Gender Differences During Toddlerhood in Autism Spectrum Disorder: A Prospective Community-Based Longitudinal Follow-Up Study

[Neurodevelopment and cerebral blood flow in children aged 2-6 years with autism spectrum disorder]

OBJECTIVES

To investigate the neurodevelopmental characteristics of children with autism spectrum disorder (ASD), analyze the correlation between neurodevelopmental indicators and cerebral blood flow (CBF), and explore the potential mechanisms of neurodevelopment in ASD children.

METHODS

A retrospective study was conducted on 145 children aged 2-6 years with newly-diagnosed ASD. Scores from the Gesell Developmental Diagnosis Scale and the Autism Behavior Checklist (ABC) and CBF results were collected to compare gender differences in the development of children with ASD and analyze the correlation between CBF and neurodevelopmental indicators.

RESULTS

Fine motor and personal-social development quotient in boys with ASD were lower than those in girls with ASD (P<0.05). Gross motor development quotient in ASD children was negatively correlated with CBF in the left frontal lobe (r=-0.200, P=0.016), right frontal lobe (r=-0.279, P=0.001), left parietal lobe (r=-0.208, P=0.012), and right parietal lobe (r=-0.187, P=0.025). The total ABC score was positively correlated with CBF in the left amygdala (r=0.295, P<0.001).

CONCLUSIONS

Early intervention training should pay attention to gender and developmental structural characteristics for precise intervention in ASD children. CBF has the potential to become a biological marker for assessing the severity of ASD.

Male and Female Toddlers with DSM-5 Autism Spectrum Disorder have Similar Developmental Profiles and Core Autism Symptoms

Compare developmental profiles and core ASD symptom manifestation between male and female toddlers with DSM-5 ASD. Retrospective record review of 500 toddlers (79% male) at time of ASD diagnosis. There were no differences in developmental functioning between males and females. When adjusting for multiple comparisons, sex differences were only noted for sensory seeking behavior occurring at a higher frequency in females. Overall, there were no significant differences in demographic characteristics, developmental functioning, or manifestation of core ASD symptoms between males versus female toddlers at the time of DSM-5 ASD diagnosis.

Investigating autism knowledge, self-efficacy, and confidence following maternal and child health nurse training for the early identification of autism

Introduction

Early identification of children with a high likelihood of autism can lead to referral for diagnostic services and access to early supports, resulting in improved outcomes for children and families. Maternal and Child Health Nurses (MCHNs) in Victoria, Australia, are well-placed to monitor infants and toddlers for signs of autism, given children and caregivers attend free, regular, well-baby consultations from birth through to school age. This study aimed to identify the impact of personal and workplace factors on MCHNs' competencies of autism knowledge, self-efficacy in identifying autistic infants and toddlers, and confidence in speaking to parents/caregivers about autism. Additionally, the study sought to identify which personal and workplace factors might predict increased competency in these areas.

Methods

After identifying training needs and current competency levels via a training needs analysis (TNA), 1,428 MCHNs received training on the early signs of autism and in the use of the Social Attention and Communication Surveillance-Revised (SACS-R) tool for early autism identification; the training program was known as Monitoring of Social Attention, Interaction, and Communication (MoSAIC).

Results

Previous MCHN autism training and knowledge of autism community resources significantly contributed to increased MCHN self-efficacy in identifying autistic infants and toddlers, while knowledge of community resources was the best predictor of confidence in speaking with parents/caregivers about autism. Perceived self-efficacy and confidence in speaking with parents/caregivers about autism significantly increased following the MoSAIC autism training.

Discussion

Targeted autism training for primary health practitioners is an important first step for early autism identification and initiating conversations with parents/caregivers.

Telehealth assessment of autism in preschoolers using the TELE-ASD-PEDS: A pilot clinical investigation

PURPOSE

Appropriate early intervention is beneficial but dependent on accurate and timely diagnoses. This has been affected by long waiting lists for face-to-face clinical services, in part due to pandemic lockdowns, with telehealth introduced in many services to continue clinical services. This pilot clinical study investigated the feasibility of integrating a specially-designed telepractice autism assessment tool into a tertiary diagnostic service.

METHOD

Eighteen boys (2;4-5;1) participated in the study. Assessment was undertaken as per standard practice (parent interview, questionnaires, review of reports), with an additional telepractice assessment, included in place of face-to-face assessment, to provide clinicians with an observation of the children's communication, behaviours, and interests. Ten parents provided feedback via semi-structured interviews.

RESULT

The TELE-ASD-PEDS was a feasible assessment tool in terms of administration, clinical experience, and information gained through the assessment process. Parents reported mostly positive experiences of the TELE-ASD-PEDS and made suggestions for improvements for future use of this tool.

CONCLUSION

It is possible to obtain useful information about a child's autism-specific behaviours using the activities in the TELE-ASD-PEDS. This information can be combined with clinical history from parents using the DSM-5 framework to provide a gold standard assessment for autism.

Sex differences in early autism screening using the Modified Checklist for Autism in Toddlers, Revised, with Follow-Up (M-CHAT-R/F)

LAY ABSTRACT

This study examined a widely used autism screening tool, the Modified Checklist for Autism in Toddlers, Revised, with Follow-Up to identify differences in screening for autism between toddler males and females. Examining sex differences in screening for autism in toddlerhood is important as it determines who will be referred for evaluations and receive diagnoses, which is critical for access to autism-specific early intervention. This study found that females were less likely to screen positive and be invited for evaluations compared with males. Females at high likelihood for autism were less likely to be diagnosed with autism, which decreases confidence in the screener's results. Importantly, the Modified Checklist for Autism in Toddlers, Revised, with Follow-Up accurately identified both males and females with autism. Future research should examine ways to improve accuracy in screening results for females.

Sex Differences on the ADOS-2

The sex difference in the prevalence of autism spectrum disorder (ASD) may be magnified by sex differences on diagnostic measures. The current study compared autistic males and females on items on the gold-standard diagnostic measure, the Autism Diagnostic Observation Schedule, Second Edition (ADOS-2). In a sample of 8-to-17-year old autistic individuals from research (n = 229) and clinical settings (n = 238), females were less likely to show atypicalities on most items related to social-communication behaviors and on total and subscale scores. When controlling for overall intensity of symptomatology, no sex differences survived statistical corrections. Diagnostic criteria and/or gold-standard assessments may be less sensitive to female presentations of ASD and/or autistic females may exhibit fewer or less intense behaviors characteristic of ASD.

Early Indicators of Autism in Infants: Development of the IMES Screening Tool

We developed the Infant, Motor, and Engagement Scale (IMES) to address the public health goal of early identification of autism spectrum disorder (ASD). The IMES is a screening tool that assesses quality of infants' interaction with people and objects during early play. We aimed to examine the IMES' preliminary psychometric properties and its value in discriminating between infants later diagnosed with ASD and typically developing infants. We used the IMES to score retrospective home videos of 15 male infants, 7 who were later diagnosed with autism. We examined interrater reliability using Cohen's Kappa, internal consistency with Cronbach's alpha and content validity through expert review. Preliminary data support validity and reliability of the IMES for early identification for infants at 6 to 9 months. With further research, the IMES has the potential to identify at risk infants at a young age that may have long-term impact on child and family outcomes.

Sex Differences in the Developmental Trajectories of Autism Spectrum Disorder

Purpose of Review

Females and males are disproportionately diagnosed with autism, a sex difference that has historically represented this neurodevelopmental condition. The current review examines lifespan developmental trajectories of autism based on sex to elucidate behavioral phenotypic differences that may contribute to differential rates of diagnosis.

Recent Findings

We review sex differences in diagnostic criteria: social communication and restricted interests/repetitive behaviors (RRBs). Results suggest RRBs are more indicative of a diagnosis in males, whereas social differences are more indicative of a diagnosis in females. Factors contributing to a later diagnosis in females include social strengths (camouflaging) and diagnostic overshadowing.

Summary

Sex differences in diagnostic criteria may contribute to differential rates of identification in males and females. Sex differences are most pronounced when assessing naturalistic social communication instead of reliance on standardized measure. Numerous future directions are identified including increasing samples of sub-threshold autistic females and evaluating longitudinal sex differences.

Intellectual disabilities moderate sex/gender differences in autism spectrum disorder: a systematic review and meta-analysis

BACKGROUND

Girls/women with autism spectrum disorder (ASD) are suggested to exhibit different symptom profiles than boys/men with ASD. Accumulating evidence suggests that intellectual disability (ID) may affect sex/gender differences in ASD. However, a systematic review and meta-analysis on this topic is missing.

METHODS

Two databases (MEDLINE and PsycINFO) were used to search for studies reporting sex/gender differences (girls/women versus boys/men) in social communication and interaction, restrictive and repetitive behaviour and interests (RRBIs), sensory processing, and linguistic and motor abilities in ASD. The final sample consisted of 79 studies. The meta-analysis was performed with Review Manager using a random-effects model. Participants with ASD without and with ID were analysed as separate subgroups, and the effects in these two subgroups were also compared with each other.

RESULTS

Girls/women with ASD without ID displayed fewer RRBIs, more sensory symptoms and less problems in linguistic abilities than their boys/men counterparts. In contrast, girls/women with ASD with ID displayed more social difficulties and RRBIs, poorer linguistic abilities and more motor problems than boys/men with ASD with ID. Comparisons of groups of participants with ASD without ID versus participants with ASD with ID confirmed differences in sex/gender effects on social difficulties, sensory processing, linguistic abilities and motor abilities.

CONCLUSIONS

Our results clearly suggest that the female phenotype of ASD is moderated by ID. Among individuals with ASD with ID, girls/women seem to be more severely affected than boys/men, whereas among individuals with ASD without ID, girls/women with ASD may have less symptoms than boys/men. Such phenotypic differences could be a potential cause of underrecognition of girls/women with ASD, and it is also possible that observed phenotypic differences may reflect underdiagnosing of girls/women with ASD.

Structural and Pragmatic Language Impairments in Children Evaluated for Autism Spectrum Disorder (ASD)

Pragmatic language impairments are common in neurodevelopmental disorders, especially in autism spectrum disorder (ASD). The relationship between structural language skills and pragmatic competence in children with autistic symptoms, however, is largely unknown. We investigated this relationship based on the Children's Communication Checklist-2 and early language delay among children (N = 177, 19% females) clinically evaluated for ASD, differentiated into ASD (n = 148) and non-ASD (n = 29). Structural language deficits were common and associated with reduced pragmatic competence in both groups. Pragmatic language impairments were most profound in children with ASD. Early language delay and structural language deficits were less common in females. Our findings suggest that assessment of structural language skills should be included in the evaluation of children with suspected ASD.

Restricted and repetitive behavior in children with autism during the first three years of life: A systematic review

Restricted and repetitive behavior (RRB) is a core diagnostic feature of autism spectrum disorder (ASD). Previous research shows that RRB is prevalent early in life and observed in neurotypical development as well. Less is known, however, about early RRB patterns, developmental trajectories, and the relation to outcomes for autistic children. The purpose of this systematic review was to synthesize findings from studies examining RRB in autistic children from birth through age 3. A detailed protocol was designed a priori based on PRISMA guidelines for systematic reviews. From the published literature, 41 peer reviewed journal articles were identified and included in this review. Our synthesis of the literature suggests that differences in RRB are evident prior to age 2 in children with or who go onto be diagnosed with autism. These differences were evident for both frequency and intensity of RRB across multiple topographies. There were mixed results regarding functional outcomes associated with early RRB, such as cognitive and adaptive behavior, though relations appeared to become stronger as children aged beyond toddlerhood. Notably, level of RRB appears unrelated to autism severity in young autistic children. A wide range of RRB have been reported to be elevated in autistic children during the first years of life, including repetitive motor behaviors, atypical sensory behaviors, insistence on sameness (IS), and self-injurious behaviors (SIBs). In contrast to studies of older children, RRB in very young autistic children do not appear to be associated with functional outcomes but may be valuable to include in early screening efforts.

Systematic review registration

https://osf.io/huzf3, unique identifier: doi: 10.17605/OSF.IO/HUZF3.

The Early Childhood Signs of Autism in Females: a Systematic Review

Compared to males, females are at a much greater likelihood of receiving a later diagnosis of autism, which impacts their opportunity to receive early support. To assist with early identification, this systematic literature review aimed to ascertain whether females differ from males in the early childhood signs of autism. The small number of heterogeneous studies made it difficult to draw conclusions, although it appears that females and males under 6 years of age are more similar than different in terms of their expression of autistic behaviours. Given the discrepant sex/gender ratio in autism, these findings highlight the importance of exploring whether there are different and/or specific, not yet identified, early signs of autism in females and males.

Behavioral gender differences across Pre-School Children with Autism Spectrum Disorders: a cross-sectional study

There is increasing literature showing that the presentation of Autism Spectrum Disorder (ASD) could be different according to the sex of the patient. Through the analysis of the Autism Diagnostic Interview Revised interview results of a study group consisting of 56 preschool children diagnosed with ASD potential differences in the presentation of ASD were searched. Variables investigated were verbal abilities, the presence/absence of unusual sensory interests, as well as of echolalia. The results showed significant differences between gender in restricted and repetitive behavior (p < 0.01), in particular for those children who have no unusual sensory interest (p < 0.05) and with minimal verbal ability (p < 0.05). The findings contribute providing evidences on phenotypical differences in preschool children with a diagnosis of Autism Spectrum Disorder.

Symptoms of Autism Spectrum Disorders Measured by the Qualitative Checklist for Autism in Toddlers in a Large Sample of Polish Toddlers

This study aimed to assess some early symptoms of autism spectrum disorders (ASD) measured by a screening tool developed for an early detection of ASD. We investigated if the early symptoms were associated with toddlers’ age, gender or ASD familial risk status. We used the Polish version of the Quantitative Checklist for Autism in Toddlers (Q-CHAT) to assess 1024 children aged 16 to 36 months. The sample included four groups of participants: typically developing toddlers, toddlers with parent-reported ASD-specific concerns, toddlers at risk for autism due to having an older sibling with ASD, and toddlers with a developmental delay. We found that mean Q-CHAT scores were significantly higher in boys than in girls. We did not find any associations between Q-CHAT scores and age. We observed that toddlers with a familial risk for ASD and those with a developmental delay scored significantly higher than controls. We collated these results with previous studies that used the Q-CHAT and other instruments.

Evaluation of sex differences in preschool children with and without autism spectrum disorder enrolled in the study to explore early development

BACKGROUND AND AIMS

Research in school-aged children, adolescents, and adults with autism spectrum disorder (ASD) has found sex-based differences in behavioral, developmental, and diagnostic outcomes. These findings have not been consistently replicated in preschool-aged children. We examined sex-based differences in a large sample of 2-5-year-old children with ASD symptoms in a multi-site community-based study.

METHODS AND PROCEDURES

Based on a comprehensive evaluation, children were classified as having ASD (n = 1480, 81.55 % male) or subthreshold ASD characteristics (n = 593, 70.15 % male). Outcomes were behavior problems, developmental abilities, performance on ASD screening and diagnostic tests, and parent-reported developmental conditions diagnosed before study enrollment.

OUTCOMES AND RESULTS

We found no statistically significant sex differences in behavioral functioning, developmental functioning, performance on an ASD screening test, and developmental conditions diagnosed before study enrollment among children with ASD or subthreshold ASD characteristics. Males in both study groups had more parent reported restricted interests and repetitive behaviors than females, but these differences were small in magnitude and not clinically meaningful.

CONCLUSIONS AND IMPLICATIONS

Preschool males and females who showed risk for ASD were more similar than different in the outcomes assessed in our study. Future research could examine sex-based differences in ASD phenotypes as children age.

Identifying Subgroups of Toddlers with DSM-5 Autism Spectrum Disorder Based on Core Symptoms

The objective of this study was to identify subgroups of toddlers with DSM-5 ASD based on core ASD symptoms using a person-based analytical framework. This is a retrospective study of 500 toddlers (mean age 26 months, 79% male) with DSM-5 ASD. Data were analyzed using latent class analyses in which profiles were formed based on ASD symptomatology. Social communication (SC) symptoms favored a three-class solution, while restricted/repetitive behaviors (RRBs) favored a two-class solution. Classes with higher consistency of SC deficits were younger, with lower developmental functioning. The class with more RRBs was older, with higher functioning. If confirmed in other populations, these classes may more precisely characterize subgroups within the heterogeneous group of toddlers at time of ASD diagnosis.

Sex Differences in Functional Connectivity of the Salience, Default Mode, and Central Executive Networks in Youth with ASD

Autism spectrum disorder (ASD) is associated with the altered functional connectivity of 3 neurocognitive networks that are hypothesized to be central to the symptomatology of ASD: the salience network (SN), default mode network (DMN), and central executive network (CEN). Due to the considerably higher prevalence of ASD in males, however, previous studies examining these networks in ASD have used primarily male samples. It is thus unknown how these networks may be differentially impacted among females with ASD compared to males with ASD, and how such differences may compare to those observed in neurotypical individuals. Here, we investigated the functional connectivity of the SN, DMN, and CEN in a large, well-matched sample of girls and boys with and without ASD (169 youth, ages 8-17). Girls with ASD displayed greater functional connectivity between the DMN and CEN than boys with ASD, whereas typically developing girls and boys differed in SN functional connectivity only. Together, these results demonstrate that youth with ASD exhibit altered sex differences in these networks relative to what is observed in typical development, and highlight the importance of considering sex-related biological factors and participant sex when characterizing the neural mechanisms underlying ASD.

Sex and gender impacts on the behavioural presentation and recognition of autism

PURPOSE OF REVIEW

With increasing awareness of potential differences of autism presentation in nonmale versus male individuals, this review summarizes the rapidly evolving literature on sex and gender impacts on autism across nosology, behavioural presentation, developmental change and contextual recognition biases.

RECENT FINDINGS

Most studies have not differentiated sex versus gender impacts. Regarding behavioural presentation, measurement invariance across sex/gender was found in several standard measures. On this basis, diagnosed females overall showed lower restricted/repetitive behaviour/interests/activities (RRBI) than males, with small and variable effects depending on age, developmental level and kinds of RRBI. Differences insufficiently captured by standard measures may include autistic females displaying female-gender-typical narrow interests, higher social attention, linguistic abilities, motivation for friendship and more camouflaging than autistic males. Regarding developmental change, diagnosed young girls were more likely to have better cognitive development, less intense autistic symptoms and reduction of symptoms over time. Difficulties in adaptive functioning and social challenges, however, may emerge more for females in adolescence. Regarding diagnosis, general expectancy biases and gender-stereotypes may impede timely recognition of autism in females.

SUMMARY

Appreciating the multilevel sex and gender impacts on presentation, development, and diagnosis is key to sex-equitable and gender-equitable care for autistic individuals. A holistic approach to understanding the person in the contexts of sex and gender is essential for timely and accurate diagnosis and support.

ASD symptoms in toddlers and preschoolers: An examination of sex differences

Although considerable work has documented higher prevalence rates of autism spectrum disorder (ASD) in boys, fewer studies have focused on sex differences within samples of young children at-risk for ASD. This study examined sex differences in ASD symptom domains and ASD screening outcomes among toddlers (18-35 months) and preschoolers (36-72 months) with ASD-related concerns. Participants included 480 children between 18 and 72 months evaluated by university-based ASD specialty clinics. Results revealed significant sex differences in severity of social communication (SC) deficits across age groups. Within the toddler group, girls diagnosed with ASD displayed greater SC deficits according to standardized observation and clinician severity ratings. Within the preschool group, girls diagnosed with ASD were rated by parents as having more severe SC deficits, but these differences were not corroborated by standardized observations or clinician ratings. No sex differences emerged for severity of restricted repetitive behaviors (RRBs) for either age group. Across the entire referred sample, boys and girls did not differ in terms of scores on commonly used screening instruments. Importantly, results suggest that two of the most commonly used ASD screeners (i.e., Modified-Checklist for Autism in Toddlers-Revised with Follow-up and Social Communication Questionnaire ) may underidentify RRBs in toddler and preschool-aged girls as screening scores were only influenced by severity of SC deficits. Greater SC deficits in young girls with ASD along with its impact on screening status suggests greater attention be placed on the under-identification of ASD in girls as well as current screening measures' ability to tap into the topography of ASD symptoms across genders. Autism Res 2020, 13: 157-166. © 2019 International Society for Autism Research, Wiley Periodicals, Inc. LAY SUMMARY: In this study, we found that young girls diagnosed with autism spectrum disorder tend to have greater social communication deficits than young boys and that these differences vary by age. Specifically, toddler-aged girls receive higher clinician ratings of social communication deficits when compared to boys, while preschool-aged girls receive higher parent ratings of social communication deficits. For girls, current screening tools seem to be more highly influenced by severity of social communication deficits than by restricted repetitive behaviors.

Empathy Impairment in Individuals With Autism Spectrum Conditions From a Multidimensional Perspective: A Meta-Analysis

Background: Although empathy has always been considered to be impaired in individuals with autism spectrum conditions (ASCs), the relevant findings have been inconsistent. The present meta-analysis aims to determine which empathy components are impaired and how culture, gender, and age moderate such empathy impairment.

Methods: By using “Autism,” “Asperger Syndrome,” “Empathy,” and related Chinese synonyms as keywords, we searched the databases of Weipu, Wanfang, CNKI, Web of Science, Science Direct, SpringerLink, and Elsevier through “subject” and “keyword” searches. We also conducted a manual search according to the references. In total, 51 studies from Eastern and Western countries were included in this meta-analysis, which comprised 144 independent effects, 2,095 individuals with ASCs and 2,869 controls without ASCs. For the retrieved data, Hedge's g was taken as the quantitative measure of effect, and CMA V2.0 software was used for publication bias tests (by using Rosenthal's Classic Failsafe-N and Egger's methods), heterogeneity tests (by using a Q-test, I²-test, and H-test) and a moderating effect test (by using a univariate regression model).

Results: The results showed that the empathy impairment evident in individuals with ASCs is component specific; that is, trait-cognitive empathy, trait-empathic concern, state-cognitive empathy, and state-empathic concern are impaired, whereas state-empathic accuracy remains intact, and trait-empathic accuracy is superior to the trait-empathic accuracy in neurotypical individuals. The univariate regression model showed that gender moderates the impairment of the trait-empathic concern, trait-empathic accuracy, and state-cognitive empathy in autistic individuals and that age moderates the impairment of the trait-cognitive empathy, trait-empathic accuracy, state-empathic concern, and state-empathic accuracy in autistic individuals. However, culture does not moderate any empathy components (trait-cognitive empathy, trait-empathic concern, or state-cognitive empathy) involved in the present meta-analysis.

Conclusions: These findings contribute to ending the controversy over the empathic integrity of individuals with ASCs and shed some light on future research about the empathy impairment of autistic individuals. More specifically, subsequent studies should distinguish specific empathy components and consider the role of gender and age when demonstrating empathy impairment in individuals with ASCs. Moreover, related studies based on Asian collectivist cultural samples and female samples should be further enriched.

Gender Differences in Pragmatic Communication in School-Aged Children with Autism Spectrum Disorder (ASD)

Possible gender differences in manifestations of autism spectrum disorder (ASD) were examined using data on production of narratives. The Expression, Reception and Recall of Narrative Instrument (ERRNI; Bishop, Expression, Reception and Recall of Narrative Instrument, Harcourt assessment, London, 2004) was administered to a sample of matched 8-year-old intellectually able boys and girls with ASD (13M, 13F), who had been selected from a large, longitudinal study. In addition, transcripts of the narratives were analyzed in detail. Significant gender differences were found in narrative production. Girls included more salient story elements than boys. On detailed language analysis, girls were also shown to tell richer stories, including more descriptors of planning or intention. Overall, our findings suggest that subtle differences in social communication may exist between intellectually able boys and girls with ASD. If reliably identifiable in young children, such gender differences may contribute to differential diagnosis of ASD. In addition, such differences may pave the way for differential approaches to intervention when the target is effective communication in sophisticated discourse contexts.

Gender Differences and Similarities: Autism Symptomatology and Developmental Functioning in Young Children

A growing body of research suggests that symptoms of autism spectrum disorder (ASD) may present differently in males and females. This study examined gender differences in ASD symptoms and developmental functioning, using the Baby and Infant Screen for Children with aUtism Traits, Part 1 (BISCUIT-Part 1) and the Battelle Developmental Inventory, 2nd Edition (BDI-2), amongst children aged 17-37 months meeting ASD diagnostic criteria (n = 1317). No gender differences were found in regards to overall symptom severity or symptom domains on the BISCUIT-Part 1 when gender groups were matched by cognitive ability. Females with ASD had greater motor deficits and less communication impairment compared to their male counterparts as measured by the BDI-2. Secondary analyses examining item endorsement patterns were also conducted. Implications of the findings are discussed.

Early childhood behavioral features that discriminate autism from other developmental problems in Japan

PROBLEM

The criteria for early detection of autism spectrum disorder (ASD) and its discrimination from other developmental problems (ODP) are not clear. The Social Attention and Communication Study, which identified methods for early identification of ASD in community settings, was modified to the Japanese situation, and we examined its discriminant validity.

METHODS

This study followed a cohort of newborns in one town for 4 years. Structured behavioral assessments were added to the standardized health examination and performed five times during toddlerhood. Of the 264 children included in the statistical analysis, four were diagnosed with ASD, and four were diagnosed with ODP.

FINDINGS

A canonical discrimination analysis indicated two significant functions. Canonical 1, which involved disturbances of "eye contact" at 27 months and "concept comprehension" at 38 months, characterized both ASD and ODP. Canonical 2, which involved disturbances of "response name call" at 15 months, "showing" at 27 months, and negative loading of vocabulary development at 20 months, discriminated between ASD and ODP. The canonical plot showed good separation, but a few cases were misclassified.

CONCLUSIONS

Evaluations of early behavioral signs by public health nurses during general toddler examinations could be useful and convenient.

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

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