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.

Autism and Epilepsy

Epilepsy is one of the most common comorbidities in individuals with autism spectrum disorders (ASDs). Risk factors include the presence of developmental delay/intellectual disability, female sex, age, and an underlying genetic condition. Due to higher prevalence of epilepsy in ASD, it is important to have a high index of suspicion for seizures and refer to a neurologist if there are concerns. Genetic testing is recommended for all children with ASD but it becomes more high yield in children with epilepsy and ASD.

Factor associated with the occurrence of epilepsy in autism: a systematic review

This systematic review aimed to identify factors significantly associated with the occurrence of epilepsy in autistic individuals and to consider the impact of study quality on findings. Electronic databases were systematically searched on October 2nd, 2020 and records retrieved were limited to those published from 2000 onwards. Study quality was categorised as 'good', 'moderate' or 'weak'. Fifty-three studies were included and in studies where the prevalence of epilepsy was reported (n = 257,892), 18,254 (7%) had co-occurring epilepsy. Intellectual disability/cognitive impairment was the most commonly reported risk factor associated with occurrence of epilepsy in autistic individuals. The evidence supporting other, potentially relevant factors was weak and inconsistent and requires further evaluation. Only 9/53 studies were considered 'good' quality.

Sex Differences in Brain Disorders

A remarkable feature of the brain is its sexual dimorphism. Sexual dimorphism in brain structure and function is associated with clinical implications documented previously in healthy individuals but also in those who suffer from various brain disorders. Sex-based differences concerning some features such as the risk, prevalence, age of onset, and symptomatology have been confirmed in a range of neurological and neuropsychiatric diseases. The mechanisms responsible for the establishment of sex-based differences between men and women are not fully understood. The present paper provides up-to-date data on sex-related dissimilarities observed in brain disorders and highlights the most relevant features that differ between males and females. The topic is very important as the recognition of disparities between the sexes might allow for the identification of therapeutic targets and pharmacological approaches for intractable neurological and neuropsychiatric disorders.

Disease similarity network analysis of Autism Spectrum Disorder and comorbid brain disorders

Autism Spectrum Disorder (ASD) is a neurodevelopmental disorder with heterogeneous clinical presentation, variable severity, and multiple comorbidities. A complex underlying genetic architecture matches the clinical heterogeneity, and evidence indicates that several co-occurring brain disorders share a genetic component with ASD. In this study, we established a genetic similarity disease network approach to explore the shared genetics between ASD and frequent comorbid brain diseases (and subtypes), namely Intellectual Disability, Attention-Deficit/Hyperactivity Disorder, and Epilepsy, as well as other rarely co-occurring neuropsychiatric conditions in the Schizophrenia and Bipolar Disease spectrum. Using sets of disease-associated genes curated by the DisGeNET database, disease genetic similarity was estimated from the Jaccard coefficient between disease pairs, and the Leiden detection algorithm was used to identify network disease communities and define shared biological pathways. We identified a heterogeneous brain disease community that is genetically more similar to ASD, and that includes Epilepsy, Bipolar Disorder, Attention-Deficit/Hyperactivity Disorder combined type, and some disorders in the Schizophrenia Spectrum. To identify loss-of-function rare de novo variants within shared genes underlying the disease communities, we analyzed a large ASD whole-genome sequencing dataset, showing that ASD shares genes with multiple brain disorders from other, less genetically similar, communities. Some genes (e.g., SHANK3, ASH1L, SCN2A, CHD2, and MECP2) were previously implicated in ASD and these disorders. This approach enabled further clarification of genetic sharing between ASD and brain disorders, with a finer granularity in disease classification and multi-level evidence from DisGeNET. Understanding genetic sharing across disorders has important implications for disease nosology, pathophysiology, and personalized treatment.

Prediction of Autism Risk From Family Medical History Data Using Machine Learning: A National Cohort Study From Denmark

Background

A family history of specific disorders (e.g., autism, depression, epilepsy) has been linked to risk for autism spectrum disorder (ASD). This study examines whether family history data could be used for ASD risk prediction.

Methods

We followed all Danish live births, from 1980 to 2012, of Denmark-born parents for an ASD diagnosis through April 10, 2017 (N = 1,697,231 births; 26,840 ASD cases). Linking each birth to three-generation family members, we identified 438 morbidity indicators, comprising 73 disorders reported prospectively for each family member. We tested various models using a machine learning approach. From the best-performing model, we calculated a family history risk score and estimated odds ratios and 95% confidence intervals for the risk of ASD.

Results

The best-performing model comprised 41 indicators: eight mental conditions (e.g., ASD, attention-deficit/hyperactivity disorder, neurotic/stress disorders) and nine nonmental conditions (e.g., obesity, hypertension, asthma) across six family member types; model performance was similar in training and test subsamples. The highest risk score group had 17.0% ASD prevalence and a 15.3-fold (95% confidence interval, 14.0-17.1) increased ASD risk compared with the lowest score group, which had 0.6% ASD prevalence. In contrast, individuals with a full sibling with ASD had 9.5% ASD prevalence and a 6.1-fold (95% confidence interval, 5.9-6.4) higher risk than individuals without an affected sibling.

Conclusions

Family history of multiple mental and nonmental conditions can identify more individuals at highest risk for ASD than only considering the immediate family history of ASD. A comprehensive family history may be critical for a clinically relevant ASD risk prediction framework in the future.

Epilepsy and electroencephalographic abnormalities in patients with diagnosis of idiopathic autism spectrum disorder in Medellín

The objective of the present study was to make a clinical and electroencephalographic characterization of the electrical findings and types of seizures in patients with idiopathic autism. Pediatric patients of any age, with the diagnosis of idiopathic ASD, contained within the database of the research “Genetic in autism” were included. An electroencephalographic recording with epilepsy protocol was performed in all the patients. 20 pediatric patients were included with an age media of 10.5 years, SD 5.48 years. The median age for the diagnosis of ASD was 53 months, and epileptic seizures were documented in 45%. 66.6% of patients with epileptic events had anti-epileptic treatment, and only 33.3% had achieved seizure control with medication. Interictal abnormal EEG records were found in 8 patients (40%), with 6 of them having epileptic seizures. The abnormal EEG activity was multifocal in 62.5%, focal in 25% and generalized in 12.5% of the cases. The most frequently compromised location was the temporal lobe.

Long-term risk of epilepsy, cerebral palsy and attention-deficit/hyperactivity disorder in children affected by a threatened abortion in utero

BACKGROUND

The birth of a child affected by a threatened abortion (TAB) in utero is associated with autism spectrum disorder; association with other neurological disorders is unknown.

METHODS

This nationwide registry-based cohort study included singletons live-born in Denmark (1979-2010), followed through 2016. The outcomes were epilepsy, cerebral palsy (CP) and attention-deficit/hyperactivity disorder (ADHD). We used Cox regression to compute hazard ratios (HRs), adjusted for birth year, birth order, parental age, morbidity, medication use and maternal socio-economic factors. To remove time-invariant family-shared confounding, we applied sibling analyses.

RESULTS

The study population included 1 864 221 singletons live-born in 1979-2010. Among the TAB-affected children (N = 59 134) vs TAB-unaffected children, at the end of follow-up, the cumulative incidence was 2.2% vs 1.6% for epilepsy, 0.4% vs 0.2% for CP and 5.5% vs 4.2% for ADHD (for children born in 1995-2010). The adjusted HRs were 1.25 [95% confidence interval (CI) 1.16-1.34] for epilepsy, 1.42 (95% CI 1.20-1.68) for CP and 1.21 (95% CI 1.14-1.29) for ADHD. In the sibling design, the adjusted HRs were unity for epilepsy (full siblings: 0.96, 95% CI 0.82-1.12; maternal: 1.04, 95% CI 0.90-1.20; paternal: 1.08, 95% CI 0.93-1.25) and ADHD (full: 1.08, 95% CI 0.92-1.27; maternal: 1.04, 95% CI 0.90-1.20; paternal: 1.08, 95% CI 0.93-1.25). For CP, HRs shifted away from unity among sibling pairs (full: 2.92, 95% CI 1.33-6.39; maternal: 2.03, 95% CI 1.15-3.57; paternal: 3.28, 95% CI 1.36-7.91).

CONCLUSIONS

The birth of a child affected by TAB in utero was associated with a greater risk of CP, but not epilepsy or ADHD.

Seizures and Epilepsy in Autism Spectrum Disorder

Epilepsy and autism frequently co-occur. Epilepsy confers an increased risk of autism and autism confers an increased risk of epilepsy. Specific epilepsy syndromes, intellectual disability, and female gender present a particular risk of autism in individuals with epilepsy. Epilepsy and autism are likely to share common etiologies, which predispose individuals to either or both conditions. Genetic factors, metabolic disorders, mitochondrial disorders, and immune dysfunction all can be implicated.

Seizures and Epilepsy in Autism Spectrum Disorder

Epilepsy and autism frequently co-occur. Epilepsy confers an increased risk of autism and autism confers an increased risk of epilepsy. Specific epilepsy syndromes, intellectual disability, and female gender present a particular risk of autism in individuals with epilepsy. Epilepsy and autism are likely to share common etiologies, which predispose individuals to either or both conditions. Genetic factors, metabolic disorders, mitochondrial disorders, and immune dysfunction all can be implicated.

Neuropsychiatric "Comorbidity" as Causal Influence in Autism

Behavioral comorbidity is the rule rather than the exception in autism spectrum disorder (ASD), and the co-occurrence of autistic traits with subclinical manifestations of other psychiatric syndromes (eg, anxiety, developmental coordination disorder) extends to the general population, where there is strong evidence for overlap in the respective genetic causes. An ASD "comorbidity" can have several fundamentally distinct causal origins: it can arise due to shared genetic risk between ASD and non-ASD phenotypes (eg, ASD and microcephaly in the context of the MECP2 mutation), as a "secondary symptom" of ASD when engendered by the same causal influence (eg, epilepsy in channelopathies associated with ASD), due to chance co-occurrence of ASD with a causally independent liability (eg, ASD and diabetes), or as the late manifestation of an independent causal influence on ASD (eg, attention-deficit/hyperactivity disorder). Here, we review evidence for the latter, that is, the role of nonspecific causal influences on the development of ASD itself. The notion that nonspecific insults to neural development, either inherited or acquired, might augment the impact of ASD-specific genetic susceptibilities in contributing to its cause has not been appreciated in the literature on comorbidity, and has significant implications for both personalized intervention and future research. Prior biomarker studies of ASD have typically not accounted for variation in such traits. The statistical power of future studies, particularly in autism genetics and neuroimaging, can be enhanced by more comprehensive attention to the measurement of comorbid behavioral traits that index causal influences on the disorder, among not only cases but (importantly) controls.

Advances in genetic testing and optimization of clinical management in children and adults with epilepsy

Introduction: Epileptic disorders are a heterogeneous group of medical conditions with epilepsy as the common denominator. Genetic causes, electro-clinical features, and management significantly vary according to the specific condition.Areas covered: Relevant diagnostic advances have been achieved thanks to the advent of Next Generation Sequencing (NGS)-based molecular techniques. These revolutionary tools allow to sequence all coding (whole exome sequencing, WES) and non-coding (whole genome sequencing, WGS) regions of human genome, with a potentially huge impact on patient care and scientific research.Expert opinion: The application of these tests in children and adults with epilepsy has led to the identification of new causative genes, widening the knowledge on the pathophysiology of epilepsy and resulting in therapeutic implications. This review will explore the most recent advancements in genetic testing and provide up-to-date approaches for the choice of the correct test in patients with epilepsy.

Childhood seizures and risk of psychiatric disorders in adolescence and early adulthood: a Danish nationwide cohort study

BACKGROUND

Paediatric seizures have been linked to psychiatric disorders in childhood, but there is a paucity of large-scale population-based studies of psychiatric comorbidity in later life. We aimed to examine the relation between childhood seizures and the risk of psychiatric disorders in adolescence and early adulthood.

METHODS

We did a register-based cohort study of all individuals born in Denmark in 1978-2002. Using diagnostic information from the Danish National Patient Register, all cohort members were categorised according to occurrence of febrile seizures and epilepsy, before entering the follow-up period on their 10th birthday. Individuals were followed up until onset of mental illness, death, emigration, or the end of the study period on Dec 31, 2012. Cox regression analyses were used to estimate the risk of five predefined groups of psychiatric disorders (substance abuse disorders, schizophrenia, mood disorder, anxiety, and personality disorder), separately and combined. Models were adjusted for relevant confounders.

FINDINGS

Between Jan 1, 1978, and Dec 31, 2002, 1 291 679 individuals were born in Denmark and followed up in our population cohort (approximately 15 million person-years). 43 148 individuals had a history of febrile seizures, 10 355 had epilepsy, and 1696 had both these disorders. 83 735 (6%) cohort members were identified with at least one of the psychiatric disorders of interest. The risk of any psychiatric disorder was raised in individuals with a history of febrile seizures (hazard ratio [HR] 1·12, 95% CI 1·08-1·17), epilepsy (1·34, 1·25-1·44), or both disorders (1·50, 1·28-1·75). Excess risk of psychiatric illness associated with childhood seizures was present across a range of different disorders, most notably schizophrenia but also anxiety and mood disorders. Associations did not differ between males and females (p=0·30) but increased with a growing number of admissions for febrile seizures (p<0·0001) and with later onset of childhood epilepsy (p<0·0001).

INTERPRETATION

Children with epilepsy and febrile seizures-with and without concomitant epilepsy-are at increased risk of developing a broad range of psychiatric disorders in later life. Clarification of the underlying mechanisms attributable to these associations is needed to identify potential options for prevention.

FUNDING

Novo Nordisk Foundation, Danish Epilepsy Association, Central Denmark Region, Lundbeck Foundation, and Stanley Medical Research Institute.

Epilepsy genetics: Current knowledge, applications, and future directions

The rapid pace of disease gene discovery has resulted in tremendous advances in the field of epilepsy genetics. Clinical testing with comprehensive gene panels, exomes, and genomes are now available and have led to higher diagnostic rates and insights into the underlying disease processes. As such, the contribution to the care of patients by medical geneticists, neurogeneticists and genetic counselors are significant; the dysmorphic examination, the necessary pre- and post-test counseling, the selection of the appropriate next-generation sequencing-based test(s), and the interpretation of sequencing results require a care provider to have a comprehensive working knowledge of the strengths and limitations of the available testing technologies. As the underlying mechanisms of the encephalopathies and epilepsies are better understood, there may be opportunities for the development of novel therapies based on an individual's own specific genotype. Drug screening with in vitro and in vivo models of epilepsy can potentially facilitate new treatment strategies. The future of epilepsy genetics will also probably include other-omic approaches such as transcriptomes, metabolomes, and the expanded use of whole genome sequencing to further improve our understanding of epilepsy and provide better care for those with the disease.

Neuropsychiatric effects of epilepsy in developmental disorders

PURPOSE OF REVIEW

The overlap of neuropsychiatric illness and developmental disability continues to be prominently recognized in clinical practice and in the academic literature. Theoretical and practical considerations may represent a frontier for understanding brain and behavior relationships. The purpose of this review is to explore this common relationship and report on recent literature that helps advance the larger fields of psychiatry and neurology.

RECENT FINDINGS

Overlap between developmental disability, epilepsy, and neuropsychiatric illness may be more common than originally thought. Excessive excitatory neurotransmitter activity may be present in epilepsy and in autism spectrum disorder. Specific seizure types may be associated with features of developmental disabilities and neuropsychiatric conditions.

SUMMARY

Neuropsychiatric illness is common in epilepsy and more frequent in developmental disabilities than generally recognized. Seizure foci in the temporal lobe may play a significant role. Brain connectivity and specific neurotransmitter systems are active areas of investigation. Antiepileptic drugs may improve neuropsychiatric symptoms in persons with developmental disability and epilepsy.

What is the Relationship Between Autism Spectrum Disorders and Epilepsy?

The association of epilepsy and autism spectrum disorders (ASD) is best understood by examining the relationship between social cognition, nonsocial cognition, and epilepsy. The relationship between ASD and epilepsy is bidirectional and is strongly linked to intellectual disability (ID). The risk of developing ASD in children with epilepsy is highest in children with early onset seizures, with a high prevalence in children with infantile spasms. The risk of developing epilepsy in children first diagnosed with ASD is highest in those with ID. The prevalence of seizures in ASD increases with age. When epilepsy and ASD coexist, they share common pathophysiological mechanisms. In epilepsy with and without ID, social-cognitive deficits are an important determinant of neurodevelopmental outcomes. Early recognition of social deficits is an important aspect of the comprehensive management of children with epilepsy. Treating the seizures in individuals with epilepsy and ASD is crucial but interventions that address social-cognitive deficits are necessary to maximize neurodevelopmental outcomes.