The Changing Epidemiology of Autism Spectrum Disorders

Increased risk of autism in extremely preterm children with a history of retinopathy of prematurity

AIM

To investigate the association between retinopathy of prematurity and autism spectrum disorder in extremely preterm children.

METHODS

Data in children born extremely preterm at <28 weeks' gestational age in the Region Västra Götaland, 2013-2017, were analysed for association between retinopathy of prematurity and neurodevelopmental disorders. We focussed on autism spectrum disorder and excluded children with perinatal brain injuries or genetic disorders.

RESULTS

Of 266 children with neurodevelopmental evaluation, 143 had no documented brain injury or genetic disorders. Of these 143, autism spectrum disorder was diagnosed in 18%, attention deficit hyperactivity disorder in 15% and intellectual disability in 7%. Of the 72/143 children with a history of no or mild retinopathy of prematurity (stage <1), 10% were diagnosed with autism spectrum disorder compared to 27% of 71/143 with prior moderate-to-severe retinopathy of prematurity (stages ≥2), (p = 0.008). A history of retinopathy of prematurity stages ≥2 was associated with a threefold increased likelihood of later autism spectrum disorder even when adjusting for gestational age and sex (p = 0.011).

CONCLUSION

Moderate-to-severe retinopathy of prematurity associated with a higher likelihood of later autism spectrum disorder diagnosis in extremely preterm children without documented brain injuries or genetic disorders.

Professionally and non-professionally applied household insecticides during pregnancy and early life and their associations with autism spectrum disorder and developmental delay in the CHARGE case-control study

BACKGROUND

Autism Spectrum Disorder (ASD) is an increasing concern globally, with risks attributed to both genetic and environmental factors, including pesticide exposures. The CHARGE case-control study collected data to examine the relationship between household insecticide use and ASD or developmental delay (DD).

METHODS

Participants (n = 1526) aged 2-5 years from the CHARGE study encompassed children with clinically confirmed ASD (n = 810), DD (n = 186), and typically developing controls (n = 530) frequency matched to ASD children by age, sex, and geographic region. Household insecticide use was determined from parent interviews, as were the timing, frequency, and type of applications (professionally or non-professionally applied; indoor, outdoor, and flea applications) from three months pre-conception to the child's second birthday. Logistic regression models were adjusted for confounders to estimate odds ratios (OR) for ASD or DD associated with insecticide exposure.

RESULTS

Professionally applied indoor insecticides were associated with greater than two-fold increased odds of ASD for all time periods (OR: pre-pregnancy, 2.62 (1.26, 5.44); pregnancy, 2.52 (1.41, 4.48); year 1, 2.20 (1.33, 3.64); year 2, 2.13 (1.29, 3.49)). Odds were also elevated for any outdoor application during years 1 and 2 (OR: 1.37 (1.05, 1.79) and 1.34 (1.03, 1.74), respectively), however, significance did not hold after false discovery rate correction. Higher exposure frequency was associated with greater odds of ASD for nearly all application types and time periods. Non-professional indoor insecticide use was associated with increased odds of DD in trimester 3 and the pregnancy period (OR: 1.72 (1.03, 2.89) and 1.58 (1.03, 2.40), respectively).

CONCLUSION

Professionally applied indoor insecticides were consistently associated with ASD. The strong trend of increased odds with more frequent exposures, additional evidence for DD, and widespread use of household insecticides support increased regulatory scrutiny and public health interventions to minimize exposure during critical developmental windows.

Associations of maternal and paternal preconception and maternal pregnancy urinary phthalate biomarker and bisphenol A concentrations with offspring autistic behaviors: The PEACE study

BACKGROUND

Environmental chemical exposures in utero may play a role in autism development. While preconception risk factors for autism are increasingly being investigated, little is known about the influence of chemical exposures during the preconception period, particularly for paternal exposures.

METHODS

In 195 children from the Preconception Environmental exposures And Childhood health Effects (PEACE) cohort born to parents recruited from a fertility clinic in Boston, Massachusetts between 2004 and 2017, we quantified concentrations of 11 phthalate metabolites and bisphenol A (BPA) in urine samples collected from mothers and fathers before conception and mothers throughout pregnancy. When children were 6-15 years old, parents completed the Social Responsiveness Scale (SRS) questionnaire assessing autistic behaviors. We used linear mixed effect models to estimate covariate-adjusted associations of phthalate biomarker and BPA concentrations, separately for maternal preconception (n = 179), paternal preconception (n = 121), and maternal pregnancy (n = 177), with SRS T-scores, based on age and gender, in offspring. We used quantile g-computation models for mixture analyses and evaluated modification by selected dietary factors.

RESULTS

The mean SRS T-score was 47.7 (±7.4), lower than the normative mean of 50. In adjusted models for individual biomarkers or mixtures, few associations were observed and estimates were generally negative (e.g., lower SRS T-scores) and imprecise. We observed associations of higher mono-isobutyl phthalate (MiBP) concentrations measured in maternal preconception and paternal preconception periods with lower SRS T-scores (βmaternal_precon = -1.6, 95% CI -2.7; -0.4; βpaternal_precon = -2.9, 95% CI -4.6; -1.2) for each loge increase. In a subset of participants with maternal preconception nutrition information, we generally observed stronger inverse associations with higher folate and iron intake, particularly for folate intake and MiBP concentrations.

CONCLUSIONS

Urinary phthalate biomarker and BPA concentrations during preconception (maternal and paternal) and pregnancy (maternal) were not associated with adverse autistic behaviors in these children. Larger studies are needed to elucidate the observed associations, while considering interactions between maternal nutrition and chemical exposures.

Associations of maternal peripregnancy cannabis use with behavioral and developmental outcomes in children with and without symptoms of autism spectrum disorder: Study to Explore Early Development

Some studies report increased prevalence of autism spectrum disorder (ASD) and associated symptoms with prenatal cannabis exposure. We examined whether associations of maternal cannabis use from 3 months preconception through delivery ("peripregnancy") with behavior and development in the offspring varied with the presence of ASD symptoms. Children ages 30-68 months with ASD symptoms (i.e., met study criteria for ASD or had ASD symptoms on standardized assessments or community ASD diagnosis, N = 2734) and without ASD symptoms (other developmental delay/disorders or general population sample, N = 3454) were evaluated with the Child Behavior Checklist and Mullen Scales of Early Learning. We examined cannabis use during three time periods: peripregnancy, pregnancy, and only preconception. Peripregnancy cannabis exposure was reported for 6.0% of children with and 4.6% of children without ASD symptoms. Preconception-only cannabis use (versus no use) was associated with more aggressive behavior, emotional reactivity, and sleep problems in children with ASD symptoms, but not in children without ASD symptoms. Cannabis use during pregnancy was associated with increased attention and sleep problems in children with ASD symptoms; these associations did not differ significantly by ASD symptoms. Peripregnancy cannabis use was not associated with child developmental abilities regardless of ASD symptoms. In summary, associations of peripregnancy cannabis use with some behavioral outcomes differed in children with and without ASD symptoms. With rising cannabis use among pregnant women, future studies that examine a range of developmental risks associated with timing and patterns of cannabis use prior to conception as well as during pregnancy could inform clinical guidance.

Evaluation of thyroid function tests among children with neurological disorders

Background

Thyroid hormones (THs) are essential for brain development. Numerous studies have identified significant links between thyroid dysfunction and cognitive function. However, research on the significance and necessity of thyroid function tests in diagnosis of neurological disorders is limited and subject to controversy.

Methods

Our study employed a combination of meta-analysis and case-control design. For the meta-analysis, we conducted a systematic search of online databases for studies that compared thyroid function tests in children with neurological disorders to controls. In our case-control study, we recruited a total of 11836 children, comprising 7035 cases and 4801 healthy controls. Wilcoxon Rank Sum Test was used to determine characteristics of thyroid function between the cases and healthy controls. In order to exclude the false discovery rate (FDR), the Benjamini-Hochberg (BH) procedure is applied.

Results

A total of 12 relevant literature sources were included in the meta-analysis. Compared with controls, free thyroxine (FT4) levels were significantly decreased in neurological disorders in meta-analysis (MD = -0.29, 95% CI: -0.50 to -0.09), whereas thyroid-stimulating hormone (TSH) levels showed no significant difference (MD = -0.07, 95% CI: -0.36 to 0.21). In our case-control study, levels of free thyroxine (FT4), total triiodothyronine (TT3), total thyroxine (TT4), and anti-thyroglobulin antibodies (TG-Ab) were notably reduced among individuals with neurological disorders, compared with healthy controls (P<0.001, P<0.001, P=0.036, P=0.006). However, thyroid-stimulating hormone (TSH) levels did not show any statistically significant differences among the cases and controls.

Conclusions

Our research demonstrates that, in comparison to controls, children with neurological disorders exhibited a significant decrease in FT4 levels, while TSH levels remained unchanged. This finding provides a reference for potential serum marker of neurological disorders in children. Replication in future studies with the assessment of THs is needed to determine whether thyroid function should be included as a routine screening in these children.

Correlations of brain structure with the social behavior of 15q11-13 duplication mice, an animal model of autism

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.

Prevalence Trends and Treatment Patterns of Autism Spectrum Disorder Among Children and Adolescents in the United States from 2017 to 2020

BACKGROUND

Autism spectrum disorder (ASD) poses a significant challenge due to its diverse impact on individuals, emphasizing the need for personalized treatment plans. The financial burden of ASD-related healthcare is substantial, necessitating a comprehensive understanding of its prevalence and evolving trends.

METHODS

This study aims to analyze the prevalence and trends of ASD, treatment patterns, gender differences, and racial-ethnic disparities in the United States from 2017 to 2020, utilizing nationally representative data from the National Survey of Children's Health (NSCH). The NSCH, a leading annual national survey, provided rich data on child health. A total of 108,142 participants aged 3-17 years were included, with ASD prevalence assessed based on self-reported diagnoses.

RESULTS

Between 2017 and 2020, ASD prevalence in children aged 3-17 was 2.94% (95% confidence interval: 2.68-3.18). Significant disparities were observed: older age and male gender correlated with higher prevalence, while family income-to-poverty ratio and insurance coverage influenced prevalence. Racial/ethnic disparities existed, with Hispanics showing the highest prevalence. Treatment trends showed stability overall, but age influenced behavioral and medication interventions. The prevalence remained stable from 2017 to 2020, with variations in age groups and a significant increase among non-Hispanic Whites.

CONCLUSIONS

This study highlights a higher but stable overall ASD prevalence, with nuanced disparities among different demographic groups. Gender differences persist, emphasizing the need for tailored interventions. Racial-ethnic disparities call for targeted healthcare strategies. The stability in treatment trends underscores the persistent challenge of addressing core ASD symptoms.

Role of Maternal Immune Factors in Neuroimmunology of Brain Development

Inflammation during pregnancy may occur due to various factors. This condition, in which maternal immune system activation occurs, can affect fetal brain development and be related to neurodevelopmental diseases. MIA interacts with the fetus's brain development through maternal antibodies, cytokines, chemokines, and microglial cells. Antibodies are associated with the development of the nervous system by two mechanisms: direct binding to brain inflammatory factors and binding to brain antigens. Cytokines and chemokines have an active presence in inflammatory processes. Additionally, glial cells, defenders of the nervous system, play an essential role in synaptic modulation and neurogenesis. Maternal infections during pregnancy are the most critical factors related to MIA; however, several studies show the relation between these infections and neurodevelopmental diseases. Infection with specific viruses, such as Zika, cytomegalovirus, influenza A, and SARS-CoV-2, has revealed effects on neurodevelopment and the onset of diseases such as schizophrenia and autism. We review the relationship between maternal infections during pregnancy and their impact on neurodevelopmental processes.

Associations between autistic and comorbid somatic problems of gastrointestinal disorders, food allergy, pain, and fatigue in adults

LAY ABSTRACT

What is already known about the topic?Autistic children frequently often have accompanying physical health problems. However, this has been much less studied in autistic men and women during adulthood.What does this article add?This is one of the first studies to investigate the associations between autistic and somatic problems in adults from the general population. Using a continuous measure of autistic symptom scores and a categorical definition of autism (referred to below as probable autism) which considered symptom severity, childhood age of onset, and functional impairment, we found that autistic problems and irritable bowel syndrome, food allergy, pain, and fatigue were associated in adults. Sex differences were present for pain and fatigue, for which the associations with autistic symptom scores were somewhat stronger in females than males. Regarding age differences, the associations with fatigue and having food allergy were more pronounced in younger adults. Conversely, older individuals had a higher risk of developing irritable bowel syndrome or experiencing pain if they met the criteria for probable autism.Implications for practice, research, or policyThere is a need for providing routine programs of screening, assessment, and treatment of autism-related somatic problems and developing evidence-based interventions for autistic individuals. These could be tailored to the needs of specific autistic populations. For example, autistic females could be given extra attention about the potential presence of pain and fatigue, younger adults about the potential presence of food allergy and fatigue, and older adults concerning the potential presence of irritable bowel syndrome and pain.

Epigenetic Insights into Autism Spectrum Disorder: DNA Methylation Levels of NR3C1, ASCL1, and FOXO3 in Korean Autism Spectrum Disorder Sibling Pairs

Objective

Previous research on autism spectrum disorder (ASD) in Koreans has primarily focused on genetic diversity because of its high heritability. However, the emerging recognition of transgenerational epigenetic changes has recently shifted research attention towards epigenetic perspectives.

Methods

This study investigated the DNA methylation patterns of the promoter regions of candidate genes such as NR3C1, ASCL1, and FOXO3 in blood samples from ASD probands and their unaffected siblings. The analysis included 54 families (ASD proband group: 54; unaffected biological sibling group: 63). The diagnostic process involved screening the probands and their siblings for ASD based on the Diagnostic and Statistical Manual of Mental Disorders 5th edition. Intelligence, social ability, and medical history were thoroughly assessed using various scales and questionnaires. Genomic DNA from blood samples was analyzed using a methylation-sensitive quantitative polymerase chain reaction to examine the DNA methylation status of candidate genes.

Results

Methylation levels in candidate gene promoter regions differed significantly between the proband and sibling groups for all candidate genes. Correlation analysis between the proband and sibling groups revealed strong and significant correlations in NR3C1 and ASCL1 methylation. Additionally, in the analysis of the relationship between DNA and ASD phenotypes, FOXO3 methylation correlated with social quotient in probands, and ASCL1 methylation was associated with nonverbal communication, and daily living skills as measured by the Korean Vineland Adaptive Behavior Scale. Notably, ASCL1 methylation was significantly associated with parental age at pregnancy.

Conclusion

This study proposes DNA methylation of NR3C1, ASCL1, and FOXO3 in peripheral blood samples is a potential epigenetic biomarker of ASD.

Shared genetic architecture and causality between autism spectrum disorder and irritable bowel syndrome, multisite pain, and fatigue

Autism spectrum disorder (ASD) often co-occurs with functional somatic syndromes (FSS), such as irritable bowel syndrome (IBS), multisite pain, and fatigue. However, the underlying genetic mechanisms and causality have not been well studied. Using large-scale genome-wide association study (GWAS) data, we investigated the shared genetic architecture and causality between ASD and FSS. Specifically, we first estimated genetic correlations and then conducted a multi-trait analysis of GWAS (MTAG) to detect potential novel genetic variants for single traits. Afterwards, polygenic risk scores (PRS) of ASD were derived from GWAS and MTAG to examine the associations with phenotypes in the large Dutch Lifelines cohort. Finally, we performed Mendelian randomization (MR) to evaluate the causality. We observed positive genetic correlations between ASD and FSS (IBS: rg = 0.27, adjusted p = 2.04 × 10-7; multisite pain: rg = 0.13, adjusted p = 1.10 × 10-3; fatigue: rg = 0.33, adjusted p = 5.21 × 10-9). Leveraging these genetic correlations, we identified 3 novel genome-wide significant independent loci for ASD by conducting MTAG, mapped to NEDD4L, MFHAS1, and RP11-10A14.4. PRS of ASD derived from both GWAS and MTAG were associated with ASD and FSS in Lifelines, and MTAG-derived PRS showed a bigger effect size, larger explained variance, and smaller p-values. We did not observe significant causality using MR. Our study found genetic associations between ASD and FSS, specifically with IBS, multisite pain, and fatigue. These findings suggest that a shared genetic architecture may partly explain the co-occurrence between ASD and FSS. Further research is needed to investigate the causality between ASD and FSS due to current limited statistical power of the GWASs.

Association between prenatal air pollutant exposure and autism spectrum disorders in young children: A matched case-control study in Canada

The direction and magnitude of association between maternal exposure to ambient air pollutants across gestational windows and offspring risk of autism spectrum disorders (ASD) remains unclear. We sought to evaluate the time-varying effects of prenatal air pollutant exposure on ASD. We conducted a matched case-control study of singleton term children born in Ontario, Canada from 1-Apr-2012 to 31-Dec-2016. Provincial birth registry data were linked with applied behavioural analysis services and ambient air pollutant datasets to ascertain prenatal exposure to nitrogen dioxide (NO2), ground-level ozone (O3), fine particulate matter (PM2.5), and ASD diagnoses. Covariate balance between cases and controls was established using coarsened exact matching. Conditional logistic regression was used to assess the association between prenatal air pollutant exposure and ASD. Distributed lag non-linear models (DLNM) were used to examine the effects of single-pollutant exposure by prenatal week. Sensitivity analyses were conducted to assess the impact of exposure period on the observed findings. The final sample included 1589 ASD cases and 7563 controls. Compared to controls, cases were more likely to be born to mothers living in urban areas, delivered by Caesarean section, and assigned male sex at birth. NO2 was a consistent and significant contributor to ASD risk after accounting for co-exposure to O3, PM2.5 and covariates. The odds ratio per interquartile range increase was 2.1 (95%CI 1.8-2.3) pre-conception, 2.2 (2.0-2.5) for the 1st trimester, 2.2 (1.9-2.5) for the 2nd trimester, and 2.1 (1.9-2.4) for the 3rd trimester. In contrast, findings for O3 and PM2.5 with ASD were inconsistent. Findings from DLNM and sensitivity analyses were similar. Exposure to NO2 before and during pregnancy was significantly associated with ASD in offspring. The relationship between prenatal O3 and PM2.5 exposure and ASD remains unclear. Further investigation into the combined effects of multi-pollutant exposure on child neurodevelopment is warranted.

Assessment of Knowledge and Attitude of General Practitioners Regarding Autism and Associated Factors at Gondar University Hospital, Gondar, Ethiopia

Background: The neurodevelopmental conditions known as autism spectrum disorders (ASDs) start in early childhood and last the entirety of a person's life. They are characterized by distorted social interaction, difficulties communicating, and repetitive, stereotypical behavior. Objective: This study sought to evaluate general practitioners (GPs)' attitudes and knowledge of ASDs and related factors at Gondar University Hospital. Methods: An institutional-based cross-sectional study design was used. Using a convenience-sample method, three-hundred sixty individuals were chosen for this study. Data were collected using a self-administered questionnaire. The GPs who took part in this survey were characterized by descriptive statistics. The relationship between the dependent variables (knowledge and attitude) and the sociodemographic characteristics was examined using an independent two-sample t-test and Pearson correlation analysis. The Statistical Package for the Social Sciences Version 25 was used for all data analyses. Results: In this study, the GPs had an average age of 31.82 years, with an average of 18 years since graduation and 16 years of practice. Participants' average overall knowledge and attitude scores on autism were 15.83 (SD = 3.27) and 29.54 (SD = 3.21), respectively, both falling within the moderate range. Using an independent t-test, we found a significant difference (p < 0.001) between the attitudes of male and female GPs regarding autism. The study also identified weakly significant correlations between GPs' age and their attitudes toward autism (r = 0.271⁣∗∗, p < 0.001) and between years of practice and attitudes (r = 0.105⁣∗, p=0.046). However, no significant correlations emerged between GPs' knowledge and their age, years since graduation, or years of practice (r = 0.069, p=0.194; r = 0.069, p=0.193; and r = -0.053, p=0.312, respectively). In addition, we observed a weakly significant association (r = 0.004⁣∗∗, p < 0.001) between GPs' knowledge and their attitudes about autism. Conclusion: Based on their total scores, the participants had a moderate level of knowledge and attitudes toward autism. There was a favorable correlation found between the study subjects' attitudes regarding autism and their age, as well as their practice year. Furthermore, a clear correlation was observed between GPs' attitudes and their understanding of autism.

Convergence on CaMK4: A Key Modulator of Autism-Associated Signaling Pathways in Neurons

Although the precise underlying cause(s) of autism spectrum disorder remain unclear, more than 1000 rare genetic variations are associated with the condition. For many people living with profound autism, this genetic heterogeneity has impeded the identification of common biological targets for therapy development for core and comorbid traits that include significant impairments in social communication and repetitive and restricted behaviors. A substantial number of genes associated with autism encode proteins involved in signal transduction and synaptic transmission that are critical for brain development and function. CAMK4 is an emerging risk gene for autism spectrum disorder that encodes the CaMK4 (calcium/calmodulin-dependent protein kinase 4) enzyme. CaMK4 is a key component of a Ca2+-activated signaling pathway that regulates neurodevelopment and synaptic plasticity. In this review, we discuss 3 genetic variants of CAMK4 found in individuals with hyperkinetic movement disorder and comorbid neurological symptoms including autism spectrum disorder that are likely pathogenic with monogenic effect. We also comment on 4 other genetic variations in CAMK4 that show associations with autism spectrum disorder, as well as 12 examples of autism-associated variations in other genes that impact CaMK4 signaling pathways. Finally, we highlight 3 environmental risk factors that impact CaMK4 signaling based on studies of preclinical models of autism and/or clinical cohorts. Overall, we review molecular, genetic, physiological, and environmental evidence that suggest that defects in the CaMK4 signaling pathway may play an important role in a common autism pathogenesis network across numerous patient groups, and we propose CaMK4 as a potential therapeutic target.

An Analysis of the Time Required for the Diagnosis of ASD and the Factors Influencing Its Duration in a Sample of the Pediatric Population from Poland

Background/Objectives: Early diagnosis of autism spectrum disorder (ASD) is a very important factor for improving the quality of life of people on the spectrum, but it still remains a major problem in Europe, especially concerning girls. In this study, we tried to answer the question of what factors affect the age of diagnosis in Poland. Additionally, we tried to establish the time between the first visit to the mental health center (MHC) and the diagnosis in this population, and what factors affect its length. Methods: 77 children were randomly recruited among the patients who came to local MHC at the Child and Family Health Centre in Sosnowiec. All participants were tested using the ADOS-2 protocol. In addition, the study used the TAS-20 test and BDI. Results: The mean age of the first enrollment in the MHC was 9.09 years for girls and 6.42 for the boys. The time needed to obtain a diagnosis from the first visit was consecutively 2.90 years and 4.29 years, but the difference was not statistically significant (p > 0.05). Obtaining a different psychiatric diagnosis did not affect the average time to diagnosis and the age of diagnosis. Conclusions: The results of the study indicate that the diagnosis of ASD is still a significant problem both in Poland and in the world. Obtaining an accurate diagnosis requires significant time, and it frequently involves consulting multiple specialists. The diagnostic process should be flexible, and the specialist should always take into account the axial symptoms but remain aware that the "overdiagnosis" of ASD can also have harmful consequences for the child.

FMT intervention decreases urine 5-HIAA levels: a randomized double-blind controlled study

Background

Autism spectrum disorder (ASD) is often linked to gastrointestinal issues and altered serotonin metabolism. Emerging evidence suggests gut microbiota influence both, with fecal microbiota transplantation (FMT) offering a potential therapeutic approach. However, its impact on serotonin metabolism and ASD symptoms is not well understood. In this study, we aimed to evaluate the clinical effects of FMT and examine changes in specific urinary metabolites in children with ASD.

Methods

A randomized double-blind controlled trial was performed to evaluate the clinical effects of FMT on GI and ASD-related symptoms. Gastrointestinal symptoms were assessed using the Gastrointestinal Symptom Rating Scale (GSRS), and the ASD-related symptoms were assessed using the Childhood Autism Rating Scale (CARS), Aberrant Behavior Checklist (ABC), and Social Responsiveness Scale (SRS) scores. Urinary metabolites were analyzed by homogeneous enzyme immunoassay using commercially available kits.

Results

Significant improvements in GI and core ASD symptoms were observed following FMT intervention. The average GSRS scores decreased from 30.17 (before) to 19 (after; p < 0.0001), CARS scores decreased from 36.22 to 33.33 (p < 0.0001), SRS scores decreased from 151.17 to 137.5 (p = 0.0002), and the ABC scores decreased 76.39 to 53.17 (p < 0.0001) in the FMT group. However, in the placebo group, GSRS, CARS, and SRS scores showed no significant changes, while ABC scores decreased from 72 to 58.75 (p = 0.034). The FMT group also showed a significant reduction in urinary 5-hydroxyindoleacetic acid (5-HIAA) levels from 8.6 to 7.32 mg/L (p = 0.022), while other metabolites showed no significant changes.

Conclusion

FMT is a safe and effective treatment for improving GI and core symptoms in children with ASD, with 5-HIAA showing potential as a urinary biomarker for treatment response.

Causal Metabolomic and Lipidomic Analysis of Circulating Plasma Metabolites in Autism: A Comprehensive Mendelian Randomization Study with Independent Cohort Validation

BACKGROUND

The increasing prevalence of autism spectrum disorder (ASD) highlights the need for objective diagnostic markers and a better understanding of its pathogenesis. Metabolic differences have been observed between individuals with and without ASD, but their causal relevance remains unclear.

METHODS

Bidirectional two-sample Mendelian randomization (MR) was used to assess causal associations between circulating plasma metabolites and ASD using large-scale genome-wide association study (GWAS) datasets-comprising 1091 metabolites, 309 ratios, and 179 lipids-and three European autism datasets (PGC 2015: n = 10,610 and 10,263; 2017: n = 46,351). Inverse-variance weighted (IVW) and weighted median methods were employed, along with robust sensitivity and power analyses followed by independent cohort validation.

RESULTS

Higher genetically predicted levels of sphingomyelin (SM) (d17:1/16:0) (OR, 1.129; 95% CI, 1.024-1.245; p = 0.015) were causally linked to increased ASD risk. Additionally, ASD children had higher plasma creatine/carnitine ratios. These MR findings were validated in an independent US autism cohort using machine learning analysis.

CONCLUSION

Utilizing large datasets, two MR approaches, robust sensitivity analyses, and independent validation, our novel findings provide evidence for the potential roles of metabolomics and circulating metabolites in ASD diagnosis and etiology.

Measurement invariance of the parent-reported Strengths and Difficulties Questionnaire in autistic adolescents

LAY ABSTRACT

Autistic people are more likely than non-autistic people to experience mental health difficulties. The Strengths and Difficulties Questionnaire is often used to screen for these difficulties and to otherwise make important decisions about mental health treatment and research in populations of autistic people. However, this study suggests that parent-reported Strengths and Difficulties Questionnaire scores may not be useful for comparing autistic and non-autistic adolescents at 11, 14 and 17 years old, as well as screening for mental health conditions in autistic adolescents. In addition, several items may be more likely to be endorsed by parents of autistic 17-year-olds than by parents of non-autistic 17-year-olds (and vice versa), which might suggest caution is needed when comparing groups on specific items.

Combined Exposure to Folate and Lead during Pregnancy and Autistic-Like Behaviors among Canadian Children from the MIREC Pregnancy and Birth Cohort

BACKGROUND

Folic acid (FA) supplementation may attenuate the associations between gestational exposure to certain chemicals and autism or autistic-like behaviors, but to our knowledge, this has not been assessed for lead.

OBJECTIVES

We examined whether the relationship between gestational blood-lead levels (BLLs) and autistic-like behaviors was modified by gestational plasma total folate concentrations, FA supplementation, and maternal methylenetetrahydrofolate reductase (MTHFR) 677C>T genotype.

METHODS

We used data from the Maternal-Infant Research on Environmental Chemicals study (2008-2011), a Canadian pregnancy and birth cohort study. Childhood autistic-like behaviors were documented in 601 children 3-4 y of age with the Social Responsiveness Scale-2 (SRS-2), where higher scores denote more autistic-like behaviors. We measured BLLs and plasma total folate concentrations during the first and third trimesters of pregnancy. We also estimated gestational FA supplementation via surveys and genotyped the maternal MTHFR 677C>T single nucleotide polymorphism (SNP). We estimated the confounder-adjusted associations between log 2 -transformed BLLs and SRS-2 scores by two indicators of folate exposure and maternal MTHFR 677C>T genotype using linear regression.

RESULTS

Third-trimester BLLs were associated with increased SRS-2 scores [β a d j = 3.3 ; 95% confidence interval (CI): 1.1, 5.5] among participants with low (< 10 th percentile), third-trimester, plasma total folate concentrations, but BLL-SRS-2 associations were null (β a d j = - 0.3 ; 95% CI: - 1.2 , 0.5) among those in the middle category (≥ 10 th and < 80 th percentiles) (p-interaction < 0.001 ). FA supplementation also attenuated these associations. Both folate indicators modified first-trimester BLL-SRS-2 associations, but to a lesser extent. Third-trimester BLL-SRS-2 associations were slightly stronger among participants who were homozygous for the T (minor) allele of the MTHFR 677C>T SNP (β a d j = 0.9 ; 95% CI: - 1.2 , 3.1) than those without the T allele (β a d j = - 0.3 ; 95% CI: - 1.3 , 0.7), but the difference was not statistically significant (p -interaction = 0.28 ).

DISCUSSION

Folate may modify the associations between gestational lead exposure and childhood autistic-like behaviors, suggesting that it mitigates the neurotoxic effects of prenatal lead exposure. https://doi.org/10.1289/EHP14479.

Groups and Subgroups in Autism Spectrum Disorder (ASD) Considering an Advanced Integrative Model (AIM)

BACKGROUND

Autism spectrum disorder (ASD) is related to social communication difficulties, repetitive behaviors, and highly restricted interests beginning early in life. Currently, ASD is more diagnosed than in the past, and new models are needed. The Advanced Integrative Model (AIM) is a new model in which genes and concomitant medical problems to diagnosis (CMPD) and the impact of their rigorous and adequate treatment are considered.

METHODS

The role of a dynamic encephalopathy from which the individual response, susceptibilities in the brain and outside the brain, gut barrier and brain-blood-barrier permeabilities, and the plastic nature of the brain is proposed as a tool for diagnosis. The concomitant medical problems (CMP) are those at and outside the brain. The individual response to treatments of CMP is analyzed.

RESULTS

The AIM allows for classification into 3 main groups and 24 subgroups.

CONCLUSIONS

The groups and subgroups in ASD are obtained taking into account CMPD treatments and individual response.

Blood and hair copper levels in childhood autism spectrum disorder: a meta-analysis based on case-control studies

OBJECTIVES

The association between copper levels and autism spectrum disorder (ASD) has been a controversial topic. This study investigated relationship between copper levels and ASD.

CONTENT

The following databases are searched until April 2022: PubMed, EMBASE and Web of Science. Combined effect size standardized mean differences (SMD) and 95% confidence intervals (95% CI) were calculated with Stata 12.0. In this meta-analysis, 29 case-control studies were included, which included 2,504 children with ASD and 2,419 healthy controls. The copper levels in hair (SMD: -1.16, 95% CI: -1.73 to -0.58) was significantly lower in ASD children than healthy controls. The copper levels in blood (SMD: 0.10, 95% CI: -0.12 to 0.32) not significantly compare ASD with controls.

SUMMARY AND OUTLOOK

Copper may be associated with the development of ASD in children.

Lived Experiences and Perceptions of Autistic Young Adults Participating in Employment Readiness Skills Training

This study aimed to examine the experiences and perceptions of participants engaged in an employment readiness program, Employment Preparation And Skills Support (EPASS), which is a manualized group-based training program designed to improve employment readiness among autistic young adults. A qualitative descriptive design was utilized to generate thick descriptions through semi-structured interviews with 22 transition-age autistic individuals (Mage = 20; 6 females; 16 males). Thematic analysis was employed to understand the experiences and career outcomes of transition-age autistic individuals pre- and post-participation in the EPASS program. Five main themes were identified: (1) More Negative Than Positive Employment-related Experiences; (2) Insight about Training Needs despite Hesitation to Participate; (3) Improved Perception and Confidence of Employment readiness through Experiential Learning; (4) Emerging Career Goals and Plans in Future Application of Knowledge and Skills; and (5) Learning Preference for More Interactive and Practice Experience. Participants reported a better understanding of job preparation skills, work-related social skills and interview etiquette. They also reported that what they learned in EPASS helped them improve their skills and confidence in obtaining and maintaining employment. Overall, participants expressed satisfaction with participating in EPASS and anticipated potential long-term impacts on their employability. This study sheds light on the training needs for transition-age autistic individuals and informs future employment readiness program development. Future studies should focus on collaborating with stakeholders to address training gaps and support needs that foster improved employment outcomes for this population.

Socio-medical Factors Associated with Neurodevelopmental Disorders on the Kenyan Coast

Background

Neurodevelopmental disorders (NDDs) are a group of conditions with their onset during the early developmental period and include conditions such as autism, intellectual disability and attention deficit hyperactivity disorder (ADHD). Occurrence of NDDs is thought to be determined by both genetic and environmental factors, but data on the role of environmental risk factors for NDD in Africa is limited. This study investigates environmental influences on NDDs in children from Kenya. This case-control study compared children with NDDs and typically developing children from two studies on the Kenyan coast that did not overlap.

Methods and Findings

We included 172 of the study participants from the Kilifi Autism Study and 151 from the NeuroDev Study who had a diagnosis of at least one NDD and 112 and 73 with no NDD diagnosis from each study, respectively. Potential risk factors were identified using unadjusted univariable analysis and adjusted multivariable logistic regression analysis. Univariable analysis in the Kilifi Autism Study sample revealed hypoxic-ischaemic encephalopathy conferred the largest odds ratio (OR) 10.52 (95%CI 4.04 - 27.41) for NDDs, followed by medical complications during pregnancy (gestational hypertension & diabetes, eclampsia, and maternal bleeding) OR: 3.17 (95%CI 1.61 - 6.23). In the NeuroDev study sample, labour and birth complications (OR: 7.30 (2.17 - 24.61)), neonatal jaundice (OR: 5.49 (95%CI 1.61 - 18.72)) and infection during pregnancy (OR: 5.31 (1.56 - 18.11)) conferred the largest risk associated with NDDs. In the adjusted analysis, seizures before age 3 years in the Kilifi Autism study and labour and birth complications in the NeuroDev study conferred the largest increased risk. Higher parity, the child being older and delivery at home were associated with a reduced risk for NDDs.

Conclusion

Recognition of important risk factors such as labour and birth complications could guide preventative interventions, developmental screening of at-risk children and monitoring progress. Further studies examining the aetiology of NDDs in population-based samples, including investigating the interaction between genetic and environmental factors, are needed.

2-Ethylhexyl Diphenyl Phosphate Induces Autism Spectrum Disorder-Like Behaviors in Offspring Mice by Disrupting Postsynaptic Development

As organophosphorus flame retardants (OPFRs) are constantly detected in human samples, the neurotoxicity of OPFRs is of concern. In this study, pregnant ICR mice were exposed to 2-ethylhexyl diphenyl phosphate (EHDPP) in drinking water from gestation to lactation to investigate its effects on autism spectrum disorder-like (ASD-like) behaviors in offspring. Serum EHDPP concentrations in dams in the 0.4, 2, and 10 mg/kg groups were 0.282 ± 0.051, 0.713 ± 0.115, and 0.974 ± 0.048 ng/mL, respectively, within the concentration range in humans. At the highest dose, EHDPP exposure induced ASD-like behaviors in both female and male offspring. Significant reductions in mature dendritic spines and structural damage to the postsynaptic density zone were noted in all but the lowest exposure groups, indicating postsynaptic membrane impairment. Mechanistically, EHDPP significantly downregulated disc large MAGUK scaffold protein 4 expression by inhibiting protein kinase B and type 1 insulin-like growth factor receptor phosphorylation. In the heterologous synapse formation assay in vivo, EHDPP significantly reduced the levels of postsynaptic density protein 95 expression in neurons at 1 μM. Overall, the study utilized in vitro and in vivo experiments to confirm that EHDPP damaged postsynaptic membrane formation and might increase the incidence of ASD in offspring.

Non-Word Repetition in Arabic-speaking children with and without Autism Spectrum Disorder (ASD): A closer look into accuracy and error patterns

Non-Word Repetition (NWR) tasks effectively identify language impairments and assess phonological skills across diverse populations and languages, including Arabic. Prior research revealed heterogeneity of performance in children with Autism Spectrum Disorder (ASD) on NWR tasks. The current study is the first to evaluate phonological skills of Palestinian-Arabic-speaking children with and without ASD, employing a Palestinian-Arabic NWR task. A total of 142 Palestinian-Arabic-speaking children, aged 5-11 participated in the study, including 75 children with Typical Language Development (TLD) and 67 children with ASD. The NWR task included 18 non-words of varying length (1-4 syllables) and complexity (with and without consonant clusters). Quantitative analysis examined the effects of length and phonological complexity on the NWR accuracy scores in children with TLD and ASD. Error pattern analysis accounting for phoneme and syllable substitutions/deletions/additions and lexicalisations aimed to shed light on the phonological representations of children with and without ASD. Within the ASD group, two subgroups emerged: 72% exhibited age-appropriate NWR performance, while 28% showed performance at-risk for phonological impairment. Non-word length, rather than complexity, significantly influenced the children's performance. Consonant substitution was the most frequent error pattern across all groups. On the theoretical side, these findings extend cross-linguistic evidence of phonological skill heterogeneity in children with ASD to Arabic-speaking children. Additionally, they highlight an overall delayed but qualitatively similar pattern of phonological development in children with ASD. On the clinical side, results underscore the importance of comprehensive language assessment in children with ASD.

A Pilot Study on the Relationship between Obstructive Sleep Apnoea-Hypopnea Syndrome, Neurodevelopment, and Ricketts' Cephalometry

Background: The aim of this research is to achieve the early detection of facial characteristics in patients diagnosed with neurodevelopmental deficits and obstructive sleep apnoea-hypopnea syndrome (OSAHS) through the analysis of the VERT index and Ricketts' cephalometry to minimise the neurocognitive morbidity associated with these disorders. Methods: This clinical study was conducted on 44 patients aged 4 to 15 years. Participants completed an initial questionnaire about sleep disturbances, followed by a polysomnography, a radiographic study, and an oral examination. Results: The maximum variability in the data was obtained in the mandibular plane angle, where we observed that the measurement was higher in patients diagnosed with OSAHS. The relative and normalised indices of facial depth and the mandibular plane showed variations between patients with a clinical picture compatible with OSAHS and the control group without pathology. Conclusions: Our findings indicate that Ricketts' VERT index by itself is unable to provide evidence of a diagnosis compatible with OSAHS in patients with early neurodevelopmental deficits, but, after analysing the results obtained, we observed that for the cephalometric measurements of the mandibular plane angle and facial depth relative to the patient's age, there are sufficiently strong variations for creating a solid method of differential diagnosis, thus preventing complications at the neurocognitive level.

miRNAs as biomarkers of autism spectrum disorder: a systematic review and meta-analysis

Autism spectrum disorder (ASD) is a neurodevelopmental disorder with complex clinical manifestations that arise between 18 and 36 months of age. Social interaction deficiencies, a restricted range of interests, and repetitive stereotyped behaviors are characteristics which are sometimes difficult to detect early. Several studies show that microRNAs (miRs/miRNAs) are strongly implicated in the development of the disorder and affect the expression of genes related to different neurological pathways involved in ASD. The present systematic review and meta-analysis addresses the current status of miRNA studies in different body fluids and the most frequently dysregulated miRNAs in patients with ASD. We used a combined approach to summarize miRNA fold changes in different studies using the mean values. In addition, we summarized p values for differential miRNA expression using the Fisher method. Our literature search yielded a total of 133 relevant articles, 27 of which were selected for qualitative analysis based on the inclusion and exclusion criteria, and 16 studies evaluating miRNAs whose data were completely reported were ultimately included in the meta-analysis. The most frequently dysregulated miRNAs across the analyzed studies were miR-451a, miR-144-3p, miR-23b, miR-106b, miR150-5p, miR320a, miR92a-2-5p, and miR486-3p. Among the most dysregulated miRNAs in individuals with ASD, miR-451a is the most relevant to clinical practice and is associated with impaired social interaction. Other miRNAs, including miR19a-3p, miR-494, miR-142-3p, miR-3687, and miR-27a-3p, are differentially expressed in various tissues and body fluids of patients with ASD. Therefore, all these miRNAs can be considered candidates for ASD biomarkers. Saliva may be the optimal biological fluid for miRNA measurements, because it is easy to collect from children compared to other biological fluids.

[Assessment of the importance of neuropediatric diagnostics in the initial clarification of autism]

BACKGROUND

The diagnostics of autism spectrum disorder is complex due to missing biological markers and numerous comorbidities. The aim was to assess the role of neuropediatric diagnostics and to develop a standard operating procedure for a targeted assessment.

METHOD

All patients presenting to the neuropediatric outpatient clinic at Saarland University Hospital between April 2014 and December 2017 with ICD code F84 pervasive developmental disorders were included.

RESULTS

A total of 82 patients were included (male 78%, female 22%; mean age 5.9 ± 2.9 years, range 2-16 years). The most frequent examination was electroencephalography (EEG) (74/82; 90.2%) with pathological findings in 33.8% (25/74). Based on the history and/or EEG epilepsy was diagnosed in 19.5% (16/82). Magnetic resonance imaging (MRI) was performed in 49/82 (59.8%) patients, 22/49 (44.9%) showed at least 1 cerebral abnormality and definite pathologies could be detected in 63.6% (14/22). A metabolic diagnostic work-up was performed in 44/82 (53.7%) cases and in 5/44 (11.4%) it resulted in a diagnosis or suspicion of a metabolic disease. Genetic testing results were available in 29/82 (35.4%) children and 12/29 (41.4%) showed abnormal results. Delay in motor development was more frequently associated with comorbidities, EEG abnormalities, epilepsy and abnormalities in metabolic and genetic testing.

CONCLUSION

Neuropediatric examination in cases of suspected autism should include a detailed history, a thorough neurological examination and an EEG. An MRI, comprehensive metabolic and genetic testing are only recommended if clinically indicated.

The Physiological and Clinical-Behavioral Effects of Heart Rate Variability Biofeedback in Adolescents with Autism: A Pilot Randomized Controlled Trial

Adolescents with autism present lower levels of cardiac vagal modulation. It was hypothesized that Heart Rate Variability Biofeedback (HRVB) increases cardiac vagal modulation in adolescents with autism, resulting in positive effects on physiological and psychosocial parameters. It was also hypothesized that home-based HRVB training is feasible. In a single-blind, randomized sham-controlled pilot trial, adolescents with autism performed supervised HRVB (n = 24) or sham training (n = 20). Subsequently, half of the adolescents received HRVB training at home, whereas the other subset did not practice. Physiological, cortisol and behavioral data were collected during stress-provoking assessments before and after each training period. Supervised HRVB resulted in a late increase in cardiac vagal modulation in adolescents with autism. Heart rate increased and cortisol decreased significantly immediately after supervised HRVB, but none of these effects remained after follow-up. Following supervised HRVB, no significant change in psychosocial functioning was found. Home-based HRVB was feasible, adolescents reported lower symptoms of stress, but a significant decrease in compliance rate was found. HRVB is feasible and effective in adolescents with autism given the late-emerging increases in cardiac vagal modulation and decrease in stress symptoms. Replicating this study with a larger sample and further exploration of the working mechanisms of HRVB are recommended. ClinicalTrials.gov , NCT04628715.

Short-chain fatty acids: bridges between diet, gut microbiota, and health

In recent years, gut microbiota has become a hot topic in the fields of medicine and life sciences. Short-chain fatty acids (SCFAs), the main metabolites of gut microbiota produced by microbial fermentation of dietary fiber, play a vital role in healthy and ill hosts. SCFAs regulate the process of metabolism, immune, and inflammation and have therapeutic effects on gastrointestinal and neurological disorders, as well as antitumor properties. This review summarized the production, distribution, and molecular mechanism of SCFAs, as well as their mechanisms of action in healthy and ill hosts. In addition, we also emphasized the negative effects of SCFAs, aiming to provide the public with a more comprehensive understanding of SCFAs.

Mapping neural correlates of biological motion perception in autistic children using high-density diffuse optical tomography

BACKGROUND

Autism spectrum disorder (ASD), a neurodevelopmental disorder defined by social communication deficits plus repetitive behaviors and restricted interests, currently affects 1/36 children in the general population. Recent advances in functional brain imaging show promise to provide useful biomarkers of ASD diagnostic likelihood, behavioral trait severity, and even response to therapeutic intervention. However, current gold-standard neuroimaging methods (e.g., functional magnetic resonance imaging, fMRI) are limited in naturalistic studies of brain function underlying ASD-associated behaviors due to the constrained imaging environment. Compared to fMRI, high-density diffuse optical tomography (HD-DOT), a non-invasive and minimally constraining optical neuroimaging modality, can overcome these limitations. Herein, we aimed to establish HD-DOT to evaluate brain function in autistic and non-autistic school-age children as they performed a biological motion perception task previously shown to yield results related to both ASD diagnosis and behavioral traits.

METHODS

We used HD-DOT to image brain function in 46 ASD school-age participants and 49 non-autistic individuals (NAI) as they viewed dynamic point-light displays of coherent biological and scrambled motion. We assessed group-level cortical brain function with statistical parametric mapping. Additionally, we tested for brain-behavior associations with dimensional metrics of autism traits, as measured with the Social Responsiveness Scale-2, with hierarchical regression models.

RESULTS

We found that NAI participants presented stronger brain activity contrast (coherent > scrambled) than ASD children in cortical regions related to visual, motor, and social processing. Additionally, regression models revealed multiple cortical regions in autistic participants where brain function is significantly associated with dimensional measures of ASD traits.

LIMITATIONS

Optical imaging methods are limited in depth sensitivity and so cannot measure brain activity within deep subcortical regions. However, the field of view of this HD-DOT system includes multiple brain regions previously implicated in both task-based and task-free studies on autism.

CONCLUSIONS

This study demonstrates that HD-DOT is sensitive to brain function that both differentiates between NAI and ASD groups and correlates with dimensional measures of ASD traits. These findings establish HD-DOT as an effective tool for investigating brain function in autistic and non-autistic children. Moreover, this study established neural correlates related to biological motion perception and its association with dimensional measures of ASD traits.

Human umbilical cord-derived mesenchymal stem cells alleviate valproate-induced immune stress and social deficiency in rats

Introduction

Autism spectrum disorders (ASD) are a set of heterogeneous neurodevelopmental disorders characterized by impaired social interactions and stereotypic behaviors. Current clinical care is palliative at the most and there remains huge unmet medical need to fully address the core symptoms of ASD. Human umbilical cord-derived mesenchymal stem cells (hUC-MSCs) are emerging as a promising candidate for ASD treatment, but the precise mechanism remains controversial.

Methods

In vitro studies we performed the transwell migration assay to explore the interaction between hUC-MSCs and the primary-cultured cortical neurons. Then we determined the therapeutic effects of intravenous administration of hUC-MSCs in rats challenged with valproic acid (VPA) during gestation, a well-defined rat model of autism.

Results

Our studies showed that hUC-MSCs promoted the growth of primary-cultured cortical neurons. Furthermore, our results demonstrated that hUC-MSCs significantly alleviated microglial activation in the brain, especially in the anterior cingulate cortex, and effectively improved the sociability of the VPA-exposed rats.

Discussion

These results offer valuable insights for clinical translation and further research on the mechanisms of hUC-MSCs in psychiatric disorders characterized by microglial activation, particularly in cases of autism, shall be warranted.

Cross-bite and oral habits among Albanian autistic children according to the stages of occlusal development

This study had two aims. First, we aimed to investigate the prevalence of ACB, PCB, and oral habits among a group of Albanian children with ASD compared with a group of children without ASD. Second, we aimed to identify the associations of ASD with ACB, PCB, and oral habits. The sample inlcuded 125 children with ASD (91 males, 34 females) from 2 special schools for children with disabilities and 2 daily residential centers in Tirana. The control group included 125 children without ASD. The relationships between categorical variables were evaluated via the chi-square test. To identify the potential risk factors for ASD, we performed binary logistic regression. No statistically significant differences were found for CB or oral habits between the primary and adolescent dentition stages. A comparison of children with ASD with CB and oral habits revealed a significant difference in the prevalence of PCB. Binary logistic regression revealed that ACB, PCB and oral habits were not associated with ASD. CB was more prevalent among children with ASD in the primary and mixed dentition stages. Oral habits were more prevalent in the mixed and adolescent dentition stages. However, ASD is not a risk factor for CB or other oral habits.

Multigenerational association between smoking and autism spectrum disorder: findings from a nationwide prospective cohort study

Animal studies have shown that exposure to cigarette smoke during pregnancy can induce neurobehavioral anomalies in multiple subsequent generations. However, little work has examined such effects in humans. We examined the risk of grandchild autism spectrum disorder (ASD) in association with grandmother's smoking during pregnancy, using data from 53 562 mothers and grandmothers and 120 267 grandchildren in Nurses' Health Study II. In 1999, Nurses' Health Study II participants with children reported on their mothers' smoking. Grandchildren's ASD diagnoses were reported by the mothers in 2005 and 2009. Among grandmothers, 13 383 (25.0%) smoked during pregnancy, and 509 (0.4%) grandchildren were diagnosed with ASD. The adjusted odds ratio for ASD for grandmother smoking during pregnancy was 1.52 (95% CI, 1.06-2.20). Results were similar with direct grandmother reporting in 2001 of her smoking during pregnancy from the Nurses' Mothers Cohort Study subgroup (n = 22 167 grandmothers, n = 49 917 grandchildren) and were stronger among grandmothers who smoked ≥15 cigarettes per day during pregnancy (adjusted odds ratio = 1.93 [95% CI, 1.10-3.40]; n = 1895 grandmothers, n = 4212 grandchildren). Results were similar when we adjusted for mother's smoking during pregnancy. There was no association with grandfather's smoking as reported by the grandmother. Our results suggest a potential persistent impact of gestational exposure to environmental insults across 3 generations.

Relationships between autistic traits, self-efficacy, and internalizing symptoms in a nonclinical sample of Indian early adolescents

INTRODUCTION

Having more "autistic traits" is associated with an increased risk of mental health conditions. However, few studies have examined autistic traits in nonclinical samples. This study aims to analyze the relationship between autistic traits and internalizing symptoms among early adolescents and to examine the moderating effect of self-efficacy.

METHODS

Survey data were collected from early adolescents ages 10-14 living in Darjeeling, India (n = 274) to assess autistic traits, self-efficacy, and internalizing symptoms.

RESULTS

Higher internalizing symptoms were significantly associated with a higher report of autistic traits. Academic, social, and emotional dimensions of self-efficacy moderated the relationship between autistic traits and internalizing symptoms.

CONCLUSION

The moderation effects between social and emotional self-efficacy among youth with high versus low autism trait scores suggest the need for social-emotional learning interventions designed for and with neurodivergent youth. Such interventions aim to reduce internalizing symptoms during early adolescence and improve future mental health trajectories.

Mechanisms of neurodevelopmental toxicity of topiramate

Prescriptions for antiseizure medications (ASMs) have been rapidly growing over the last several decades due, in part, to an expanding list of clinical indications for which they are now prescribed. This trend has raised concern for potential adverse neurodevelopmental outcomes in ASM-exposed pregnancies. Recent large scale population studies have suggested that the use of topiramate (TOPAMAX, Janssen-Cilag), when prescribed for seizure control, migraines, and/or weight management, is associated with an increased risk for autism spectrum disorder (ASD), intellectual disability, and attention-deficit/hyperactivity disorder (ADHD) in exposed offspring. Here, we critically review epidemiologic evidence demonstrating the neurobehavioral teratogenicity of topiramate and speculate on the neuromolecular mechanisms by which prenatal exposure may perturb neurocognitive development. Specifically, we explore the potential role of topiramate's pharmacological interactions with ligand- and voltage-gated ion channels, especially GABAergic signaling, its effects on DNA methylation and histone acetylation, whether topiramate induces oxidative stress, and its association with fetal growth restriction as possible mechanisms contributing to neurodevelopmental toxicity. Resolving this biology will be necessary to reduce the risk of adverse pregnancy outcomes caused by topiramate or other ASMs.

Completion of Upper Secondary Mainstream School in Autistic Students in Sweden

Higher education is an increasingly necessary achievement to attain employment. However, even in cases where a student has the academic skills to succeed, educational environments may not support students across all other domains necessary for education success, including social and communication needs. This is especially true for students with disabilities and autistic students, where the rate of completion of non-compulsory education is unknown. We used the Stockholm Youth Cohort (children aged 0-17 years from 2001 to 2011), a total population cohort (N = 736,180) including 3,918 autistic individuals, to investigate the association between autism without intellectual disability and completion of upper secondary education. We assessed the impact of sex and co-occurring Attention-Deficit/Hyperactivity Disorder (ADHD) on this association. By age 20 years (the expected age of completion), 68% of autistic students and 91% of non-autistic students admitted to upper secondary education had completed. In logistic regression models adjusted for student demographics, autistic students had almost five-fold higher odds of not completing secondary school (OR 4.90, 95% CI 4.56 5.26) compared to their non-autistic peers. Autistic students with ADHD had particularly high odds of non-completion of upper secondary school. Autistic students without intellectual disability attending mainstream education are substantially less likely to complete upper secondary education as compared to their peers. These findings have implications for the appraisal of how inclusive school policies serve autistic students' academic and social needs, ultimately addressing population health and independent living.

Prenatal 1-Nitropyrene Exposure Causes Autism-Like Behavior Partially by Altering DNA Hydroxymethylation in Developing Brain

Autism spectrum disorder (ASD) is a neurodevelopmental disorder, characterized by social communication disability and stereotypic behavior. This study aims to investigate the impact of prenatal exposure to 1-nitropyrene (1-NP), a key component of motor vehicle exhaust, on autism-like behaviors in a mouse model. Three-chamber test finds that prenatal 1-NP exposure causes autism-like behaviors during the weaning period. Patch clamp shows that inhibitory synaptic transmission is reduced in medial prefrontal cortex of 1-NP-exposed weaning pups. Immunofluorescence finds that prenatal 1-NP exposure reduces the number of prefrontal glutamate decarboxylase 67 (GAD67) positive interneurons in fetuses and weaning pups. Moreover, prenatal 1-NP exposure retards tangential migration of GAD67-positive interneurons and downregulates interneuron migration-related genes, such as Nrg1, Erbb4, and Sema3F, in fetal forebrain. Mechanistically, prenatal 1-NP exposure reduces hydroxymethylation of interneuron migration-related genes through inhibiting ten-eleven translocation (TET) activity in fetal forebrain. Supplement with alpha-ketoglutarate (α-KG), a cofactor of TET enzyme, reverses 1-NP-induced hypohydroxymethylation at specific sites of interneuron migration-related genes. Moreover, α-KG supplement alleviates 1-NP-induced migration retardation of interneurons in fetal forebrain. Finally, maternal α-KG supplement improves 1-NP-induced autism-like behaviors in weaning offspring. In conclusion, prenatal 1-NP exposure causes autism-like behavior partially by altering DNA hydroxymethylation of interneuron migration-related genes in developing brain.

A critical review of the impact of candidate copy number variants on autism spectrum disorder

Autism spectrum disorder (ASD) is a complex neurodevelopmental disorder (NDD) influenced by genetic, epigenetic, and environmental factors. Recent advancements in genomic analysis have shed light on numerous genes associated with ASD, highlighting the significant role of both common and rare genetic mutations, as well as copy number variations (CNVs), single nucleotide polymorphisms (SNPs) and unique de novo variants. These genetic variations disrupt neurodevelopmental pathways, contributing to the disorder's complexity. Notably, CNVs are present in 10 %-20 % of individuals with autism, with 3 %-7 % detectable through cytogenetic methods. While the role of submicroscopic CNVs in ASD has been recently studied, their association with genomic loci and genes has not been thoroughly explored. In this review, we focus on 47 CNV regions linked to ASD, encompassing 1632 genes, including protein-coding genes and long non-coding RNAs (lncRNAs), of which 659 show significant brain expression. Using a list of ASD-associated genes from SFARI, we detect 17 regions harboring at least one known ASD-related protein-coding gene. Of the remaining 30 regions, we identify 24 regions containing at least one protein-coding gene with brain-enriched expression and a nervous system phenotype in mouse mutants, and one lncRNA with both brain-enriched expression and upregulation in iPSC to neuron differentiation. This review not only expands our understanding of the genetic diversity associated with ASD but also underscores the potential of lncRNAs in contributing to its etiology. Additionally, the discovered CNVs will be a valuable resource for future diagnostic, therapeutic, and research endeavors aimed at prioritizing genetic variations in ASD.

Prevalence of autism spectrum disorder diagnosis by birth weight, gestational age, and size for gestational age: a systematic review, meta-analysis, and meta-regression

We aimed to comprehensively pool the prevalence of autism spectrum disorder (ASD) diagnosis by birth weight, gestational age, and size for gestational age. PubMed, EMBASE, Web of Science, Ovid PsycINFO, and Cochrane Library were searched up to December 22, 2021. We pooled data using the random-effects model and quantified heterogeneity using the I2 statistic. Of 66 643 records initially identified, 75 studies were included in the meta-analysis. The pooled prevalence estimates of ASD diagnosis are as follows: very-low-birth weight, 3.1% (912 ASD/66,445 individuals); low-birth weight, 2.3% (5672 ASD/593,927 individuals); normal-birth weight, 0.5% (17,361 ASD/2,378,933 individuals); high-birth weight, 0.6% (4505 ASD/430,699 individuals); very preterm, 2.8% (2113 ASD/128,513 individuals); preterm, 2.1% (19 672 ASD/1 725 244 individuals); term, 0.6% (113,261 ASD/15,297,259 individuals); postterm, 0.6% (9419 ASD/1,138,215 individuals); small-for-gestational-age, 1.9% (6314 ASD/796,550 individuals); appropriate-for-gestational-age, 0.7% (21,026 ASD/5,936,704 individuals); and large-for-gestational-age, 0.6% (2607 ASD/635,666 individuals). Compared with the reference prevalence (those in normal-birth weight, term, and appropriate-for-gestational-age individuals), the prevalence estimates of ASD diagnosis in very-low-birth weight, low-birth weight, very preterm, preterm, and small-for-gestational-age individuals increased significantly, while those in high-birth weight, postterm, and large-for-gestational-age individuals did not change significantly. There were geographical differences in the prevalence estimates. This meta-analysis provided reliable estimates of the prevalence of ASD diagnosis by birth weight, gestational age, and size for gestational age, and suggested that low-birth weight (especially very-low-birth weight), preterm (especially very preterm), and small-for-gestational-age births, rather than high-birth weight, postterm, and large-for-gestational-age births, were associated with increased risk of ASD diagnosis. However, in view of marked between-study heterogeneity in most conditions, unknown effects of certain important confounders associated with ASD due to limited information in original articles, and included studies from a relatively small number of countries, the findings of this study should be interpreted with caution.

The association between prenatal oxidative stress levels measured by isoprostanes and offspring neurodevelopmental outcomes at 36 months

Oxidative stress during pregnancy has been a mechanistic pathway implicated in autism development, yet few studies have examined this association directly. Here, we examined the association of prenatal levels of 8-iso-PGF2α, a widely used measure of oxidative stress, and several neurodevelopmental outcomes related to autism in children. Participants included 169 mother-child pairs from the Early Autism Risk Longitudinal Investigation (EARLI), which enrolled mothers who had an autistic child from a previous pregnancy and followed them through a subsequent pregnancy and until that child reached age 3 years. Maternal urine samples were collected during the second trimester of pregnancy and were later measured for levels of isoprostanes. Child neurodevelopmental assessments included the Mullen Scales of Early Learning (MSEL), the Social Responsiveness Scale (SRS), and the Vineland Adaptive Behavior Scale (VABS), and were conducted around 36 months of age. Primary analyses examined associations between interquartile range (IQR) increases in 8-iso-PGF2α levels, and total composite scores from each assessment using quantile regression. In adjusted analyses, we did not observe statistically significant associations, though estimates suggested modestly lower cognitive scores (β for MSEL = -3.68, 95% CI: -10.09, 2.70), and minor increases in autism-related trait scores (β for SRS T score = 1.68, 95% CI: -0.24, 3.60) with increasing 8-iso-PGF2α. These suggestive associations between decreased cognitive scores and increased autism-related traits with increasing prenatal oxidative stress point to the need for continued investigation in larger samples of the role of oxidative stress as a mechanistic pathway in autism and related neurodevelopmental outcomes.

Food, nutrition, and autism: from soil to fork

Food and nutrition-related factors have the potential to impact development of autism spectrum disorder (ASD) and quality of life for people with ASD, but gaps in evidence exist. On 10 November 2022, Tufts University's Friedman School of Nutrition Science and Policy and Food and Nutrition Innovation Institute hosted a 1-d meeting to explore the evidence and evidence gaps regarding the relationships of food and nutrition with ASD. This meeting report summarizes the presentations and deliberations from the meeting. Topics addressed included prenatal and child dietary intake, the microbiome, obesity, food-related environmental exposures, mechanisms and biological processes linking these factors and ASD, food-related social factors, and data sources for future research. Presentations highlighted evidence for protective associations with prenatal folic acid supplementation and ASD development, increases in risk of ASD with maternal gestational obesity, and the potential for exposure to environmental contaminants in foods and food packaging to influence ASD development. The importance of the maternal and child microbiome in ASD development or ASD-related behaviors in the child was reviewed, as was the role of discrimination in leading to disparities in environmental exposures and psychosocial factors that may influence ASD. The role of child diet and high prevalence of food selectivity in children with ASD and its association with adverse outcomes were also discussed. Priority evidence gaps identified by participants include further clarifying ASD development, including biomarkers and key mechanisms; interactions among psychosocial, social, and biological determinants; interventions addressing diet, supplementation, and the microbiome to prevent and improve quality of life for people with ASD; and mechanisms of action of diet-related factors associated with ASD. Participants developed research proposals to address the priority evidence gaps. The workshop findings serve as a foundation for future prioritization of scientific research to address evidence gaps related to food, nutrition, and ASD.

Association between pre- and postnatal exposure to endocrine-disrupting chemicals and birth and neurodevelopmental outcomes: an extensive review

Endocrine-disrupting chemicals (EDCs) are natural or synthetic chemicals that mimic, block, or interfere with the hormones in the body. The most common and well- studied EDCs are bisphenol A, phthalates, and persistent organic pollutants including polychlorinated biphenyls, polybrominated diphenyl ethers, per- and polyfluoroalkyl substances, other brominated flame retardants, organochlorine pesticides, dioxins, and furans. Starting in embryonic life, humans are constantly exposed to EDCs through air, diet, skin, and water. Fetuses and newborns undergo crucial developmental processes that allow adaptation to the environment throughout life. As developing organisms, they are extremely sensitive to low doses of EDCs. Many EDCs can cross the placental barrier and reach the developing fetal organs. In addition, newborns can be exposed to EDCs through breastfeeding or formula feeding. Pre- and postnatal exposure to EDCs may increase the risk of childhood diseases by disrupting the hormone-mediated processes critical for growth and development during gestation and infancy. This review discusses evidence of the relationship between pre- and postnatal exposure to several EDCs, childbirth, and neurodevelopmental outcomes. Available evidence suggests that pre- and postnatal exposure to certain EDCs causes fetal growth restriction, preterm birth, low birth weight, and neurodevelopmental problems through various mechanisms of action. Given the adverse effects of EDCs on child development, further studies are required to clarify the overall associations.

Mesenchymal Stem Cells and Purinergic Signaling in Autism Spectrum Disorder: Bridging the Gap between Cell-Based Strategies and Neuro-Immune Modulation

The prevalence of autism spectrum disorder (ASD) is still increasing, which means that this neurodevelopmental lifelong pathology requires special scientific attention and efforts focused on developing novel therapeutic approaches. It has become increasingly evident that neuroinflammation and dysregulation of neuro-immune cross-talk are specific hallmarks of ASD, offering the possibility to treat these disorders by factors modulating neuro-immunological interactions. Mesenchymal stem cell-based therapy has already been postulated as one of the therapeutic approaches for ASD; however, less is known about the molecular mechanisms of stem cell influence. One of the possibilities, although still underestimated, is the paracrine purinergic activity of MSCs, by which stem cells ameliorate inflammatory reactions. Modulation of adenosine signaling may help restore neurotransmitter balance, reduce neuroinflammation, and improve overall brain function in individuals with ASD. In our review article, we present a novel insight into purinergic signaling, including but not limited to the adenosinergic pathway and its role in neuroinflammation and neuro-immune cross-talk modulation. We anticipate that by achieving a greater understanding of the purinergic signaling contribution to ASD and related disorders, novel therapeutic strategies may be devised for patients with autism in the near future.

EEG decoding for effects of visual joint attention training on ASD patients with interpretable and lightweight convolutional neural network

Visual joint attention, the ability to track gaze and recognize intent, plays a key role in the development of social and language skills in health humans, which is performed abnormally hard in autism spectrum disorder (ASD). The traditional convolutional neural network, EEGnet, is an effective model for decoding technology, but few studies have utilized this model to address attentional training in ASD patients. In this study, EEGNet was used to decode the P300 signal elicited by training and the saliency map method was used to visualize the cognitive properties of ASD patients during visual attention. The results showed that in the spatial distribution, the parietal lobe was the main region of classification contribution, especially for Pz electrode. In the temporal information, the time period from 300 to 500 ms produced the greatest contribution to the electroencephalogram (EEG) classification, especially around 300 ms. After training for ASD patients, the gradient contribution was significantly enhanced at 300 ms, which was effective only in social scenarios. Meanwhile, with the increase of joint attention training, the P300 latency of ASD patients gradually shifted forward in social scenarios, but this phenomenon was not obvious in non-social scenarios. Our results indicated that joint attention training could improve the cognitive ability and responsiveness of social characteristics in ASD patients.

Translational toxicology of metal(loid) species: linking their bioinorganic chemistry in the bloodstream to organ damage onset

The quantification of arsenic, mercury, cadmium and lead in the human bloodstream is routinely used today to assess exposure to these toxic metal(loid)s, but the interpretation of the obtained data in terms of their cumulative health relevance remains problematic. Seemingly unrelated to this, epidemiological studies strongly suggest that the simultaneous chronic exposure to these environmental pollutants is associated with the etiology of autism, type 2 diabetes, irritable bowel disease and other diseases. This from a public health point of view undesirable situation urgently requires research initiatives to establish functional connections between human exposure to multiple toxic metal(loid) species and adverse health effects. One way to establish causal exposure-response relationships is a molecular toxicology approach, which requires one to unravel the biomolecular mechanisms that unfold after individual toxic metal(loid)s enter the bloodstream/organ nexus as these interactions ultimately determine which metabolites impinge on target organs and thus provide mechanistic links to diseases of unknown etiology. In an attempt to underscore the importance of the toxicological chemistry of metal(loid)s in the bloodstream, this review summarizes recent progress into relevant bioinorganic processes that are implicated in the etiology of adverse organ-based health effects and possibly diseases. A better understanding of these bioinorganic processes will not only help to improve the regulatory framework to better protect humans from the adverse effects of toxic metal(loid) species, but also represents an important starting point for the development of treatments to ameliorate pollution-induced adverse health effects on human populations, including pregnant women, the fetus and children.

Prevalence of Autism Spectrum Disorder Among Children and Adolescents in the United States from 2021 to 2022

PURPOSE

The prevalence of autism spectrum disorder (ASD) among children and adolescents seem to be high in countries around the world, and it's worth understanding the latest prevalence and trends of ASD in children and adolescents. The purpose of this study was to examine the latest prevalence and decade trend of ASD among individuals aged 3-17 years in the United States.

METHODS

A total of 13,198 individuals aged 3-17 years were included. Annual data were examined from the National Health Interview Survey (2021-2022). Weighted prevalence for each of the selected developmental disabilities were calculated.

RESULTS

This cross-sectional study estimated the weighted prevalence of autism spectrum disorder were 3.05, 3.79, and 3.42% among individuals aged 3-17 years in the US in 2021, 2022, and the 2-year overall, respectively. We also observed a decade-long upward trend even after adjusting for demographic characteristics (P for trend < .05).

CONCLUSION

The results of this study showed that the prevalence of ASD among children and adolescents aged 3-17 years in the United States remained high and has increased over the past decade. The further investigation is necessary to evaluate potential modifiable risk factors and causes of ASD.

Establishment of a two-hit mouse model of environmental factor induced autism spectrum disorder

Autism spectrum disorder (ASD) is a group of developmental diseases characterized by social dysfunction and repetitive stereotype behaviors. Besides genetic mutations, environmental factors play important roles in the development of ASD. Valproic acid (VPA) is widely used for modeling environmental factor induced ASD in rodents. However, traditional VPA modeling is low-in-efficiency and the phenotypes often vary among different batches of experiments. To optimize this ASD-modeling method, we tested "two-hit" hypothesis by single or double exposure of VPA and poly:IC at the critical time points of embryonic and postnatal stage. The autistic-like behaviors of mice treated with two-hit schemes (embryonic VPA plus postnatal poly:IC, embryonic poly:IC plus postnatal VPA, embryonic VPA plus poly: IC, or postnatal VPA plus poly:IC) were compared with mice treated with traditional VPA protocol. The results showed that all single-hit and two-hit schemes produced core ASD phenotypes as VPA single treatment did. Only one group, namely, mice double-hit by VPA and poly:IC simultaneously at E12.5 showed severe impairment of social preference, social interaction and ultrasonic communication, as well as significant increase of grooming activity and anxiety-like behaviors, in comparation with mice treated with the traditional VPA protocol. These data demonstrated that embryonic two-hit of VPA and poly:IC is more efficient in producing ASD phenotypes in mice than the single-hit of VPA, indicating this two-hit scheme could be utilized for modeling environmental factors induced ASD.