Etiology Of Autism Spectrum Disorder Research Articles

Calcium Hexacyanoferrate (III) Nanocatalyst Enables Redox Homeostasis for Autism Spectrum Disorder Treatment.

Autism spectrum disorder (ASD) is a multifaced neurodevelopmental disorder with considerable heterogeneity, in which over-generated reactive oxygen species (ROS) induce a cascade of pathological changes, including cellular apoptosis and inflammatory responses. Given the complex etiology of ASD, no effective treatment is available for ASD. In this work, a specific catalytic nanoenzyme, calcium hexacyanoferrate (III) nanocatalysts (CaH NCs), is designed and engineered for efficient ASD treatment. CaH NCs can mimic the activities of natural enzymes including superoxide dismutase, peroxidase, catalase, and glutathione peroxidase, which mitigates intracellular excessive ROS and regulates redox equilibrium. These CaH NCs modulate mitochondrial membrane potential, elevate B-cell lymphoma-2 levels, and suppress pro-apoptotic proteins, including Caspase-3 and B-cell lymphoma-2-associated X, thus effectively reducing cellular apoptosis. Importantly, CaH NCs alleviate inflammation by upregulating anti-inflammatory cytokine interleukin-10 and downregulating pro-inflammatory factors, resulting in attenuated activation of microglial and astrocytic and subsequent reduction in neuroinflammation. Subsequently, CaH NCs enhance social abilities, decrease anxiety levels, ameliorate repetitive behaviors, and improve learning and memory in ASD animal models through inflammation regulation and apoptosis inhibition. The CaH NCs in managing and preventing ASD represents a paradigm shift in autism treatment, paving the alternative but efficient way for clinical interventions in neurological conditions.

Gut Microbiota and Autism Spectrum Disorder: A Neuroinflammatory Mediated Mechanism of Pathogenesis?

Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by impairments in social communication and behavior, frequently accompanied by restricted and repetitive patterns of interests or activities. The gut microbiota has been implicated in the etiology of ASD due to its impact on the bidirectional communication pathway known as the gut-brain axis. However, the precise involvement of the gut microbiota in the causation of ASD is unclear. This study critically examines recent evidence to rationalize a probable mechanism in which gut microbiota symbiosis can induce neuroinflammation through intermediator cytokines and metabolites. To develop ASD, loss of the integrity of the intestinal barrier, activation of microglia, and dysregulation of neurotransmitters are caused by neural inflammatory factors. It has emphasized the potential role of neuroinflammatory intermediates linked to gut microbiota alterations in individuals with ASD. Specifically, cytokines like brain-derived neurotrophic factor, calprotectin, eotaxin, and some metabolites and microRNAs have been considered etiological biomarkers. We have also overviewed how probiotic trials may be used as a therapeutic strategy in ASD to reestablish a healthy balance in the gut microbiota. Evidence indicates neuroinflammation induced by dysregulated gut microbiota in ASD, yet there is little clarity based on analysis of the circulating immune profile. It deems the repair of microbiota load would lower inflammatory chaos in the GI tract, correct neuroinflammatory mediators, and modulate the neurotransmitters to attenuate autism. The interaction between the gut and the brain, along with alterations in microbiota and neuroinflammatory biomarkers, serves as a foundational background for understanding the etiology, diagnosis, prognosis, and treatment of autism spectrum disorder.

Evaluating the Role of Susceptibility Inducing Cofactors and of Acetaminophen in the Etiology of Autism Spectrum Disorder

More than 20 previously reported lines of independent evidence from clinical observations, studies in laboratory animal models, pharmacokinetic considerations, and numerous temporal and spatial associations indicate that numerous genetic and environmental factors leading to inflammation and oxidative stress confer vulnerability to the aberrant metabolism of acetaminophen during early development, leading to autism spectrum disorder (ASD). Contrary to this conclusion, multivariate analyses of cohort data adjusting for inflammation-associated factors have tended to show little to no risk of acetaminophen use for neurodevelopment. To resolve this discrepancy, here we use in silico methods to create an ideal (virtual) population of 120,000 individuals in which 50% of all cases of virtual ASD are induced by oxidative stress-associated cofactors and acetaminophen use. We demonstrate that Cox regression analysis of this ideal dataset shows little to no risk of acetaminophen use if the cofactors that create aberrant metabolism of acetaminophen are adjusted for in the analysis. Further, under-reporting of acetaminophen use is shown to be a considerable problem for this analysis, leading to large and erroneously low calculated risks of acetaminophen use. In addition, we argue that factors that impart susceptibility to acetaminophen-induced injury, and propensity for acetaminophen use itself, can be shared between the prepartum, peripartum, and postpartum periods, creating additional difficulty in the analysis of existing datasets to determine risks of acetaminophen exposure for neurodevelopment during a specific time frame. It is concluded that risks of acetaminophen use for neurodevelopment obtained from multivariate analysis of cohort data depend on underlying assumptions in the analyses, and that other evidence, both abundant and robust, demonstrate the critical role of acetaminophen in the etiology of ASD.

Metabolomic Profiles in Jamaican Children With and Without Autism Spectrum Disorder.

Autism spectrum disorder (ASD) is a complex neurodevelopmental condition with a wide range of behavioral and cognitive impairments. While genetic and environmental factors are known to contribute to its etiology, metabolic perturbations associated with ASD, which can potentially connect genetic and environmental factors, remain poorly understood. Therefore, we conducted a metabolomic case-control study and performed a comprehensive analysis to identify significant alterations in metabolite profiles between children with ASD and typically developing (TD) controls in order to identify specific metabolites that may serve as biomarkers for the disorder. We conducted metabolomic profiling on plasma samples from participants in the second phase of Epidemiological Research on Autism in Jamaica, an age and sex-matched cohort of 200 children with ASD and 200 TD controls (2-8years old). Using high-throughput liquid chromatography-mass spectrometry techniques, we performed a targeted metabolite analysis, encompassing amino acids, lipids, carbohydrates, and other key metabolic compounds. After quality control and missing data imputation, we performed univariable and multivariable analysis using normalized metabolites while adjusting for covariates, age, sex, socioeconomic status, and child's parish of birth. Our findings revealed unique metabolic patterns in children with ASD for four metabolites compared to TD controls. Notably, three metabolites were fatty acids, including myristoleic acid, eicosatetraenoic acid, and octadecenoic acid. The amino acid sarcosine exhibited a significant association with ASD. These findings highlight the role of metabolites in the etiology of ASD and suggest opportunities for the development of targeted interventions.

Unravelling the Cerebellar Involvement in Autism Spectrum Disorders: Insights into Genetic Mechanisms and Developmental Pathways.

Autism spectrum disorders (ASDs) are complex neurodevelopmental conditions characterized by deficits in social interaction and communication, as well as repetitive behaviors. Although the etiology of ASD is multifactorial, with both genetic and environmental factors contributing to its development, a strong genetic basis is widely recognized. Recent research has identified numerous genetic mutations and genomic rearrangements associated with ASD-characterizing genes involved in brain development. Alterations in developmental programs are particularly harmful during critical periods of brain development. Notably, studies have indicated that genetic disruptions occurring during the second trimester of pregnancy affect cortical development, while disturbances in the perinatal and early postnatal period affect cerebellar development. The developmental defects must be viewed in the context of the role of the cerebellum in cognitive processes, which is now well established. The present review emphasizes the genetic complexity and neuropathological mechanisms underlying ASD and aims to provide insights into the cerebellar involvement in the disorder, focusing on recent advances in the molecular landscape governing its development in humans. Furthermore, we highlight when and in which cerebellar neurons the ASD-associated genes may play a role in the development of cortico-cerebellar circuits. Finally, we discuss improvements in protocols for generating cerebellar organoids to recapitulate the long period of development and maturation of this organ. These models, if generated from patient-induced pluripotent stem cells (iPSC), could provide a valuable approach to elucidate the contribution of defective genes to ASD pathology and inform diagnostic and therapeutic strategies.

Assessment of 8-Hydroxy-2’-Deoxyguanosine (8-OH-dG) Level in Urine as a Urinary Marker of Oxidative Stress in Children with Autism Spectrum Disorder

Abstract Background Autism spectrum disorder (ASD) is a developmental disorder characterized by deficits in social interaction, restricted interest and repetitive behavior. Oxidative stress in response to environmental exposure plays a role in virtually every human disease and represents a significant avenue of research into the etiology of ASD. Objective The aim of this study was to asses 8-hydroxy-2’-deoxyguanosine (8-OH-dG) level in urine as a urinary marker of oxidative stress in children with autism spectrum disorder in comparison to sex and age matched healthy control group. Patients and Methods We included 51 children with autism (43 males and 8 females whose age ranged from 2 to 16 years). They were compared to 51 children of the same age as a control group. The diagnosis of autism was made based on the criteria of autistic disorders as defined in the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSMV). In the patients group, detailed medical history included sociodemographic form and family history was taken for autistic group also Intelligence Quotient test IQ test and Childhood Autism Rating Scale (CARS) used to measure the severity of autism. In the study, 8-OHdG values in urine were investigated using the enzyme-linked immunosorbent assay (ELISA) method and Urinary creatinine was determined with the Beckham Coulter analyzer and was used to normalize all biochemical measurements then the urinary 8-OHdG/creatinine levels were corrected to the urinary concentration of creatinine. Results The median age was 9.9 in the ASD group and 9.1 in the control group (P = 0.256). In the ASD group, (8-OH-dG)/creatinine ratio values were found to be significantly higher than those of the controls (P < 0.001). but also No statistically significant correlation between (8-OH- dG)/creatinie ratio and CARS score or IQ score (P = 0,7). Conclusion The data from this study supported the hypothesis of the oxidant/antioxidant balance as a key piece that may contribute to the autistic pathology

Genetic causal relationship between placental weight and autism spectrum disorder: A two-sample Mendelian randomization study

ObjectPrevious research has suggested an association between placental tissue abnormalities and the diagnosis of autism spectrum disorder. This study aims to explore the causal relationship between placental weight and autism spectrum disorder. MethodsThis study employed Mendelian randomization analysis to investigate the potential causal relationship between placental weight and autism spectrum disorder. The study design involved two sample populations, with data for the exposed population sourced from previous studies focusing on PW, and data for the outcome population obtained from the Integrative Psychiatric Research and the Psychiatric Genomics Consortium study. To ensure the robustness of the results, three sensitivity analyses were performed, including heterogeneity testing, pleiotropy testing, and a leave-one-out analysis. The inverse variance weighted method served as the gold standard for the Mendelian randomization analysis. ResultsThe results of the first analysis revealed a significant correlation between an increase in placental weight and an elevated risk of autism spectrum disorder (p = 0.02). Sensitivity analysis detected heterogeneity and outliers. After removing two outlier SNPs in the second round of analysis, the results still supported a genetic causal relationship between placental weight and autism spectrum disorder (p = 0.01). The second-round sensitivity analysis did not reveal any heterogeneity or outliers. ConclusionOur study provides compelling evidence supporting a causal relationship between elevated placental weight and increased risk of autism spectrum disorder. These findings underscore the significance of placental development in the etiology of autism spectrum disorder and propose a potential early predictive indicator for autism spectrum disorder.

Rare variation in non-coding regions with evolutionary signatures contributes to autism spectrum disorder risk.

Little is known about the role of non-coding regions in the etiology of autism spectrum disorder (ASD). We examined three classes of non-coding regions: human accelerated regions (HARs), which show signatures of positive selection in humans; experimentally validated neural VISTA enhancers (VEs); and conserved regions predicted to act as neural enhancers (CNEs). Targeted and whole-genome analysis of >16,600 samples and >4,900 ASD probands revealed that likely recessive, rare, inherited variants in HARs, VEs, and CNEs substantially contribute to ASD risk in probands whose parents share ancestry, which enriches for recessive contributions, but modestly contribute, if at all, in simplex family structures. We identified multiple patient variants in HARs near IL1RAPL1 and in VEs near OTX1 and SIM1 and showed that they change enhancer activity. Our results implicate both human-evolved and evolutionarily conserved non-coding regions in ASD risk and suggest potential mechanisms of how regulatory changes can modulate social behavior.

Autism Spectrum Disorders: Etiology, Epidemiology, and Challenges for Public Health.

Autism spectrum disorder (ASD) is a growing public health problem. American psychiatrist Leo Kanner is considered the "father of autism." ASD encompasses a range of neurodevelopmental disorders that last throughout life. Symptoms of ASD include impairments in social skills, including specific repetitive behaviors, as well as abnormal sensory responses. The clinical symptoms of ASD vary among patients. Their severity also differs, both in the area of social communication and cognitive functioning. The etiology of ASD is still unclear, although a role is attributed to both genetic and environmental factors. According to the World Health Organization, 1/100 children have ASD, but these estimates vary depending on the methodology used. Nevertheless, early detection of ASD and initiation of appropriate therapy may be essential in the continued functioning of patients and their families. The purpose of this article is to provide an overview of current knowledge about autism spectrum disorders. We discuss factors associated with autism and the prevalence of ASD in various parts of the world, and identify the most common diseases comorbid with ASD, pointing to limitations in the quality of life of patients with ASD and their families.

Prenatal & Perinatal Risk Factors of Autism Spectrum Disorder

Background: Autism spectrum disorder (ASD) is lifelong neurodevelopmental disorder characterized by impairments in social function, communication, and certain behaviors. The etiology of ASD is unclear & it is believed to be multi-factorial, among those several prenatal & perinatal factors are found to be significant. So, the necessity of this study is to detect the presence of known risk factors of ASD which in turn may help in the early diagnosis and intervention for better long-term outcomes. Objective: To find out prenatal and perinatal risk factors of ASD. Method: A case control study was conducted with 112 cases of ASD and 201 controls of 2-6 years of age. The study was carried out in Center for Neurodevelopment and Autism in Children (CNAC), in the department of Paediatrics, Bangabandhu Sheikh Mujib Medical University and Autism Welfare Foundation (AWF). ASD was diagnosed by DSM-IV TR criteria. Mothers were interviewed and data were collected by semistructured questionnaires. Results: Total 5 risk factors were identified as the risk factors of ASD. They were: advanced paternal age (OR=2.84) and maternal age (OR=1.87); male baby (OR=2.01); environmental stress during pregnancy (OR=1.61) and preterm delivery (OR=1.80). Conclusions: It is concluded that advanced paternal age, maternal age, male baby, environmental stress during pregnancy and preterm delivery are associated with increased risk of ASD. BANGLADESH J CHILD HEALTH 2022; VOL 46 (3) : 115-121

Microglial Dysfunction in Autism Spectrum Disorder.

Autism spectrum disorder (ASD) is a highly heterogeneous neurodevelopmental disorder with onset in childhood. The molecular mechanisms underlying ASD have not yet been elucidated completely. Evidence has emerged to support a link between microglial dysfunction and the etiology of ASD. This review summarizes current research on microglial dysfunction in neuroinflammation and synaptic pruning, which are associated with altered transcriptomes and autophagy in ASD. Dysbiosis of gut microbiota in ASD and its correlation with microglial dysfunction are also addressed.

Management of Autism Spectrum Disorder Through Ayurvedic Intervention and Diet Modifications

Autism spectrum disorder includes a group of neurodevelopmental disorders, which disrupts normal functioning of the brain and impairs communication, social interaction, emotional balance with the presence of repetitive stereotypic mannerisms. Underlying etiology of autism spectrum disorder is still unknown. Studies on genetic causes, immune system dysregulation, inflammation, exposure to environmental toxicants, defective gut microbiome are still continuing. In ayurveda, most psycho social abnormalities are included in the category of Unmada. Along with other etiological factors, impaired digestive and metabolic functions are postulated as the root cause of Unmada. And in accord with the gut brain axis, systemic accumulation of metabolic wastes also disrupts the functional integrity of the brain. The present study describes the case of a child with ASD with hyperactivity, who has been clinically diagnosed and treated with Ayurvedic medications, Sneha sweda therapies and diet modifications, which helps in maintaining the healthy functioning of the brain. Within 3 months of intervention, the child became symptomatically better. Case study briefs Ayurvedic concepts and Ayurvedic treatment protocols regarding ASD.

Environmental Risk Factors in Autism Spectrum Disorder: A Narrative Review.

Existing evidence indicates that environmental factors might contribute up to 50% of the variance in autism spectrum disorder (ASD) risk. This structured narrative review offers a comprehensive synthesis of current knowledge on environmental risk factors in ASD, including evaluation of conflicting evidence, exploration of underlying mechanisms, and suggestions for future research directions. Analysis of diverse epidemiological investigations indicates that certain environmental factors, including advanced parental age, preterm birth, delivery complications, and exposure to toxic metals, drugs, air pollutants, and endocrine-disrupting chemicals, are linked to an increased ASD risk through various mechanisms such as oxidative stress, inflammation, hypoxia, and its consequences, changes in neurotransmitters, disruption of signaling pathways and some others. On the other hand, pregnancy-related factors such as maternal diabetes, maternal obesity, and caesarian section show a weaker association with ASD risk. At the same time, other environmental factors, such as vaccination, maternal smoking, or alcohol consumption, are not linked to the risk of ASD. Regarding nutritional elements data are inconclusive. These findings highlight the significance of environmental factors in ASD etiology and emphasize that more focused research is needed to target the risk factors of ASD. Environmental interventions targeting modifiable risk factors might offer promising avenues for ASD prevention and treatment.

Study of the genetic association between selected 3q29 region genes and schizophrenia and autism spectrum disorder in the Japanese population.

Psychiatric disorders are highly inheritable, and most psychiatric disorders exhibit genetic overlap. Recent studies associated the 3q29 recurrent deletion with schizophrenia (SCZ) and autism spectrum disorder (ASD). In this study, we investigated the association of genes in the 3q29 region with SCZ and ASD. TM4SF19 and PAK2 were chosen as candidate genes for this study based on evidence from previous research. We sequenced TM4SF19 and PAK2 in 437 SCZ cases, 187 ASD cases and 524 controls in the Japanese population. Through targeted sequencing, we identified 6 missense variants among the cases (ASD & SCZ), 3 missense variants among controls, and 1 variant common to both cases and controls; however, no loss-of-function variants were identified. Fisher's exact test showed a significant association of variants in TM4SF19 among cases (p=0.0160). These results suggest TM4SF19 variants affect the etiology of SCZ and ASD in the Japanese population. Further research examining 3q29 region genes and their association with SCZ and ASD is thus needed.

Classification of Autism Spectrum Disorder using Resting State-Functional Magnetic Resonance Imaging and Artificial Neural Network

Autism Spectrum Disorder (ASD) represents a growing challenge in public health, characterized by irreversible neurodevelopmental abnormalities. Despite a rising prevalence, the underlying aetiology and neural substrates of ASD remain incompletely understood. Resting state-functional Magnetic Resonance Imaging (rs-fMRI) has emerged as a valuable non-invasive tool for probing the organization and cognitive functions of the brain by capturing hemodynamic changes. This study explores the relationship between Functional Connectivity (FC) alterations, measured by rs-fMRI, and the manifestation of ASD-related brain disorders. In this paper, we propose a hybrid approach employing an InfoMax Independent Component Analysis (ICA) algorithm and Artificial Neural Network to distinguish between the ASD subjects and Healthy Controls (HCs). Initially, rs-fMRI datasets are preprocessed using Statistical Parametric Mapping (SPM). Further, these datasets are processed using InfoMax ICA to extract the distinct features such as fractional Amplitude of Low-Frequency Fluctuations (fALFF) and Dynamic Range and visualize the FC alterations by region mapping. In addition to this, the number of activated voxels for each brain regions are estimated to observe the neural abnormalities. Finally, the extracted features are fed as input to train, test and validate the ANN classifier. The efficacy of the proposed network is evaluated using the Autism Brain Imaging Data Exchange (ABIDE) dataset and an accuracy of 75.3 percentage is achieved.

Effect of Enriched Environment on Cerebellum and Social Behavior of Valproic Zebrafish

The etiology of autism spectrum disorder (ASD) has been linked to both genetic and epigenetic factors. Among the epigenetic factors, exposure to valproic acid (VPA), an antiepileptic and mood-modulating drug, has been shown to induce characteristic traits of ASD when exposed to during embryogenesis. Conversely, in animal models, enriched environment (EE) has demonstrated positive behavioral and neural effects, suggesting its potential as a complementary treatment to pharmacological approaches in central nervous system disorders. In this study, we utilized zebrafish to model ASD characteristics induced by VPA and hypothesized that sensory stimulation through EE could ameliorate the behavioral and neuroanatomical features associated with ASD. To test this hypothesis, we assessed social behavior, cerebellar volume, and Purkinje cell populations via histology and immunohistochemistry after exposing the fish to EE. The results revealed that zebrafish exposed to VPA exhibited social deficits, reduced cerebellar cortex volume, and a decrease in c-Fos-positive cells in the Purkinje layer. In contrast, VPA-exposed fish treated with EE showed increased socialization, augmented cerebellar cortex volume, and an elevation in c-Fos-positive Purkinje cells. These findings suggest that alterations induced by VPA may be ameliorated through EE treatment, highlighting the potential therapeutic impact of sensory stimulation in conditions related to ASD.

Conduction velocity, G-ratio, and extracellular water as microstructural characteristics of autism spectrum disorder.

The neuronal differences contributing to the etiology of autism spectrum disorder (ASD) are still not well defined. Previous studies have suggested that myelin and axons are disrupted during development in ASD. By combining structural and diffusion MRI techniques, myelin and axons can be assessed using extracellular water, aggregate g-ratio, and a new approach to calculating axonal conduction velocity termed aggregate conduction velocity, which is related to the capacity of the axon to carry information. In this study, several innovative cellular microstructural methods, as measured from magnetic resonance imaging (MRI), are combined to characterize differences between ASD and typically developing adolescent participants in a large cohort. We first examine the relationship between each metric, including microstructural measurements of axonal and intracellular diffusion and the T1w/T2w ratio. We then demonstrate the sensitivity of these metrics by characterizing differences between ASD and neurotypical participants, finding widespread increases in extracellular water in the cortex and decreases in aggregate g-ratio and aggregate conduction velocity throughout the cortex, subcortex, and white matter skeleton. We finally provide evidence that these microstructural differences are associated with higher scores on the Social Communication Questionnaire (SCQ) a commonly used diagnostic tool to assess ASD. This study is the first to reveal that ASD involves MRI-measurable in vivo differences of myelin and axonal development with implications for neuronal and behavioral function. We also introduce a novel formulation for calculating aggregate conduction velocity, that is highly sensitive to these changes. We conclude that ASD may be characterized by otherwise intact structural connectivity but that functional connectivity may be attenuated by network properties affecting neural transmission speed. This effect may explain the putative reliance on local connectivity in contrast to more distal connectivity observed in ASD.

Roles of Epigenetics and Glial Cells in Drug-Induced Autism Spectrum Disorder.

Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by severe deficits in social communication and interaction, repetitive movements, abnormal focusing on objects, or activity that can significantly affect the quality of life of the afflicted. Neuronal and glial cells have been implicated. It has a genetic component but can also be triggered by environmental factors or drugs. For example, prenatal exposure to valproic acid or acetaminophen, or ingestion of propionic acid, can increase the risk of ASD. Recently, epigenetic influences on ASD have come to the forefront of investigations on the etiology, prevention, and treatment of this disorder. Epigenetics refers to DNA modifications that alter gene expression without making any changes to the DNA sequence. Although an increasing number of pharmaceuticals and environmental chemicals are being implicated in the etiology of ASD, here, we specifically focus on the molecular influences of the abovementioned chemicals on epigenetic alterations in neuronal and glial cells and their potential connection to ASD. We conclude that a better understanding of these phenomena can lead to more effective interventions in ASD.

Innate Immune Dysfunction and Neuroinflammation in Autism Spectrum Disorder (ASD).

Autism spectrum disorder (ASD) is a highly heterogeneous neurodevelopmental disorder characterized by communication and social behavior deficits. The presence of restricted and repetitive behaviors often accompanies these deficits, and these characteristics can range from mild to severe. The past several decades have seen a significant rise in the prevalence of ASD. The etiology of ASD remains unknown; however, genetic and environmental risk factors play a role. Multiple hypotheses converge to suggest that neuroinflammation, or at least the interaction between immune and neural systems, may be involved in the etiology of some ASD cases or groups. Repeated evidence of innate immune dysfunction has been seen in ASD, often associated with worsening behaviors. This evidence includes data from circulating myeloid cells and brain resident macrophages/microglia in both human and animal models. This comprehensive review presents recent findings of innate immune dysfunction in ASD, including aberrant innate cellular function, evidence of neuroinflammation, and microglia activation. Appeared originally in Brain Behav Immun 2023; 108:245-254.

The genetic landscape of autism spectrum disorder in the Middle Eastern population.

Introduction: Autism spectrum disorder (ASD) is characterized by aberrations in social interaction and communication associated with repetitive behaviors and interests, with strong clinical heterogeneity. Genetic factors play an important role in ASD, but about 75% of ASD cases have an undetermined genetic risk. Methods: We extensively investigated an ASD cohort made of 102 families from the Middle Eastern population of Qatar. First, we investigated the copy number variations (CNV) contribution using genome-wide SNP arrays. Next, we employed Next Generation Sequencing (NGS) to identify de novo or inherited variants contributing to the ASD etiology and its associated comorbid conditions in families with complete trios (affected child and the parents). Results: Our analysis revealed 16 CNV regions located in genomic regions implicated in ASD. The analysis of the 88 ASD cases identified 41 genes in 39 ASD subjects with de novo (n = 24) or inherited variants (n = 22). We identified three novel de novo variants in new candidate genes for ASD (DTX4, ARMC6, and B3GNT3). Also, we have identified 15 de novo variants in genes that were previously implicated in ASD or related neurodevelopmental disorders (PHF21A, WASF1, TCF20, DEAF1, MED13, CREBBP, KDM6B, SMURF1, ADNP, CACNA1G, MYT1L, KIF13B, GRIA2, CHM, and KCNK9). Additionally, we defined eight novel recessive variants (RYR2, DNAH3, TSPYL2, UPF3B KDM5C, LYST, and WNK3), four of which were X-linked. Conclusion: Despite the ASD multifactorial etiology that hinders ASD genetic risk discovery, the number of identified novel or known putative ASD genetic variants was appreciable. Nevertheless, this study represents the first comprehensive characterization of ASD genetic risk in Qatar's Middle Eastern population.