Autism Spectrum Disorder Risk Research Articles

Short tandem repeat expansions in cortical layer-specific genes implicate in phenotypic severity and adaptability of autism spectrum disorder.

Short tandem repeats (STRs) are repetitive DNA sequences and highly mutable in various human disorders. While the involvement of STRs in various genetic disorders has been extensively studied, their role in autism spectrum disorder (ASD) remains largely unexplored. In this study, we aimed to investigate genetic association of STR expansions with ASD using whole genome sequencing (WGS) and identify risk loci associated with ASD phenotypes. We analyzed WGS data of 634 ASD families and performed genome-wide evaluation for 12,929 STR loci. We found rare STR expansions that exceeded normal repeat lengths in autism cases compared to unaffected controls. By integrating single cell RNA and ATAC sequencing datasets of human postmortem brains, we prioritized STR loci in genes specifically expressed in cortical development stages. A deep learning method was used to predict functionality of ASD-associated STR loci. In ASD cases, rare STR expansions predominantly occurred in early cortical layer-specific genes involved in neurodevelopment, highlighting the cellular specificity of STR-associated genes in ASD risk. Leveraging deep learning prediction models, we demonstrated that these STR expansions disrupted the regulatory activity of enhancers and promoters, suggesting a potential mechanism through which they contribute to ASD pathogenesis. We found that individuals with ASD-associated STR expansions exhibited more severe ASD phenotypes and diminished adaptability compared to non-carriers. Short tandem repeat expansions in cortical layer-specific genes are associated with ASD and could potentially be a risk genetic factor for ASD. Our study is the first to show evidence of STR expansion associated with ASD in an under-investigated population.

Generation and transcriptomic characterization of MIR137 knockout miniature pig model for neurodevelopmental disorders

BackgroundNeurodevelopmental disorders (NDD), such as autism spectrum disorders (ASD) and intellectual disorders (ID), are highly debilitating childhood psychiatric conditions. Genetic factors are recognized as playing a major role in NDD, with a multitude of genes and genomic regions implicated. While the functional validation of NDD-associated genes has predominantly been carried out using mouse models, the significant differences in brain structure and gene function between mice and humans have limited the effectiveness of mouse models in exploring the underlying mechanisms of NDD. Therefore, it is important to establish alternative animal models that are more evolutionarily aligned with humans.ResultsIn this study, we employed CRISPR/Cas9 and somatic cell nuclear transplantation technologies to successfully generate a knockout miniature pig model of the MIR137 gene, which encodes the neuropsychiatric disorder-associated microRNA miR-137. The homozygous knockout of MIR137 (MIR137–/–) effectively suppressed the expression of mature miR-137 and led to the birth of stillborn or short-lived piglets. Transcriptomic analysis revealed significant changes in genes associated with neurodevelopment and synaptic signaling in the brains of MIR137–/– miniature pig, mirroring findings from human ASD transcriptomic data. In comparison to miR-137-deficient mouse and human induced pluripotent stem cell (hiPSC)-derived neuron models, the miniature pig model exhibited more consistent changes in critical neuronal genes relevant to humans following the loss of miR-137. Furthermore, a comparative analysis identified differentially expressed genes associated with ASD and ID risk genes in both miniature pig and hiPSC-derived neurons. Notably, human-specific miR-137 targets, such as CAMK2A, known to be linked to cognitive impairments and NDD, exhibited dysregulation in MIR137–/– miniature pigs. These findings suggest that the loss of miR-137 in miniature pigs affects genes crucial for neurodevelopment, potentially contributing to the development of NDD.ConclusionsOur study highlights the impact of miR-137 loss on critical genes involved in neurodevelopment and related disorders in MIR137–/– miniature pigs. It establishes the miniature pig model as a valuable tool for investigating neurodevelopmental disorders, providing valuable insights for potential applications in human research.

The relationship of immune cells with autism spectrum disorder: a bidirectional Mendelian randomization study

BackgroundObservational studies have indicated a correlation between immunological inflammation and the risk of autism spectrum disorder (ASD). However, the causal relationship between immunological inflammation and ASD remains uncertain.MethodsImmunity-wide data sources were retrieved from the GWAS catalog. Genetic summary data on ASD were retrieved from two independent GWAS. We performed two independent bi-directional, two-sample Mendelian randomization (MR) analyses and a meta-analysis based on the two independent MR estimates to assess the causal relationship between ASD and immune cell signatures.ResultsWe have discovered 26 potential correlations between genetic predisposition in the immunophenotypes and ASD. The meta-analysis of the two inverse variance weighted (IVW)-produced estimates provided further evidence supporting the potential causal relationship between immunophenotypes and ASD. Based on the findings of the reverse MR analysis, it was determined that there are two potential negative causal relationships between ASD and immunophenotypes. However, the meta-analysis of the two IVW-derived MR estimates indicated that immunophenotypes were not significantly influenced by ASD (OR = 0.87, 95% CI = 0.73 -1.03, P = 0.09; OR = 0.91, 95% CI = 0.81–1.01, P = 0.08).ConclusionsThis study expanded immune cell subtypes that were potentially causally associated with ASD risk as well as identified ASD-specific immune cell subtypes. The discovery has the potential to lead to earlier detection and more effective treatment techniques.

Assessing the impact of medically assisted reproduction on autism spectrum disorder risk

PurposeTechniques of medically assisted reproduction interact with the embryo at crucial developmental stages, yet their impact on the fetus and subsequent child’s health remains unclear. Given rising infertility rates and more frequent use of fertility treatments, we aimed to investigate if these methods heighten the risk of autism spectrum disorder (ASD) in children.MethodsA population-based cohort study was conducted at Soroka University Medical Center, a tertiary referral hospital, encompassing singleton births. The incidence of ASD in offspring, incorporating either hospital or community-based diagnoses, was compared in relation to the conception method. To examine the cumulative incidence of ASD, a Kaplan–Meier survival curve was utilized. Cox proportional hazards model was employed to adjust for confounders.ResultsAmong 115,081 pregnancies, 0.5% involved ovulation induction (OI) and 1.7% in vitro fertilization (IVF), with the rest conceived naturally. Fertility treatments were more common in older patients and linked to more diabetes, hypertensive disorders, preterm, and cesarean deliveries. Out of 767 ASD diagnoses, offspring from OI and IVF had higher initial ASD rates (2.1% and 1.3%) than natural conceptions (0.6%). In a Cox model accounting for maternal age, ethnicity, and gender, neither OI nor IVF was significantly associated with ASD. The adjusted hazard ratios were 0.83 (95% CI 0.48–1.43) for OI and 1.34 (95% CI 0.91–1.99) for IVF. When considering fertility treatments combined, the association with ASD remained non-significant (aHR 1.11, 95% CI 0.80–1.54, p = 0.52).ConclusionFertility treatments, including OI and IVF, do not exhibit a significant association with heightened ASD risk in offspring.

Prevalence of Autism risk among children undergoing regular Psychophysical Development Screening in Kazakhstan

BackgroundInformation about the situation with autism in Kazakhstan is extremely limited due to the lack of research on autism in both Kazakhstan and Central Asia. The prevalence of autism spectrum disorder risk among young children during routine screening was assessed using the M-CHAT-R/F tool. MethodsThis study took place in the offices of pediatric neurologists and family doctors in three primary healthcare organizations in the Karaganda, Kazakhstan. The researchers offered participation in the study and M-CHAT-R checklist completion during visits by parents and children to pediatric neurologists and family doctors for the purpose of screening for psychophysical development. Linear regression analysis was used to determine risk factors for the development of autism spectrum disorder. ResultsThe results of an analysis of 526 study participants showed the prevalence of high-risk autism spectrum disorders to be 27.4 %. Factors associated with a high risk of autism spectrum disorder in this study were child age, gender, parental age, and a diagnosis of developmental disorder. ConclusionsThe use of specific tools to screen for developmental disorders by primary care organizations is recommended. Primary care providers have regular contact with children before they reach school age and can provide family-centered, comprehensive, and coordinated care, including more comprehensive medical assessments.

Population-Based Risk of Psychiatric Disorders Associated With Recurrent Copy Number Variants

Recurrent copy number variants (rCNVs) have been associated with increased risk of psychiatric disorders in case-control studies, but their population-level impact is unknown. To provide unbiased population-based estimates of prevalence and risk associated with psychiatric disorders for rCNVs and to compare risks across outcomes, rCNV dosage type (deletions or duplications), and locus features. This genetic association study is an analysis of data from the Lundbeck Foundation Initiative for Integrative Psychiatric Research (iPSYCH) case-cohort sample of individuals born in Denmark in 1981-2008 and followed up until 2015, including (1) all individuals (n = 92 531) with a hospital discharge diagnosis of attention-deficit/hyperactivity disorder (ADHD), autism spectrum disorder (ASD), bipolar disorder, major depressive disorder (MDD), or schizophrenia spectrum disorder (SSD) and (2) a subcohort (n = 50 625) randomly drawn from the source population. Data were analyzed from January 2021 to August 2023. Carrier status of deletions and duplications at 27 autosomal rCNV loci was determined from neonatal blood samples genotyped on single-nucleotide variant microarrays. Population-based rCNV prevalence was estimated with a survey model using finite population correction to account for oversampling of cases. Hazard ratio (HR) estimates and 95% CIs for psychiatric disorders were derived using weighted Cox proportional hazard models. Risks were compared across outcomes, dosage type, and locus features using generalized estimating equation models. A total of 3547 rCNVs were identified in 64 735 individuals assigned male at birth (53.8%) and 55 512 individuals assigned female at birth (46.2%) whose age at the end of follow-up ranged from 7.0 to 34.7 years (mean, 21.8 years). Most observed increases in rCNV-associated risk for ADHD, ASD, or SSD were moderate, and risk estimates were highly correlated across these disorders. Notable exceptions included high ASD-associated risk observed for Prader-Willi/Angelman syndrome duplications (HR, 20.8; 95% CI, 7.9-55). No rCNV was associated with increased MDD risk. Also, rCNV-associated risk was positively correlated with locus size and gene constraint but not with dosage type. Comparison with published case-control and community-based studies revealed a higher prevalence of deletions and lower associated increase in risk for several rCNVs in iPSYCH2015. This study found that several rCNVs were more prevalent and conferred less risk of psychiatric disorders than estimated previously. Most case-control studies overestimate rCNV-associated risk of psychiatric disorders, likely because of selection bias. In an era where genetics is increasingly being clinically applied, these results highlight the importance of population-based risk estimates for genetics-based predictions.

Early environmental predictors for attention-deficit hyperactivity disorder (ADHD), autism spectrum disorder (ASD) and their co-occurrence: The prospective ABIS-Study

ADHD and ASD are highly heritable and show a high co-occurrence and persistence into adulthood. This study aimed to identify pre and perinatal risk factors, and early psychosocial exposures related to later diagnosis of ADHD, ASD, and their co-occurrence. 16,365 children born 1997–1999 and their families, involved in the prospective population-based ABIS study (All Babies in Southeast Sweden), were included in this sub-study. Pre and perinatal factors and early environmental psychosocial exposures were collected from parental-questionnaires at birth and 1-year follow-up. Diagnoses from birth up to 23 years of age were obtained from the Swedish National Diagnosis Register in 2020. The cumulative incidence of ADHD, ASD, and their co-occurrence in the ABIS-cohort Study were 4.6%, 1.7%, and 1.1%, respectively. Being male was associated with an increased risk for ADHD, ASD, and their co-occurrence (aOR 1.30, 1.56, and 1.91, respectively), while higher household income reduced it (aOR 0.82, 0.73, and 0.64). Serious life events during pregnancy (aOR 1.40) and maternal smoking (aOR 1.51) increased the risk of ADHD, while older maternal age (aOR 0.96), higher parental education (aOR 0.72 maternal and aOR 0.74 paternal) and longer exclusive breastfeeding (aOR 0.72) reduced it. Non-Swedish paternal nationality (aOR 0.40) and higher maternal education (aOR 0.74) were associated with a lower risk of ASD, while a family history of autoimmune diseases increased the risk of the co-occurrence of both disorders (aOR 1.62). Obtained results suggest that the etiology of ADHD, ASD, and their co-occurrence is independently associated with environmental psychosocial predictors. The co-occurrence seems to overlap the etiology of ADHD, in which psychosocial determinants have a larger role, however, it is also independently influenced by a family history of autoimmune diseases.

Pathogenic variants in autism gene KATNAL2 cause hydrocephalus and disrupt neuronal connectivity by impairing ciliary microtubule dynamics

Enlargement of the cerebrospinal fluid (CSF)-filled brain ventricles (cerebral ventriculomegaly), the cardinal feature of congenital hydrocephalus (CH), is increasingly recognized among patients with autism spectrum disorders (ASD). KATNAL2, a member of Katanin family microtubule-severing ATPases, is a known ASD risk gene, but its roles in human brain development remain unclear. Here, we show that nonsense truncation of Katnal2 (Katnal2Δ17) in mice results in classic ciliopathy phenotypes, including impaired spermatogenesis and cerebral ventriculomegaly. In both humans and mice, KATNAL2 is highly expressed in ciliated radial glia of the fetal ventricular-subventricular zone as well as in their postnatal ependymal and neuronal progeny. The ventriculomegaly observed in Katnal2Δ17 mice is associated with disrupted primary cilia and ependymal planar cell polarity that results in impaired cilia-generated CSF flow. Further, prefrontal pyramidal neurons in ventriculomegalic Katnal2Δ17 mice exhibit decreased excitatory drive and reduced high-frequency firing. Consistent with these findings in mice, we identified rare, damaging heterozygous germline variants in KATNAL2 in five unrelated patients with neurosurgically treated CH and comorbid ASD or other neurodevelopmental disorders. Mice engineered with the orthologous ASD-associated KATNAL2 F244L missense variant recapitulated the ventriculomegaly found in human patients. Together, these data suggest KATNAL2 pathogenic variants alter intraventricular CSF homeostasis and parenchymal neuronal connectivity by disrupting microtubule dynamics in fetal radial glia and their postnatal ependymal and neuronal descendants. The results identify a molecular mechanism underlying the development of ventriculomegaly in a genetic subset of patients with ASD and may explain persistence of neurodevelopmental phenotypes in some patients with CH despite neurosurgical CSF shunting.

Newborn Dried Blood Spot Folate in Relation to Maternal Self-reported Folic Acid Intake, Autism Spectrum Disorder, and Developmental Delay.

Maternal folic acid intake has been associated with decreased risk for neurodevelopmental disorders including autism spectrum disorder (ASD). Genetic differences in folate metabolism could explain some inconsistencies. To our knowledge, newborn folate concentrations remain unexamined. We measured folate in archived newborn dried blood spots of children from the CHARGE (Childhood Autism Risks from Genetics and the Environment) case-control study who were clinically confirmed at 24-60 months to have ASD (n = 380), developmental delay (n = 128), or typical development (n = 247). We quantified monthly folic acid intake from maternally-reported supplements and cereals consumed during pregnancy and 3 months prior. We assessed associations of newborn folate with maternal folic acid intake and with ASD or developmental delay using regression. We stratified estimates across maternal and child MTHFR genotypes. Among typically developing children, maternal folic acid intake in prepregnancy and each pregnancy month and prepregnancy prenatal vitamin intake were positively associated with newborn folate. Among children with ASD, prenatal vitamin intake in pregnancy months 2-9 was positively associated with newborn folate. Among children with developmental delay, maternal folic acid and prenatal vitamins during the first pregnancy month were positively associated with neonatal folate. Associations differed by MTHFR genotype. Overall, neonatal folate was not associated with ASD or developmental delay, though we observed associations with ASD in children with the MTHFR 677 TT genotype (odds ratio: 1.76, 95% CI = 1.19, 2.62; P for interaction = 0.08). Maternal prenatal folic acid intake was associated with neonatal folate at different times across neurodevelopmental groups. Neonatal folate was not associated with reduced ASD risk. MTHFR genotypes modulated these relationships.

Dentate Gyrus Morphogenesis is Regulated by an Autism Risk Gene Trio Function in Granule Cells.

Autism Spectrum Disorders (ASDs) are reported as a group of neurodevelopmental disorders. The structural changes of brain regions including the hippocampus were widely reported in autistic patients and mouse models with dysfunction of ASD risk genes, but the underlying mechanisms are not fully understood. Here, we report that deletion of Trio, a high-susceptibility gene of ASDs, causes a postnatal dentate gyrus (DG) hypoplasia with a zigzagged suprapyramidal blade, and the Trio-deficient mice display autism-like behaviors. The impaired morphogenesis of DG is mainly caused by disturbing the postnatal distribution of postmitotic granule cells (GCs), which further results in a migration deficit of neural progenitors. Furthermore, we reveal that Trio plays different roles in various excitatory neural cells by spatial transcriptomic sequencing, especially the role of regulating the migration of postmitotic GCs. In summary, our findings provide evidence of cellular mechanisms that Trio is involved in postnatal DG morphogenesis.

Reduction of Glyoxalase 1 Expression Links Fetal Methylmercury Exposure to Autism Spectrum Disorder Pathogenesis.

Glyoxalase 1 (Glo1) is an essential enzyme to detoxify methylglyoxal (MGO), a cytotoxic byproduct of glycolysis. Accumulating studies have shown an important role of Glo1 in regulating cortical development and neurogenesis, potentially contributing to the pathogenesis of autism spectrum disorder (ASD) when impaired. We have previously shown that prenatal exposure to non-apoptotic low-dose methylmercury (MeHg), an environmental pollutant, induces premature cortical neurogenesis and ASD-like behaviors in a rodent model. In this study, we aimed to determine the underlying molecular mechanisms that mediate prenatal MeHg-induced premature neuronal differentiation and abnormal neurodevelopment. Using single-cell RNA sequencing (scRNA-seq) and real-time quantitative PCR (RT-qPCR), we found that prenatal MeHg exposure at a non-apoptotic dose significantly reduced Glo1 gene expression in embryonic cultured radial glia precursors (RGPs). In cultured RGPs, the knockdown of Glo1 expression increased neuronal production at the expense of the cultured RGPs population, while overexpression of Glo1 restored MeHg-induced neuronal differentiation back to normal levels. Furthermore, we found that co-treatment with both MeHg and multiple MGO scavengers or a CREB inhibitor (iCREB) mitigated MeHg-induced premature neuronal differentiation, reinforcing the role of Glo1 and CREB in mediating MeHg-induced neuronal differentiation. Our findings demonstrate a direct link between MeHg exposure and expression of an ASD risk gene Glo1 in cortical development, supporting the important role of gene-environment interaction in contributing to the etiology of neural developmental disorders, such as ASD.

Arid1b haploinsufficiency in cortical inhibitory interneurons causes cell-type-dependent changes in cellular and synaptic development.

Autism spectrum disorder (ASD) presents with diverse cognitive and behavioral abnormalities beginning during early development. Although the neural circuit mechanisms remain unclear, recent work suggests pathology in cortical inhibitory interneurons (INs) plays a crucial role. However, we lack fundamental information regarding changes in the physiology of synapses to and from INs in ASD. Here, we used transgenic mice to conditionally knockout one copy of the high confidence ASD risk gene Arid1b from the progenitors of parvalbumin-expressing fast-spiking (PV-FS) INs and somatostatin-expressing non-fast-spiking (SST-NFS) INs. In brain slices, we performed paired whole-cell recordings between INs and excitatory projection neurons (PNs) to investigate changes in synaptic physiology. In neonates, we found reduced synaptic input to INs but not PNs, with a concomitant reduction in the frequency of spontaneous network events, which are driven by INs in immature circuits. In mature mice, we found a reduction in the number of PV-FS INs in cortical layers 2/3 and 5. However, changes in PV-FS IN synaptic physiology were cortical layer and PN cell-type dependent. In layer 5, synapses from PV-FS INs to subcortical-projecting PNs were weakened. In contrast, in layer 2/3, synapses to and from PV-FS INs and corticocortical-projecting PNs were strengthened, leading to enhanced feedforward inhibition of input from layer 4. Finally, we found a novel synaptic deficit among SST-NFS INs, in which excitatory synapses from layer 2/3 PNs failed to facilitate. Our data highlight that changes in unitary synaptic dynamics among INs in ASD depend on neuronal cell-type.

Evidence supporting the relationship between maternal asthma and risk for autism spectrum disorders.

Evidence supporting the relationship between maternal asthma and risk for autism spectrum disorders.

EE319 Cost-Effectiveness of Assigning Early Interventions to Infants at High Risk for Autism Spectrum Disorder Using MRI Screening

EE319 Cost-Effectiveness of Assigning Early Interventions to Infants at High Risk for Autism Spectrum Disorder Using MRI Screening

Long-term Neurobehavioral and Metabolic Outcomes in Offspring of Mothers With Diabetes During Pregnancy: A Large, Population-Based Cohort Study in Ontario, Canada.

Offspring of women with diabetes are at increased risk of developing neurobehavioral and cardiometabolic disorders, but there is scant evidence regarding the association between glycemic level during pregnancy and these long-term offspring outcomes. We conducted a population-based, cohort study of deliveries in Ontario between April 1991 and March 2018. Women had preexisting diabetes, gestational diabetes, or no diabetes. We applied a Cox proportional hazard model to examine the risk of developing attention deficit hyperactivity disorder (ADHD), autism spectrum disorder (ASD), and cardiometabolic outcomes in offspring and assessed the association between pregnancy HbA1c levels and risk of outcomes, adjusting for confounders. A total of 3,407,961 mother/infant pairs were followed up to 29 years. Using a Cox proportional hazard model, offspring of women with type 1 diabetes had the highest risk of ADHD (adjusted hazard ratio [aHR] 1.43 [95% CI 1.36-1.49]), ASD (aHR 1.94 [1.80-2.09]), diabetes (aHR 4.73 [4.34-5.16]), hypertension (aHR 2.32 [2.07-2.61]), and cardiovascular disease (CVD) (aHR 1.72 [1.56-1.90]), followed by offspring of women with type 2 diabetes and gestational diabetes compared with those unexposed. Among women with preexisting diabetes, there was an association between level of pregnancy HbA1c and offspring diabetes (aHR 1.22 [95% CI 1.12-1.32]), hypertension (aHR 1.42 [1.29-1.57]), and CVD (aHR 1.20 [1.11-1.29]) but no statistically significant association with neurobehavioral outcomes. In utero exposure to maternal diabetes was associated with an increase in ADHD, ASD, and cardiometabolic outcomes in offspring, with differences seen across diabetes subtypes. Pregnancy glycemia was associated with cardiometabolic outcomes, but not neurobehavioral outcomes, and provides a potentially modifiable risk factor to decrease cardiometabolic outcomes in offspring.

Autism Spectrum Disorder Diagnoses and Congenital Cytomegalovirus.

To examine the association between congenital cytomegalovirus (cCMV) and autism spectrum disorder (ASD) administrative diagnoses in US children. Cohort study using 2014 to 2020 Medicaid claims data. We used diagnosis codes to identify cCMV (exposure), ASD (outcome), and covariates among children enrolled from birth through ≥4 to <7 years. Covariates include central nervous system (CNS) anomaly or injury diagnosis codes, including brain anomaly, microcephaly within 45 days of birth, cerebral palsy, epilepsy, or chorioretinitis. We used Cox proportional hazards regression models to estimate hazard ratios and 95% confidence intervals, overall and stratified by sex, birth weight and gestational age outcome (low birth weight or preterm birth), and presence of CNS anomaly or injury. Among 2 989 659 children, we identified 1044 (3.5 per 10 000) children with cCMV and 74 872 (25.0 per 1000) children with ASD. Of those with cCMV, 49% also had CNS anomaly or injury diagnosis codes. Children with cCMV were more likely to have ASD diagnoses (hazard ratio: 2.5; 95% confidence interval: 2.0-3.2, adjusting for birth year, sex, and region). This association differed by sex and absence of CNS anomaly or injury but not birth outcome. Children with (versus without) cCMV diagnoses in Medicaid claims data, most of whom likely had symptomatic cCMV, were more likely to have ASD diagnoses. Future research investigating ASD risk among cohorts identified through universal cCMV screening may help elucidate these observed associations.

Neurodevelopment and Metabolism in the Maternal-Placental-Fetal Unit.

Disturbances in maternal, placental, and fetal metabolism are associated with developmental outcomes. Associations of maternal, placental, and fetal metabolism with subsequent neurodevelopmental outcomes in the child are understudied. To investigate the metabolic associations within the maternal-placental-fetal unit and subsequent neurodevelopmental outcomes in younger siblings of children with autism spectrum disorder (ASD). This cohort study was conducted within a subset of the Markers of Autism Risk in Babies, Learning Early Signs (MARBLES) cohort. MARBLES is a prospective birth cohort of younger siblings of children with ASD assessed for neurodevelopmental outcomes at approximately age 36 months. Participants in MARBLES were recruited through the UC Davis MIND Institute. This subset of the MARBLES cohort included younger siblings born between 2009 and 2015. Maternal third trimester serum, placental tissue, and umbilical cord serum samples were collected from participants. Only pregnancies with at least 2 of these sample types were included in this analysis. Data analysis was conducted from March 1, 2023, to March 15, 2024. Quantitative metabolomics analysis was conducted on maternal third trimester serum, as well as placental tissue and umbilical cord serum collected at delivery. Using the Autism Diagnostic Observation Schedule and Mullen Scales of Early Learning, outcomes were classified as ASD, other nontypical development (non-TD), and typical development (TD). This analysis included 100 maternal serum samples, 141 placental samples, and 124 umbilical cord serum samples from 152 pregnancies (median [IQR] maternal age, 34.6 [30.8-38.3] years; median [IQR] gestational age, 39.0 [38.6-39.7] weeks; 87 [57.2%] male infants). There was no evidence that the maternal third trimester serum metabolome was significantly associated with the other metabolomes. The placental and cord serum metabolomes were highly correlated (first latent variate pair: R2 = 0.75; P < .001) and the variate scores for each tissue were significantly associated with reduced risk of non-TD (placenta: relative risk [RR], 0.13; 95% CI, 0.02-0.71; cord: RR, 0.13; 95% CI, 0.03-0.70) but not ASD (placenta: RR, 1.09; 95% CI, 0.42-2.81; cord: RR, 0.63; 95% CI, 0.23-1.73) compared with the TD reference group. In this cohort study of children with high familial risk of ASD, placental and cord serum metabolism at delivery were highly correlated. Furthermore, placental and cord serum metabolic profiles were associated with risk of non-TD.

Linking PM2.5 to autism spectrum disorder

This paper elaborates the potential link between PM2.5 air pollution and Autism Spectrum Disorder (ASD), exploring mechanisms such as placental transmission, oxidative stress, signal transduction, and endocrine disruption. Referencing studies from Southwestern Pennsylvania, Shanghai, and animal experiments, together they reveal a consistent association between PM2.5 exposure during prenatal development and an increased risk of ASD. Mechanistically, PM2.5 is found to affect placental function, induce oxidative stress, and disrupt endocrine pathways, providing insights into potential pathways for neurodevelopmental disorders. The analysis emphasizes the impact on communities of lower socioeconomic status, where PM2.5 exposure is higher, emphasizing the need for environmental protection. Hence, global research efforts are encouraged when considering the current lack of understanding on ASD prevalence in diverse populations. In the broad scope, this work contributes to the growing amount of evidence that links environmental factors, particularly air pollution, to neuropsychiatric development, urging further exploration into the impacts of pollution on human health.

Maternal thyroid function in early pregnancy and offspring school performance and neurodevelopmental disorders.

Thyroid hormones are critical for neural development, and during the first trimester of pregnancy the fetus relies fully on maternal thyroid hormone production. To investigate the associations between maternal thyroid hormone levels in the first trimester with the child's school performance, risk of attention deficit hyperactivity disorder (ADHD) and autism spectrum disorder (ASD). From the Copenhagen Primary Care Laboratory Pregnancy Database information on first trimester TSH and fT4 measurements in mothers of children born in 2000-2014 were linked with information on the child's standardized test scores in school, ADHD (patient record diagnoses and medication) and ASD (patient record diagnoses) until end of 2018. Associations of TSH and fT4 with the outcomes were individually assessed by linear mixed models and Cox regression models. The analyses were stratified by preexisting maternal thyroid disorders. TSH measurements were available for 17,909 mother-child dyads. Among those with children born in 2000-2009, 6,126 had a standardized school test score and were analyzed for the association between maternal thyroid hormone levels and child's school performance, and no support for an association was found. The association between thyroid hormone levels and child's risk of ADHD and ASD were analyzed for the 17,909 dyads and with no support for an association between thyroid hormone levels and these neurodevelopmental disorders. Stratification by preexisting maternal thyroid disorders did not affect the results. We found no evidence for associations between first trimester maternal thyroid hormone levels and child's school performance, or risk of ADHD or ASD.

Association between exposure to antibiotics during pregnancy or early infancy and risk of autism spectrum disorder, intellectual disorder, language disorder, and epilepsy in children: population based cohort study

ObjectiveTo evaluate the association between antibiotic use during pregnancy or early infancy and the risk of neurodevelopmental disorders in children.DesignNationwide population based cohort study and sibling analysis.SettingKorea’s National Health Insurance...