The emergence of autism spectrum disorder: insights gained from studies of brain and behaviour in high-risk infants

Caregiver Narratives of Children with Autism Spectrum Disorder: Exploring Symptom Recognition, Diagnosis, and Interventions

The diagnosis of autism spectrum disorder (ASD) poses myriad challenges for families, yet there is a scarcity of research focusing on their journey from recognizing initial anomalies to implementing interventions. This qualitative study examines how caregivers in Sylhet, Bangladesh, perceive and manage ASD in their children, including early symptom identification, diagnostic processes, and intervention strategies. Data for this study were collected through semi-structured interviews, case studies, and observations involving 22 caregivers of children with ASD. Participants were chosen using purposive-convenience sampling, and data collection continued until interpretive saturation was achieved. The study findings unveil nuanced caregiver perceptions of ASD causation, influenced by sociocultural factors, religious beliefs, and genetic predispositions. These determinants wield significant influence over treatment modalities and the child's developmental trajectory. Importantly, the prevalence of supernatural beliefs and myths often surpasses biomedical explanations, highlighting gaps in awareness, educational outreach, and understanding of ASD. Nevertheless, religious beliefs and rituals concurrently serve as adaptive coping mechanisms, offering solace amidst uncertainty. Furthermore, a striking observation emerges: despite parents frequently identifying anomalies in their children within a 24-month, a substantial delay of 3 to 5 years persists between initial symptom recognition and formal diagnosis. This delay predominantly stems from caregiver hesitancy driven by societal stigmatization, familial dismissal attitudes, and limited diagnostic and specialized services. This study highlights the challenging diagnostic journey and caregiving for children with ASD in Bangladesh, stressing the need for systemic improvements in services, awareness, and research to enhance the well-being of individuals with ASD.

Exploring early life social and executive function development in infants and risk for autism: a prospective cohort study protocol of NICU graduates and infants at risk for cerebral palsy

BACKGROUND

Delays in early social and executive function are predictive of later developmental delays and eventual neurodevelopmental diagnoses. There is limited research examining such markers in the first year of life. High-risk infant groups commonly present with a range of neurodevelopmental challenges, including social and executive function delays, and show higher rates of autism diagnoses later in life. For example, it has been estimated that up to 30% of infants diagnosed with cerebral palsy (CP) will go on to be diagnosed with autism later in life.

METHODS

This article presents a protocol of a prospective longitudinal study. The primary aim of this study is to identify early life markers of delay in social and executive function in high-risk infants at the earliest point in time, and to explore how these markers may relate to the increased risk for social and executive delay, and risk of autism, later in life. High-risk infants will include Neonatal Intensive Care Unit (NICU) graduates, who are most commonly admitted for premature birth and/or cardiovascular problems. In addition, we will include infants with, or at risk for, CP. This prospective study will recruit 100 high-risk infants at the age of 3-12 months old and will track social and executive function across the first 2 years of their life, when infants are 3-7, 8-12, 18 and 24 months old. A multi-modal approach will be adopted by tracking the early development of social and executive function using behavioural, neurobiological, and caregiver-reported everyday functioning markers. Data will be analysed to assess the relationship between the early markers, measured from as early as 3-7 months of age, and the social and executive function as well as the autism outcomes measured at 24 months.

DISCUSSION

This study has the potential to promote the earliest detection and intervention opportunities for social and executive function difficulties as well as risk for autism in NICU graduates and/or infants with, or at risk for, CP. The findings of this study will also expand our understanding of the early emergence of autism across a wider range of at-risk groups.

Primitive reflexes in very low birth weight infants later diagnosed with autism spectrum disorder

BACKGROUND

As early screening and diagnosis is very important in treatment and intervention of autism spectrum disorder (ASD), we investigated the relationship between primitive reflexes and ASD.

METHODS

Of 88 very low birth weight infants (<1500 g) born from April 2010 to March 2012, subjects comprised 38 examined for 18 primitive reflexes between age 38 and 45 weeks corrected age and followed-up over 6 years. ASD was diagnosed using Diagnostic and Statistical Manual of Mental Disorders fifth edition (DSM-5) and Autism Diagnostic Observation Schedule Second Edition (ADOS-2). We compared the number of abnormal primitive reflexes between two groups (11 children with and 19 without ASD) after excluding eight children with cerebral palsy in this case-control study.

RESULTS

Twenty cases showed one to four hypoactive reflex(es) and two showed one hyperactive reflex together with hypoactive reflex(es). Ten out of 11 cases with ASD had one to four abnormal reflex(es). The number of abnormal hypoactive primitive reflexes was significantly higher in the ASD group (P=0.002).

CONCLUSIONS

The result suggests primitive reflexes can be one of the key elements in very early infancy to identify ASD in low-birth-weight infants. Abnormal hypoactive primitive reflex of low-birth-weight infants with ASD may inform future research of the pathogenesis of ASD.

Circuit-level theories for sensory dysfunction in autism: convergence across mouse models

Individuals with autism spectrum disorder (ASD) exhibit a diverse range of behavioral features and genetic backgrounds, but whether different genetic forms of autism involve convergent pathophysiology of brain function is unknown. Here, we analyze evidence for convergent deficits in neural circuit function across multiple transgenic mouse models of ASD. We focus on sensory areas of neocortex, where circuit differences may underlie atypical sensory processing, a central feature of autism. Many distinct circuit-level theories for ASD have been proposed, including increased excitation-inhibition (E-I) ratio and hyperexcitability, hypofunction of parvalbumin (PV) interneuron circuits, impaired homeostatic plasticity, degraded sensory coding, and others. We review these theories and assess the degree of convergence across ASD mouse models for each. Behaviorally, our analysis reveals that innate sensory detection behavior is heightened and sensory discrimination behavior is impaired across many ASD models. Neurophysiologically, PV hypofunction and increased E-I ratio are prevalent but only rarely generate hyperexcitability and excess spiking. Instead, sensory tuning and other aspects of neural coding are commonly degraded and may explain impaired discrimination behavior. Two distinct phenotypic clusters with opposing neural circuit signatures are evident across mouse models. Such clustering could suggest physiological subtypes of autism, which may facilitate the development of tailored therapeutic approaches.

Sleep quality and temperament in association with autism spectrum disorder among infants in Japan

BACKGROUND

Sleep problems and irritable temperaments are common among infants with autism spectrum disorder (ASD). The prospective association between such sleep problems and irritable temperaments and ASDs needs to be determined for elucidating the mechanism and exploring the future intervention study. Thus, in this study, we investigated whether sleep quality and temperament in 1-month-old infants are associated with the onset of ASD in 3-year-old children. We also assessed its sex-stratified associations.

METHODS

We conducted a longitudinal study using data from 69,751 mothers and infants from a large-cohort study, the Japan Environment and Children's Study. We examined the prospective association between infant sleep quality and temperament at 1 month of age and ASD diagnosis by 3 years of age.

RESULTS

Here we show infants with longer daytime sleep have a higher risk of later ASD than those with shorter daytime sleep (risk ratio [RR]: 1.33, 95% confidence interval [CI]: 1.01-1.75). Infants who experienced intense crying have a higher risk of ASD than those who did not (RR: 1.31, 95% CI: 1.00-1.72). There is a difference in sex in the association between a bad mood and later ASD. In particular, female infants experiencing bad moods have a higher risk of ASD than others (RR: 3.59, 95% CI: 1.91-6.75).

CONCLUSIONS

The study findings provide important information for future intervention to reduce the risk of future ASD.

Prototypical autism: New diagnostic criteria and asymmetrical bifurcation model

The current "autism spectrum" DSM 5 diagnostic criteria and autism standardized diagnostic instruments promote considerable heterogeneity or clinical indecision and may be detrimental to the advancement of fundamental research on autism mechanisms. To increase clinical specificity and reorient research towards core autistic presentations, we propose new diagnostic criteria for prototypical autism during the age of 2- to 5-years. We include autism within other non-dominant, familiarly aggregated phenomena sharing asymmetrical developmental bifurcations, such as twin pregnancy, left handedness, and breech presentation/delivery. Following this model, nature, trajectory, and positive/negative signs structure of autism would result from the polarized problem of whether or not language and information is processed in a socially biased manner. Prototypical autism would follow a canonical developmental trajectory by which a gradual decline in social bias in the processing of incoming information, overtly beginning at the end of the first year, bifurcates into a prototypical autistic presentation in the second half of the second year of life. This bifurcation event is followed by a plateau, in which these atypicalities show maximal stringency and distinctiveness, and then ultimately, in most cases, by partial normalization. During the plateau period, the orientation towards, and processing of, information is considerably modified, with an absence of bias for social information, contrasting with a high level of interest in complex, unbiased information, independently of its social or non-social nature. Integrating autism into asymmetrical developmental bifurcations would explain the absence of deleterious neurological and genetic markers and the presence of familial transmission in canonical autistic presentations.

Efficacy of Children Neuropsychological and Behavioral Scale in Screening for Autism Spectrum Disorders through a Combination of Developmental Surveillance

OBJECTIVE

This study aimed to explore the clinical value of Children Neuropsychological and Behavioral Scale-Revision 2016 (CNBS-R2016) for Autism Spectrum Disorder (ASD) screening in the presence of developmental surveillance.

METHODS

All participants were evaluated by the CNBS-R2016 and Gesell Developmental Schedules (GDS). Spearman's correlation coefficients and Kappa values were obtained. Taking GDS as a reference assessment, the performance of the CNBS-R2016 for detecting the developmental delays of children with ASD was analyzed with receiver operating characteristic (ROC) curves. The efficacy of the CNBS-R2016 to screen for ASD was explored by comparing Communication Warning Behavior with Autism Diagnostic Observation Schedule, Second Edition (ADOS-2).

RESULTS

In total, 150 children aged 12-42 months with ASD were enrolled. The developmental quotients of the CNBS-R2016 were correlated with those of the GDS (r=0.62-0.94). The CNBS-R2016 and GDS had good diagnostic agreement for developmental delays (Kappa=0.73-0.89), except for Fine Motor. There was a significant difference between the proportions of Fine Motor, delays detected by the CNBS-R2016 and GDS (86.0% vs. 77.3%). With GDS as a standard, the areas under the ROC curves of the CNBS-R2016 were above 0.95 for all the domains except Fine Motor, which was 0.70. In addition, the positive rate of ASD was 100.0% and 93.5% when the cut-off points of 7 and 12 in the Communication Warning Behavior subscale were used, respectively.

CONCLUSION

The CNBS-R2016 performed well in developmental assessment and screening for children with ASD, especially by Communication Warning Behaviors subscale. Therefore, the CNBS-R2016 is worthy of clinical application in children with ASD in China.

The Regulatory Network of METTL3 in the Nervous System: Diagnostic Biomarkers and Therapeutic Targets

Methyltransferase-like 3 (METTL3) is a typical component of N6-methyladenosine writers that exhibits methyltransferase activity and deposits methyl groups on RNA. Currently, accumulating studies have demonstrated the involvement of METTL3 in the regulation of neuro-physiological and pathological events. However, no reviews have comprehensively summarized and analyzed the roles and mechanisms of METTL3 in these events. Herein, we are focused on reviewing the roles of METTL3 in regulating normal neurophysiological (Neurogenesis, Synaptic Plasticity and Glial Plasticity, Neurodevelopment, Learning and Memory,) and neuropathological (Autism Spectrum Disorder, Major Depressive Disorder, Neurodegenerative disorders, Brain Tumors, Brain Injuries, and Other Brain Disorders) events. Our review found that although the down-regulated levels of METTL3 function through different roles and mechanisms in the nervous system, it primarily inactivates neuro-physiological events and triggers or worsens neuropathological events. In addition, our review suggests that METTL3 could be used as a diagnostic biomarker and therapeutic target in the nervous system. Collectively, our review has provided an up-to-date research outline of METTL3 in the nervous system. In addition, the regulatory network for METTL3 in the nervous system has been mapped, which could provide directions for future research, biomarkers for clinical diagnosis, and targets for disease treatment. Furthermore, this review has provided a comprehensive view, which could improve our understanding of METTL3 functions in the nervous system.

Advancing research on early autism through an integrated risk and resilience perspective

To date, a deficit-oriented approach dominates autism spectrum disorder (ASD) research, including studies of infant siblings of children with ASD at high risk (HR) for the disabilities associated with this disorder. Despite scientific advances regarding early ASD-related risk, there remains little systematic investigation of positive development, limiting the scope of research and quite possibly a deeper understanding of pathways toward and away from ASD-related impairments. In this paper, we argue that integrating a resilience framework into early ASD research has the potential to enhance knowledge on prodromal course, phenotypic heterogeneity, and developmental processes of risk and adaptation. We delineate a developmental systems resilience framework with particular reference to HR infants. To illustrate the utility of a resilience perspective, we consider the "female protective effect" and other evidence of adaptation in the face of ASD-related risk. We suggest that a resilience framework invites focal questions about the nature, timing, levels, interactions, and mechanisms by which positive adaptation occurs in relation to risk and developmental pathways toward and away from ASD-related difficulties. We conclude with recommendations for future research, including more focus on adaptive development and multisystem processes, pathways away from disorder, and reconsideration of extant evidence within an integrated risk-and-resilience framework.

Whole exome screening of neurodevelopmental regression disorders in a cohort of Egyptian patients

Developmental regression describes a child who begins to lose his previously acquired milestones skills after he has reached a certain developmental stage and though affects his childhood development. It is associated with neurodegenerative diseases including leukodystrophy and neuronal ceroid lipofuscinosis diseases (NCLs), one of the most frequent childhood-onset neurodegenerative disorders. The current study focused on screening causative genes of developmental regression diseases comprising neurodegenerative disorders in Egyptian patients using next-generation sequencing (NGS)-based analyses as well as developing checklist to support clinicians who are not familiar with these diseases. A total of 763 Egyptian children (1 to 11 years), mainly diagnosed with developmental regression, seizures, or visual impairment, were studied using whole exome sequencing (WES). Among 763 Egyptian children, 726 cases were early clinically and molecularly diagnosed, including 482 cases that had pediatric stroke, congenital infection, and hepatic encephalopathy; meanwhile, 192 had clearly dysmorphic features, 31 showed central nervous system (CNS) malformation, 17 were diagnosed by leukodystrophy, 2 had ataxia telangiectasia, and 2 were diagnosed with tuberous sclerosis. The remained 37 out of 763 candidates were suspected with NCLs symptoms; however, 28 were confirmed to be NCLs patients, 1 was Kaya-Barakat-Masson syndrome, 1 was diagnosed as infantile neuroaxonal dystrophy, and 7 cases required further molecular diagnosis. This study provided an NGS-based approach of the genetic causes of developmental regression and neurodegenerative diseases as it comprised different variants and de novo mutations with complex phenotypes of these diseases which in turn help in early diagnoses and counseling for affected families.

Attitudes Towards Evidence-Based Practice of Professionals Working with Children and Adolescents with Autism Spectrum Disorder in Bangladesh

Like in many lower-middle-income countries (LMIC), progress in implementing evidence-based practices (EBPs) for children with autism spectrum disorder (ASD) has been slow in Bangladesh. This cross-sectional study examined professionals' attitudes towards evidence-based practice (EBP) for children and adolescents with ASD and explored how providers' demographic factors are related to attitudes to and adoption of EBPs in Bangladesh. The sample consisted of 150 mental health professionals and special teachers from the urban area of Dhaka. Attitudes were assessed by the Evidence-based Practice Attitude Scale-36. Findings indicated that professionals have favorable attitudes towards EBP. Their attitudes varied depending on service settings (public clinical, private clinical, and special school) and caseload per year. Professionals who work in private and special school settings claimed to be more willing to adopt an EBP when required and perceived a higher fit of EBPs and their work than those in public clinical settings. The number of different EBPs used also differed by service setting. Every type of intervention (except medication) was used by more professionals in special schools than in private and public clinical settings. Many professionals reported few barriers to the implementation of EBPs. These findings indicate conditions that are often conducive to the implementation of EBPs. However, these results do not reflect the situation in rural areas, in which poverty is more widespread and the number of specialized professionals is low.

Effectiveness of interventions for children and adolescents with autism spectrum disorder in high-income vs. lower middle-income countries: An overview of systematic reviews and research papers from LMIC

Background

There is a multitude of systematic reviews of interventions for children and adolescents with autism spectrum disorder (ASD). However, most reviews seem to be based on research conducted in High-Income Countries (HIC). Thus, summary findings may not directly apply to Lower Middle-Income Countries (LMIC). Therefore, we conducted a Meta-Review analyzing systematic reviews on the effectiveness of interventions for target outcomes in children and adolescents with ASD to find out whether there are differences in effectiveness between HIC and LMIC and which interventions can be considered evidence-based in LMIC.

Methods

Electronic databases (PsycINFO, PubMed, Cochrane database of systematic reviews) were searched for reviews on interventions for ASD in children and adolescents from January 2011 through December 2021, which included studies not coming from HIC. Systematic reviews with qualitative and quantitative syntheses of findings were included. Two investigators independently assessed studies against predetermined inclusion/exclusion criteria and extracted relevant data including quality and evidence assessments. Evidence for different types of interventions in HIC vs. LMIC was planned to be compared, but none of the reviews assessed potential differences. Therefore, a narrative review of the studies from LMIC was conducted including an assessment of quality and evidence.

Results

Thirty-five reviews fulfilled the inclusion criteria. Eleven considered findings from HIC and LMIC. Sixty-nine percent included studies with various research designs; 63% provided a qualitative synthesis of findings; 77% percent assessed the quality of studies; 43% systematically assessed the level of evidence across studies. No review compared evidence from HIC and LMIC. A review of the studies from LMIC found some promising results, but the evidence was not sufficient due to a small number of studies, sometimes poor quality, and small sample sizes.

Conclusion

Systematic reviews on interventions for children and adolescents with ASD did not look for potential differences in the effectiveness of interventions in HIC and LMIC. Overall, there is very little evidence from LMIC. None of the interventions can be considered evidence-based in LMIC. Hence, additional research and mutually agreed methodological standards are needed to provide a more secure basis for evidence-based treatments in LMIC trying to establish evidence-based practices.

Clinical autism subscales have common genetic liabilities that are heritable, pleiotropic, and generalizable to the general population

The complexity of autism's phenotypic spectra is well-known, yet most genetic research uses case-control status as the target trait. It is undetermined if autistic symptom domain severity underlying this heterogeneity is heritable and pleiotropic with other psychiatric and behavior traits in the same manner as autism case-control status. In N = 6064 autistic children in the SPARK cohort, we investigated the common genetic properties of twelve subscales from three clinical autism instruments measuring autistic traits: the Social Communication Questionnaire (SCQ), the Repetitive Behavior Scale-Revised (RBS-R), and the Developmental Coordination Disorder Questionnaire (DCDQ). Educational attainment polygenic scores (PGS) were significantly negatively correlated with eleven subscales, while ADHD and major depression PGS were positively correlated with ten and eight of the autism subscales, respectively. Loneliness and neuroticism PGS were also positively correlated with many subscales. Significant PGS by sex interactions were found-surprisingly, the autism case-control PGS was negatively correlated in females and had no strong correlation in males. SNP-heritability of the DCDQ subscales ranged from 0.04 to 0.08, RBS-R subscales ranged from 0.09 to 0.24, and SCQ subscales ranged from 0 to 0.12. GWAS in SPARK followed by estimation of polygenic scores (PGS) in the typically-developing ABCD cohort (N = 5285), revealed significant associations of RBS-R subscale PGS with autism-related behavioral traits, with several subscale PGS more strongly correlated than the autism case-control PGS. Overall, our analyses suggest that the clinical autism subscale traits show variability in SNP-heritability, PGS associations, and significant PGS by sex interactions, underscoring the heterogeneity in autistic traits at a genetic level. Furthermore, of the three instruments investigated, the RBS-R shows the greatest evidence of genetic signal in both (1) autistic samples (greater heritability) and (2) general population samples (strongest PGS associations).

Functional Connectivity Underlying Symptoms in Preschool Boys With Autism: A Resting-State Functional Magnetic Resonance Imaging Study

Background

Single-sex children have been regarded as one of the best subjects to understand the abnormal development patterns of autism spectrum disorders (ASDs). However, the functional connectivity (FC) behind their symptoms is still unknown.

Methods

Based on FC analysis, the acquired resting-state functional magnetic resonance imaging (rs-fMRI) data sets, including 86 boys with ASD and 54 normal controls (NC), were used to detect the neural synchronous activity between brain regions. Pearson correlation analysis was used to evaluate the relationship between the abnormal FC value and clinical features.

Results

Individuals with ASD showed enhanced FC between the right calcarine and the right lingual gyrus (LG). The right medial orbital frontal cortex also showed increased FC with bilateral inferior temporal gyrus (ITG) [two-tailed, voxel-level p &lt; 0.001, gaussian random field (GRF) correction, cluster-level p &lt; 0.05]. We did not find a correlation between the abnormal FC value and clinical scales.

Conclusion

Our study reveals a possible relationship between atypical visual attention and poor learning ability in subjects with ASD, and delayed social language development may be a secondary symptom to ASD.

Early Motor Signs in Autism Spectrum Disorder

A growing number of literature data suggest the presence of early impairments in the motor development of children with autism spectrum disorder, which could be often recognized even before the appearance of the classical social communication deficits of autism. In this narrative review, we aimed at performing an update about the available data on the early motor function in children with autism spectrum disorder. Early motor impairment in these children can manifest itself both as a mere delay of motor development and as the presence of atypicalities of motor function, such as a higher rate and a larger inventory, of stereotyped movements both with and without objects. In the perspective of a timely diagnosis, the presence of early motor signs can be an important clue, especially in an individual considered at high risk for autism. Motor and communication (both verbal and non-verbal) skills are connected and a pathogenetic role of early motor dysfunctions in the development of autism can be hypothesized. From this, derives the importance of an early enabling intervention aimed at improving motor skills, which could also have favorable effects on other aspects of development.

Motor impairments in Chinese toddlers with autism spectrum disorder and its relationship with social communicative skills

OBJECTIVE

Motor impairments are prevalent in children with autism spectrum disorder (ASD) and persistent across age. Our current study was designed to investigate motor deficits in Chinese toddlers with ASD and to explore the relationships between motor deficits and social communication skills.

METHODS

For this cross-sectional study, we recruited a total of 210 Chinese toddlers with ASD aged between 18 and 36 months in the study during December 2017 to December 2020. Griffiths Developmental Scales-Chinese (GDS-C), Autism Diagnostic Observation Schedule-Second Edition (ADOS-2) and Communication and Symbolic Behavior Scales Developmental Profile-Infant-Toddler Checklist (CSBS-DP-ITC) were administered in these toddlers to evaluate their development, social communicative skills, and autism severity. We compared the developmental and social communicational profiles of ASD toddlers in different gross and fine motor subgroups, and explored potential associated factors. The univariate generalized linear model tested the relationship of fine and gross motor skills and social communicative skills.

RESULTS

The prevalence of gross and fine motor deficits were 59.5 and 82.5%, respectively, which are almost equivalent in boys and girls. The motor impairments tended to be more severe with age in toddlers. After adjusting for age, sex, non-verbal development quotient (DQ) and restricted, repetitive behaviors, severer gross motor impairments were significantly related to higher comparison score of ADOS-2 and higher social composite score of CSBS-DP-ITC, without interactions with other variables. Meanwhile, lower fine motor skills were associated with more deficits of social communication and higher severity of ASD, also depending on non-verbal DQ. In the lower non-verbal DQ subgroup, both fine motor deficits and restricted repetitive behaviors (RRBs) might have effects on autism symptomology.

CONCLUSION

Motor impairments are common in Chinese toddlers with ASD. Toddlers with weaker gross and fine motor skills have greater deficits in social communicative skills. Gross motor impairment might be an independent predictor of the severity of autism and social communication skills, while the effect of fine motor deficits might be affected by non-verbal DQ and RRBs of toddlers with ASD. We provide further justification for the inclusion of motor impairments in the early intervention for toddlers with ASD.

Predicting Autism in Infancy

Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by social communication and interaction deficits and restricted, repetitive patterns of interests and behavior that are evident in early childhood. Its prevalence has grown substantially over the past several decades, with current estimates ranging from 1.7% to 2.5% in the United States.^1,2 This represents more than 1.5 million children with ASD, the vast majority of whom receive or will receive specialized services.² Each year, approximately 100,000 (and growing) individuals with ASD reach adulthood, and many face myriad challenges related to employment, housing, mental health, and overburdened or insufficient support services.^3-5 A host of significant costs can be associated with ASD, from direct costs related to the provision of special education programs, housing, and medical care to indirect costs, such as loss of productivity affecting both individuals with ASD and their families.⁶ Currently, overall lifetime cost of care per person with ASD can exceed $3 million, totaling more than $265 billion annually in the United States and rising to an estimated $1 trillion by 2025.^7,8.

A white paper on a neurodevelopmental framework for drug discovery in autism and other neurodevelopmental disorders

In the last decade there has been a revolution in terms of genetic findings in neurodevelopmental disorders (NDDs), with many discoveries critical for understanding their aetiology and pathophysiology. Clinical trials in single-gene disorders such as fragile X syndrome highlight the challenges of investigating new drug targets in NDDs. Incorporating a developmental perspective into the process of drug development for NDDs could help to overcome some of the current difficulties in identifying and testing new treatments. This paper provides a summary of the proceedings of the 'New Frontiers Meeting' on neurodevelopmental disorders organised by the European College of Neuropsychopharmacology in conjunction with the Innovative Medicines Initiative-sponsored AIMS-2-TRIALS consortium. It brought together experts in developmental genetics, autism, NDDs, and clinical trials from academia and industry, regulators, patient and family associations, and other stakeholders. The meeting sought to provide a platform for focused communication on scientific insights, challenges, and methodologies that might be applicable to the development of CNS treatments from a neurodevelopmental perspective. Multidisciplinary translational consortia to develop basic and clinical research in parallel could be pivotal to advance knowledge in the field. Although implementation of clinical trials for NDDs in paediatric populations is widely acknowledged as essential, safety concerns should guide each aspect of their design. Industry and academia should join forces to improve knowledge of the biology of brain development, identify the optimal timing of interventions, and translate these findings into new drugs, allowing for the needs of users and families, with support from regulatory agencies.

Is Smiling the Key? Machine Learning Analytics Detect Subtle Patterns in Micro-Expressions of Infants with ASD

Time is a key factor to consider in Autism Spectrum Disorder. Detecting the condition as early as possible is crucial in terms of treatment success. Despite advances in the literature, it is still difficult to identify early markers able to effectively forecast the manifestation of symptoms. Artificial intelligence (AI) provides effective alternatives for behavior screening. To this end, we investigated facial expressions in 18 autistic and 15 typical infants during their first ecological interactions, between 6 and 12 months of age. We employed Openface, an AI-based software designed to systematically analyze facial micro-movements in images in order to extract the subtle dynamics of Social Smiles in unconstrained Home Videos. Reduced frequency and activation intensity of Social Smiles was computed for children with autism. Machine Learning models enabled us to map facial behavior consistently, exposing early differences hardly detectable by non-expert naked eye. This outcome contributes to enhancing the potential of AI as a supportive tool for the clinical framework.

Early infant behavioural correlates of social skills in adolescents

BACKGROUND

Autism Spectrum Disorder (ASD) is a neurodevelopmental disorder typically diagnosed after the second year of life; however, differences in brain structure and function associated with ASD have been ascertained in early infancy. Identifying behavioural markers of ASD risk in early infancy has the potential to facilitate early detection and intervention.

OBJECTIVES

We examined associations between infant behaviour and adolescent behaviours associated with ASD.

METHODS

Analyses leveraged data available on 370 participants from the New Bedford Cohort, a sociodemographically diverse prospective birth cohort of children born from 1993 to 1998 to mothers residing near the New Bedford Harbor Superfund site in Massachusetts. Longitudinal assessments were used to examine the associations between behaviours when children were approximately 2 weeks old (measured by the Neonatal Behavioral Assessment Scale [NBAS]), and subsequent maladaptive behaviours associated with ASD at approximately 15 years old [measured by the Behavior Assessment System for Children, 2nd Edition-Teacher Rating Scale (BASC-2 TRS) scores which are standardised to a mean (SD) of 50 (10)].

RESULTS

Poorer performance on select individual items and cluster scales of the NBAS was associated with an increase in behaviours associated with ASD in adolescents. Associations were strongest for neonatal measures of self-regulation, response to auditory input, and autonomic nervous system regulation. For example, in covariate-adjusted models, infants with Regulation of State NBAS cluster scores in the lowest tertile (poorest performance) compared to infants with scores in the higher two tertiles had adolescent BASC-2 TRS Developmental Social Disorders T-scores that were 2.9 points higher (95% CI: 0.8, 4.9), indicating more behaviours associated with ASD.

CONCLUSION

The NBAS is an established and accessible instrument that assesses a broad range of behaviours in very young infants, and may be a useful tool for newborn assessments of developmental risk, including risk of ASD-associated behaviours.

Polygenic Risk Scores for Developmental Disorders, Neuromotor Functioning During Infancy, and Autistic Traits in Childhood

BACKGROUND

Impaired neuromotor development is often one of the earliest observations in children with autism spectrum disorder (ASD). We investigated whether a genetic predisposition to developmental disorders was associated with nonoptimal neuromotor development during infancy and examined the genetic correlation between nonoptimal neuromotor development and autistic traits in the general population.

METHODS

In a population-based cohort in The Netherlands (2002-2006), we calculated polygenic risk scores (PRSs) for ASD and attention-deficit/hyperactivity disorder (ADHD) using genome-wide association study summary statistics. In 1921 children with genetic data, parents rated autistic traits at 6 years of age. Among them, 1174 children (61.1%) underwent neuromotor examinations (tone, responses, senses, and other observations) during infancy (9-20 weeks of age). We used linear regressions to examine associations of PRSs with neuromotor scores and autistic traits. We performed a bivariate genome-based restricted maximum likelihood analysis to explore whether genetic susceptibility underlies the association between neuromotor development and autistic traits.

RESULTS

Higher PRSs for ASD were associated with less optimal overall infant neuromotor development, in particular low muscle tone. Higher PRSs for ADHD were associated with less optimal senses. PRSs for ASD and those for ADHD both were associated with autistic traits. The single nucleotide polymorphism-based heritability of overall motor development was 20% (SE = .21) and of autistic traits was 68% (SE = .26). The genetic correlation between overall motor development and autistic traits was .35 (SE = .21, p < .001).

CONCLUSIONS

We found that genetic liabilities for ASD and ADHD covary with neuromotor development during infancy. Shared genetic liability might partly explain the association between nonoptimal neuromotor development during infancy and autistic traits in childhood.

Latent trajectories of adaptive behaviour in infants at high and low familial risk for autism spectrum disorder

Background

Autism spectrum disorder (ASD) is characterised by persisting difficulties in everyday functioning. Adaptive behaviour is heterogeneous across individuals with ASD, and it is not clear to what extent early development of adaptive behaviour relates to ASD outcome in toddlerhood. This study aims to identify subgroups of infants based on early development of adaptive skills and investigate their association with later ASD outcome.

Methods

Adaptive behaviour was assessed on infants at high (n = 166) and low (n = 74) familial risk for ASD between 8 and 36 months using the Vineland Adaptive Behavior Scales (VABS-II). The four domains of VABS-II were modelled in parallel using growth mixture modelling to identify distinct classes of infants based on adaptive behaviour. Then, we associated class membership with clinical outcome and ASD symptoms at 36 months and longitudinal measures of cognitive development.

Results

We observed three classes characterised by decreasing trajectories below age-appropriate norms (8.3%), stable trajectories around age-appropriate norms (73.8%), and increasing trajectories reaching average scores by age 2 (17.9%). Infants with declining adaptive behaviour had a higher risk (odds ratio (OR) = 4.40; confidence interval (CI) 1.90; 12.98) for ASD and higher parent-reported symptoms in the social, communication, and repetitive behaviour domains at 36 months. Furthermore, there was a discrepancy between adaptive and cognitive functioning as the class with improving adaptive skills showed stable cognitive development around average scores.

Conclusions

Findings confirm the heterogeneity of trajectories of adaptive functioning in infancy, with a higher risk for ASD in toddlerhood linked to a plateau in the development of adaptive functioning after the first year of life.

Diagnostic Value of Two-Dimensional plus Four-Dimensional Ultrasonography in Fetal Craniocerebral Anomalies

BACKGROUND

To assess the clinical value of two-dimensional (2D) plus four-dimensional (4D) ultrasonography in diagnosis of fetal craniocerebral anomalies.

METHODS

Retrospective analysis was performed on the sonographic features of 83 maternity patients admitted to Northwest Women's and Children's Hospital, Xian China from January 2013 to December 2017 diagnosed with suspected fetal anomalies of the brain and skull through 2D and 4D ultrasonography.

RESULTS

Fifty six patients were diagnosed with the anomalies by 2D ultrasonography only, 65 patients by 4D ultrasonography only, and 74 patients by 2D plus 4D ultrasonography.76 patients were confirmed to have fetal craniocerebral anomalies after birth or induced labor. Diagnostic accuracies of 2D ultrasound only, 4D ultra-sound only, and 2D plus 4D ultrasound were 68.67%, 81.93% and 95.18%, respectively (P<0.05). The accuracy of 2D plus 4D ultrasound was greater than those of 2D ultrasound only and 4D ultrasound only, and the accuracy of 4D ultrasound only was higher than that of 2D ultrasound only (P<0.05). The sensitivity of 2D plus 4D ultrasound was greater than those of 2D ultrasound only and 4D ultrasound only (P<0.05). The specificity of 2D plus 4D ultrasound was greater than those of 2D ultrasound only and 4D ultrasound only (P<0.05).

CONCLUSION

Combined ultrasonography can better differentiate fetal craniocerebral anomalies, providing early and more accurate information for clinicians as well as maternity patients to make a decision. This clinical practice would be valuable for improving the quality of the newborn population.

EEG Analytics for Early Detection of Autism Spectrum Disorder: A data-driven approach

Autism spectrum disorder (ASD) is a complex and heterogeneous disorder, diagnosed on the basis of behavioral symptoms during the second year of life or later. Finding scalable biomarkers for early detection is challenging because of the variability in presentation of the disorder and the need for simple measurements that could be implemented routinely during well-baby checkups. EEG is a relatively easy-to-use, low cost brain measurement tool that is being increasingly explored as a potential clinical tool for monitoring atypical brain development. EEG measurements were collected from 99 infants with an older sibling diagnosed with ASD, and 89 low risk controls, beginning at 3 months of age and continuing until 36 months of age. Nonlinear features were computed from EEG signals and used as input to statistical learning methods. Prediction of the clinical diagnostic outcome of ASD or not ASD was highly accurate when using EEG measurements from as early as 3 months of age. Specificity, sensitivity and PPV were high, exceeding 95% at some ages. Prediction of ADOS calibrated severity scores for all infants in the study using only EEG data taken as early as 3 months of age was strongly correlated with the actual measured scores. This suggests that useful digital biomarkers might be extracted from EEG measurements.

Unconscious avoidance of eye contact in autism spectrum disorder

Atypical responses to direct gaze are one of the most characteristic hallmarks of autism spectrum disorder (ASD). The cause and mechanism underlying this phenomenon, however, have remained unknown. Here we investigated whether the atypical responses to eye gaze in autism spectrum disorder is dependent on the conscious perception of others’ faces. Face stimuli with direct and averted gaze were rendered invisible by interocular suppression and eye movements were recorded from participants with ASD and an age and sex matched control group. Despite complete unawareness of the stimuli, the two groups differed significantly in their eye movements to the face stimuli. In contrast to the significant positive saccadic index observed in the TD group, indicating an unconscious preference to the face with direct gaze, the ASD group had no such preference towards direct gaze and instead showed a tendency to prefer the face with averted gaze, suggesting an unconscious avoidance of eye contact. These results provide the first evidence that the atypical response to eye contact in ASD is an unconscious and involuntary response. They provide a better understanding of the mechanism of gaze avoidance in autism and might lead to new diagnostic and therapeutic interventions.

Neurocognitive and observational markers: prediction of autism spectrum disorder from infancy to mid-childhood

Background

Prospective studies of infants at high familial risk for autism spectrum disorder (ASD) have identified a number of putative early markers that are associated with ASD outcome at 3 years of age. However, some diagnostic changes occur between toddlerhood and mid-childhood, which raises the question of whether infant markers remain associated with diagnosis into mid-childhood.

Methods

First, we tested whether infant neurocognitive markers (7-month neural response to eye gaze shifts and 14-month visual disengagement latencies) as well as an observational marker of emerging ASD behaviours (the Autism Observation Scale for Infants; AOSI) predicted ASD outcome in high-risk (HR) 7-year-olds with and without an ASD diagnosis (HR-ASD and HR-No ASD) and low risk (LR) controls. Second, we tested whether the neurocognitive markers offer predictive power over and above the AOSI.

Results

Both neurocognitive markers distinguished children with an ASD diagnosis at 7 years of age from those in the HR-No ASD and LR groups. Exploratory analysis suggested that neurocognitive markers may further differentiate stable versus lost/late diagnosis across the 3 to 7 year period, which will need to be tested in larger samples. At both 7 and 14 months, combining the neurocognitive marker with the AOSI offered a significantly improved model fit over the AOSI alone.

Conclusions

Infant neurocognitive markers relate to ASD in mid-childhood, improving predictive power over and above an early observational marker. The findings have implications for understanding the neurodevelopmental mechanisms that lead from risk to disorder and for identification of potential targets of pre-emptive intervention.

Electronic supplementary material

The online version of this article (10.1186/s13229-017-0167-3) contains supplementary material, which is available to authorized users.

Cry, baby, cry: Expression of Distress as a Biomarker and Modulator in Autism Spectrum Disorder

Background:

Early diagnosis of autism spectrum disorder is critical, because early intensive treatment greatly improves its prognosis.

Methods:

We review studies that examined vocalizations of infants with autism spectrum disorder and mouse models of autism spectrum disorder as a potential means to identify autism spectrum disorder before the symptomatic elements of autism spectrum disorder emerge. We further discuss clinical implications and future research priorities in the field.

Results:

Atypical early vocal calls (i.e., cry) may represent an early biomarker for autism spectrum disorder (or at least for a subgroup of children with autism spectrum disorder), and thus can assist with early detection. Moreover, cry is likely more than an early biomarker of autism spectrum disorder; it is also an early causative factor in the development of the disorder. Specifically, atypical crying, as recently suggested, might induce a “self-generated environmental factor” that in turn, influences the prognosis of the disorder. Because atypical crying in autism spectrum disorder is difficult to understand, it may have a negative impact on the quality of care by the caregiver (see graphical abstract).

Conclusions:

Evidence supports the hypothesis that atypical vocalization is an early, functionally integral component of autism spectrum disorder.