Autism Risk Research Articles

The role of choline in the physiology of reproductivity

Choline is an essential nutrient, but intake among pregnant women is insufficient – only 7% of them consume adequate amounts of choline. The discrepancy between choline requirements and actual intake raises questions about the need for choline supplementation and its potential benefits for pregnant women. The diet of the expectant mother, rich in choline, in the preconception period ensures folliculogenesis and better quality of oocytes, changes the foetal epigenome, counteracting genomic defects during intrauterine development and reducing the susceptibility to metabolic changes in adulthood. Choline is a source of methyl groups and its consumption reduces the risk of NTDs by 7 times, so a promising trend in nutritional support of pregnancy and prevention of NTDs is the intake of folates and choline in combination with other micronutrients. Choline promotes the growth, proliferation and functioning of placental cells, transport of macronutrients, and has an anti-inflammatory effect. The risk of low foetal weight is reduced by 69% when choline is added to the mother’s regular diet. A significant connection has been shown between high levels of choline in the mother and a 2-fold reduction in the risk of preeclampsia, premature birth and a significant effect on the neurodevelopment and mental health of the child – improving neurocognitive functions and reducing the risk of autism and attention deficit hyperactivity disorder. A choline supplement at a dose of 130 mg/day as part of the vitamin-mineral complex Femibion 1 is sufficient to meet the needs for this nutrient during the preconception period and in the first trimester of pregnancy. The need for choline supplementation in the pregravid period and the first trimester of pregnancy is because on folliculogenesis and oocyte protection, epigenetic programming, the effectiveness of preventing congenital malformations of the foetus, participation in metabolic and physiological processes in the placenta, reducing the risk of placenta-associated complications, influence on the development of nervous tissue and brain of the foetus and newborn.

Gestational phthalate exposure and behavioral problems in preschool-aged children with increased likelihood of autism spectrum disorder

BackgroundExperimental studies have shown associations between gestational phthalate exposure and behavioral problems among offspring; however, epidemiological evidence is still mixed. This study aims to investigate whether gestational phthalate exposure is associated with behavioral problems in preschool-aged children. MethodsParticipants include 178 mother-child pairs from MARBLES (Markers of Autism Risk in Babies – Learning Early Signs), a cohort with high familial likelihood of autism spectrum disorder (ASD). We quantified 14 phthalate metabolites in multiple maternal urine samples collected during the 2nd and 3rd trimesters. Preschool behavior problems were assessed using the Child Behavioral Checklist (CBCL), a standardized instrument for evaluating behavior problems of children aged 1.5–5 years. To examine associations of CBCL scores with both individual phthalate biomarker concentrations and their mixture, we used negative binomial regression and weighted quantile sum regression. ResultsOverall, maternal phthalate biomarker concentrations were not associated with child behavior problems. Monoisobutyl phthalate (MiBP) concentrations were inversely associated with child anxious/depressed symptoms and somatic complaints. Mono-hydroxy-isobutyl phthalate (MHiBP) and monobenzyl phthalate (MBzP) were also inversely associated with somatic complaints. When assessing trimester-specific associations, more behavior problems were associated with the 2nd trimester biomarker concentrations: mono(3-carboxypropyl) phthalate (MCPP) and monocarboxyisononyl phthalate (MCNP) were positively associated with somatic complaints. All associations became non-significant after false discovery rate correction. No association between a mixture of phthalates and CBCL scores was found. ConclusionsOur study observed no clear evidence of gestational phthalate exposure on child behavior problems. However, our findings based on the biomonitoring assessment of multiple samples per participant could improve our understanding of gestational phthalate exposure in association with behavior problems in preschool-aged children.

Screen Time Before 2 Years of Age and Risk of Autism at 12 Years of Age

This cohort study evaluates the association between screen time and autism spectrum disorder by considering socioeconomic factors as instrumental variables.

A review of the risk factors for Autism

Abstract Background Autism Spectrum Disorder (or Autism) is a neurodevelopmental and neurological condition, with prevalence of 1 in 100 children globally. This review examines the most common factors associated with Autism. Methods We conducted a scoping review of factors associated with an increased risk of developing Autism. These included genetic predisposition, parental age, gender, birth complications and morbidities due to other medical conditions. Results Evidence from twin studies shows a 90% genetic predisposition towards Autism - with 102 genes strongly associated with Autism, including SCN1A and SLC6A1. There are also genetic syndromes and chromosomal disorders associated with Autism, including Fragile X syndrome and Tuberous Sclerosis complex (TSC). Several studies have demonstrated an increased risk with advanced parental age (>35 years) (e.g., fathers >50 years are 2.2 times more likely to have a child with Autism than those <30 years). Other factors include infections during pregnancy (e.g. immune dysfunction) and gestational diabetes. Prematurity, such as low birth weight (<1500g) and low gestational age (<32 weeks) are also associated with an increased risk of Autism. With regard to gender, boys are more likely to be diagnosed with Autism - gender ratio of 3:1 and 4:1 has been reported in different populations. Abnormalities in brain development during early prenatal or postnatal periods may increase the risk of Autism. These abnormalities can lead to social, communication, and behavioural challenges characteristic of Autism. Conclusions Autism is a complex and heterogeneous condition that likely arises from a combination of factors such as genetic susceptibility and pre- and postnatal factors. An understanding of these factors is important for early detection, intervention, and support for children to improve their quality of life and reduce morbidity. Key messages • Risk factors associated with an increased risk of developing Autism include genetic predisposition, parental age, gender, birth complications and other comorbidities. • There is need to increase awareness of the risk factors of Autism to improve quality of life.

Evaluating Autism Risk Factors and Their Impact on Children in Thi-Qar, Iraq

Evaluating Autism Risk Factors and Their Impact on Children in Thi-Qar, Iraq

Regional differences in autism and intellectual disability risk associated with cesarean section delivery.

Prior epidemiological studies investigating the association between delivery mode (i.e., vaginal birth and cesarean section [C-section]) and autism spectrum disorder (ASD) and intellectual disability (ID) risk have reported mixed findings. This study examined ASD and ID risks associated with primary and repeat C-section within diverse US regions. During even years 2000-2016, 8-years-olds were identified with ASD and/or ID and matched to birth records [ASD only (N = 8566, 83.6% male), ASD + ID (N = 3445, 79.5% male), ID only (N = 6158, 60.8% male)] using the Centers for Disease Control and Prevention's Autism and Developmental Disabilities Monitoring Network methodology. The comparison birth cohort (N = 1,456,914, 51.1% male) comprised all births recorded in the National Center for Health Statistics corresponding to birth years and counties in which surveillance occurred. C-section rates in the birth cohort demonstrated significant regional variation with lowest rates in the West. Overall models demonstrate increased odds of disability associated with primary and repeat C-section. Adjusted models, stratified by region, identified significant variability in disability likelihood associated with repeat C-section: increased odds occurred for all case groups in the Southeast, for ASD only and ID only in the Mid-Atlantic, and no case groups in the West. Regional variability in disability risk associated with repeat C-section coincides with differences in birth cohorts' C-section rates. This suggests increased likelihood of disability is not incurred by the procedure itself, but rather C-section serves as a proxy for exposures with regional variability that influence fetal development and C-section rates.

A genome-first study of sex chromosome aneuploidies provides evidence of Y chromosome dosage effects on autism risk

A female protective effect has long been postulated as the primary explanation for the four-fold increase of autism spectrum disorder (ASD) diagnoses in males versus females. However, genetic and epidemiological investigations of this hypothesis have so far failed to explain the large difference in ASD prevalence between the sexes. To address this knowledge gap, we examined sex chromosome aneuploidy in a large ASD case-control cohort to evaluate the relationship between X and Y chromosome dosage and ASD risk. From these data, we modeled three relationships between sex chromosome dosage and ASD risk: the extra Y effect, the extra X effect, and sex chromosome haploinsufficiency. We found that the extra Y effect increased ASD risk significantly more than the extra X effect. Among females, we observed a large association between 45, X and ASD, confirming sex chromosome haploinsufficiency as a strong ASD risk factor. These results provide a framework for understanding the relationship between X and Y chromosome dosage on ASD, which may inform future research investigating genomic contributors to the observed sex difference.

Gestational exposure to organophosphate esters and autism spectrum disorder and other non-typical development in a cohort with elevated familial likelihood

BackgroundGestational exposure to organophosphate esters (OPEs) is known to affect offspring neurodevelopment in animal studies. However, epidemiological evidence is inconsistent. MethodsParticipants were 277 mother-child pairs from MARBLES (Markers of Autism Risk in Babies – Learning Early Signs), a cohort with elevated familial likelihood of autism spectrum disorder (ASD). Nine OPE biomarker concentrations were quantified in maternal urine collected during the 2nd or 3rd trimesters of pregnancy. At age 3 years, children underwent clinical assessment for ASD and were classified into ASD, other non-typical development (non-TD), or typical development (TD). Multinomial logistic regression was used to estimate associations between each OPE biomarker and relative risk ratios for ASD and non-TD compared to TD. We examined effect modification by child sex and socioeconomic status. We also conducted a secondary analysis by using a continuous measure of ASD symptom severity as an outcome. Quantile-based g-computation was performed to examine the associations for an OPE mixture. ResultsOverall, no significant association was observed between the concentrations of each OPE biomarker or their mixture and relative risk for either ASD or non-TD. Effect modifications by child sex and maternal education were not observed. When the analysis was stratified by homeownership, among non-homeowners, ASD likelihood was increased with increased levels of bis(1-chloro-2-propyl) phosphate, bis(butoxyethyl) phosphate, and sum of di-n-butyl phosphate and di-iso-butyl phosphate (DBUP/DIBP) (pint < 0.10). Higher DBUP/DIBP were associated with increased ASD symptom severity scores. ConclusionThere was no clear evidence of gestational OPE exposure in association with relative risk for ASD; however, potential effect modification by homeownership was observed. Although our cohort includes children with elevated familial likelihood of ASD, this is the first study investigating the association between gestational OPE exposure and clinically-diagnosed ASD. Further research is needed to confirm our findings in the general population.

A Scoping Review: Risk of Autism in Children Born from Assisted Reproductive Technology

Background/Objectives: As the incidence of autism spectrum disorder (ASD) and use of assisted reproductive technologies (ART) continue to rise in tandem, their relationship to one another, as well as the general risks of ART, are increasingly being explored. The purpose of this review is to summarize the literature on ASD risk, as well as the risks for other neurological and neurodevelopmental disorders, in children born following the implementation of ART. Methods: Here we review studies published between 2000−2023 that elucidate relationships between ASD and some of the most common forms of ART, including in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI), using fresh vs. frozen embryo transfer. Articles were identified by searching Google Scholar and PubMed databases. Results: Though some studies report adverse neurodevelopmental outcomes in ART-conceived children, such as ASD, attention-deficit/hyperactivity disorder (ADHD), and cerebral palsy, a majority of studies do not show a significant association between ART and neurodevelopmental disorders. Additionally, many confounding factors like multiple and preterm births, underlying infertility, and advanced parental age have been discussed, highlighting the need for studies that effectively control for these confounders. Potential mechanisms implicated in the pathogenesis of ASD, including epigenetic mechanisms of gene expression, that may be related to ART procedures, are also discussed. Conclusion: ART may pose a low additional risk to development of ASD, but confounding factors likely account for most of this risk. Several steps in the process of ART may cause epigenetic changes that are implicated in the development of ASD.

DNA methylation signatures of prenatal socioeconomic position associated with 36-month language outcomes

BackgroundSocioeconomic position (SEP), which reflects one’s position in society and access to resources, is strongly tied to neurodevelopment and is associated with epigenetic changes. AIM: This study examined whether DNA methylation signatures of prenatal SEP, measured in birth samples, are associated with child neurodevelopmental outcomes at 36 months of age. METHODS: Prenatal SEP DNA methylation scores were derived using 97 placenta and 127 cord blood biospecimens in the Early Autism Risk Longitudinal Investigation cohort. Participants completed the Mullen Scales of Early Learning (MSEL) and Vineland Adaptive Behavior Scales (VABS) at 36 months of age. Generalized regression analyses, adjusting for maternal age and race, were performed to test the association between SEP methylation score, for each birth biospecimen type, and MSEL and VABS scores. RESULTS: Significant associations were observed between placenta SEP methylation score and MSEL Expressive Language outcomes (beta = −2.7, p = 0.046, 95 % CI [- 5.43, −0.05]) and Receptive Language outcomes (beta = −2.5, p = 0.037, 95 % CI [-4.82, −0.16]). In cord blood, methylation-SEP scores were significantly associated with Receptive Language outcomes (beta = −2.0, p = 0.037, 95 % CI [-3.85, −0.12]). No significant associations were observed with VABS scores. CONCLUSION: Our results confirm associations between prenatal SEP and early childhood language development using a novel empiric DNA methylation measure of exposure

Childhood anaesthesia and autism risk: population and murine study.

Early childhood exposure to general anaesthesia has been linked to potential changes in infant brain morphology and behaviour in preclinical studies, contributing to long-term behaviours associated with autism spectrum disorder. This study investigates the association between early childhood exposure to general anaesthesia and the risk of autism, using a population-based cohort study with matching for baseline characteristics and evaluates the effect of sevoflurane exposure on autism-like behaviour in mice, using the Taiwan Maternal and Child Health Database. Children aged 0-3 who received at least one exposure to general anaesthesia between 2004 and 2014 were matched 1:1 with children who were not exposed. Risk ratios and confidence intervals were used to assess the relationship between general anaesthesia and the occurrence of autism. Additionally, mice were exposed to sevoflurane for 2 h on postnatal days 5-7, and changes in behaviour related to autism were evaluated. Propensity score matching resulted in 7530 children in each group. The incidence rates (IRs) of autism were 11.26 and 6.05 per 100 000 person-years in the exposed and unexposed groups, respectively. The incidence ratio for autism following exposure to general anaesthesia was 1.86 (95% confidence interval, 1.34-2.59). In mice, sevoflurane exposure induced autism-like behaviours and led to the downregulation of high-risk autism genes, including ARID1B, GABRA5, GABRB3, GRIN2B, SHANK3 and SUV420H1. Early childhood exposure to general anaesthesia is associated with an increased risk of autism. Repeated exposure to sevoflurane in mice induces autism-like behaviours, suggesting a potential link between anaesthesia and the development of autism.

Female Infertility and Neurodevelopmental Disorders in Children: associations and evidence for familial confounding in Denmark.

Existing research suggests the impact of infertility on the risk of neurodevelopmental disorders in children, however, studies to date have failed to separate the impact of male and female infertility, often blurring the lines with proxies that encompass all forms of infertility. Moreover, while both health conditions co-occurring with infertility and genetic factors operating upstream have been suggested to influence the association between infertility and child outcomes, their roles and potential impact on observed associations remain unclear. The objectives of this study are to investigate the relationship between female infertility and autism in the child, differentiating it from the effects of male and the couple infertility; consider the role of various maternal and birth factors in the association; and examine the effects of shared familial confounders on the association. Danish population-based cohort study, including all singleton live births in Denmark 1998-2015, their parents and parents' siblings. The cohort was followed up until December 31, 2016. The exposure was a history of female infertility in the mother and the mother's sister. We examined four definitions of female infertility based on the ICD-10 codes derived from the Danish National Patient Register - any female infertility; specified female infertility; female exclusive infertility; and female or male infertility. The outcome was diagnosis of autism spectrum disorder (ASD) in the Danish Psychiatric Central Research Register or the national patient register. A multivariable Cox regression model was used to estimate the associations between female infertility and autism, accounting for child's sex, year of birth, maternal age, education level, chronic comorbidities, and pregnancy and birth complications. The effects of shared familial factors on the association were analyzed using exposure information from the child's maternal aunt. The cohort included 1,131,899 mother-child pairs, among which 18,374 children with ASD diagnosis. History of female infertility in the mother (all definitions) was significantly associated with autism in the child, with the association remaining robust after adjustment for covariates (HRadj=1.14 (95% CI, 1.03-1.26) for specified infertility). The diagnosis of infertility in a child's maternal aunt was also significantly linked to the child's autism risk, even after adjustment for maternal infertility (HRadj=1.10 (95% CI, 1.00-1.20). in This population-based birth cohort study, we found a slightly higher risk of autism in children born to mothers with a history of infertility, with the association remaining consistent across various definitions of female infertility and robust to adjustments for demographic, child, and maternal factors. The study suggests for the first time that shared familial factors, possibly both genetic and non-genetic, could be influencing both female infertility and the risk of autism in children, indicating a need for further investigation into these familial effects.

Commonly used genomic arrays may lose information due to imperfect coverage of discovered variants for autism spectrum disorder

BackgroundCommon genetic variation has been shown to account for a large proportion of ASD heritability. Polygenic scores generated for autism spectrum disorder (ASD-PGS) using the most recent discovery data, however, explain less variance than expected, despite reporting significant associations with ASD and other ASD-related traits. Here, we investigate the extent to which information loss on the target study genome-wide microarray weakens the predictive power of the ASD-PGS.MethodsWe studied genotype data from three cohorts of individuals with high familial liability for ASD: The Early Autism Risk Longitudinal Investigation (EARLI), Markers of Autism Risk in Babies-Learning Early Signs (MARBLES), and the Infant Brain Imaging Study (IBIS), and one population-based sample, Study to Explore Early Development Phase I (SEED I). Individuals were genotyped on different microarrays ranging from 1 to 5 million sites. Coverage of the top 88 genome-wide suggestive variants implicated in the discovery was evaluated in all four studies before quality control (QC), after QC, and after imputation. We then created a novel method to assess coverage on the resulting ASD-PGS by correlating a PGS informed by a comprehensive list of variants to a PGS informed with only the available variants.ResultsPrior to imputations, None of the four cohorts directly or indirectly covered all 88 variants among the measured genotype data. After imputation, the two cohorts genotyped on 5-million arrays reached full coverage. Analysis of our novel metric showed generally high genome-wide coverage across all four studies, but a greater number of SNPs informing the ASD-PGS did not result in improved coverage according to our metric.Limitations.The studies we analyzed contained modest sample sizes. Our analyses included microarrays with more than 1-million sites, so smaller arrays such as Global Diversity and the PsychArray were not included. Our PGS metric for ASD is only generalizable to samples of European ancestries, though the coverage metric can be computed for traits that have sufficiently large-sized discovery findings in other ancestries.ConclusionsWe show that commonly used genotyping microarrays have incomplete coverage for common ASD variants, and imputation cannot always recover lost information. Our novel metric provides an intuitive approach to reporting information loss in PGS and an alternative to reporting the total number of SNPs included in the PGS. While applied only to ASD here, this metric can easily be used with other traits.

Maternal folic acid over-supplementation impairs cardiac function in mice offspring by inhibiting SOD1 expression.

Folic acid (FA) supplementation during pregnancy aims to protect foetal development. However, maternal over-supplementation of FA has been demonstrated to cause metabolic dysfunction and increase the risk of autism, retinoblastoma, and respiratory illness in the offspring. Moreover, FA supplementation reduces the risk of congenital heart disease. However, little is known about its possible adverse effects on cardiac health resulting from maternal over-supplementation. In this study, we assessed the detrimental effects of maternal FA over-supplementation on the cardiac health of the offspring. Eight-week-old C57BL/6J pregnant mice were randomly divided into control and over-supplemented groups. The offspring cardiac function was assessed using echocardiography. Cardiac fibrosis was assessed in the left ventricular myocardium by histological analysis. Proteomic, protein, RNA, and DNA methylation analyses were performed by liquid chromatography-tandem mass spectrometry, western blotting, real-time quantitative PCR, and bisulfite sequencing, respectively. We found that maternal periconceptional FA over-supplementation impaired cardiac function with the decreased left ventricular ejection fraction in the offspring. Biochemical indices and tissue staining further confirmed impaired cardiac function in offspring caused by maternal FA over-supplementation. The combined proteomic, RNA expression, and DNA methylation analyses suggested that key genes involved in cardiac function were inhibited at the transcriptional level possibly due to increased DNA methylation. Among these, superoxide dismutase 1 was downregulated, and reactive oxygen species (ROS) levels increased in the mouse heart. Inhibition of ROS generation using the antioxidant N-acetylcysteine rescued the impaired cardiac function resulting from maternal FA over-supplementation. Our study revealed that over-supplementation with FA during mouse pregnancy is detrimental to cardiac function with the decreased left ventricular ejection fraction in the offspring and provides insights into the mechanisms underlying the association between maternal FA status and health outcomes in the offspring.

Telehealth general case parent training for children at risk for autism.

Parent-mediated interventions for infants and young children with an increased likelihood of autism may help ameliorate developmental concerns; however, generalization of parents' teaching strategies to novel child target skills has not been consistently demonstrated. This study expanded our parent training program, Parent Intervention for Children at-Risk for Autism (PICARA), by incorporating telehealth general case training (PICARA-TGCT) to promote generalization of teaching skills. Five parent-child dyads participated. Child target skills were chosen from the categories of imitation, receptive language, and expressive language. A concurrent multiple-baseline-across-participants design was used to evaluate the effect of training across two cohorts of parent-child dyads. Dependent variables included the percentage of correct parent teaching skills and the percentage of child correct responses. Parent teaching skills increased across all participants for both trained and untrained child target skills, as did child skills. This study provides support for PICARA-TGCT as an efficacious and efficient early intervention model.

Risk of Autism After Prenatal Topiramate, Valproate, or Lamotrigine Exposure

Risk of Autism After Prenatal Topiramate, Valproate, or Lamotrigine Exposure

Sleep need driven oscillation of glutamate synaptic phenotype.

Sleep loss increases AMPA-synaptic strength and number in the neocortex. However, this is only part of the synaptic sleep loss response. We report increased AMPA/NMDA EPSC ratio in frontal-cortical pyramidal neurons of layers 2-3. Silent synapses are absent, decreasing the plastic potential to convert silent NMDA to active AMPA synapses. These sleep loss changes are recovered by sleep. Sleep genes are enriched for synaptic shaping cellular components controlling glutamate synapse phenotype, overlap with autism risk genes and are primarily observed in excitatory pyramidal neurons projecting intra-telencephalically. These genes are enriched with genes controlled by the transcription factor, MEF2c and its repressor, HDAC4. Sleep genes can thus provide a framework within which motor learning and training occurs mediated by sleep-dependent oscillation of glutamate-synaptic phenotypes.

Cord blood cytokine profiles in children later diagnosed with autism spectrum disorder: Results from the prospective MARBLES study

In studies investigating the etiology and pathophysiology of autism spectrum disorder (ASD), immune dysregulation is commonly observed, with elevated levels of inflammatory cytokines frequently found in gestational tissues. However, studies investigating the relationship between early immune dysregulation within the umbilical cord blood (CB) compartment and neurodevelopmental outcomes remains limited. In this exploratory study, we utilized data from the prospective Markers for Autism Risk in Babies – Learning Early Signs (MARBLES) study to examine cytokine levels in the plasma fraction of CB in infants later diagnosed with ASD (n = 38) compared to infants typically developing (TD) at age 3 years (n = 103), using multiplex cytokine assays. Our findings reveal altered levels of several inflammatory cytokines in children later diagnosed with ASD, including increased granulocyte colony-stimulating factor (G-CSF) and decreased interleukin-1α (IL-1α), IL-1β, and IL-4 in CB. Furthermore, we identified several associations between behaviors and levels of cytokines, chemokines and growth factors. IL-1α, IL-17A, interferon γ-induced protein 10 (IP-10), and epidermal growth factor (EGF) were associated with worse scores on Autism Diagnostic Observation Schedule (ADOS) and the Mullen Scales of Early Learning (MSEL) assessments. In summary, our study demonstrates dysregulated levels of inflammatory cytokine mediators in the CB of children later diagnosed with ASD and that inflammatory mediators were associated with ASD severity, comorbid behaviors, and neurodevelopmental measures. These findings have important implications for the possible predictive value of early cytokine measures in neurodevelopmental outcomes and subsequent behavioral manifestations.

Autism spectrum disorder (ASD) diagnosis: A biochemical investigation into the diagnostic utility of S-adenosylmethionine (SAM), S-adenosylhomocysteine (SAH) levels and the SAM/SAH ratio

BackgroundThe balance between SAM and SAH ratios is critical for cellular methylation capacity such that a decrease in this ratio signals decrease the methylation potential, impacting cellular functions. In Autism Spectrum Disorder (ASD), impaired methylation processes are prominent, disrupting essential methyl group transfers crucial for DNA methylation, neurotransmitter synthesis, and detoxification. This disturbance affects gene expression and neural function, contributing to ASD development. This paper aims to explore ASD's pathogenesis by investigating biochemical parameters linked to the methylation cycle. For this purpose, some laboratory parameters are employed to aid in the understanding of potential laboratory abnormalities in ASD in children aged 2 to 8 years. Materials and MethodsThis study included a cohort of 43 children aged 2 to 8 years diagnosed ASD, alongside a control group of 43 age-and gender-matched healthy subjects. The serum of blood samples taken was used to measure biochemical factors. Specimens were processed using ELISA instrumentation and hemogram auto analyzers. The study conducted a statistical comparison between the ASD-diagnosed subjects and healthy controls, focusing on levels of S-adenosyl methionine (SAM), S-adenosyl homocysteine (SAH), Glycine N-methyltransferase (GNMT), and platelet counts. RESULTSThe levels of SAH and platelets were significantly higher in the case group compared to the control group. Conversely, levels of SAM, as well as the SAM/SAH ratio, were found to be significantly lower in the case group than in the control group (p < 0.05). No statistically significant difference was observed in the levels of GNMT when compared (p > 0.05). Receiver Operating Characteristic (ROC) analysis revealed that the diagnostic performance for SAM had an area under the curve (AUC) of 0.876, with a cut-off point determined at 286.9 ng/mL, yielding a sensitivity of 85 % and a specificity of 75 %. For SAH, the AUC was calculated to be 0.671, with a cut-off point set at 0.49 ng/mL, resulting in a sensitivity and specificity of 64 %. The SAM/SAH ratio demonstrated an AUC of 0.806, with the cut-off point established at 576.3, leading to a sensitivity and specificity of 72 %. A significant negative correlation was detected between the scores of the Modified Checklist for Autism in Toddlers (M-CHAT) and both SAM levels and the SAM/SAH ratio. The analysis indicated that an increase of one unit (1 ng/mL) in SAM levels is associated with a decreased autism risk by a factor of 1/0.914 = 1.1 %, whereas an increase of one unit (1 × 103/µL) in platelet count is associated with an increased autism risk by a factor of 1.019 %. Regarding glycine N-methyltransferase, no significant difference was observed between the two groups. ConclusionFollow-up studies with larger samples will be needed to better understand the potential for SAM, SAH, and SAM/SAH as a potential biomarker, at least for a subset of those with ASD. The correlation between these markers and the total score on the M-Chat raises further interest in this possibility. The correlation between these markers and the total score on the M-Chat further supports their utility as clinical biochemical laboratory parameters that could aid in the diagnosis of ASD.

Prenatal air pollution exposure and risk of autism: findings from ECHO cohorts

Prenatal air pollution exposure and risk of autism: findings from ECHO cohorts