Proband and Familial Autoimmune Diseases Are Associated With Proband Diagnosis of Autism Spectrum Disorders

Biomarkers of mitochondrial dysfunction in autism spectrum disorder: A systematic review and meta-analysis

Autism spectrum disorder (ASD) is a neurodevelopmental disorder affecting 1 in 36 children and is associated with physiological abnormalities, most notably mitochondrial dysfunction, at least in a subset of individuals. This systematic review and meta-analysis discovered 204 relevant articles which evaluated biomarkers of mitochondrial dysfunction in ASD individuals. Significant elevations (all p < 0.01) in the prevalence of lactate (17%), pyruvate (41%), alanine (15%) and creatine kinase (9%) were found in ASD. Individuals with ASD had significant differences (all p < 0.01) with moderate to large effect sizes (Cohen's d' ≥ 0.6) compared to controls in mean pyruvate, lactate-to-pyruvate ratio, ATP, and creatine kinase. Some studies found abnormal TCA cycle metabolites associated with ASD. Thirteen controlled studies reported mitochondrial DNA (mtDNA) deletions or variations in the ASD group in blood, peripheral blood mononuclear cells, lymphocytes, leucocytes, granulocytes, and brain. Meta-analyses discovered significant differences (p < 0.01) in copy number of mtDNA overall and in ND1, ND4 and CytB genes. Four studies linked specific mtDNA haplogroups to ASD. A series of studies found a subgroup of ASD with elevated mitochondrial respiration which was associated with increased sensitivity of the mitochondria to physiological stressors and neurodevelopmental regression. Lactate, pyruvate, lactate-to-pyruvate ratio, carnitine, and acyl-carnitines were associated with clinical features such as delays in language, social interaction, cognition, motor skills, and with repetitive behaviors and gastrointestinal symptoms, although not all studies found an association. Lactate, carnitine, acyl-carnitines, ATP, CoQ10, as well as mtDNA variants, heteroplasmy, haplogroups and copy number were associated with ASD severity. Variability was found across biomarker studies primarily due to differences in collection and processing techniques as well as the intrinsic heterogeneity of the ASD population. Several studies reported alterations in mitochondrial metabolism in mothers of children with ASD and in neonates who develop ASD. Treatments targeting mitochondria, particularly carnitine and ubiquinol, appear beneficial in ASD. The link between mitochondrial dysfunction in ASD and common physiological abnormalities in individuals with ASD including gastrointestinal disorders, oxidative stress, and immune dysfunction is outlined. Several subtypes of mitochondrial dysfunction in ASD are discussed, including one related to neurodevelopmental regression, another related to alterations in microbiome metabolites, and another related to elevations in acyl-carnitines. Mechanisms linking abnormal mitochondrial function with alterations in prenatal brain development and postnatal brain function are outlined. Given the multisystem complexity of some individuals with ASD, this review presents evidence for the mitochondria being central to ASD by contributing to abnormalities in brain development, cognition, and comorbidities such as immune and gastrointestinal dysfunction as well as neurodevelopmental regression. A diagnostic approach to identify mitochondrial dysfunction in ASD is outlined. From this evidence, it is clear that many individuals with ASD have alterations in mitochondrial function which may need to be addressed in order to achieve optimal clinical outcomes. The fact that alterations in mitochondrial metabolism may be found during pregnancy and early in the life of individuals who eventually develop ASD provides promise for early life predictive biomarkers of ASD. Further studies may improve the understanding of the role of the mitochondria in ASD by better defining subgroups and understanding the molecular mechanisms driving some of the unique changes found in mitochondrial function in those with ASD.

3-generation family histories of mental, neurologic, cardiometabolic, birth defect, asthma, allergy, and autoimmune conditions associated with autism: an open-source catalogue of findings

The relatively few conditions and family members investigated in autism family health history limits etiologic understanding. For more comprehensive understanding and hypothesis-generation we produced an open-source catalogue of autism associations with family histories of mental, neurologic, cardiometabolic, birth defect, asthma, allergy, and autoimmune conditions. All live births in Denmark, 1980-2012, of Denmark-born parents (1,697,231 births), and their 3-generation family members were followed through April 10, 2017 for each of 90 diagnoses (including autism), emigration or death. Adjusted hazard ratios (aHR) were estimated via Cox regression for each diagnosis-family member type combination, adjusting for birth year, sex, birth weight, gestational age, parental ages at birth, and number of family member types of index person; aHRs also calculated for sex-specific co-occurrence of each disorder. We obtained 6,462 individual family history aHRS across autism overall (26,840 autistic persons; 1.6% of births), by sex, and considering intellectual disability (ID); and 350 individual co-occurrence aHRS. Results are catalogued in interactive heat maps and down-loadable data files: https://ncrr-au.shinyapps.io/asd-riskatlas/ and interactive graphic summaries: https://public.tableau.com/views/ASDPlots_16918786403110/e-Figure5. While primarily for reference material or use in other studies (e.g., meta-analyses), results revealed considerable breadth and variation in magnitude of familial health history associations with autism by type of condition, family member type, sex of the family member, side of the family, sex of the index person, and ID status, indicative of diverse genetic, familial, and non-genetic autism etiologic pathways. Careful attention to sources of autism likelihood in family health history, aided by our open data resource, may accelerate understanding of factors underlying neurodiversity.

Risk of Autoimmune Disease in Research-Identified Cases of Autism Spectrum Disorder: A Longitudinal, Population-Based Birth Cohort Study

OBJECTIVE

Determine the risk of autoimmune disease in research-identified cases of autism spectrum disorder (ASD) compared with referents using a longitudinal, population-based birth cohort.

METHODS

ASD incident cases were identified from a population-based birth cohort of 31,220 individuals. Inclusive ASD definition based on DSM-IV-TR autistic disorder, Asperger syndrome, and pervasive developmental disorder, not otherwise specified, was used to determine ASD cases. For each ASD case, 2 age- and sex-matched referents without ASD were identified. Diagnosis codes assigned between birth and December 2017 were electronically obtained. Individuals were classified as having an autoimmune disorder if they had at least 2 diagnosis codes more than 30 days apart. Cox proportional hazards models were fit to estimate the hazard ratio (HR) between ASD status and autoimmune disorder.

RESULTS

Of 1014 ASD cases, 747 (73.7%) were male. Fifty ASD cases and 59 of the 1:2 matched referents were diagnosed with first autoimmune disorder at the median age of 14 and 17.1 years, respectively. ASD cases had increased risk of autoimmune disease compared with matched referents (HR 1.74; 95% confidence interval [CI], 1.21-2.52). The increased risk was statistically significant among male patients (HR 2.01; 95% CI, 1.26-3.21) but not among the smaller number of female subjects (HR 1.38; 95% CI, 0.76-2.50).

CONCLUSION

This study provides evidence from a longitudinal, population-based birth cohort for co-occurrence of ASD and autoimmune disorders. Thus, children with ASD should be monitored for symptoms of autoimmune disease and appropriate workup initiated.

Dysregulation of immune and metabolism pathways in maternal immune activation induces an increased risk of autism spectrum disorders

AIMS

Maternal immune activation (MIA) via infection during pregnancy is known to be an environmental risk factor for neurodevelopmental disorders and the development of autism spectrum disorders (ASD) in the offspring, but it still remains elusive that the molecular relevance between infection-induced abnormal neurodevelopmental events and an increased risk for ASD development.

MAIN METHODS

Fully considering the extremely high genetic heterogeneity of ASD and the universality of risk-gene with minimal effect-sizes, the gene and pathway-based association analysis was performed with the transcriptomic and DNA methylation landscapes of temporal human embryonic brain development and ASD, and the time-course transcriptional profiling of MIA. We conducted the transcriptional profiling of mouse abnormal neurodevelopment two days following induced MIA via LPS injection at E10.5.

KEY FINDINGS

A novel evidence was proved that illustrated altering four immune and metabolism-related risk pathways, including starch and sucrose metabolism, ribosome, protein processing in endoplasmic reticulum, and retrograde endocannabinoid signaling pathway, which were prominent involvement in the process of MIA regulating abnormal fetal brain development to induce an increased risk of ASD. Here, we have observed that almost all key genes within these risk pathways are significantly differentially expressed at embryonic days (E) 10.5-12.5, which is considered to be the optimal coincidence window of mouse embryonic brain development to study the intimate association between MIA and ASD using mouse animal models.

SIGNIFICANCE

There search establishes that MIA causes dysregulation of immune and metabolic pathways, which leads to abnormal embryonic neurodevelopment, thus promoting development of ASD symptoms in offspring.

Novel maternal autoantibodies in autism spectrum disorder: Implications for screening and diagnosis

Introduction

Autism spectrum disorder (ASD) is a complex neurodevelopmental disorder for which early recognition is a major challenge. Autoantibodies against fetal brain antigens have been found in the blood of mothers of children with ASD (m-ASD) and can be transferred to the fetus where they can impact neurodevelopment by binding to fetal brain proteins. This study aims to identify novel maternal autoantibodies reactive against human fetal brain antigens, and explore their use as biomarkers for ASD screening and diagnosis.

Methods

A custom-made human fetal brain cDNA phage display library was constructed, and screened for antibody reactivity in m-ASD samples from the Simons Simplex Collection (SSC) of the Simons Foundation Autism Research Initiative (SFARI). Antibody reactivity against 6 identified antigens was determined in plasma samples of 238 m-ASD and 90 mothers with typically developing children (m-TD).

Results

We identified antibodies to 6 novel University Hasselt (UH)-ASD antigens, including three novel m-ASD autoantigens, i.e., ribosomal protein L23 (RPL23), glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and calmodulin-regulated spectrin-associated protein 3 (CAMSAP3). Antibody reactivity against a panel of four of these targets was found in 16% of m-ASD samples, compared to 4% in m-TD samples (p = 0.0049).

Discussion

Maternal antibodies against 4 UH-ASD antigens could therefore provide a novel tool to support the diagnosis of ASD in a subset of individuals.

Schmidt R, N. Pearce E. Prenatal Exposure to Per- and Polyfluoroalkyl Substances, Maternal Thyroid Dysfunction, and Child Autism Spectrum Disorder

Autism spectrum disorder (ASD), with its high economic and societal costs, is a growing public health concern whose prevalence has risen steadily over the last two decades. Although actual increased incidence versus improved diagnosis remains controversial, the increased prevalence of ASD suggests non-inherited factors as likely contributors. There is increasing epidemiologic evidence that abnormal maternal thyroid function during pregnancy is associated with increased risk of child ASD and other neurodevelopmental disorders. Prenatal exposure to endocrine-disrupting chemicals such as per- and polyfluoroalkyl substances (PFAS) is known to disrupt thyroid function and can affect early brain development; thus, thyroid dysfunction is hypothesized to mediate this relationship. The concept of a potential pathway from prenatal PFAS exposure through thyroid dysfunction to ASD etiology is not new; however, the extant literature on this topic is scant. The aim of this review is to evaluate and summarize reports with regard to potential mechanisms in this pathway.

Association of maternal autoimmune disease and early childhood infections with offspring autism spectrum disorder: A population-based cohort study

The aim of this study was to examine potential synergistic effects between maternal autoimmune disease and early childhood infections and their association with autism spectrum disorder (ASD) in offspring. Both exposures have been associated with increased risk of ASD in previous studies, but potential synergistic effects remain underexplored. We conducted a population-based cohort study of singleton children born at term gestation (37-41 weeks) in New South Wales, Australia from January 2002 to December 2008. Maternal autoimmune diagnoses and childhood infections before age 2 years were identified from linked maternal and child hospital admissions, and ASD diagnoses by age 9 years were identified from linked disability services data. Multivariable logistic regression assessed the association between each exposure and ASD and additive interaction between exposures, controlling for potential confounders. A total of 18,451 children exposed to maternal autoimmune disease were propensity score matched (1:2) to 36,902 unexposed children. Any maternal autoimmune disease (adjusted odds ratio (aOR) 1.25, 95% confidence interval (CI) 1.07-1.47) and any childhood infection before age 2 years (aOR 1.38, 95% CI 1.15-1.67) were each associated with ASD. However, there was no evidence of additive interaction between the two exposures (relative excess risk due to interaction [RERI] 0.128, 95% CI -0.418-0.675) resulting in increased odds of ASD in offspring. Future studies could examine potential interactions between other sources of maternal immune activation and childhood infection and impact on ASD and other neurodevelopmental disorders.

Impact of parental rheumatoid arthritis on risk of autism spectrum disorders in offspring: A systematic review and meta-analysis

BACKGROUND

To investigate the association of risk of offspring autism spectrum disorder (ASD) with both maternal and paternal rheumatoid arthritis (RA).

METHODS

The Embase, Medline, Cochrane Library databases were searched for studies that investigated the association of parental RA with risk of offspring ASD. The primary outcome was the associations of maternal/paternal RA with the risk of offspring ASD. Subgroup analyses were conducted based on the timing of maternal RA diagnosis (i.e., before/after childbirth) and geographical location (i.e., Western vs. Asian countries) of studies.

RESULTS

Ten studies published between 2005 and 2022 involving 6,177,650 participants were analyzed. Pooled results revealed a significant association between maternal RA and the risk of ASD (OR = 1.246, p < 0.001, 10 studies), while there was no association of paternal RA with the risk of offspring ASD (OR = 1.104, p = 0.253, four studies). Subgroup analysis demonstrated no correlation between diagnosis of maternal RA before childbirth and the risk of offspring ASD (OR = 1.449, p = 0.192, four studies), while there was a significant association of maternal RA regardless of the timing of diagnosis with the risk of offspring ASD (OR = 1.227, p = 0.001, six studies). Subgroup analysis on geographical location showed a significant association of maternal RA with the risk of offspring ASD regardless of the study location (all p < 0.05).

CONCLUSION

Our findings supported an association between maternal RA and an elevated risk of ASD in offspring. However, given the limited numbers of studies investigating the risk of offspring ASD in mothers diagnosed with RA before childbirth, further studies are warranted to elucidate this issue.

SYSTEMATIC REVIEW REGISTRATION

[www.crd.york.ac.uk/prospero/], identifier [CRD42022358470].

Catatonia in autism and other neurodevelopmental disabilities: a state-of-the-art review

Individuals with neurodevelopmental disabilities (NDDs) may be at increased risk for catatonia, which can be an especially challenging condition to diagnose and treat. There may be symptom overlap between catatonia and NDD-associated behaviors, such as stereotypies. The diagnosis of catatonia should perhaps be adjusted to address symptom overlap and to include extreme behaviors observed in patients with NDDs, such as severe self-injury. Risk factors for catatonia in individuals with NDDs may include trauma and certain genetic variants, such as those that disrupt SHANK3. Common etiologic features between neurodevelopmental disabilities and catatonia, such as excitatory/inhibitory imbalance and neuroimmune dysfunction, may partially account for comorbidity. New approaches leveraging genetic testing and neuroimmunologic evaluation may allow for more precise diagnoses and effective treatments.

Association of complement component 4 with neuroimmune abnormalities in the subventricular zone in schizophrenia and autism spectrum disorders

An early inflammatory insult is the most recognized risk factor associated with neurodevelopmental psychiatric disorders, even more so than genetic variants. Notably, complement component 4 (C4), a molecule involved in inflammatory responses, has been strongly associated with schizophrenia (SZ) and its role in other neurodevelopmental disorders, such as autism (ASD), is an area of active investigation. However, while C4 in SZ has been implicated in the context of synaptic pruning, little is known about its neuroinflammatory role. The subventricular zone (SVZ) is a region heavily involved in neurodevelopment and neuroimmune interactions through the lifespan; thus, it is a region wherein C4 may play a vital role in disease pathology. Using in situ hybridization with radioactive riboprobes and RNAscope, we identified robust astrocytic expression of C4 in the SVZ and in the septum pellucidum. C4 was also expressed in ependyma, neurons, and Ki67⁺ progenitor cells. Examination of mRNA levels showed elevated C4 in both ASD and SZ, with higher expression in SZ compared to controls. Targeted transcriptomic analysis of inflammatory pathways revealed a strong association of complement system genes with SZ, and to a lesser extent, ASD, as well as generalized immune dysregulation without a strong association with known infectious pathways. Analysis of differentially expressed genes (DEGs) showed that ASD DEGs were enriched in adaptive immune system functions such as Th cell differentiation, while SZ DEGs were enriched in innate immune system functions, including NF-κB and toll like receptor signaling. Moreover, the number of Ki67⁺ cells was significantly higher in ASD compared to SZ and controls. Taken together, these results support a role for C4 into inflammatory-neuroimmune dysregulation observed in SZ and ASD pathology.

Association between autism spectrum disorder and diabetes: systematic review and meta-analysis

There is mixed evidence on the link between autism spectrum disorder (ASD) and diabetes. We conducted the first systematic review/meta-analysis on their association. Based on a pre-registered protocol (PROSPERO: CRD42021261114), we searched Pubmed, Ovid, and Web of Science databases up to 6 December 2021, with no language/type of document restrictions. We assessed study quality using the Newcastle-Ottawa Scale (NOS). We included 24 studies (total: 3427,773 individuals; 237,529 with ASD and 92,832 with diabetes) in the systematic review and 20 in the meta-analysis (mean stars number on the NOS: 5.89/10). There was a significant association, albeit characterized by significant heterogeneity, when pooling unadjusted OR (1.535, 95% CI = 1.109-2.126), which remained significant when restricting the analysis to children and type 2 diabetes, but became non-significant when considering adjusted ORs (OR: 1.528, 95% CI = 0.954-2.448). No significant prospective association was found (n = 2) on diabetes predicting ASD (HR: 1.232, 0.826-11.837). Therefore, the association between ASD and diabetes is likely confounded by demographic and clinical factors that should be systematically investigated in future studies.

Parental autoimmune and autoinflammatory disorders as multiple risk factors for common neurodevelopmental disorders in offspring: a systematic review and meta-analysis

Epidemiological studies have raised concerns about the risk of neurodevelopmental disorders (NDD) in children of patients with autoimmune or inflammatory disorders (AID). The pathophysiological pathways underlying this association are still unknown and little is known about the specific and distinct risk of each AID. To explore these questions, we investigated the association between the occurrences of several NDD in the offspring of mothers or fathers with different IDA. We conducted a meta-analysis-PROSPERO (CRD42020159250)-examining the risk of NDD in the offspring of mothers or fathers with AID. We performed specific analyses separately in fathers or mothers of NDD patients as well as subgroup analyses for each NDD and AID. We searched MEDLINE, Embase, PsycINFO, Cochrane Central Register of Controlled Trials, and Web of Science Core Collection published until December 2021. From an initial pool of 2074 potentially relevant references, 14 studies were included, involving more than 1,400,000 AID and 10,000,000 control parents, 180,000 children with NDD and more than 14,000,000 control children. We found AID in mothers (Adjusted OR 1.27 [95% CI 1.03; 1.57] p = 0.02, [I² = 65%, Tau² = 0.03 p = 0.01] and adjusted OR 1.31 [95% CI 1.11; 1.55] p = 0.001, [I² = 93%, Tau² = 0.13 p = 0.001] and, although in a lesser extent, in fathers (adjusted OR 1.18 [95% CI 1.07; 1.30] p = 0.01, [I² = 15.5%, Tau² = 0.002 p = 0.47]) and adjusted OR 1.14 [95% CI 1.10; 1.17] p < 0.0001, [I² = 0%, Tau² = 0 p = 0.29]) to be associated with ASD and ADHD in the offspring. This difference in the strength of the association was found in the AID-specific analyses, suggesting that AID increase the risk of NDD by a shared mechanism but that a specific maternal route appears to represent an additional excess risk. Inflammatory bowel disease were not associated with an additional risk (neither in fathers nor in mothers) of NDD in offspring. Our results suggest that complex and multiple AID-specific pathophysiological mechanisms may underlie the association of AID and NDD in offspring. Further, comprehensive studies of the different AID and NDD are needed to draw definitive conclusions about the pathophysiological links between parental AID and NDD in children.

Neuronal Cell Adhesion Molecules May Mediate Neuroinflammation in Autism Spectrum Disorder

Autism spectrum disorder (ASD) is a complex neurodevelopmental condition characterized by restrictive and repetitive behaviors, alongside deficits in social interaction and communication. The etiology of ASD is largely unknown but is strongly linked to genetic variants in neuronal cell adhesion molecules (CAMs), cell-surface proteins that have important roles in neurodevelopment. A combination of environmental and genetic factors are believed to contribute to ASD pathogenesis. Inflammation in ASD has been identified as one of these factors, demonstrated through the presence of proinflammatory cytokines, maternal immune activation, and activation of glial cells in ASD brains. Glial cells are the main source of cytokines within the brain and, therefore, their activity is vital in mediating inflammation in the central nervous system. However, it is unclear whether the aforementioned neuronal CAMs are involved in modulating neuroimmune signaling or glial behavior. This review aims to address the largely unexplored role that neuronal CAMs may play in mediating inflammatory cascades that underpin neuroinflammation in ASD, primarily focusing on the Notch, nuclear factor-κB (NF-κB), and mitogen-activated protein kinase (MAPK) cascades. We will also evaluate the available evidence on how neuronal CAMs may influence glial activity associated with inflammation. This is important when considering the impact of environmental factors and inflammatory responses on ASD development. In particular, neural CAM1 (NCAM1) can regulate NF-κB transcription in neurons, directly altering proinflammatory signaling. Additionally, NCAM1 and contactin-1 appear to mediate astrocyte and oligodendrocyte precursor proliferation which can alter the neuroimmune response. Importantly, although this review highlights the limited information available, there is evidence of a neuronal CAM regulatory role in inflammatory signaling. This warrants further investigation into the role other neuronal CAM family members may have in mediating inflammatory cascades and would advance our understanding of how neuroinflammation can contribute to ASD pathology.

Role of Pediatrician in Early Risk Evaluation, Diagnosis and Management of Children with Autism Spectrum Disorders

The article discusses recent ideas about autism: classification approaches, incidence, etiology and pathogenesis, clinical manifestations and diagnosis, comorbid medical conditions, early detection approaches and medical care for children with autism spectrum disorders. The focus is on the information needed for pediatricians in their practice to provide effective medical care for children with neurodevelopmental disorders.

The association of serologically documented maternal thyroid conditions during pregnancy with bipolar disorder in offspring

OBJECTIVES

Higher rates of thyroid conditions are reported in individuals with bipolar disorder. However, no study to date has considered whether maternal thyroid conditions during pregnancy are associated with offspring risk of bipolar disorder, even though the fetus exclusively relies on maternal thyroid hormones through the early second trimester. We therefore examined the association between offspring bipolar disorder and serologically documented maternal thyroid conditions.

METHODS

The study was based on a nested case-control design that utilized data from the Child Health and Development Study, a birth cohort that enrolled pregnant women from 1959 to 1966. Eighty-five cases with DSM-IV-TR were ascertained and matched to controls (1:2) by date of birth, sex, gestational timing of the serum draws, and residence in Alameda County the first year receiving treatment. Archived prenatal maternal serum drawn during early to mid-gestation was used to measure two thyroid hormones, free thyroxine (fT4) and thyroid stimulating hormone (TSH). Subclinical and clinical hypothyroxinemia, hypothyroidism, and hyperthyroidism were determined based on standard methods.

RESULTS

Exposure to maternal hypothyroxinemia was associated with a five-fold increased risk of offspring bipolar disorder with psychotic features, but not without psychotic features. In stratified analysis, female offspring demonstrated increased risk for bipolar disorder with exposure to maternal hypothyroxinemia. No significant association was found between maternal hypothyroidism and offspring bipolar disorder.

CONCLUSIONS

These findings suggest that prenatal thyroid hormone deficiency, particularly a thyroid condition marked by low levels of thyroxine, may be an important developmental mechanism related to the risk of bipolar disorder with psychotic features.

Bridging the Gap Between Physical Health and Autism Spectrum Disorder

Autism spectrum disorder (ASD) is a highly complex and heterogeneous developmental disorder that affects how individuals communicate with other people and relate to the world around them. Research and clinical focus on the behavioural and cognitive manifestations of ASD, whilst important, have obscured the recognition that ASD is also commonly associated with a range of physical and mental health conditions. Many physical conditions appear with greater frequency in individuals with ASD compared to non-ASD populations. These can contribute to a worsening of social communication and behaviour, lower quality of life, higher morbidity and premature mortality. We highlight some of the key physical comorbidities affecting the immune and the gastrointestinal systems, metabolism and brain function in ASD. We discuss how healthcare professionals working with individuals with ASD and parents/carers have a duty to recognise their needs in order to improve their overall health and wellbeing, deliver equality in their healthcare experiences and reduce the likelihood of morbidity and early mortality associated with the condition.

Increased Risk of Atopic Diseases in the Siblings of Patients with Autism Spectrum Disorder: A Nationwide Population-Based Cohort Study

Several studies have shown a strong association between atopic diseases and autism spectrum disorder (ASD). However, the risk of atopic diseases in individuals having ASD-affected siblings has never been investigated. This nationwide population-based cohort study included 2762 individuals with ASD-affected siblings and 11,048 controls. Diagnoses of atopic diseases, including asthma, atopic dermatitis, allergic rhinitis, and allergic conjunctivitis, were ascertained from 1996 or the birth data to the end of 2011. Individuals with ASD-affected siblings had a higher risk for asthma, atopic dermatitis, allergic rhinitis, allergic conjunctivitis, and multiple atopic diseases compared with controls. In conclusion, individuals with ASD-affected siblings were more likely than were the controls to develop atopic diseases, suggesting shared familial mechanisms underlying the two conditions.

Editorial: Autism Spectrum Disorder and Autoimmune Diseases: A Pathway in Common?

The diagnosis of autism spectrum disorder (ASD) has increased significantly in the past decade. A rare condition at the time Kanner (1942) initially described it, ASD has become a public health issue with great social and financial burdens. In 2018, the Centers for Disease Control and Prevention estimated the prevalence of autism at 16.8 for every 1,000 (1:59) children by 8 years of age, affecting 26.6 of 1,000 boys and 6.6 of 1,000 girls. These numbers represent an increase of approximately 150% from 2000 to 2014.¹.