The Changing Epidemiology of Autism Spectrum Disorders

Environmental and Genetic Factors in Autism Spectrum Disorders: Special Emphasis on Data from Arabian Studies

One of the most common neurodevelopmental disorders worldwide is autism spectrum disorder (ASD), which is characterized by language delay, impaired communication interactions, and repetitive patterns of behavior caused by environmental and genetic factors. This review aims to provide a comprehensive survey of recently published literature on ASD and especially novel insights into excitatory synaptic transmission. Even though numerous genes have been discovered that play roles in ASD, a good understanding of the pathophysiologic process of ASD is still lacking. The protein⁻protein interactions between the products of NLGN, SHANK, and NRXN synaptic genes indicate that the dysfunction in synaptic plasticity could be one reason for the development of ASD. Designing more accurate diagnostic tests for the early diagnosis of ASD would improve treatment strategies and could enhance the appropriate monitoring of prognosis. This comprehensive review describes the psychotropic and antiepileptic drugs that are currently available as effective pharmacological treatments and provides in-depth knowledge on the concepts related to clinical, diagnostic, therapeutic, and genetic perspectives of ASD. An increase in the prevalence of ASD in Gulf Cooperation Council countries is also addressed in the review. Further, the review emphasizes the need for international networking and multidimensional studies to design novel and effective treatment strategies.

Clinical Presentation of a Complex Neurodevelopmental Disorder Caused by Mutations in ADNP

BACKGROUND

In genome-wide screening studies for de novo mutations underlying autism and intellectual disability, mutations in the ADNP gene are consistently reported among the most frequent. ADNP mutations have been identified in children with autism spectrum disorder comorbid with intellectual disability, distinctive facial features, and deficits in multiple organ systems. However, a comprehensive clinical description of the Helsmoortel-Van der Aa syndrome is lacking.

METHODS

We identified a worldwide cohort of 78 individuals with likely disruptive mutations in ADNP from January 2014 to October 2016 through systematic literature search, by contacting collaborators, and through direct interaction with parents. Clinicians filled in a structured questionnaire on genetic and clinical findings to enable correlations between genotype and phenotype. Clinical photographs and specialist reports were gathered. Parents were interviewed to complement the written questionnaires.

RESULTS

We report on the detailed clinical characterization of a large cohort of individuals with an ADNP mutation and demonstrate a distinctive combination of clinical features, including mild to severe intellectual disability, autism, severe speech and motor delay, and common facial characteristics. Brain abnormalities, behavioral problems, sleep disturbance, epilepsy, hypotonia, visual problems, congenital heart defects, gastrointestinal problems, short stature, and hormonal deficiencies are common comorbidities. Strikingly, individuals with the recurrent p.Tyr719* mutation were more severely affected.

CONCLUSIONS

This overview defines the full clinical spectrum of individuals with ADNP mutations, a specific autism subtype. We show that individuals with mutations in ADNP have many overlapping clinical features that are distinctive from those of other autism and/or intellectual disability syndromes. In addition, our data show preliminary evidence of a correlation between genotype and phenotype.

Acceptability of the Transitional Wearable Companion "+me" in Typical Children: A Pilot Study

This work presents the results of the first experimentation of +me-the first prototype of Transitional Wearable Companion-run on 15 typically developed (TD) children with ages between 8 and 34 months. +me is an interactive device that looks like a teddy bear that can be worn around the neck, has touch sensors, can emit appealing lights and sounds, and has input-output contingencies that can be regulated with a tablet via Bluetooth. The participants were engaged in social play activities involving both the device and an adult experimenter. +me was designed with the objective of exploiting its intrinsic allure as an attractive toy to stimulate social interactions (e.g., eye contact, turn taking, imitation, social smiles), an aspect potentially helpful in the therapy of Autism Spectrum Disorders (ASD) and other Pervasive Developmental Disorders (PDD). The main purpose of this preliminary study is to evaluate the general acceptability of the toy by TD children, observing the elicited behaviors in preparation for future experiments involving children with ASD and other PDD. First observations, based on video recording and scoring, show that +me stimulates good social engagement in TD children, especially when their age is higher than 24 months.

Assessing the Relation between Plasma PCB Concentrations and Elevated Autistic Behaviours using Bayesian Predictive Odds Ratios

Autism spectrum disorder (ASD) is a neurodevelopmental condition characterized by impaired social communication and repetitive or stereotypic behaviours. In utero exposure to environmental chemicals, such as polychlorinated biphenyls (PCBs), may play a role in the etiology of ASD. We examined the relation between plasma PCB concentrations measured during pregnancy and autistic behaviours in a subset of children aged 3⁻4 years old in the Maternal-Infant Research on Environmental Chemicals (MIREC) Study, a pregnancy and birth cohort of 546 mother-infant pairs from Canada (enrolled: 2008⁻2011). We quantified the concentrations of 6 PCB congeners that were detected in >40% of plasma samples collected during the 1st trimester. At age 3⁻4 years, caregivers completed the Social Responsiveness Scale-2 (SRS), a valid and reliable measure of children's reciprocal social and repetitive behaviours and restricted interests. We examined SRS scores as both a continuous and binary outcome, and we calculated Bayesian predictive odds ratios for more autistic behaviours based on a latent variable model for SRS scores >60. We found no evidence of an association between plasma PCB concentrations and autistic behaviour. However, we found small and imprecise increases in the mean SRS score and odds of more autistic behaviour for the highest category of plasma PCB concentrations compared with the lowest category; for instance, an average increase of 1.4 (95%PCI: -0.4, 3.2) in the mean SRS (exposure contrast highest versus lowest PCB category) for PCB138 translated to an odds ratio of 1.8 (95%PCI: 1.0, 2.9). Our findings illustrate the importance of measuring associations between PCBs and autistic behaviour on both continuous and binary scales.

Prevalence and Treatment Patterns of Autism Spectrum Disorder in the United States, 2016

IMPORTANCE

Autism spectrum disorder (ASD) is a complex neurodevelopmental disorder. Previous surveys have reported a steady increase in ASD prevalence in US children over the past decades. Several behavioral therapies and medications have been developed to treat the symptoms of ASD; however, little is known about the current status of treatment usage for children diagnosed as having ASD.

OBJECTIVE

To estimate the prevalence and treatment patterns of ASD among US children using nationally representative data.

DESIGN, SETTING, AND PARTICIPANTS

This study used data from the 2016 National Survey of Children's Health, a nationwide, population-based, cross-sectional survey. We included 43 032 children aged 3 to 17 years. Data were collected through questionnaires completed by a parent or guardian. Data were analyzed from February 2018 to March 2018.

MAIN OUTCOMES AND MEASURES

Outcome variables included ASD diagnosed by a physician or health professional and the use of behavioral treatment or medication treatment among children with ASD.

RESULTS

Of the 43 032 included participants, 22 072 (51.3%) were male, and the mean (SD) age was 10.7 (4.4) years. The weighted prevalence of ever-diagnosed ASD and current ASD were 2.79% (95% CI, 2.46-3.12) and 2.50% (95% CI, 2.21-2.79), respectively. The state-level prevalence of ever-diagnosed ASD varied from 1.54% (95% CI, 0.60-2.48) in Texas to 4.88% (95% CI, 2.72-7.05) in Florida. Nationally, about 70% of children with current ASD (70.5%; 95% CI, 65.1-75.8) were treated; 43.3% (95% CI, 37.4-49.2) received behavioral treatment only, 6.9% (95% CI, 3.7-10.1) received medication treatment only, and 20.3% (95% CI, 16.5-24.1) received both behavioral and medication treatments. The remaining 29.5% (95% CI, 24.2-34.9) of children with current ASD did not receive either behavioral or medication treatment.

CONCLUSIONS AND RELEVANCE

This study showed that the prevalence of ASD in the United States was relatively high, and it varied substantially across US states. Almost 30% of US children with ASD did not receive behavioral or medication treatment, which calls for a critical need to understand and address the barriers for those children to receive appropriate treatments.

Reduced Local and Increased Long-Range Functional Connectivity of the Thalamus in Autism Spectrum Disorder

It is hypothesized that brain network abnormalities in autism spectrum disorder (ASD) reflect local overconnectivity and long-range underconnectivity. However, this is not a consistent finding in recent studies, which could reflect the developmental nature and the heterogeneity of ASD. Here, we tested 565 ASD and 602 neurotypical (NT) males, and 91 ASD and 233 NT females using local functional connectivity density (lFCD) mapping and seed-voxel correlation analyses to assess how local and long-range connectivities differ in ASD. Compared with NT males, ASD males had lower and weaker age-related increases in thalamic lFCD, which were associated with symptoms of autism. Post-hoc seed-voxel correlation analyses for the thalamus cluster revealed stronger connectivity with auditory, somatosensory, motoric, and interoceptive cortices for ASD than for NT, both in males and in females, which decreased with age in both ASD and NT. These results document the disruption of local thalamic connectivity and dysregulation of thalamo-cortical networks, which might contribute to perceptual, motoric, and interoceptive impairments, and are also consistent with a developmental delay in functional connectivity in ASD.

Associations between parental broader autism phenotype and child autism spectrum disorder phenotype in the Study to Explore Early Development

The autism spectrum disorder phenotype varies by social and communication ability and co-occurring developmental, behavioral, and medical conditions. Etiology is also diverse, with myriad potential genetic origins and environmental risk factors. Examining the influence of parental broader autism phenotype-a set of sub-clinical characteristics of autism spectrum disorder-on child autism spectrum disorder phenotypes may help reduce heterogeneity in potential genetic predisposition for autism spectrum disorder. We assessed the associations between parental broader autism phenotype and child phenotype among children of age 30-68 months enrolled in the Study to Explore Early Development (N = 707). Child autism spectrum disorder phenotype was defined by a replication of latent classes derived from multiple developmental and behavioral measures: Mild Language Delay with Cognitive Rigidity, Mild Language and Motor Delay with Dysregulation (e.g. anxiety/depression), General Developmental Delay, and Significant Developmental Delay with Repetitive Motor Behaviors. Scores on the Social Responsiveness Scale-Adult measured parent broader autism phenotype. Broader autism phenotype in at least one parent was associated with a child having increased odds of being classified as mild language and motor delay with dysregulation compared to significant developmental delay with repetitive motor behaviors (odds ratio: 2.44; 95% confidence interval: 1.16, 5.09). Children of parents with broader autism phenotype were more likely to have a phenotype qualitatively similar to broader autism phenotype presentation; this may have implications for etiologic research.

Association between antidepressant use during pregnancy and autism spectrum disorder in children: a retrospective cohort study based on Japanese claims data

Background

Studies using data from Western countries have raised concerns that treating pregnant women with antidepressants may increase the risk of autism spectrum disorders (ASDs) in their offspring. However, to date, the studies are inconclusive. We therefore examined the association between antidepressant use and ASD using claims data collected in Japan.

Methods

This retrospective cohort study was based on claims data from mothers and their children from January 2005 to July 2014, obtained from the Japan Medical Data Center. The information from mothers and children was linked using the family identification code. Information on antidepressant prescriptions during pregnancy was extracted from the database. To collect information on ASD, children for whom data were available 24 months or more after birth were followed up from birth through July 2014 or up until their withdrawal from the database. To ensure appropriate diagnosis of ASD, mother-child pairs where the children's data did not cover the 24 months after birth or pairs where children had a diagnosis of ASD within only 23 months after birth were excluded from the study cohort. We used logistic regression analyses to evaluate the association between antidepressant use during pregnancy and the children's ASD diagnosis. All statistical analyses were performed using IBM SPSS (Statistical Package for the Social Sciences) Statistics ver. 21.0.

Results

Of the 53,864 eligible mother-child pairs, 26,925 met the study criteria. Crude analysis showed that the ASD prevalence in children was significantly higher with any antidepressant use than with non-use (odds ratio [OR], 2.32; 95% confidence interval [CI], 1.08, 4.95). However, when the analysis was adjusted for the confounding effect of maternal depression during pregnancy, statistical significance was lost (OR, 0.76; CI, 0.27, 2.18).

Conclusions

After adjustment for confounders, we found no significant association between antidepressant use during pregnancy and ASD in children in Japan. This result provides additional evidence to support the idea that antidepressant use during pregnancy itself is not associated with an increase in ASD in children. In addition, this represents the first evidence based on Asian data.

Geographic Disparities in Treatment for Children with Autism Spectrum Disorder

OBJECTIVE

Geographic differences may provide insight into what factors influence the likelihood that a child is diagnosed with autism spectrum disorder (ASD) in the United States; yet, there have been few nationally representative surveys that have explored this topic. The current study expands the limited literature by analyzing regional differences in ASD prevalence, service utilization, and the presence of unmet needs within a nationally representative sample of children.

METHODS

Data were drawn from the 2014-2016 National Health Interview Survey (NHIS), a nationally representative household survey of the noninstitutionalized US population. Children 3 to 17 years of age were included in the analytic sample. Prevalence estimates accounted for the complex survey design of the NHIS, and differences between geographic regions were compared using logistic/linear regressions with and without adjustment for child/family characteristics.

RESULTS

The prevalence of ASD was highest in the Northeast (3.0%), followed by the Midwest (2.4%), South (2.4%), and West (2.3%). A significant difference was found between the Northeast and West (P < .05); however, after accounting for child and family characteristics, this difference was no longer significant. Children with ASD in the Northeast were the most likely to have seen a specialist in the past year. Approximately 1 in 8 children with ASD experienced at least 1 unmet need, but there were no differences found by geographic region.

CONCLUSIONS

Although differences in prevalence were not significant after adjustment, service utilization differences remained. It appears that children with ASD in the Northeast utilize the greatest number of specialty services when compared to children with ASD from other parts of the country.

Brief Report: Maternal Opioid Prescription from Preconception Through Pregnancy and the Odds of Autism Spectrum Disorder and Autism Features in Children

Opioid use during pregnancy is associated with suboptimal pregnancy outcomes. Little is known about child neurodevelopmental outcomes. We examined associations between maternal opioid prescriptions preconception to delivery (peri-pregnancy) and child's risk of ASD, developmental delay/disorder (DD) with no ASD features, or ASD/DD with autism features in the Study to Explore Early Development, a case-control study of neurodevelopment. Preconception opioid prescription was associated with 2.43 times the odds of ASD [95% confidence interval (CI) 0.99, 6.02] and 2.64 times the odds of ASD/DD with autism features (95% CI 1.10, 6.31) compared to mothers without prescriptions. Odds for ASD and ASD/DD were non-significantly elevated for first trimester prescriptions. Work exploring mechanisms and timing between peri-pregnancy opioid use and child neurodevelopment is needed.

Genetic mutations in Ca2+ signaling alter dendrite morphology and social approach in juvenile mice

Dendritic morphology is a critical determinant of neuronal connectivity, and calcium signaling plays a predominant role in shaping dendrites. Altered dendritic morphology and genetic mutations in calcium signaling are both associated with neurodevelopmental disorders (NDDs). In this study we tested the hypothesis that dendritic arborization and NDD-relevant behavioral phenotypes are altered by human mutations that modulate calcium-dependent signaling pathways implicated in NDDs. The dendritic morphology of pyramidal neurons in CA1 hippocampus and somatosensory cortex was quantified in Golgi-stained brain sections from juvenile mice of both sexes expressing either a human gain-of-function mutation in ryanodine receptor 1 (T4826I-RYR1), a human CGG repeat expansion (170-200 CGG repeats) in the fragile X mental retardation gene 1 (FMR1 premutation), both mutations (double mutation; DM), or wildtype mice. In hippocampal neurons, increased dendritic arborization was observed in male T4826I-RYR1 and, to a lesser extent, male FMR1 premutation neurons. Dendritic morphology of cortical neurons was altered in both sexes of FMR1 premutation and DM animals with the most pronounced differences seen in DM females. Genotype also impaired behavior, as assessed using the three-chambered social approach test. The most striking lack of sociability was observed in DM male and female mice. In conclusion, mutations that alter the fidelity of calcium signaling enhance dendritic arborization in a brain region- and sex-specific manner and impair social behavior in juvenile mice. The phenotypic outcomes of these mutations likely provide a susceptible biological substrate for additional environmental stressors that converge on calcium signaling to determine individual NDD risk.

The Gut-Immune-Brain Axis in Autism Spectrum Disorders; A Focus on Amino Acids

Autism spectrum disorder (ASD) is a range of neurodevelopmental conditions that affect communication and social behavior. Besides social deficits, systemic inflammation, gastrointestinal immune-related problems, and changes in the gut microbiota composition are characteristic for people with ASD. Animal models showed that these characteristics can induce ASD-associated behavior, suggesting an intimate relationship between the microbiota, gut, immune system and the brain in ASD. Multiple factors can contribute to the development of ASD, but mutations leading to enhanced activation of the mammalian target of rapamycin (mTOR) are reported frequently. Hyperactivation of mTOR leads to deficits in the communication between neurons in the brain and to immune impairments. Hence, mTOR might be a critical factor linking the gut-brain-immune axis in ASD. Pharmacological inhibition of mTOR is shown to improve ASD-associated behavior and immune functions, however, the clinical use is limited due to severe side reactions. Interestingly, studies have shown that mTOR activation can also be modified by nutritional stimuli, in particular by amino acids. Moreover, specific amino acids are demonstrated to inhibit inflammation, improve gut barrier function and to modify the microbiota composition. In this review we will discuss the gut-brain-immune axis in ASD and explore the potential of amino acids as a treatment option for ASD, either via modification of mTOR activity, the immune system or the gut microbiota composition.

Autism Associated With Anti-NMDAR Encephalitis: Glutamate-Related Therapy

The purpose of this review is to correlate autism with autoimmune dysfunction in the absence of an explanation for the etiology of autism spectrum disorder. The anti-N-methyl-D-aspartate receptor (anti-NMDAR) autoantibody is a typical synaptic protein that can bind to synaptic NMDA glutamate receptors, leading to dysfunctional glutamate neurotransmission in the brain that manifests as psychiatric symptoms (psychosis, hallucinations, and personality changes). Detection of autoantibodies, cytokines, decreased lymphocytes, serum immunoglobulin level imbalance, T-cell mediated immune profile, maternal infection history, and children's infection history can all be vital biological markers of autoimmune autism. Diagnosing autoimmune encephalitis sooner can increase the effectiveness of curative treatments-such as immune therapy or immune modulatory therapy-that may prevent the long-term consequence of being misdiagnosed with autism spectrum disorder. Glutamate therapy primarily normalizes glutamate neurotransmission and can be a new add-on intervention alongside antipsychotics for treating autoimmune autism.

Maternal Pre-pregnancy Body Mass Index and Gestational Weight Gain in Relation to Autism Spectrum Disorder and other Developmental Disorders in Offspring

Most prior studies examining maternal pre-pregnancy body mass index (BMI) in relation to offspring autism spectrum disorders (ASD) have reported an association, though findings are not uniform and few have also examined gestational weight gain (GWG). Therefore, we examined both in the Study to Explore Early Development, a multi-site case-control study of children born in 2003-2006. Children identified from clinics, schools, and birth certificates were enrolled at ages 2-5 year and using standardized developmental evaluations, classified as: ASD, other developmental delays (DD), or population-based controls. Maternal height, weight, and GWG were self-reported during the telephone interview. Three primary weight risk factors were examined: (a) Pre-pregnancy BMI, classified as underweight to obese, (b) GWG continuous and categorized as quintiles, and (c) Institute of Medicine clinical weight-gain recommendations. Odds ratios adjusted (AOR) for sociodemographic and prenatal factors were calculated among term singletons, comparing the ASD (n = 540) or DD (n = 720) groups to the control group (n = 776). The AOR of ASD and maternal obesity was 1.37 (95%CI 0.98-1.92). Associations with higher GWG were stronger (Quintile5 vs. Quintile3 AOR = 1.58, 95%CI 1.08-2.31), and particularly so among overweight/obese women (AOR = 1.90, 95%CI 0.98-3.68). DD was associated with maternal overweight and obesity (obesity AOR = 1.48, 95%CI 1.08-2.02), but not with total GWG or clinical recommendations. High maternal BMI and GWG are risk factors for other pregnancy and child outcomes, and our results suggest they may also represent modifiable risk factors for neurodevelopmental outcomes. Autism Res 2019, 12: 316-327 © 2018 International Society for Autism Research, Wiley Periodicals, Inc. LAY SUMMARY: In a large, national study, we found that children with autism were more likely than unaffected children to have mothers with higher weight gain during pregnancy; risk of autism may be even stronger if mothers were also overweight before pregnancy. Children with other developmental delays were more likely to have mothers who were overweight or obese before pregnancy, but not who gained more weight during pregnancy. Overweight and weight gain may represent factors that could be modified.

The Utility of Zebrafish as a Model for Screening Developmental Neurotoxicity

The developing central nervous system and the blood brain barrier are especially vulnerable and sensitive to different chemicals, including environmental contaminants and drugs. Developmental exposure to these compounds has been involved in several neurological disorders, such as autism spectrum disorders as well as Alzheimer's and Parkinson's diseases. Zebrafish (Danio Rerio) have emerged as powerful toxicological model systems that can speed up chemical hazard assessment and can be used to extrapolate neurotoxic effects that chemicals have on humans. Zebrafish embryos and larvae are convenient for high-throughput screening of chemicals, due to their small size, low-cost, easy husbandry, and transparency. Additionally, zebrafish are homologous to other higher order vertebrates in terms of molecular signaling processes, genetic compositions, and tissue/organ structures as well as neurodevelopment. This mini review underlines the potential of the zebrafish as complementary models for developmental neurotoxicity screening of chemicals and describes the different endpoints utilized for such screening with some studies illustrating their use.

Prenatal exposure to phthalates and autism spectrum disorder in the MARBLES study

BACKGROUND

Evidence from experimental and observational studies suggests that prenatal phthalate exposures may be associated with autism spectrum disorder (ASD). We examined whether prenatal phthalate exposures were associated with an increased risk of ASD.

METHODS

We quantified 14 metabolites of eight phthalates in 636 multiple maternal urine samples collected during 2nd and 3rd trimesters of pregnancy from 201 mother-child pairs in MARBLES (Markers of Autism Risk in Babies - Learning Early Signs), a high-risk ASD longitudinal cohort. At 3 years old, children were clinically assessed for ASD and classified into three diagnostic categories: ASD (n = 46), non-typical development (Non-TD, n = 55), and typical development (TD, n = 100). We used multinomial logistic regression to evaluate the association of phthalate metabolite concentrations with ASD and Non-TD.

RESULTS

Most associations of phthalate biomarkers with both ASD and Non-TD were null, with the exception that monoethyl phthalate (MEP) was significantly associated with an increased risk of Non-TD (per 2.72-fold relative increase in concentration: Relative risk ratio (RRR) = 1.38; 95% confidence interval (CI): 1.01, 1.90). When stratified by prenatal vitamin use during the first month of pregnancy, among mothers who took vitamins, ASD risk was inversely associated with mono-isobutyl phthalate (MiBP, RRR = 0.44; 95% CI: 0.21, 0.88), mono(3-carboxypropyl) phthalate (MCPP, RRR = 0.41; 95% CI: 0.20, 0.83) and mono-carboxyisooctyl phthalate (MCOP, RRR = 0.49; 95% CI: 0.27, 0.88), but among mothers who did not take prenatal vitamins, Non-TD risk was positively associated with MCPP (RRR = 5.09; 95% CI: 2.05, 12.6), MCOP (RRR = 1.86; 95% CI: 1.01, 3.39), and mono-carboxyisononyl phthalate (MCNP, RRR = 3.67; 95% CI: 1.80, 7.48). When stratified by sex, among boys, MEP, monobenzyl phthalate, MCPP, MCNP, and sum of di(2-ethylhexyl) phthalate metabolites (ΣDEHP) were positively associated with Non-TD risk, but associations with ASD were null. Among girls, associations with both ASD and Non-TD were null.

CONCLUSIONS

Our study showed that phthalate exposures in mid- to late pregnancy were not associated with ASD in children from this high-risk ASD cohort. Further studies should be conducted in the general population without high-risk genes to confirm our findings.

Dioxins as potential risk factors for autism spectrum disorder

Autism spectrum disorder (ASD) has emerged as a major public health concern due to its fast-growing prevalence in recent decades. Environmental factors are thought to contribute substantially to the variance in ASD. Interest in environmental toxins as causes of ASD has arisen due to the high sensitivity of the developing human brain to toxic chemicals, particularly to dioxin and certain dioxin-like compounds (dioxins). As a group of typical persistent organic pollutants, dioxins have been found to exert adverse effects on human brain development. In this paper, we review the evidence for association of exposure to dioxins with neurodevelopmental abnormalities related to ASD based on both human epidemiological and animal studies. It has been documented that exposure to dioxins during critical developmental periods increased risk for ASD. This notion has been demonstrated in different populations exposed to high or background level of dioxins. Furthermore, the effects and mechanisms of action of dioxins relevant to the pathophysiology and pathogenesis of ASD are summarized, describing potential underlying mechanisms linking dioxin exposure with ASD onset. Further studies focusing on effects of prenatal/perinatal exposure to individual dioxin congeners or to mixtures of dioxins on ASD-associated behavioral and neurobiological consequences in animal models, and on the mechanisms of actions of dioxins, are needed in order to better understand how dioxin exposure might contribute to increased risk for ASD.

Air pollution and Autism in Denmark

Supplemental Digital Content is available in the text.

Background:

Previous autism spectrum disorder (ASD) and air pollution studies focused on pregnancy exposures, but another vulnerable period is immediate postnatally. Here, we examined early life exposures to air pollution from the pre- to the postnatal period and ASD/ASD subtypes in the Danish population.

Methods:

With Danish registers, we conducted a nationwide case–control study of 15,387 children with ASD born 1989–2013 and 68,139 population controls matched by birth year and sex identified from the birth registry. We generated air dispersion geographic information system (AirGIS) model estimates for nitrogen dioxide (NO₂), sulfur dioxide (SO₂), particulate matter 2.5 (PM_2.5), and particulate matter 10 (PM₁₀) at mothers’ home from 9 months before to 9 months after pregnancy and calculated odds ratios (ORs) and 95% confidence intervals (CIs), adjusting for parental age, neighborhood socioeconomic indicators, and maternal smoking using conditional logistic regression.

Results:

In models that included all exposure periods, we estimated adjusted ORs for ASD per interquartile range (IQR) increase for 9 months after pregnancy with NO₂ of 1.08 (95% CI = 1.01, 1.15) and with PM_2.5 of 1.06 (95% CI = 1.01, 1.11); associations were smaller for PM₁₀ (1.04; 95% CI = 1.00, 1.09) and strongest for SO₂ (1.21; 95% CI = 1.13, 1.29). Also, associations for pollutants were stronger in more recent years (2000–2013) and in larger cities compared with provincial towns/rural counties. For particles and NO₂, associations were only specific to autism and Asperger diagnoses.

Conclusions:

Our data suggest that air pollutant exposure in early infancy but not during pregnancy increases the risk of being diagnosed with autism and Asperger among children born in Denmark.

The Prevalence of Parent-Reported Autism Spectrum Disorder Among US Children

: media-1vid110.1542/5839990273001PEDS-VA_2017-4161Video Abstract OBJECTIVES: To estimate the national prevalence of parent-reported autism spectrum disorder (ASD) diagnosis among US children aged 3 to 17 years as well as their treatment and health care experiences using the 2016 National Survey of Children's Health (NSCH).

METHODS

The 2016 NSCH is a nationally representative survey of 50 212 children focused on the health and well-being of children aged 0 to 17 years. The NSCH collected parent-reported information on whether children ever received an ASD diagnosis by a care provider, current ASD status, health care use, access and challenges, and methods of treatment. We calculated weighted prevalence estimates of ASD, compared health care experiences of children with ASD to other children, and examined factors associated with increased likelihood of medication and behavioral treatment.

RESULTS

Parents of an estimated 1.5 million US children aged 3 to 17 years (2.50%) reported that their child had ever received an ASD diagnosis and currently had the condition. Children with parent-reported ASD diagnosis were more likely to have greater health care needs and difficulties accessing health care than children with other emotional or behavioral disorders (attention-deficit/hyperactivity disorder, anxiety, behavioral or conduct problems, depression, developmental delay, Down syndrome, intellectual disability, learning disability, Tourette syndrome) and children without these conditions. Of children with current ASD, 27% were taking medication for ASD-related symptoms, whereas 64% received behavioral treatments in the last 12 months, with variations by sociodemographic characteristics and co-occurring conditions.

CONCLUSIONS

The estimated prevalence of US children with a parent-reported ASD diagnosis is now 1 in 40, with rates of ASD-specific treatment usage varying by children's sociodemographic and co-occurring conditions.

Infections in children with autism spectrum disorder: Study to Explore Early Development (SEED)

Immune system abnormalities have been widely reported among children with autism spectrum disorder (ASD), which may increase the risk of childhood infections. The Study to Explore Early Development (SEED) is a multisite case-control study of children aged 30-69 months, born in 2003-2006. Cases are children previously diagnosed and newly identified with ASD enrolled from education and clinical settings. Children with a previously diagnosed non-ASD developmental condition were included in the developmental delay/disorder (DD) control group. The population (POP) control group included children randomly sampled from birth certificates. Clinical illness from infection during the first 28 days ("neonatal," from medical records) and first three years of life (caregiver report) in cases was compared to DD and POP controls; and between cases with and without regression. Children with ASD had greater odds of neonatal (OR = 1.8; 95%CI: 1.1, 2.9) and early childhood infection (OR = 1.7; 95%CI: 1.5, 1.9) compared to POP children, and greater odds of neonatal infection (OR = 1.5; 95%CI: 1.1, 2.0) compared to DD children. Cases with regression had 1.6 times the odds (95%CI: 1.1, 2.3) of caregiver-reported infection during the first year of life compared to cases without regression, but neonatal infection risk and overall early childhood infection risk did not differ. Our results support the hypothesis that children with ASD are more likely to have infection early in life compared to the general population and to children with other developmental conditions. Future studies should examine the contributions of different causes, timing, frequency, and severity of infection to ASD risk. Autism Research 2019, 12: 136-146. © 2018 International Society for Autism Research, Wiley Periodicals, Inc. LAY SUMMARY: We looked at infections during early childhood in relation to autism spectrum disorder (ASD). We found that children with ASD were more likely to have an infection in the first 28 days of life and before age three compared to children with typical development. Children with ASD were also more likely than children with other developmental delays or disorders to have an infection in the first 28 days of life.

Brief Report: Regional Variations in Characteristics of ASD Hospitalizations in the U.S

Regional differences in ASD inpatient care remain understudied. We used the Nationwide Inpatient Sample to examine contributory causes and potential determinants associated with regional variations in ASD hospitalizations. We performed univariate and multivariate analyses to identify differences in ASD hospitalizations across four U.S. Census Bureau-defined regions. Our results revealed considerable variations in ASD hospitalizations across U.S. regions. Compared with patients in the Northeast, those in the Midwest, South, and West were less likely to be hospitalized for ASD. Significant differences were observed among regions with regard to the effect of health insurance type, hospital length of stay, hospital bed size, hospital location and teaching status on ASD hospitalizations. The region-specific analysis provides direction for further investigation.

Maternal Gestational Immune Response and Autism Spectrum Disorder Phenotypes at 7 Years of Age in the Seychelles Child Development Study

Findings from observational and experimental studies suggest that maternal inflammation during pregnancy is associated with autism spectrum disorder (ASD). We report the first study in humans to examine this association in a large prospective birth cohort. We studied 788 mother-child pairs from the Seychelles Child Development Study Nutrition Cohort 2. Thirteen inflammatory markers were measured in mothers' serum at 28 weeks' gestation, along with the sum of T-helper 1 (Th1) and 2 (Th2) cytokines. The Social Communication Questionnaire (SCQ) and Social Responsiveness Scale (SRS) were administered at age 7 years to obtain information on ASD phenotype. We evaluated associations between maternal inflammatory markers and ASD phenotype using multivariable linear regression. For the SCQ, increased MCP-1 (a chemokine that is upregulated in response to pro-inflammatory cytokines) was associated with fewer ASD symptoms (B = - 0.40; 95% CI = - 0.72, - 0.09). Increased IL-4 (a cytokine that is typically associated with an enhanced anti-inflammatory response) was associated with more ASD symptoms (B = 2.10; 95% CI = 0.78, 3.43). For the SRS, higher concentrations of the anti-inflammatory cytokine IL-10 were associated with fewer ASD symptoms (B = - 0.18; 95% CI = - 0.35, - 0.01), but only after removal of outliers. No associations were observed for other markers. These findings suggest that a shift in the maternal immune balance during pregnancy may be associated with ASD symptomatology. While the use of well-established measures that capture ASD phenotypic variability is a strength of the study, measurement of peripheral immune markers only once during gestation is a limitation. Our results should be confirmed using maternal immune markers measured throughout gestation.

Diagnostic approach with genetic tests for global developmental delay and/or intellectual disability: Single tertiary center experience

The child with global developmental delay (GDD)/intellectual disability (ID) is deserving of the appropriate evaluation available for improving the health and well-being of patients and their families. To better elucidate the diagnostic approach of genetic tests for patients with GDD and/or ID, we evaluated the results in a cohort of 75 patients with clinical features of GDD and/or ID who were referred for diagnostic workup. A total of 75 children were investigated for GDD or ID in the pediatric neurology department. Ten patients (13%, 10/75) with a clinically recognizable syndrome were diagnosed by single-gene analysis. Next, chromosomal microarray was performed as a first-tier test, and 25 patients (33%, 25/75) showed structural abnormalities. Then, two fragile X syndrome (3%, 2/75) were confirmed by FMR1 gene fragment analysis. Thirty-eight remaining patients received a gene panel by next-generation sequencing. Eight patients were found to have an underlying genetic etiology: CHD8, ZDHHC9, MBD5, CACNA1H, SMARCB1, FOXP1, NSD1, and PAX6. As a result, 45 patients (60%, 45/75) had been diagnosed by genetic tests. Among 30 undiagnosed patients, brain structural abnormalities related to GDD/ID were observed in eight patients (11%, 8/75). However, in 22 patients (29%, 22/75), the causes of GDD/ID remained uncertain. A genetic diagnostic approach of GDD/ID by sequential molecular analysis can help in the planning of treatment, assigning the risk of occurrence in siblings, and providing emotional relief for the family.

Equine assisted activities and therapies in children with autism spectrum disorder: A systematic review and a meta-analysis

INTRODUCTION

The multifactorial nature of Autism Spectrum Disorder (ASD) is the reason why complementary and alternative methods of treatment are sought in order to support the classic approach.

OBJECTIVES

The aim of the study was to assess the effectiveness of Equine-Assisted Activities and Therapies (EAAT) in ASD patients based on a review of the literature.

METHODS

A review of the literature and a meta-analysis were conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. PUBMED, Cochrane Library, Web of Science, ClinicalTrials.gov and PEDro databases were searched until July 20, 2017. Only articles published in English, in a journal with a review process, after 1999, with a control group or presentation of comparative pre-/post-therapy results in ASD patients, and clear inclusion/exclusion criteria were considered. The methodological quality of the included studies was assessed using the Quality Assessment Tool for Quantitative Studies (QATQS).The meta-analysis of three studies was conducted.

RESULTS

A total of 15 studies with 390 participants (aged: 3-16 years) were included. The interaction between psychosocial functioning and EAAT was investigated in most studies. Improvement was reported in the following domains: socialization, engagement, maladaptive behaviors, and shorter reaction time in problem-solving situations after EAAT. The meta-analysis revealed no statistically significant differences for the investigated effects.

CONCLUSIONS

Despite the need for further, more standardized research, the results of the studies included in this review allow us to conclude that EAAT may be a useful form of therapy in children with ASD.

A perspective on pre-eclampsia and neurodevelopmental outcomes in the offspring: Does maternal inflammation play a role?

Pre-eclampsia is a leading cause of maternal death and maternal and perinatal morbidity. Whilst the clinical manifestations of pre-eclampsia often occur in late pregnancy, the molecular events leading into the onset of this disease are thought to originate in early pregnancy and result in insufficient placentation. Although the causative molecular basis of pre-eclampsia remains poorly understood, maternal inflammation is recognised as a core clinical feature. While the adverse effects of pre-eclampsia on maternal and fetal health in pregnancy is well-recognised, the long-term impact of pre-eclampsia exposure on the risk of autism spectrum disorder (ASD) in exposed offspring is a topic of on-going debate. In particular, a recent systematic review has reported an association between exposure to pre-eclampsia and increased risk of ASD, however the molecular basis of this association is unknown. Here we review recent evidence for; 1) maternal inflammation in pre-eclampsia; 2) epidemiological evidence for alterations in neurodevelopmental outcomes in offspring exposed to pre-eclampsia; 3) long-term changes in the brains of offspring exposed to pre-eclampsia; and 4) how maternal inflammation may lead to altered neurodevelopmental outcomes in pre-eclampsia exposed offspring. Finally, we discuss the implications of this for the development of future studies in this field.

Hippocampal deficits in neurodevelopmental disorders

Neurodevelopmental disorders result from impaired development or maturation of the central nervous system. Both genetic and environmental factors can contribute to the pathogenesis of these disorders; however, the exact causes are frequently complex and unclear. Individuals with neurodevelopmental disorders may have deficits with diverse manifestations, including challenges with sensory function, motor function, learning, memory, executive function, emotion, anxiety, and social ability. Although these functions are mediated by multiple brain regions, many of them are dependent on the hippocampus. Extensive research supports important roles of the mammalian hippocampus in learning and cognition. In addition, with its high levels of activity-dependent synaptic plasticity and lifelong neurogenesis, the hippocampus is sensitive to experience and exposure and susceptible to disease and injury. In this review, we first summarize hippocampal deficits seen in several human neurodevelopmental disorders, and then discuss hippocampal impairment including hippocampus-dependent behavioral deficits found in animal models of these neurodevelopmental disorders.

Use of Psychotropic Drugs among Children and Adolescents with Autism Spectrum Disorders in Denmark: A Nationwide Drug Utilization Study

Children with autism spectrum disorder (ASD) have a considerable use of psychotropics. Leveraging nationwide registry data, we aimed to describe the use of psychotropics among children and adolescents with ASD in Denmark. Use of melatonin and attention-deficit/hyperactivity disorder (ADHD) medication increased from 2010 to 2017, while there were limited changes in use of antidepressants and antipsychotics. Thirty percent of the identified children used psychotropics in 2017 most commonly ADHD medication (17%) and melatonin (13%). Methylphenidate, sertraline and risperidone were most often prescribed. Most children filled more than one prescription and, across drug classes, at least 38% received treatment two years after treatment initiation. Use of psychotropics followed psychiatric comorbidities. Comorbidities did not affect age at treatment initiation. Use of psychotropics varied according to age and sex with limited use in the youngest children. In summary, psychotropic drug use has increased in children with ASD mainly due to an increase in the use of ADHD medication and melatonin. In accordance with previous studies, use seems to follow comorbidities. The long treatment duration underlines the need to investigate long-term effects of psychotropic drug use in children with ASD.

Ascending Vaginal Infection Using Bioluminescent Bacteria Evokes Intrauterine Inflammation, Preterm Birth, and Neonatal Brain Injury in Pregnant Mice

Preterm birth is a serious global health problem and the leading cause of infant death before 5 years of age. At least 40% of cases are associated with infection. The most common way for pathogens to access the uterine cavity is by ascending from the vagina. Bioluminescent pathogens have revolutionized the understanding of infectious diseases. We hypothesized that bioluminescent Escherichia coli can be used to track and monitor ascending vaginal infections. Two bioluminescent strains were studied: E. coli K12 MG1655-lux, a nonpathogenic laboratory strain, and E. coli K1 A192PP-lux2, a pathogenic strain capable of causing neonatal meningitis and sepsis in neonatal rats. On embryonic day 16, mice received intravaginal E. coli K12, E. coli K1, or phosphate-buffered saline followed by whole-body bioluminescent imaging. In both cases, intravaginal delivery of E. coli K12 or E. coli K1 led to bacterial ascension into the uterine cavity, but only E. coli K1 induced preterm parturition. Intravaginal administration of E. coli K1 significantly reduced the proportion of pups born alive compared with E. coli K12 and phosphate-buffered saline controls. However, in both groups of viable pups born after bacterial inoculation, there was evidence of comparable brain inflammation by postnatal day 6. This study ascribes specific mechanisms by which exposure to intrauterine bacteria leads to premature delivery and neurologic inflammation in neonates.

PCB 95 promotes dendritic growth in primary rat hippocampal neurons via mTOR-dependent mechanisms

Polychlorinated biphenyls (PCBs), and in particular non-dioxin-like (NDL) congeners, continue to pose a significant risk to the developing nervous system. PCB 95, a prevalent NDL congener in the human chemosphere, promotes dendritic growth in rodent primary neurons by activating calcium-dependent transcriptional mechanisms that normally function to link activity to dendritic growth. Activity-dependent dendritic growth is also mediated by calcium-dependent translational mechanisms involving mechanistic target of rapamycin (mTOR), suggesting that the dendrite-promoting activity of PCB 95 may also involve mTOR signaling. Here, we test this hypothesis using primary neuron-glia co-cultures derived from the hippocampi of postnatal day 0 Sprague Dawley rats. PCB 95 (1 nM) activated mTOR in hippocampal cultures as evidenced by increased phosphorylation of mTOR at ser2448. Pharmacologic inhibition of mTOR signaling using rapamycin (20 nM), FK506 (5 nM), or 4EGI-1 (1 µM), and siRNA knockdown of mTOR, or the mTOR complex binding proteins, raptor or rictor, blocked PCB 95-induced dendritic growth. These data identify mTOR activation as a novel molecular mechanism contributing to the effects of PCB 95 on dendritic arborization. In light of clinical data linking gain-of-function mutations in mTOR signaling to neurodevelopmental disorders, our findings suggest that mTOR signaling may represent a convergence point for gene by environment interactions that confer risk for adverse neurodevelopmental outcomes.

Evidenced-Based Interventions for Children With Autism Spectrum Disorder

This paper reviews evidenced-based interventions for children with autism spectrum disorders (ASD) across the disciplines of psychology, speech-language pathology, occupational therapy, and developmental pediatrics.

BACKGROUND

rates of ASD diagnoses have been steadily rising over the past 2 decades. There are a wide range of therapies and interventions, of varying levels of evidence, across disciplines that are now available to treat children with ASD. The field has moved toward a greater emphasis on the identification and utilization of evidenced-based treatments.

METHODS

a review and summary of recent literature was conducted by professionals in an interdisciplinary autism center. An emphasis was placed on results of the National Autism Center's National Standards Project.

RESULTS AND CONCLUSIONS

within each discipline, interventions exist that vary in level of evidenced-based support. Although disciplines may differ in their definitions of evidence-based treatments, it is important for each discipline to strive to offer and promote practices with the best evidenced-based support according to each field's standards.

Developmental disabilities among children younger than 5 years in 195 countries and territories, 1990-2016: a systematic analysis for the Global Burden of Disease Study 2016

BACKGROUND

The Sustainable Development Goals (SDGs) mandate systematic monitoring of the health and wellbeing of all children to achieve optimal early childhood development. However, global epidemiological data on children with developmental disabilities are scarce. The Global Burden of Diseases, Injuries, and Risk Factors Study 2016 provides a comprehensive assessment of prevalence and years lived with disability (YLDs) for development disabilities among children younger than 5 years in 195 countries and territories from 1990 to 2016.

METHODS

We estimated prevalence and YLDs for epilepsy, intellectual disability, hearing loss, vision loss, autism spectrum disorder, and attention deficit hyperactivity disorder. YLDs were estimated as the product of the prevalence estimate and the disability weight for each mutually exclusive disorder, corrected for comorbidity. We used DisMod-MR 2.1, a Bayesian meta-regression tool, on a pool of primary data derived from systematic reviews of the literature, health surveys, hospital and claims databases, cohort studies, and disease-specific registries.

FINDINGS

Globally, 52·9 million (95% uncertainty interval [UI] 48·7-57·3; or 8·4% [7·7-9·1]) children younger than 5 years (54% males) had developmental disabilities in 2016 compared with 53·0 million (49·0-57·1; or 8·9% [8·2-9·5]) in 1990. About 95% of these children lived in low-income and middle-income countries. YLDs among these children increased from 3·8 million (95% UI 2·8-4·9) in 1990 to 3·9 million (2·9-5·2) in 2016. These disabilities accounted for 13·3% of the 29·3 million YLDs for all health conditions among children younger than 5 years in 2016. Vision loss was the most prevalent disability, followed by hearing loss, intellectual disability, and autism spectrum disorder. However, intellectual disability was the largest contributor to YLDs in both 1990 and 2016. Although the prevalence of developmental disabilities among children younger than 5 years decreased in all countries (except for North America) between 1990 and 2016, the number of children with developmental disabilities increased significantly in sub-Saharan Africa (71·3%) and in North Africa and the Middle East (7·6%). South Asia had the highest prevalence of children with developmental disabilities in 2016 and North America had the lowest.

INTERPRETATION

The global burden of developmental disabilities has not significantly improved since 1990, suggesting inadequate global attention on the developmental potential of children who survived childhood as a result of child survival programmes, particularly in sub-Saharan Africa and south Asia. The SDGs provide a framework for policy and action to address the needs of children with or at risk of developmental disabilities, particularly in resource-poor countries.

FUNDING

The Bill & Melinda Gates Foundation.

Autistic spectrum disorder and offending behaviour – a brief review of the literature

Purpose

The purpose of this paper to synthesise much of the existing research on autistic spectrum disorder (ASD) and offending behaviour.

Design/methodology/approach

It considers three key areas, namely, first, a discussion about the nature of ASD and how it might be related to offending behaviour; second, a brief commentary about the prevalence of this population; and, finally, an exploration of the effective management and possible treatment outcomes.

Findings

Methodological limitations have resulted in variable findings which has hindered our understanding of this population. Some of the research is based on small, highly specialist samples making prevalence difficult to measure. The link between ASD and offending is still not well understood, and despite advances in staff training, awareness amongst practitioners remains an underdeveloped area, thus yielding variable treatment outcomes.

Originality/value

This review continues to demonstrate the urgent need for robust research in order to better understand the link between ASD and offending behaviour, to provide tailored, needs-led interventions, and reduce the risk of offending amongst this group as a whole.

Prevalence of HSV1/2 Congenital Infection Assessed Through Genome Detection on Dried Blood Spot in Individuals with Autism Spectrum Disorders

BACKGROUND/AIM

Etiopathogenesis of autism spectrum disorders (ASD) remains to be elucidated. Congenital infections, particularly viral infections, have repeatedly been associated with the onset of such disorders. Our study aimed at assessing the prevalence of herpes simplex type 1 and 2 (HSV1/2) congenital infections in patients with ASD.

MATERIALS AND METHODS

In our case-control study, a total of 38 children with ASD were compared to 44 age- and sex-matched controls regarding the presence of HSV1/2 infection though viral DNA polymerase chain reaction performed on dried blood spots collected at birth.

RESULTS

No HSV congenital infection was detected in either group.

CONCLUSION

Our negative finding is in agreement with other studies that failed to demonstrate a definitive role of HSV on the onset of ASD. Further investigation of congenital HSV prevalence in larger and more powerful studies is needed to undeniably discard a role of such virus in the etiopathogenesis of ASD.

5-Hydroxymethylcytosine alterations in the human postmortem brains of autism spectrum disorder

Autism spectrum disorders (ASDs) include a group of syndromes characterized by impaired language, social and communication skills, in addition to restrictive behaviors or stereotypes. However, with a prevalence of 1.5% in developed countries and high comorbidity rates, no clear underlying mechanism that unifies the heterogeneous phenotypes of ASD exists. 5-hydroxymethylcytosine (5hmC) is highly enriched in the brain and recognized as an essential epigenetic mark in developmental and brain disorders. To explore the role of 5hmC in ASD, we used the genomic DNA isolated from the postmortem cerebellum of both ASD patients and age-matched controls to profile genome-wide distribution of 5hmC. We identified 797 age-dependent differentially hydroxymethylated regions (DhMRs) in the young group (age ≤ 18), while no significant DhMR was identified in the groups over 18 years of age. Pathway and disease association analyses demonstrated that the intragenic DhMRs were in the genes involved in cell-cell communication and neurological disorders. Also, we saw significant 5hmC changes in the larger group of psychiatric genes. Interestingly, we found that the predicted cis functions of non-coding intergenic DhMRs strikingly associate with ASD and intellectual disorders. A significant fraction of intergenic DhMRs overlapped with topologically associating domains. These results together suggest that 5hmC alteration is associated with ASD, particularly in the early development stage, and could contribute to the pathogenesis of ASD.

Autism-related behaviors in the cyclooxygenase-2-deficient mouse model

Prostaglandin E2 (PGE2) is an endogenous lipid molecule involved in normal brain development. Cyclooxygenase-2 (COX2) is the main regulator of PGE2 synthesis. Emerging clinical and molecular research provides compelling evidence that abnormal COX2/PGE2 signaling is associated with autism spectrum disorder (ASD). We previously found that COX2 knockout mice had dysregulated expression of many ASD genes belonging to important biological pathways for neurodevelopment. The present study is the first to show the connection between irregular COX2/PGE2 signaling and autism-related behaviors in male and female COX2-deficient knockin, (COX)-2^- , mice at young (4-6 weeks) or adult (8-11 weeks) ages. Autism-related behaviors were prominent in male (COX)-2^- mice for most behavioral tests. In the open field test, (COX)-2^- mice traveled more than controls and adult male (COX)-2^- mice spent less time in the center indicating elevated hyperactive and anxiety-linked behaviors. (COX)-2^- mice also buried more marbles, with males burying more than females, suggesting increased anxiety and repetitive behaviors. Young male (COX)-2^- mice fell more frequently in the inverted screen test revealing motor deficits. The three-chamber sociability test found that adult female (COX)-2^- mice spent less time in the novel mouse chamber indicative of social abnormalities. In addition, male (COX)-2^- mice showed altered expression of several autism-linked genes: Wnt2, Glo1, Grm5 and Mmp9. Overall, our findings offer new insight into the involvement of disrupted COX2/PGE2 signaling in ASD pathology with age-related differences and greater impact on males. We propose that (COX)-2^- mice might serve as a novel model system to study specific types of autism.

Autism spectrum disorder

Autism spectrum disorder is a term used to describe a constellation of early-appearing social communication deficits and repetitive sensory-motor behaviours associated with a strong genetic component as well as other causes. The outlook for many individuals with autism spectrum disorder today is brighter than it was 50 years ago; more people with the condition are able to speak, read, and live in the community rather than in institutions, and some will be largely free from symptoms of the disorder by adulthood. Nevertheless, most individuals will not work full-time or live independently. Genetics and neuroscience have identified intriguing patterns of risk, but without much practical benefit yet. Considerable work is still needed to understand how and when behavioural and medical treatments can be effective, and for which children, including those with substantial comorbidities. It is also important to implement what we already know and develop services for adults with autism spectrum disorder. Clinicians can make a difference by providing timely and individualised help to families navigating referrals and access to community support systems, by providing accurate information despite often unfiltered media input, and by anticipating transitions such as family changes and school entry and leaving.

Family history of immune conditions and autism spectrum and developmental disorders: Findings from the study to explore early development

Numerous studies have reported immune system disturbances in individuals with autism and their family members; however, there is considerable variability in findings with respect to the specific immune conditions involved, their timing, and the family members affected and little understanding of variation by autism subphenotype. Using data from the Study to Explore Early Development (SEED), a multi-site case-control study of children born 2003-2006 in the United States, we examined the role of family history of autoimmune diseases, asthma, and allergies in autism spectrum disorder (ASD) as well as other developmental disorders (DD). We investigated maternal immune conditions during the pregnancy period, as well as lifetime history of these conditions in several family members (mother, father, siblings, and study child). Logistic regression analyses included 663 children with ASD, 984 children with DD, and 915 controls ascertained from the general population (POP). Maternal history of eczema/psoriasis and asthma was associated with a 20%-40% increased odds of both ASD and DD. Risk estimates varied by specific ASD subphenotypes in association with these exposures. In addition, children with ASD were more likely to have a history of psoriasis/eczema or allergies than POP controls. No association was observed for paternal history or family history of these immune conditions for either ASD or DD. These data support a link between maternal and child immune conditions and adverse neurodevelopmental outcomes, and further suggest that associations may differ by ASD phenotype of the child. Autism Research 2019, 12: 123-135. © 2018 International Society for Autism Research, Wiley Periodicals, Inc. LAY SUMMARY: Using data from a large multi-site study in the US-the Study to Explore Early Development-we found that women with a history of eczema/psoriasis and asthma are more likely to have children with ASD or DD. In addition, children with ASD are more likely to have a history of psoriasis/eczema or allergies than typically developing children. These data support a link between maternal and child immune conditions and adverse neurodevelopmental outcomes.

Immune aberrations in children with Autism Spectrum Disorder: a case-control study from a tertiary care neuropsychiatric hospital in India

Multiple studies have identified the presence of peripheral immune aberrations in subjects with Autism Spectrum Disorder (ASD). However, comprehensive assessment of these peripheral immune aberrations, in the cellular and systemic compartments, in a single group of subjects with ASD is lacking. We assessed proportions of various subsets of immune cells in peripheral blood (T helper cells, T regulatory cells, B cells, monocytes, Natural Killer cells, dendritic cells) by multi-parametric flow cytometry in 50 children with ASD and compared it with thirty healthy controls matched for age, gender, socio-economic status and body mass index. There were no significant differences noted in the proportion of T regulatory cells, B cells, monocytes and Natural Killer cells, between ASD subjects and controls. On the contrary, the proportion of activated Th17 and myeloid dendritic cells were significantly higher in children with ASD. Based on these findings, group comparison of serum levels of Th17 cytokines (interleukin-6, interleukin-17A) was performed. Elevated serum levels of interleukin-6 and interleukin-17A in children with ASD corroborated our immunophenotyping findings. We did not find any significant differences among the pro-inflammatory (interleukin-1β), Th1 (interferon-γ) and Th2 (interleukin-4) cytokines. This is the first evidence with concurrent findings from immunophenotyping and cytokine data demonstrating activation of the Th17 pathway in subjects with ASD. This finding assumes significance in the light of recent maternal immune activation mouse model study that has highlighted the role of Th17 pathway in the pathophysiology of ASD. Future longitudinal studies are needed to clarify the role of this dysregulated immune pathway in the development of ASD.

A Feasibility Clinical Trial to Improve Social Attention in Autistic Spectrum Disorder (ASD) Using a Brain Computer Interface

Deficits in the interpretation of others' intentions from gaze-direction or other social attention cues are well-recognized in ASD. Here we investigated whether an EEG brain computer interface (BCI) can be used to train social cognition skills in ASD patients. We performed a single-arm feasibility clinical trial and enrolled 15 participants (mean age 22y 2m) with high-functioning ASD (mean full-scale IQ 103). Participants were submitted to a BCI training paradigm using a virtual reality interface over seven sessions spread over 4 months. The first four sessions occurred weekly, and the remainder monthly. In each session, the subject was asked to identify objects of interest based on the gaze direction of an avatar. Attentional responses were extracted from the EEG P300 component. A final follow-up assessment was performed 6-months after the last session. To analyze responses to joint attention cues participants were assessed pre and post intervention and in the follow-up, using an ecologic “Joint-attention task.” We used eye-tracking to identify the number of social attention items that a patient could accurately identify from an avatar's action cues (e.g., looking, pointing at). As secondary outcome measures we used the Autism Treatment Evaluation Checklist (ATEC) and the Vineland Adaptive Behavior Scale (VABS). Neuropsychological measures related to mood and depression were also assessed. In sum, we observed a decrease in total ATEC and rated autism symptoms (Sociability; Sensory/Cognitive Awareness; Health/Physical/Behavior); an evident improvement in Adapted Behavior Composite and in the DLS subarea from VABS; a decrease in Depression (from POMS) and in mood disturbance/depression (BDI). BCI online performance and tolerance were stable along the intervention. Average P300 amplitude and alpha power were also preserved across sessions. We have demonstrated the feasibility of BCI in this kind of intervention in ASD. Participants engage successfully and consistently in the task. Although the primary outcome (rate of automatic responses to joint attention cues) did not show changes, most secondary neuropsychological outcome measures showed improvement, yielding promise for a future efficacy trial.

(clinical-trial ID: NCT02445625—clinicaltrials.gov).

Prenatal exposure to environmental insults and enhanced risk of developing Schizophrenia and Autism Spectrum Disorder: focus on biological pathways and epigenetic mechanisms

When considering neurodevelopmental disorders (NDDs), Schizophrenia (SZ) and Autism Spectrum Disorder (ASD) are considered to be among the most severe in term of prevalence, morbidity and impact on the society. Similar features and overlapping symptoms have been observed at multiple levels, suggesting common pathophysiological bases. Indeed, recent genome-wide association studies (GWAS) and epidemiological data report shared vulnerability genes and environmental triggers across the two disorders. In this review, we will discuss the possible biological mechanisms, including glutamatergic and GABAergic neurotransmissions, inflammatory signals and oxidative stress related systems, which are targeted by adverse environmental exposures and that have been associated with the development of SZ and ASD. We will also discuss the emerging role of the gut microbiome as possible interplay between environment, immune system and brain development. Finally, we will describe the involvement of epigenetic mechanisms in the maintenance of long-lasting effects of adverse environments early in life. This will allow us to better understand the pathophysiology of these NDDs, and also to identify novel targets for future treatment strategies.

Opportunities and challenges for using the zebrafish to study neuronal connectivity as an endpoint of developmental neurotoxicity

Chemical exposures have been implicated as environmental risk factors that interact with genetic susceptibilities to influence individual risk for complex neurodevelopmental disorders, including autism spectrum disorder, schizophrenia, attention deficit hyperactivity disorder and intellectual disabilities. Altered patterns of neuronal connectivity represent a convergent mechanism of pathogenesis for these and other neurodevelopmental disorders, and growing evidence suggests that chemicals can interfere with specific signaling pathways that regulate the development of neuronal connections. There is, therefore, a growing interest in developing screening platforms to identify chemicals that alter neuronal connectivity. Cell-cell, cell-matrix interactions and systemic influences are known to be important in defining neuronal connectivity in the developing brain, thus, a systems-based model offers significant advantages over cell-based models for screening chemicals for effects on neuronal connectivity. The embryonic zebrafish represents a vertebrate model amenable to higher throughput chemical screening that has proven useful in characterizing conserved mechanisms of neurodevelopment. Moreover, the zebrafish is readily amenable to gene editing to integrate genetic susceptibilities. Although use of the zebrafish model in toxicity testing has increased in recent years, the diverse tools available for imaging structural differences in the developing zebrafish brain have not been widely applied to studies of the influence of gene by environment interactions on neuronal connectivity in the developing zebrafish brain. Here, we discuss tools available for imaging of neuronal connectivity in the developing zebrafish, review what has been published in this regard, and suggest a path forward for applying this information to developmental neurotoxicity testing.

Early human brain development: Starring the subplate

This review summarizes early human brain development on the basis of neuroanatomical data and functional connectomics. It indicates that the most significant changes in the brain occur during the second half of gestation and the first three months post-term, in particular in the cortical subplate and cerebellum. As the transient subplate pairs a high rate of intricate developmental changes and interactions with clear functional activity, two phases of development are distinguished: a) the transient cortical subplate phase, ending at 3 months post-term when the permanent circuitries in the primary motor, somatosensory and visual cortices have replaced the subplate; and subsequently, b) the phase in which the permanent circuitries dominate. In the association areas the subplate dissolves in the remainder of the first postnatal year. During both phases developmental changes are paralleled by continuous reconfigurations in network activity. The reviewed literature also suggests that disruption of subplate development may play a pivotal role in developmental disorders, such as cerebral palsy, autism spectrum disorders, attention deficit hyperactivity disorder and schizophrenia.

Elevated protein concentrations in newborn blood and the risks of autism spectrum disorder, and of social impairment, at age 10 years among infants born before the 28th week of gestation

Among the 1 of 10 children who are born preterm annually in the United States, 6% are born before the third trimester. Among children who survive birth before the 28th week of gestation, the risks of autism spectrum disorder (ASD) and non-autistic social impairment are severalfold higher than in the general population. We examined the relationship between top quartile inflammation-related protein concentrations among children born extremely preterm and ASD or, separately, a high score on the Social Responsiveness Scale (SRS total score ≥65) among those who did not meet ASD criteria, using information only from the subset of children whose DAS-II verbal or non-verbal IQ was ≥70, who were assessed for ASD, and who had proteins measured in blood collected on ≥2 days (N = 763). ASD (N = 36) assessed at age 10 years is associated with recurrent top quartile concentrations of inflammation-related proteins during the first post-natal month (e.g., SAA odds ratio (OR); 95% confidence interval (CI): 2.5; 1.2-5.3) and IL-6 (OR; 95% CI: 2.6; 1.03-6.4)). Top quartile concentrations of neurotrophic proteins appear to moderate the increased risk of ASD associated with repeated top quartile concentrations of inflammation-related proteins. High (top quartile) concentrations of SAA are associated with elevated risk of ASD (2.8; 1.2-6.7) when Ang-1 concentrations are below the top quartile, but not when Ang-1 concentrations are high (1.3; 0.3-5.8). Similarly, high concentrations of TNF-α are associated with heightened risk of SRS-defined social impairment (N = 130) (2.0; 1.1-3.8) when ANG-1 concentrations are not high, but not when ANG-1 concentrations are elevated (0.5; 0.1-4.2).

Association of Food Allergy and Other Allergic Conditions With Autism Spectrum Disorder in Children

IMPORTANCE

The prevalence of autism spectrum disorder (ASD) in US children has increased during the past decades. Immunologic dysfunction has recently emerged as a factor associated with ASD. Although children with ASD are more likely to have gastrointestinal disorders, little is known about the association between food allergy and ASD.

OBJECTIVE

To examine the association of food allergy and other allergic conditions with ASD in US children.

DESIGN, SETTING, AND PARTICIPANTS

This population-based, cross-sectional study used data from the National Health Interview Survey collected between 1997 and 2016. The data analysis was performed in 2018. All eligible children aged 3 to 17 years were included. Food allergy, respiratory allergy, and skin allergy were defined based on an affirmative response in the questionnaire by a parent or guardian.

MAIN OUTCOMES AND MEASURES

Reported ASD diagnosed by a physician or other health professional.

RESULTS

This analysis included 199 520 children (unweighted mean [SD] age, 10.21 [4.41] years; 102 690 boys [51.47%]; 55 476 Hispanic [27.80%], 97 200 non-Hispanic white [48.72%], 30 760 non-Hispanic black [15.42%], and 16 084 non-Hispanic other race [8.06%]). Among them, 8734 (weighted prevalence, 4.31%) had food allergy, 24 555 (12.15%) had respiratory allergy, and 19 399 (9.91%) had skin allergy. A diagnosis of ASD was reported in 1868 children (0.95%). The weighted prevalence of reported food, respiratory, and skin allergies was higher in children with ASD (11.25%, 18.73%, and 16.81%, respectively) compared with children without ASD (4.25%, 12.08%, and 9.84%, respectively). In analyses adjusting for age, sex, race/ethnicity, family highest education level, family income level, geographical region, and mutual adjustment for other allergic conditions, the associations between allergic conditions and ASD remained significant. The odds ratio (OR) of ASD increased in association with food allergy (OR, 2.29; 95% CI, 1.87-2.81), respiratory allergy (OR, 1.28; 95% CI, 1.10-1.50), and skin allergy (OR, 1.50; 95% CI, 1.28-1.77) when comparing children with these conditions and those without.

CONCLUSIONS AND RELEVANCE

In a nationally representative sample of US children, a significant and positive association of common allergic conditions, in particular food allergy, with ASD was found. Further investigation is warranted to elucidate the causality and underlying mechanisms.

Placental adaptations to micronutrient dysregulation in the programming of chronic disease

Poor nutrition during pregnancy is known to impair foetal development and increase the risk of chronic disease in offspring. Both macronutrients and micronutrients are required for a healthy pregnancy although significantly less is understood about the role of micronutrients in the programming of chronic disease. This is despite the fact that modern calorie rich diets are often also deficient in key micronutrients. The importance of micronutrients in gestational disorders is clearly understood but how they impact long term disease in humans requires further investigation. In contrast, animal studies have demonstrated how diets high or low in specific micronutrients influence offspring physiology. Many of these studies highlight the importance of the placenta in determining disease risk. This review will explore the effects of individual vitamins, minerals and trace elements on offspring disease outcomes and discuss several key placental adaptations that are affected by multiple micronutrients. These placental adaptations include micronutrient induced dysregulation of oxidative stress, altered methyl donor availability and its impact on epigenetic mechanisms as well as endocrine dysfunction. Critical gaps in our current knowledge and the relative importance of different micronutrients at different gestational ages will also be highlighted. Finally, this review will discuss the need for further studies to characterise the micronutrient status of Australian women of reproductive age and correlate micronutrient status to placental adaptations, pregnancy complications and offspring disease.

Population Health in Pediatric Speech and Language Disorders: Available Data Sources and a Research Agenda for the Field

PURPOSE

The aim of the study was to provide an overview of population science as applied to speech and language disorders, illustrate data sources, and advance a research agenda on the epidemiology of these conditions.

METHOD

Computer-aided database searches were performed to identify key national surveys and other sources of data necessary to establish the incidence, prevalence, and course and outcome of speech and language disorders. This article also summarizes a research agenda that could enhance our understanding of the epidemiology of these disorders.

RESULTS

Although the data yielded estimates of prevalence and incidence for speech and language disorders, existing sources of data are inadequate to establish reliable rates of incidence, prevalence, and outcomes for speech and language disorders at the population level.

CONCLUSIONS

Greater support for inclusion of speech and language disorder-relevant questions is necessary in national health surveys to build the population science in the field.

Current Enlightenment About Etiology and Pharmacological Treatment of Autism Spectrum Disorder

Autistic Spectrum Disorder (ASD) is a complex neurodevelopmental brain disorder characterized by two core behavioral symptoms, namely impairments in social communication and restricted/repetitive behavior. The molecular mechanisms underlying ASD are not well understood. Recent genetic as well as non-genetic animal models contributed significantly in understanding the pathophysiology of ASD, as they establish autism-like behavior in mice and rats. Among the genetic causes, several chromosomal mutations including duplications or deletions could be possible causative factors of ASD. In addition, the biochemical basis suggests that several brain neurotransmitters, e.g., dopamine (DA), serotonin (5-HT), gamma-amino butyric acid (GABA), acetylcholine (ACh), glutamate (Glu) and histamine (HA) participate in the onset and progression of ASD. Despite of convincible understanding, risperidone and aripiprazole are the only two drugs available clinically for improving behavioral symptoms of ASD following approval by Food and Drug Administration (FDA). Till date, up to our knowledge there is no other drug approved for clinical usage specifically for ASD symptoms. However, many novel drug candidates and classes of compounds are underway for ASD at different phases of preclinical and clinical drug development. In this review, the diversity of numerous aetiological factors and the alterations in variety of neurotransmitter generation, release and function linked to ASD are discussed with focus on drugs currently used to manage neuropsychiatric symptoms related to ASD. The review also highlights the clinical development of drugs with emphasis on their pharmacological targets aiming at improving core symptoms in ASD.

The medical home for children with autism spectrum disorder: an essential element whose time has come

PURPOSE OF REVIEW

The purpose of this review is to describe the role of the medical home in children with autism spectrum disorder (ASD). A high-quality medical home is essential, given the increase in prevalence of ASD and the array of services, community partners, specialists, therapists, and healthcare team members needed to care for this population.

RECENT FINDINGS

Providing care through the medical home model results in fewer unmet needs. Care coordination and integration are the aspects of the medical home currently most lacking. Navigating the healthcare landscape for children with ASD may be enhanced with patient navigators, integration of physical and behavioral health, and telehealth services.

SUMMARY

Children with ASD have an increased number of medical and mental health needs. Obtaining care via a medical home has been shown to decrease unmet healthcare needs. However, they are less likely to receive care through the medical home model compared with other children with special healthcare needs. Barriers identified by families include a lack of early identification, limited knowledge on educational plans, and unknown community resources. Barriers identified by providers include lack of time, training, and resources. Providing care coordination and family-centered care in a medical home model are essential for children with ASD.