11.2DS, expressive language deficits were more pronounced than receptive deficits. In contrast, only in children with 16p11.2Dup did nonverbal intelligence influence their language outcomes., Conclusions: The current study contributes to the deeper understanding of language profiles in 16p11.2 CNVs in a clinically ascertained cohort, indicating generalized deficits across multiple language domains, rather than a syndrome-specific pattern targeting specific subdomains. The findings underscore the importance of early diagnosis, targeted therapy, and monitoring of language skills in children with 16p11.2 CNVs., Supplemental Material: https://doi.org/10.23641/asha.27228702.

Dogs interact with humans effectively and intimately. However, the neural underpinnings for such interspecies social communication are not understood. It is known that interbrain activity coupling, i.e., the synchronization of neural activity between individuals, represents the neural basis of social interactions. Here, previously unknown cross-species interbrain activity coupling in interacting human-dog dyads is reported. By analyzing electroencephalography signals from both dogs and humans, it is found that mutual gaze and petting induce interbrain synchronization in the frontal and parietal regions of the human-dog dyads, respectively. The strength of the synchronization increases with growing familiarity of the human-dog dyad over five days, and the information flow analysis suggests that the human is the leader while the dog is the follower during human-dog interactions. Furthermore, dogs with Shank3 mutations, which represent a promising complementary animal model of autism spectrum disorders (ASD), show a loss of interbrain coupling and reduced attention during human-dog interactions. Such abnormalities are rescued by the psychedelic lysergic acid diethylamide (LSD). The results reveal previously unknown interbrain synchronizations within an interacting human-dog dyad which may underlie the interspecies communication, and suggest a potential of LSD for the amelioration of social impairment in patients with ASD., (© 2024 The Author(s). Advanced Science published by Wiley‐VCH GmbH.)

Non-invasive brain stimulation therapy for autism spectrum disorder (ASD) has shown beneficial effects. Recently, we and others demonstrated that visual sensory stimulation using rhythmic 40 Hz light flicker effectively improved cognitive deficits in mouse models of Alzheimer's disease and stroke. However, whether rhythmic visual 40 Hz light flicker stimulation can ameliorate behavioral deficits in ASD remains unknown. Here, we show that 16p11.2 deletion female mice exhibit a strong social novelty deficit, which was ameliorated by treatment with a long-term 40 Hz light stimulation. The elevated power of local-field potential (LFP) in the prefrontal cortex (PFC) of 16p11.2 deletion female mice was also effectively reduced by 40 Hz light treatment. Importantly, the 40 Hz light flicker reversed the excessive excitatory neurotransmission of PFC pyramidal neurons without altering the firing rate and the number of resident PFC neurons. Mechanistically, 40 Hz light flicker evoked adenosine release in the PFC to modulate excessive excitatory neurotransmission of 16p11.2 deletion female mice. Elevated adenosine functioned through its cognate A 1 receptor (A 1 R) to suppress excessive excitatory neurotransmission and to alleviate social novelty deficits. Indeed, either blocking the A 1 R using a specific antagonist DPCPX or knocking down the A 1 R in the PFC using a shRNA completely ablated the beneficial effects of 40 Hz light flicker. Thus, this study identified adenosine as a novel neurochemical mediator for ameliorating social novelty deficit by reducing excitatory neurotransmission during 40 Hz light flicker treatment. The 40 Hz light stimulation warrants further development as a non-invasive ASD therapeutics., (© 2024. The Author(s).)

This study aimed to uncover novel genes associated with neurodevelopmental disorders (NDD) by leveraging recent large-scale de novo burden analysis studies to enhance a virtual gene panel used in a diagnostic setting. We re-analyzed historical trio-exome sequencing data from 745 individuals with NDD according to the most recent diagnostic standards, resulting in a cohort of 567 unsolved individuals. Next, we designed a virtual gene panel containing candidate genes from three large de novo burden analysis studies in NDD and prioritized candidate genes by stringent filtering for ultra-rare de novo variants with high pathogenicity scores. Our analysis revealed an increased burden of de novo variants in our selected candidate genes within the unsolved NDD cohort and identified qualifying de novo variants in seven candidate genes: RIF1, CAMK2D, RAB11FIP4, AGO3, PCBP2, LEO1, and VCP. Clinical data were collected from six new individuals with de novo or inherited LEO1 variants and three new individuals with de novo PCBP2 variants. Our findings add additional evidence for LEO1 as a risk gene for autism and intellectual disability. Furthermore, we prioritize PCBP2 as a candidate gene for NDD associated with motor and language delay. In summary, by leveraging de novo burden analysis studies, employing a stringent variant filtering pipeline, and engaging in targeted patient recruitment, our study contributes to the identification of novel genes implicated in NDDs., Competing Interests: Competing interests YB is an employee of GeneDx, LLC. The Department of Molecular and Human Genetics at Baylor College of Medicine receives revenue from clinical genetic testing completed at Baylor Genetics Laboratories. All other authors declare no conflict of interest. Ethics approval and consent to participate This study was conducted with approval from the Ethical Committee of the University of Antwerp. All institutions involved in human participant research received local IRB approval. All families or legal guardians of recruited participants provided informed consent for this study. Participant data were de-identified., (© 2024. The Author(s), under exclusive licence to European Society of Human Genetics.)

Autism represents a large spectrum of diverse individuals with varying underlying genetic architectures and needs. For some individuals, a single de novo or ultrarare genetic variant has a large effect on the intensity of specific dimensions of the phenotype, while, for others, a combination of thousands of variants commonly found in the general population are involved. The variants with large impact are found in up to 30% of autistic individuals presenting with intellectual disability, significant speech delay, motor delay, and/or seizures. The common variants are shared with those found in individuals with attention-deficit/hyperactivity disorder, major depressive disorders, greater educational attainment, and higher cognitive performance, suggesting overlapping genetic architectures. The genetic variants modulate the function of chromatin remodeling and synaptic proteins that influence the connectivity of neuronal circuits and, in interaction with the environment of each individual, the subsequent cognitive and personal trajectory of the child. Overall, this genetic heterogeneity mirrors the phenotypic diversity of autistic individuals and provides a helpful bridge between biomedical and neurodiversity perspectives. We propose that participative and multidisciplinary research should use this information to understand better the assessment, treatments, and accommodations that individuals with autism and families need.

Homo sapiens and Neanderthals underwent hybridization during the Middle/Upper Paleolithic age, culminating in retention of small amounts of Neanderthal-derived DNA in the modern human genome. In the current study, we address the potential roles Neanderthal single nucleotide polymorphisms (SNP) may be playing in autism susceptibility in samples of black non-Hispanic, white Hispanic, and white non-Hispanic people using data from the Simons Foundation Powering Autism Research (SPARK), Genotype-Tissue Expression (GTEx), and 1000 Genomes (1000G) databases. We have discovered that rare variants are significantly enriched in autistic probands compared to race-matched controls. In addition, we have identified 25 rare and common SNPs that are significantly enriched in autism on different ethnic backgrounds, some of which show significant clinical associations. We have also identified other SNPs that share more specific genotype-phenotype correlations but which are not necessarily enriched in autism and yet may nevertheless play roles in comorbid phenotype expression (e.g., intellectual disability, epilepsy, and language regression). These results strongly suggest Neanderthal-derived DNA is playing a significant role in autism susceptibility across major populations in the United States., (© 2024. The Author(s).)

There is increasing evidence of mitochondrial dysfunction in autism spectrum disorders (ASD), but the causal relationships are unclear. In an ASD patient whose identical twin was unaffected, we identified a postzygotic mosaic mutation p.Q639* in the TRAP1 gene, which encodes a mitochondrial chaperone of the HSP90 family. Additional screening of 176 unrelated ASD probands revealed an identical TRAP1 variant in a male patient who had inherited it from a healthy mother. Notably, newly generated knock-in Trap1 p.Q641* mice display ASD-related behavioral abnormalities that are more pronounced in males than in females. Accordingly, Trap1 p.Q641* mutation also resulted in sex-specific changes in synaptic plasticity, the number of presynaptic mitochondria, and mitochondrial respiration. Thus, the TRAP1 p.Q639* mutation is the first example of a monogenic ASD caused by impaired mitochondrial protein homeostasis., Competing Interests: Disclosure and competing interests statement The authors declare no competing interests., (© 2024. The Author(s).)

Background: Autism spectrum disorder (ASD) is a lifelong condition. It is characterized by complex etiologies, including disruptions in exogenous retinoic acid (RA) signaling, which may serve as an environmental risk factor. Targeting the RA pathway presents a promising therapeutic avenue, though the precise mechanisms remain to be elucidated., Methods: Female Sprague-Dawley rats were treated with valproic acid (VPA) during pregnancy to induce an ASD model in their offspring. Some offspring received RA treatment postnatally. Social behavior and brain-functional connectivity were assessed using behavioral tests and functional magnetic resonance imaging (fMRI), respectively. Transcriptomics analysis and proteomics analysis of the hypothalamus identified differentially expressed genes (DEGs) and differentially expressed proteins (DEPs). These were intersected with ASD pathogenic genes (APGs) and ASD pathogenic proteins (APPs) to identify differentially expressed APGs (DE-APGs) and differentially expressed APPs (DE-APPs), which were validated by real-time reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and western blotting. Analyses of enrichment of signaling pathways were done using the Kyoto Encyclopedia of Genes and Genomes database., Results: RA treatment significantly improved social behaviors and revealed distinct patterns of hypo- and hyper-connectivity across various brain regions, with notable changes involving the hypothalamus and facial nerve. Differential analysis revealed 4165 DEGs (DEG 1) and 329 DEPs (DEP 1) between control and VPA groups, and 1610 DEGs (DEG 2) and 197 DEPs (DEP 2) between VPA and RA supplementation (RAS) groups. Twenty-two DE-APGs and five DE-APPs were identified, with key associations found between proteins such as Tbl1xr1 and Myo5a and >13 genes including Nrxn1, Cacna1e, and Gabrb2. Significant alterations in DE-APGs, including Grin2b, Nrxn1, Cacna1e, and Gabrb2, were confirmed via real-time RT-PCR and western blotting. In addition, 22 key signaling pathways were enriched in DEPs and DEGs., Conclusion: RA supplementation in ASD rats induced by VPA may ameliorate social deficits and modulated functional connectivity, especially in the hypothalamus and facial nerve regions. This suggests potential therapeutic benefits for neural circuitry dysregulation in ASD. Additionally, RA altered critical gene and protein expressions in hypothalamus, implicating its role in modulating key signaling pathways to mitigate social deficits in ASD. This study provides new insights into the molecular mechanisms of ASD and supports the development of novel therapeutic strategies., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

There is an increasing body of evidence suggesting that a single exposure to certain chemicals can have transgenerational effects, with the underlying mechanism believed to be epigenetic. However, it remains largely unknown whether psychiatric conditions like ADHD or autism, induced by environmental chemicals, can be inherited across generations. Pregnant rats were purchased from a commercial breeder. On the 7th day of gestation (E7), they were divided into two groups: one group was orally exposed to silver nanoparticles (AgNP; 4 mg/kg), while the control group received vehicle alone. The subsequent generation (F1) underwent spontaneous motor activity (SMA) measurements at 8-11 weeks of age. For breeding at 26 weeks of age, rats with higher SMA were selected from hyperactive litters, while untreated rats were randomly selected. This process was continued for four generations in both groups. The AgNP-primed rats at 4th generation displayed significantly higher SMA, 1.8 times greater than that of untreated rats. Intraperitoneal injection of valproic acid (150 mg/kg), an epigenetic modifier to 5-day-old rats causes adult hyperactivity (1.4-fold), suggesting that epigenetic modification contributes to rat hyperactivity. Global DNA methylation profiles in the mesencephalon were positively correlated in both groups of hyperactive rats. Furthermore, there were 7-8 common genes showing both hypermethylation and hypomethylation, which are involved in neuronal development, neuronal function, transcriptional activity, DNA binding activity, cell differentiation, ubiquitination processes, or histone modification, including Pax 6 and Mecp 2. Thus, it is most likely that rats retain hyperactivity through mesencephalic DNA methylation status across transgeneration., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Genetic testing for autism has been a controversial topic within the autistic community. Opinions regarding the benefits, risks, and limitations of genetic testing often differ between autistic people, researchers, and healthcare providers. The present study sought to understand the beliefs, attitudes, and intentions to pursue genetic testing of autistic adults and compare perspectives of autistic people who have had genetic testing with those who have not. An international sample of 173 autistic adults (19 [11%] who had previously undergone autism-related genetic testing) completed an online survey with questions assessing beliefs, attitudes, and intentions to pursue genetic testing. Beliefs and attitudes about genetic testing varied widely across the sample. Autistic individuals who had received prior genetic testing had much more positive beliefs about autism-related genetic testing (d = 0.87, 95% CI [0.37, 1.36]) and attitudes toward genetic testing (d = 1.14, 95% CI [0.66, 1.61]) compared to those who had not received such testing, although there were no meaningful differences between those same groups regarding beliefs about genetic testing unrelated to autism (d = 0.02, 95% CI [-0.45, 0.49], p = 0.93). Intention to genetically test oneself or one's (hypothetical) children was also significantly predicted by autism-specific beliefs, attitudes, and prior genetic testing status. A large majority of the sample (78.6%) also agreed that autistic individuals would benefit from contact with a genetic counselor in certain situations. These findings suggest that the autistic community does not have a singular view of genetic testing, and for those Autistic individuals who are interested in pursuing genetic testing for themselves or a family member, genetic counselors have the potential to play a key role in clinical care., (© 2024 The Authors. Journal of Genetic Counseling published by Wiley Periodicals LLC on behalf of National Society of Genetic Counselors.)

The present study investigated metaplasticity-related mRNA expressions in valproic acid (VPA)-rats, focusing on the PI3K/AKT pathway. Wistar dams were treated with a single intraperitoneal injection of 600 mg/kg VPA or saline on embryonic day E12.5 or an equal volume of saline solution. Three behavioral tests were conducted on these males' offspring: grid-walking test, negative geotaxis test, and three-chamber social interaction test. Metaplasticity was induced in 60-day-old male progeny by giving high-frequency stimulation for 5 minutes following low-frequency stimulation to the perforant pathway. For the baseline stimulation protocol (n = 6), stimulation was delivered to the dentate gyrus at the previously determined stimulation intensity (0.33 Hz 0.175 msec 30 s) for 75 min. The percent change of slope of field excitatory postsynaptic potential (fEPSP) and amplitude of population spike were calculated 55-60 min after induction protocol. The mRNA levels of PI3K, PTEN, AKT, GSK-3β, and MAPT were measured in the hippocampus by using quantitative rt-PCR. We found that offspring of VPA-treated rats showed significantly impaired sensorimotor coordination, decreased sociability, impaired preference for social novelty, and reduced input-output curve of fEPSP slope, compared to control animals. Despite a similar metaplastic response, mRNA levels of genes of interest were similar but considerably down-regulated after induction in offspring of VPA-treated dams. Our study provides evidence that the induced expression of autism-related genes has evolved to enable an adaptation mechanism during metaplastic control of long-term potentiation., (© 2024 International Society for Developmental Neuroscience.)

Background: The genetic and environmental aetiology of autistic and Attention Deficit Hyperactivity Disorder (ADHD) traits is known to vary spatially, but does this translate into variation in the association of specific common genetic variants?, Methods: We mapped associations between polygenic scores for autism and ADHD and their respective traits in the Avon Longitudinal Study of Parents and Children (N = 4,255-6,165) across the area surrounding Bristol, UK, and compared them to maps of environments associated with the prevalence of autism and ADHD., Results: Our results suggest genetic associations vary spatially, with consistent patterns for autistic traits across polygenic scores constructed at different p-value thresholds. Patterns for ADHD traits were more variable across thresholds. We found that the spatial distributions often correlated with known environmental influences., Conclusions: These findings shed light on the factors that contribute to the complex interplay between the environment and genetic influences in autistic and ADHD traits., (© 2024 The Author(s). Journal of Child Psychology and Psychiatry published by John Wiley & Sons Ltd on behalf of Association for Child and Adolescent Mental Health.)

Mitochondrial dysfunction is thought to be a key component of neurodevelopmental disorders such as autism, intellectual disability, and attention-deficit hyperactivity disorder (ADHD). However, little is known about the molecular mechanisms that protect against mitochondrial dysfunction during neurodevelopment. Here, we address this question through the investigation of rbm-26, the Caenorhabditis elegans ortholog of the RBM27 autism candidate gene, which encodes an RNA-binding protein whose role in neurons is unknown. We report that RBM-26 (RBM26/27) protects against axonal defects by negatively regulating expression of the MALS-1 (MALSU1) mitoribosomal assembly factor. Autism-associated missense variants in RBM-26 cause a sharp decrease in RBM-26 protein expression along with defects in axon overlap and axon degeneration that occurs during larval development. Using a biochemical screen, we identified the mRNA for the MALS-1 mitoribosomal assembly factor as a binding partner for RBM-26. Loss of RBM-26 function causes a dramatic overexpression of mals-1 mRNA and MALS-1 protein. Moreover, genetic analysis indicates that this overexpression of MALS-1 is responsible for the mitochondrial and axon degeneration defects in rbm-26 mutants. These observations reveal a mechanism that regulates expression of a mitoribosomal assembly factor to protect against axon degeneration during neurodevelopment., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Chowdhury et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)