A family study of autism: cognitive patterns and levels in parents and siblings

Developmental changes in prefrontal cortex activation in children with or without autism spectrum traits on near-infrared spectroscopy

BACKGROUND

Autism spectrum disorder (ASD) ranges from mild to severe symptoms, with autistic traits possibly distributed throughout the population. However, the precise neurodevelopmental differences in children with autistic traits remain unknown.

SUBJECTS AND METHODS

Fifty-three healthy volunteers (32 male and 21 female, mean [standard deviation] age: 12.9 [2.5] years) having a normal intelligence quotient and without social impairment were divided into two groups according to scores of the Pervasive Developmental Disorders Autism Society Japan Rating Scale (PARS). Subjects with or without autistic traits were placed into the high-PARS (n = 14) or low-PARS (n = 39) group, respectively. Activation of the prefrontal cortex was estimated using change in hemoglobin oxygenation concentration (Δ[oxy-Hb]) on near-infrared spectroscopy (NIRS) during a verbal fluency test. Age-related changes in prefrontal cortex activation were first assessed for each group. Then, the effects of age (elementary school age or junior/senior high school age) and PARS score on Δ[oxy-Hb] in the task were analyzed by two-way analysis of variance.

RESULTS

We observed significant positive correlations between mean Δ[oxy-Hb] and age in the prefrontal cortex region in the low-PARS group. Mean Δ[oxy-Hb] in the low-PARS group was significantly higher than in the high-PARS group. Task performance results were comparable between the groups.

CONCLUSION

In PARS-determined typically developed children, prefrontal cortex activation on NIRS correlated positively with age. In healthy volunteers without ASD but harboring autistic traits, prefrontal cortex activation was markedly lower than in normal counterparts. Our results provide biological evidence that ASD may be a pervasively distributed disorder.

Prevalence of Developmental, Psychiatric, and Neurologic Conditions in Older Siblings of Children with and without Autism Spectrum Disorder: Study to Explore Early Development

This study evaluated developmental, psychiatric, and neurologic conditions among older siblings of children with and without autism spectrum disorder (ASD) to understand the extent of familial clustering of these diagnoses. Using data from the Study to Explore Early Development, a large multi-site case-control study, the analyses included 2,963 children aged 2-5 years with ASD, other developmental disabilities (DD group), and a population-based control group (POP). Percentages of index children with older siblings with select developmental, psychiatric, and neurologic conditions were estimated and compared across index child study groups using chi-square tests and multivariable modified Poisson regression. In adjusted analyses, children in the ASD group were significantly more likely than children in the POP group to have one or more older siblings with ASD, developmental delay, attention-deficit/hyperactivity disorder, intellectual disability, sensory integration disorder (SID), speech/language delays, or a psychiatric diagnosis (adjusted prevalence ratio [aPR] range: 1.4-3.7). Children in the DD group were significantly more likely than children in the POP group to have an older sibling with most of the aforementioned conditions, except for intellectual disability and psychiatric diagnosis (aPR range: 1.4-2.2). Children in the ASD group were significantly more likely than children in the DD group to have one or more older siblings with ASD, developmental delay, SID, or a psychiatric diagnosis (aPR range: 1.4-1.9). These findings suggest that developmental disorders cluster in families. Increased monitoring and screening for ASD and other DDs may be warranted when an older sibling has a DD diagnosis or symptoms.

Relationship of autistic traits and the severity of fear of the COVID-19 pandemic in the general population

Background

The aim of the study was to investigate the level of fear of the COVID-19 pandemic and to detect a possible correlation between the autistic traits and the level of fear and to learn about other factors that may affect the level of fear.

Methods

The study utilised a questionnaire and was conducted online in the period from 16.02.2021 to 11.06.2021. The test group consisted of 214 respondents with an average age of 23.78 years (95%CI: 22.48 - 25.08; max: 61, min: 14) from the general population. The study used The Autism-Spectrum Quotient (AQ) questionnaire to assess the degree of autistic traits in the general population and The Fear of COVID-19 Scale, which was used to assess the level of fear of COVID-19.

Results

Among the respondents, 9 people scored ≥32 on the AQ test and were considered to have a high degree of autistic traits. In multiple regression (R2 = 0.1, p<0.0001), a positive relationship between the severity of fear of COVID-19 and the autistic traits (p=0.01) and age (p<0.001) was obtained. Additionally, a second multiple regression (R2 = 0.1, p<0.000001) including the subscales of AQ was performed and a positive relationship between the severity of fear of COVID-19 and the difficulties in attention switching (p=0.0004) and age (p=0.00001) was obtained.

Conclusion

People with higher autistic traits present greater fear of the COVID-19 pandemic. We suggest that it might be caused by cognitive stiffness and disorders in emotions regulation, according to the literature. The elderly also present higher levels of fear. The other variables did not affect the level of fear of the COVID-19 pandemic.

Neurocognitive and self-reported psychosocial and behavioral functioning in siblings of individuals with neurodevelopmental conditions: a study using remote self-administered testing

OBJECTIVE

This study compared and explored the neurocognitive profiles of siblings of persons with and without neurodevelopmental conditions (NDCs) and associations between objective test performance and self-reported psychosocial functioning.

METHODS

Siblings of persons with and without NDCs (64 NDC and 64 control siblings; mean age 19.88 years, range 11-27 years, 73.44% female, 75.78% White Caucasian) completed self-report questionnaires and self-administered computerized neurocognitive tests of executive functioning (EF). Using Bayesian analyses, we examined cross-sectional associations between self-reported psychosocial functioning and cognitive test performance, and predictors of EF over 15 months.

RESULTS

NDC siblings had poorer working memory, inhibition, attention, and shifting compared to controls, as measured by experimental paradigms on the backward Corsi span, N-Back 2-back task, Stop Signal Task, Sustained Attention to Response Task, and the Wisconsin Card Sorting Test (effect size δ ranging 0.49 to 0.64). Bayesian cross-sectional networks revealed negative emotion reactivity and working memory difficulties were central to the NDC sibling network. Over 15 months, poorer EF (k low test scores) was predicted by negative emotion reactivity, sleep problems, and anxiety, over and above effects of age and subclinical autistic and ADHD traits. Siblings of autistic individuals and persons with fetal alcohol spectrum disorder had higher rates of neurocognitive and psychiatric difficulties than other NDCs and controls (Bayes factors >20).

CONCLUSIONS

Neurocognitive difficulties were associated with transdiagnostic vulnerability to poorer wellbeing in NDC siblings. These findings demonstrate the feasibility of remote online cognitive testing and highlight the importance of individualized prevention and intervention for NDC siblings.

Childhood Academic Performance: A Potential Marker of Genetic Liability to Autism

Autism spectrum disorder (ASD), a heritable neurodevelopmental disorder, confers genetic liability that is often expressed among relatives through subclinical, genetically-meaningful traits, or endophenotypes. For instance, relative to controls, parents of individuals with ASD differ in language-related skills, with differences emerging in childhood. To examine ASD-related endophenotypes, this study investigated developmental academic profiles among clinically unaffected siblings of individuals with ASD (n = 29). Lower performance in language-related skills among siblings mirrored previously-reported patterns among parents, which were also associated with greater subclinical ASD-related traits in themselves and their parents, and with greater symptom severity in their sibling with ASD. Findings demonstrated specific phenotypes, derived from standardized academic testing, that may represent childhood indicators of genetic liability to ASD in first-degree relatives.

The Clinical Implications of the Academic Performance of the Siblings of Individuals With Autism Spectrum Disorder

We all know that autism spectrum disorder (ASD) can affect academic performance. Many children with autism face different challenges at school. However, less attention is paid to the siblings of autistic children, who are at a high risk of ASD or the broad autism phenotype (BAP). Recent data also shows that many siblings of ASD children suffer from neurodevelopmental disorders, mental health problems as well as poor academic performance. This review will look at the possible etiologies of the poor school performance of autistic children's siblings, with an emphasis on the challenges they face. We will also highlight the clinical implications of these findings, and the possible solutions that can help this vulnerable group.

The Association of Paternal IQ With Autism Spectrum Disorders and Its Comorbidities: A Population-Based Cohort Study

OBJECTIVE

Original case descriptions of autism noted that parents of the affected children tended to be highly educated and intelligent, a characterization that has endured publicly. Recent genetic studies indicate that risk for autism spectrum disorders (ASD) is associated with high intelligence. We examined the association between paternal intelligence and ASD, considering co-occurring intellectual disability (ID) and attention-deficit/hyperactivity disorder (ADHD).

METHOD

We used a register-based cohort study design including 360,151 individuals with fathers conscripted to the Swedish military, resident in Stockholm, Sweden, born from 1984 to 2008, and followed until December 31, 2011, for diagnosis of ASD, ADHD, and/or ID. Risk of neurodevelopmental disorders relative to paternal IQ (rated on a 9-point scale) was assessed using a score of 5 (average intelligence) as the referent in models accounting for potentially nonlinear relationships and clustering of siblings.

RESULTS

We observed an association between high paternal IQ and offspring risk of ASD without ID/ADHD in models adjusted for individual and family characteristics (OR_IQ=9 1.32, 95% CI 1.15-1.52), an association that appeared to be driven largely by the fathers' score on the technical comprehension portion of the test (OR_{Technical IQ = 9} 1.53, 95% CI 1.31-1.78). Conversely, low paternal IQ was associated with ASD+ID (OR_{IQ = 1}1.78, 95% CI 1.27-2.49) and ASD+ADHD (OR_{IQ = 1}1.40, 95% CI 1.16-1.70); low paternal IQ was strongly associated with ID (OR_{IQ = 1} 4.46, 95% CI 3.62-5.49) and present also for ADHD (OR_{IQ = 1}1.56, 95% CI 1.42-1.72)] without co-occurring ASD or ID.

CONCLUSION

The relationship between paternal IQ and offspring risk of ASD was nonmonotonic and varied by the presence of co-occurring disorders, probably reflecting phenotypic diversity among affected individuals.

Social (Pragmatic) Communication Disorder: Another name for the Broad Autism Phenotype?

The Diagnostic and Statistical Manual of Mental Disorders' (5th ed.) Social (Pragmatic) Communication Disorder is meant to capture the social elements of communication dysfunction in children who do not meet autism spectrum disorder criteria. It is unclear whether Social (Pragmatic) Communication Disorder captures these elements without overlapping with Autism Spectrum Disorder or the Diagnostic and Statistical Manual of Mental Disorders' (5th ed.) Language Disorder. Standardized behavioral assessments administered during a family genetics study were used to evaluate the social communication impairment and the restricted interests and repetitive behaviors in persons with autism spectrum disorder, language impairment, or neither. Social communication impairment and restricted interests and repetitive behavior were significantly correlated in all family members regardless of affection status. Rates of social communication impairment and restricted interests and repetitive behavior were highest in individuals with autism spectrum disorder. One-third of family members with language impairment presented with at least mild/moderate levels of social communication impairment (36.6%) and restricted interests and repetitive behavior (43.3%). A subset of unaffected members also presented with mild/moderate levels of social communication impairment (parents = 10.1%, siblings 11.6%) and restricted interests and repetitive behavior (parents = 14.0%, siblings = 22.1%). The majority of child family members with mild/moderate levels of social communication impairment had similar restricted interest and repetitive behavior levels reflecting criteria representing the Broad Autism Phenotype. These data suggest that social pragmatic communication disorder does not capture the profiles of children who have both social communication impairment and restricted interests and repetitive behavior but are in need of clinical services.

School Functions in Unaffected Siblings of Youths with Autism Spectrum Disorders

This study investigated school functioning among unaffected siblings of youths with autistic spectrum disorder (ASD) and identified the correlates for school maladjustment. We recruited 66 youths with a clinical diagnosis of ASD, aged 8-19, their unaffected siblings and 132 typically developing controls (TD). We found that ASD youths had poorer school functions than unaffected siblings and TD. Unaffected siblings had poorer attitude toward schoolwork and more severe behavioral problems at school than TD. Several associated factors for different scholastic functional domains (i.e., academic performance, attitude toward school work, social interactions, behavioral problems) in the siblings included IQ, autistic traits, inattention/oppositional symptoms, sibling relationships, etc. Our findings suggest the need of assessing school functions in unaffected siblings of ASD.

TRIAL REGISTRATION

Clinical trial registration identifier: NCT01582256.

Broader autism phenotype in parents of children with autism: a systematic review of percentage estimates

The broader autism phenotype (BAP) is a collection of sub-diagnostic autistic traits more common in families of individuals with autism spectrum disorder (ASD) than in the general population. BAP is a latent construct that can be defined using different domains, measured using multiple instruments, and reported using different techniques. Therefore, estimates of BAP may vary greatly across studies. Our objective was to systematically review studies that reported occurrence of BAP in parents of children with ASD in order to quantify and describe heterogeneity in estimates. We systematically searched PubMed and Scopus using PRISMA guidelines for studies quantifying percentage of parents of children with ASD who had BAP We identified 41 studies that measured BAP in parents of children with ASD. These studies used eight different instruments, four different forms of data collection, and had a wide range of sample sizes (N=4 to N=3299). Percentage with BAP ranged from 2.6% to 80%. BAP was more prevalent in fathers than mothers. Parental BAP may be an important tool for parsing heterogeneity in ASD etiology and for developing parent-mediated ASD interventions. However, the variety in measurement instruments and variability in study samples limits our ability to synthesize estimates. To improve measurement of BAP and increase consistency across studies, universal methods should be accepted and adopted across studies. A more consistent approach to BAP measurement may enable efficient etiologic research that can be meta-analyzed and may allow for a larger evidence base that can be used to account for BAP when developing parent-mediated interventions.

Cross-Disorder Cognitive Impairments in Youth Referred for Neuropsychiatric Evaluation

OBJECTIVES

Studies suggest that impairments in some of the same domains of cognition occur in different neuropsychiatric conditions, including those known to share genetic liability. Yet, direct, multi-disorder cognitive comparisons are limited, and it remains unclear whether overlapping deficits are due to comorbidity. We aimed to extend the literature by examining cognition across different neuropsychiatric conditions and addressing comorbidity.

METHODS

Subjects were 486 youth consecutively referred for neuropsychiatric evaluation and enrolled in the Longitudinal Study of Genetic Influences on Cognition. First, we assessed general ability, reaction time variability (RTV), and aspects of executive functions (EFs) in youth with non-comorbid forms of attention-deficit/hyperactivity disorder (ADHD), mood disorders and autism spectrum disorder (ASD), as well as in youth with psychosis. Second, we determined the impact of comorbid ADHD on cognition in youth with ASD and mood disorders.

RESULTS

For EFs (working memory, inhibition, and shifting/ flexibility), we observed weaknesses in all diagnostic groups when participants' own ability was the referent. Decrements were subtle in relation to published normative data. For RTV, weaknesses emerged in youth with ADHD and mood disorders, but trend-level results could not rule out decrements in other conditions. Comorbidity with ADHD did not impact the pattern of weaknesses for youth with ASD or mood disorders but increased the magnitude of the decrement in those with mood disorders.

CONCLUSIONS

Youth with ADHD, mood disorders, ASD, and psychosis show EF weaknesses that are not due to comorbidity. Whether such cognitive difficulties reflect genetic liability shared among these conditions requires further study. (JINS, 2018, 24, 91-103).

Investigating the Evidence of Behavioral, Cognitive, and Psychiatric Endophenotypes in Autism: A Systematic Review

Substantial evidence indicates that parents of autistic individuals often display milder forms of autistic traits referred to as the broader autism phenotype (BAP). To determine if discrete endophenotypes of autism can be identified, we reviewed the literature to assess the evidence of behavioral, cognitive, and psychiatric profiles of the BAP. A systematic review was conducted using EMBASE, MEDLINE, PsycINFO, PsycEXTRA, and Global Health. Sixty papers met our inclusion criteria and results are discussed according to the proportion of studies that yield significant deficits per domain. The behavioral, cognitive, and psychiatric endophenotypes in parents of autistic probands are still not clarified; however, evidence suggests mild social/communication deficits, rigid/aloof personality traits, and pragmatic language difficulties as the most useful sociobehavioral candidate endophenotype traits. The existence of deficits in the cognitive domain does suggest familial vulnerability for autism. Furthermore, increased depressed mood and anxiety can also be useful markers; however, findings should be interpreted with caution because of the small number of studies in such heterogeneously broad domains and several methodological limitations.

Defining language impairments in a subgroup of children with autism spectrum disorder

Autism spectrum disorder (ASD) is diagnosed on the basis of core impairments in pragmatic language skills, which are found across all ages and subtypes. In contrast, there is significant heterogeneity in language phenotypes, ranging from nonverbal to superior linguistic abilities, as defined on standardized tests of vocabulary and grammatical knowledge. The majority of children are verbal but impaired in language, relative to age-matched peers. One hypothesis is that this subgroup has ASD and co-morbid specific language impairment (SLI). An experiment was conducted comparing children with ASD to children with SLI and typically developing controls on aspects of language processing that have been shown to be impaired in children with SLI: repetition of nonsense words. Patterns of performance among the children with ASD and language impairment were similar to those with SLI, and contrasted with the children with ASD and no language impairment and typical controls, providing further evidence for the hypothesis that a subgroup of children with ASD has co-morbid SLI. The findings are discussed in the context of brain imaging studies that have explored the neural bases of language impairment in ASD and SLI, and overlap in the genes associated with elevated risk for these disorders.

Non-ASD outcomes at 36 months in siblings at familial risk for autism spectrum disorder (ASD): A baby siblings research consortium (BSRC) study

We characterized developmental outcomes of a large sample of siblings at familial high-risk of autism spectrum disorder (ASD), who themselves did not have ASD (n = 859), and low-risk controls with no family history of ASD (n = 473). We report outcomes at age 3 years using the Mullen Scales of Early Learning, the Autism Diagnostic Observation Schedule (ADOS), the Autism Diagnostic Interview-Revised (ADI-R) and adaptive functioning on the Vineland Adaptive Behavior Scales. Around 11% of high-risk siblings had mild-to-moderate levels of developmental delay, a rate higher than the low-risk controls. The groups did not differ in the proportion of toddlers with mild-to-moderate language delay. Thirty percent of high-risk siblings had elevated scores on the ADOS, double the rate seen in the low-risk controls. High-risk siblings also had higher parent reported levels of ASD symptoms on the ADI-R and lower adaptive functioning on the Vineland. Males were more likely to show higher levels of ASD symptoms and lower levels of developmental ability and adaptive behavior than females across most measures but not mild-to-moderate language delay. Lower maternal education was associated with lower developmental and adaptive behavior outcomes. These findings are evidence for early emerging characteristics related to the "broader autism phenotype" (BAP) previously described in older family members of individuals with ASD. There is a need for ongoing clinical monitoring of high-risk siblings who do not have an ASD by age 3 years, as well as continued follow-up into school age to determine their developmental and behavioral outcomes. Autism Res 2017, 10: 169-178. © 2016 International Society for Autism Research, Wiley Periodicals, Inc.

Is There Really a Link Between Engineering and Autism?

Baron-Cohen, Wheelwright, Scott, Bolton and Goodyear (1997) found that engineering was over-represented as an occupation among fathers of individuals with autism, in comparison to fathers of non-autistic individuals. We present further analyses of their data which suggest that while engineering is indeed more common than would be expected, so too are the occupations of medicine, science, and accounting. In addition, skilled and unskilled manual workers are less common as fathers than would be predicted. Moreover, our analyses indicate that accountancy and science may be as strongly associated with fathers of individuals with autism as is engineering. These results could be seen as being consistent with a link between parental occupation and incidence of autism. However, we also consider whether they might arise from a sampling bias, with generally 'less-professional' occupations being under-represented among Baron-Cohen and colleagues' sample.

The Broad Autism Phenotype

This study aimed to determine if relatives of children with autism and less severe pervasive developmental disorders (PDDs) have higher rates of various components of the broad autistic phenotype. Psychiatric and medical disorders were investigated. Parents of children with PDDs were selected from an epidemiological survey and compared with parents of control children with non-autistic developmental problems. Rates of abnormalities and disorders were compared in relatives of 79 cases and 61 controls. Medical and autoimmune disorders in both groups were endorsed by few relatives. Specific developmental disorders were commoner in parents of controls. Depression and anxiety were significantly more prevalent in mothers of children with PDDs. Significantly more PDD children had at least one firstdegree relative with anxiety and one second-degree relative with OCD. PDDs were commoner in first-degree relatives. The implications of the findings for the definition of the broad phenotype of autism are discussed.

Extending the 'cross-disorder' relevance of executive functions to dimensional neuropsychiatric traits in youth

BACKGROUND

Evidence that different neuropsychiatric conditions share genetic liability has increased interest in phenotypes with 'cross-disorder' relevance, as they may contribute to revised models of psychopathology. Cognition is a promising construct for study; yet, evidence that the same cognitive functions are impaired across different forms of psychopathology comes primarily from separate studies of individual categorical diagnoses versus controls. Given growing support for dimensional models that cut across traditional diagnostic boundaries, we aimed to determine, within a single cohort, whether performance on measures of executive functions (EFs) predicted dimensions of different psychopathological conditions known to share genetic liability.

METHODS

Data are from 393 participants, ages 8-17, consecutively enrolled in the Longitudinal Study of Genetic Influences on Cognition (LOGIC). This project is conducting deep phenotyping and genomic analyses in youth referred for neuropsychiatric evaluation. Using structural equation modeling, we examined whether EFs predicted variation in core dimensions of the autism spectrum disorder, bipolar illness, and schizophrenia (including social responsiveness, mania/emotion regulation, and positive symptoms of psychosis, respectively).

RESULTS

We modeled three cognitive factors (working memory, shifting, and executive processing speed) that loaded on a second-order EF factor. The EF factor predicted variation in our three target traits, but not in a negative control (somatization). Moreover, this EF factor was primarily associated with the overlapping (rather than unique) variance across the three outcome measures, suggesting that it related to a general increase in psychopathology symptoms across those dimensions.

CONCLUSIONS

Findings extend support for the relevance of cognition to neuropsychiatric conditions that share underlying genetic risk. They suggest that higher-order cognition, including EFs, relates to the dimensional spectrum of each of these disorders and not just the clinical diagnoses. Moreover, results have implications for bottom-up models linking genes, cognition, and a general psychopathology liability.

School-age outcomes of infants at risk for autism spectrum disorder

Studies of infants at risk for autism spectrum disorder (ASD) have proliferated, but few of these samples have been followed longer-term. We conducted a follow-up study, at age 5.5-9 years, of younger siblings of children with ASD (high-risk group, n = 79) or typical development (low-risk group, n = 60), originally recruited as infants. Children with ASD were excluded because of the focus on understanding the range of non-ASD outcomes among high-risk siblings. Using examiner ratings, parent ratings, and standardized assessments, we evaluated differences in clinical outcomes, psychopathology symptoms, autism symptoms, language skills, and nonverbal cognitive abilities. After adjusting for covariates, the high-risk group had increased odds of any clinically elevated/impaired score across measures relative to the low-risk group (43% vs. 12%, respectively). The high-risk group also had increased odds of examiner-rated Clinical Concerns (CC) outcomes (e.g., ADHD concerns, broader autism phenotype, speech-language difficulties, anxiety/mood problems, learning problems) relative to the low-risk group (38% vs. 13%, respectively). The high-risk group with CC outcomes had higher parent-reported psychopathology and autism symptoms, and lower directly-assessed language skills, than the Low-Risk Typically Developing (TD) and High-Risk TD groups, which did not differ. There were no differences in nonverbal cognitive skills. For some in the high-risk group, clinical concerns persisted from early childhood, whereas for others clinical concerns were first evident at school-age. Results suggest continued vulnerability in at least a subgroup of school-age children with a family history of ASD and suggest that this population may benefit from continued screening and monitoring into the school-age years. Autism Res 2016, 9: 632-642. © 2015 International Society for Autism Research, Wiley Periodicals, Inc.

Memory in language-impaired children with and without autism

Background

A subgroup of young children with autism spectrum disorders (ASD) have significant language impairments (phonology, grammar, vocabulary), although such impairments are not considered to be core symptoms of and are not unique to ASD. Children with specific language impairment (SLI) display similar impairments in language. Given evidence for phenotypic and possibly etiologic overlap between SLI and ASD, it has been suggested that language-impaired children with ASD (ASD + language impairment, ALI) may be characterized as having both ASD and SLI. However, the extent to which the language phenotypes in SLI and ALI can be viewed as similar or different depends in part upon the age of the individuals studied. The purpose of the current study is to examine differences in memory abilities, specifically those that are key “markers” of heritable SLI, among young school-age children with SLI, ALI, and ALN (ASD + language normal).

Methods

In this cross-sectional study, three groups of children between ages 5 and 8 years participated: SLI (n = 18), ALI (n = 22), and ALN (n = 20). A battery of cognitive, language, and ASD assessments was administered as well as a nonword repetition (NWR) test and measures of verbal memory, visual memory, and processing speed.

Results

NWR difficulties were more severe in SLI than in ALI, with the largest effect sizes in response to nonwords with the shortest syllable lengths. Among children with ASD, NWR difficulties were not associated with the presence of impairments in multiple ASD domains, as reported previously. Verbal memory difficulties were present in both SLI and ALI groups relative to children with ALN. Performance on measures related to verbal but not visual memory or processing speed were significantly associated with the relative degree of language impairment in children with ASD, supporting the role of verbal memory difficulties in language impairments among early school-age children with ASD.

Conclusions

The primary difference between children with SLI and ALI was in NWR performance, particularly in repeating two- and three-syllable nonwords, suggesting that shared difficulties in early language learning found in previous studies do not necessarily reflect the same underlying mechanisms.

Electronic supplementary material

The online version of this article (doi:10.1186/s11689-015-9111-z) contains supplementary material, which is available to authorized users.

Broader Autism Phenotype in Siblings of Children with ASD--A Review

Although less pronounced, social, cognitive, and personality characteristics associated with autism spectrum disorders (ASD) may be present in people who do not meet ASD diagnostic criteria, especially in first-degree relatives of individuals with ASD. Research on these characteristics, referred to as broader autism phenotype (BAP), provides valuable data on potential expressions of autism-specific deficits in the context of family relations. This paper offers a review of research on BAP in siblings of individuals with ASD, focusing on reports regarding social, communication, and cognitive deficits, published from 1993 to 2014. The studies are divided into two groups based on participants’ age: papers on preschool and older siblings of individuals with ASD; and publications on infants at risk for ASD. On the basis of this review, suggestions are offered for further research and its significance for our understanding of the genetic determinants of autism.

Self and informant reports of mental health difficulties among adults with autism findings from a long-term follow-up study

Data on psychiatric problems in adults with autism are inconsistent, with estimated rates ranging from around 25% to over 75%. We assessed difficulties related to mental health in 58 adults with autism (10 females, 48 males; mean age 44 years) whom we have followed over four decades. All were of average non-verbal intelligence quotient when diagnosed as children. Overall ratings of mental health problems were based on data from the Family History Schedule (Bolton et al., 1994). Informant reports indicated that many of the cohort (44%) had experienced no mental health problems in adulthood; 28% had experienced mild to moderate difficulties, 23% had severe and 5% very severe problems. Depression was the most commonly reported problem. Among those adults ( n = 22) able to report on their own mental state, again many (45%) reported no mental health problems, although 27% reported very severe mental health problems related to anxiety, depression and/or obsessive–compulsive symptoms. Informant ratings of poor mental health were not associated with gender, severity of autism in childhood, or child or adult intelligence quotient, but there were small correlations with overall social functioning (rho = 0.34) and current autism severity (rho = 0.37). The findings highlight the difficulties of assessing mental health problems in adults with autism and the need for appropriately validated measures.

New Interview and Observation Measures of the Broader Autism Phenotype: Description of Strategy and Reliability Findings for the Interview Measures

Clinical genetic studies confirm the broader autism phenotype (BAP) in some relatives of individuals with autism, but there are few standardized assessment measures. We developed three BAP measures (informant interview, self-report interview, and impression of interviewee observational scale) and describe the development strategy and findings from the interviews. International Molecular Genetic Study of Autism Consortium data were collected from families containing at least two individuals with autism. Comparison of the informant and self-report interviews was restricted to samples in which the interviews were undertaken by different researchers from that site (251 UK informants, 119 from the Netherlands). Researchers produced vignettes that were rated blind by others. Retest reliability was assessed in 45 participants. Agreement between live scoring and vignette ratings was very high. Retest stability for the interviews was high. Factor analysis indicated a first factor comprising social-communication items and rigidity (but not other repetitive domain items), and a second factor comprised mainly of reading and spelling impairments. Whole scale Cronbach's alphas were high for both interviews. The correlation between interviews for factor 1 was moderate (adult items 0.50; childhood items 0.43); Kappa values for between-interview agreement on individual items were mainly low. The correlations between individual items and total score were moderate. The inclusion of several factor 2 items lowered the overall Cronbach's alpha for the total set. Both interview measures showed good reliability and substantial stability over time, but the findings were better for factor 1 than factor 2. We recommend factor 1 scores be used for characterising the BAP.

Language abilities in preschool-aged siblings of children with autism spectrum disorders – preliminary report

<b>Background</b><br /> The characteristics of autism spectrum disorders (ASD) observed among relatives of people affected with autism are referred to as broader autism phenotype (BAP). Among the components of BAP are language and communication skills. Research to date on these skills amongst the relatives of individuals with ASD is inconclusive. Furthermore, limited data are available about preschool-aged siblings of children with ASD.<br /> <br /> <b>Participants and procedure</b><br /> Eighty-six children aged 4 years and 6 months – 6 years and 11 months took part in the study (32 girls and 54 boys). They were divided into four groups: siblings of children with autism (S/ASD), high-functioning children diagnosed with autism spectrum disorders (HF/ASD), siblings of children with Down syndrome (S/DS) and siblings of typically developing children (Controls, C). Communication and language skills were tested using the Vocabulary Test for Children (TSD). It was used to assess two kinds of verbal skills: receptive language (passive) and expressive language (active).<br /> <br /> <b>Results</b><br /> No differences were observed in expressive lanquage or receptive language between siblings of children with ASD and siblings of children with DS as well as typically developing children. In terms of receptive language and general communication skills, siblings of children with ASD scored higher than high functioning children with ASD. High functioning children with ASD displayed difficulties with receptive language, expressive language, general language and communication skills.<br /> <br /> <b>Conclusions</b><br /> The results suggest that siblings of children with ASD do not display deficits in communication and language skills. It is however important to note that due to a small sample size this study should be considered as preliminary.

Is child intelligence associated with parent and sibling intelligence in individuals with developmental disorders? An investigation in youth with 22q11.2 deletion (velo-cardio-facial) syndrome

Children with 22q11.2 deletion syndrome (22q11DS), a copy-number variation (CNV) genetic disorder, demonstrate a great deal of variability in IQ scores and are at particular risk for cognitive difficulties, with up to 45% experiencing intellectual disability. This study explored the IQ relationship between individuals with 22q11DS, their parents and their siblings. Participants included individuals with 22q11DS, unaffected siblings and community controls, who participated in a longitudinal study of 22q11DS. Significant associations between proband and relative (parent, sibling) IQ scores were found. Results suggest that the cognitive functioning of first-degree relatives could be a useful marker of general genetic background and/or environmental effects, and can explain some of the large phenotypic variability in 22q11DS. These findings underscore the importance of including siblings and parents in studies of 22q11DS whenever possible.

Cognitive abilities in siblings of children with autism spectrum disorders

The aim of the present study was to assess the cognitive profiles of children with autistic spectrum disorder and of their healthy siblings (Siblings). With the term cognitive profile, we indicate the relationship extant among the values of verbal and performance subtests of the Wechsler Intelligence Scale. The conducted statistical analyses indicated that, although siblings showed a normal intelligent quotient and did not differ in this aspect from typically developing group, their cognitive profile was amazingly similar to that of their relatives affected by autism. A k-means clustering analysis on the values of single subtests further confirmed this result, showing a clear separation between typically developing children on the one side, and autistics and their siblings on the other. We suggest that the common cognitive profile observed in autistic children and their siblings could represent a marker of liability to autism and, thus, a possible intermediate phenotype of this syndrome.

The local, global, and neural aspects of visuospatial processing in autism spectrum disorders

Behavioral studies have documented a relative advantage in some aspects of visuospatial cognition in autism although it is not consistently found in higher functioning individuals with autism. The purpose of this functional neuroimaging study was to examine the neural activity in high functioning individuals with autism while they performed a block design task that systematically varied with regard to whether a global pattern was present. Participants were 14 adults with high-functioning autism and 14 age and IQ matched typical controls. The task was to identify a missing block in target figures which had either an obvious global shape or was an arbitrary array of blocks. Behavioral results showed intact, but not superior, performance in our participants with autism. A key group difference was that the participants with autism showed reliably greater activation in occipital and parietal regions in both tasks suggesting an increased reliance of the autism group on posterior brain areas to mediate visuospatial tasks. Thus, increased reliance on relatively posterior brain regions in itself may not guarantee superior performance as seen in the present study.

The broad autism phenotype in parents of individuals with autism: a systematic review of the literature

The broad autism phenotype (BAP) is a milder manifestation of the defining symptoms of the syndrome in individuals without autism. This study conducted a systematic review of studies about behavioral characteristics of interpersonal relationships, communication and rigidity, as well as about three cognitive models, Theory of Mind, central coherence and executive function, in parents of individuals with autism. The indexed databases were LILACS, IBECS, Web of Science, and MEDLINE, and the studies retrieved were published between 1991 and March 2012. Parents of individuals with autism have more difficulties in interpersonal relationships and in pragmatic language use and have more rigidity traits. The inclusions of the cognitive theories in the group of BAP characteristics were inconclusive.

Social outcomes in mid- to later adulthood among individuals diagnosed with autism and average nonverbal IQ as children

OBJECTIVE

To describe current social functioning in a clinical sample of 60 adults with autism (mean age = 44 years) who were all of average nonverbal IQ (70+) when first diagnosed (mean age = 6.75 years).

METHOD

Outcome measures included standardized diagnostic and cognitive assessments and questionnaires on social functioning. Child and adult variables related to current outcomes were explored.

RESULTS

All individuals continued to meet criteria for autism spectrum disorder (ASD) on the Autism Diagnostic Interview-Revised (ADI-R), but severity of autism symptoms declined over time. Nevertheless, only 10 individuals (17%) were rated as having a "good" or "very good" outcome; the majority (60%) were assessed as having "poor" or "very poor" outcomes. The strongest predictor of adult outcome was the Reciprocal Social Interaction domain score on the ADI at diagnostic confirmation. Change over time was further examined in a subgroup (n = 44) previously assessed 20 years ago earlier (mean age = 26 years). Although severity of autism had continued to decrease during the adult period, social outcomes were poorer than in younger adulthood.

CONCLUSIONS

In this cohort of adults first diagnosed with autism, on average, 37 years previously, social inclusion remains very limited, despite general improvements in autism symptomatology with age. Whether these findings will be replicated in future generations of children with autism, who now have the benefits of earlier diagnosis and wider access to specialist provision, needs to be the focus of further longitudinal research.

[Endophenotypes and autism spectrum disorders]

Genetic factors of ASD stay unknown after 30 years of research. The concept of "endophenotype" seems an interesting approach toward these factors. "Enlarged phenotypes" in families of ASD persons could lead to the definition of ASD endophenotypes. "Enlarged phenotypes" include clinical symptoms, morphological and functional brain anomalies enlightening ASD physiopathology and brain physiology. Knowledge of endophenotypes will lead to ASD genetic risk factors. This knowledge will open ethical questions about prenatal diagnosis.

Communication and social deficits in relatives of individuals with SLI and relatives of individuals with ASD

We investigate two aspects of the autism triad, communication and social difficulties, in relatives of specific language impairment (SLI) probands (with and without additional autistic symptomatology) as compared to relatives of autism spectrum disorder (ASD) and Down's syndrome (DS) probands. Findings involving 726 first degree relatives of 85 SLI, 99 ASD and 36 DS probands revealed a higher rate of communication difficulties in relatives of both subgroups of SLI probands compared to ASD and DS relatives. Similar levels of social deficits were found in relatives of SLI + ASD and ASD probands. There was a higher than would be expected rate (4.3 %) of ASD, particularly in siblings of SLI + ASD probands. Communication and social deficits appear to breed true in SLI and ASD.

A review of intentional and cognitive control in autism

Different clinical studies have provided empirical evidence for impairments in cognitive control in individuals with autism spectrum disorders (ASD). The challenge arises, however, when trying to specify the neurocognitive mechanisms behind the reported observations of deviant patterns of goal-directed behavior in ASD. Studies trying to test specific assumptions by applying designs that are based on a more controlled experimental conditions often fail in providing strong evidence for an impairment in specific cognitive functions. In this review, we summarize and critically reflect on behavioral findings and their theoretical explanations regarding cognitive control processing in autism, also from a developmental perspective. The specific focus of this review is the recent evidence of deficits in intentional control – a specific subset of cognitive control processes that biases the choice of our behavioral goals – coming from different research fields. We relate this evidence to the cognitive rigidity observed in ASD and argue that individuals with ASD experience problems at the intentional level rather than at the level of implementation of intentions. Both these processes are related to cognitive control mechanisms but in different ways. Finally, we discuss new directions in studying cognitive control in ASD and how these relate to adaptive cognition.

The Broad Autism Phenotype Questionnaire: mothers versus fathers of children with an autism spectrum disorder

Parents of individuals with autism were examined using the Broad Autism Phenotype Questionnaire (BAPQ; Hurley et al. in J Autism Dev Disord 37:1679-1690, 2007) assessing BAP-related personality and language characteristics. The BAPQ was administered to parents as a self-report and as an informant (spouse)-based measure. Results indicated the same pattern of differences for the informant and best-estimate (average between self-report and informant scores) reports. Fathers were rated as more "aloof" than mothers, whereas mothers were rated as more "rigid" than fathers. Fathers described their wives as less "aloof" and more "rigid" compared to the mothers' self-descriptions. Correlational analyses revealed no significant associations among parent/child characteristics and parents' BAPQ scores. Results are discussed in reference to sex differences in BAP-related characteristics in parents of children with autism.

Defining genetically meaningful language and personality traits in relatives of individuals with fragile X syndrome and relatives of individuals with autism

Substantial phenotypic overlap exists between fragile X syndrome (FXS) and autism, suggesting that FMR1 (the gene causing FXS) poses a significant risk for autism. Cross-population comparisons of FXS and autism therefore offer a potentially valuable method for refining the range of phenotypes associated with variation in FMR1. This study adopted a broader phenotype approach, focusing on parents who are at increased genetic liability for autism or FXS. Women who were carriers of FMR1 in its premutation state were compared with mothers of individuals with autism, and controls in an attempt to determine whether subtle features of the broad autism phenotype may express at elevated rates among FMR1 premutation carriers. The principal personality and language features comprising the broad autism phenotype (i.e., rigid and aloof personality, and particular patterns of pragmatic language use) were assessed among 49 premutation carriers who were mothers of individuals with FXS, 89 mothers of individuals with autism, and 23 mothers of typically developing individuals. Relative to controls, the autism and premutation parent groups showed elevated rates of certain personality and language characteristics of the broad autism phenotype. Findings suggest partially overlapping personality and language profiles among autism and premutation parent groups, with rigid personality style and patterns of pragmatic language use emerging as features most clearly shared between groups. These results provide further evidence for the overlap of autism and FXS, and may implicate FMR1 in some of the subtle features comprising the broad autism phenotype.

Interpretation of compound nouns by adolescents with specific language impairment and autism spectrum disorders: an investigation of phenotypic overlap

The study aimed to investigate (i) whether adolescents with Specific Language Impairment (SLI) and Autism plus Language Impairment (ALI) experience word-formation difficulties, and (ii) whether these two groups present with a similar language phenotype. The study investigated four groups using a 2 (language status) ×2 (autism status) design; adolescents with SLI (n = 14), ALI (n = 16), Autism Language-Typical (ALT; n = 14), and language matched controls (n = 17), with all groups presenting with typical non-verbal skills. Mean age was 14;10. Comprehension of conventional Noun-Noun lexical compounds (e.g., snowman), synthetic compounds (SCs, e.g., cat chaser), and novel root compounds (RCs, e.g., sheep socks), was assessed using a forced-choice picture selection task. The SLI and ALI participants frequently mis-parsed the SCs, interpreting the first noun as the agent. Those with poorer vocabularies and non-word repetition had greater difficulties. Reaction time (RT) profiles were flatter in the ASD groups, with similar RTs across different compounds. Language difficulties in the SLI and ALI groups extend to word-formation processes; for example, comprehension of SCs. This may reflect difficulties making analogies with stored lexical items. Overall the results support the hypothesis of a phenotypic overlap between SLI and ALI.

Adults with autism spectrum disorders

In the decades since autism was first formally described in the 1940s, there have been major advances in research relating to diagnosis, causation, and treatment approaches for children with this condition. However, research into prognosis, outcomes, or effective interventions for adults with autism spectrum disorders (ASDs) is much more limited. In this paper, we review studies of outcome in adulthood. The findings indicate that, as adults, many people with ASD, including those of normal IQ, are significantly disadvantaged regarding employment, social relationships, physical and mental health, and quality of life. Support to facilitate integration within the wider society is frequently lacking, and there has been almost no research into ways of developing more effective intervention programs for adults. Moreover, most of the research on outcome has involved relatively young people in their 20s and 30s-much less is known about outcomes for people with ASD as they reach mid-late adulthood. Systematic follow-up studies from childhood through adulthood are needed if we are to gain a better understanding of trajectories of development over the lifespan, to identify the factors that influence prognosis, and to determine how these factors exert their effects and how they may be modified to ensure a better future.

Autistic traits below the clinical threshold: re-examining the broader autism phenotype in the 21st century

Diagnosis, intervention and support for people with autism can be assisted by research into the aetiology of the condition. Twin and family studies indicate that autism spectrum conditions are highly heritable; genetic relatives of people with autism often show milder expression of traits characteristic for autism, referred to as the Broader Autism Phenotype (BAP). In the past decade, advances in the biological and behavioural sciences have facilitated a more thorough examination of the BAP from multiple levels of analysis. Here, the candidate phenotypic traits delineating the BAP are summarised, including key findings from neuroimaging studies examining the neural substrates of the BAP. We conclude by reviewing the value of further research into the BAP, with an emphasis on deriving heritable endophenotypes which will reliably index autism susceptibility and offer neurodevelopmental mechanisms that bridge the gap between genes and a clinical autism diagnosis.

The broader autism phenotype and its implications on the etiology and treatment of autism spectrum disorders

The presence of autism-related traits has been well documented in undiagnosed family members of individuals with autism spectrum disorder (ASD). The most common finding is mild impairments in social and communication skills that are similar to those shown by individuals with autism, but exhibited to a lesser degree. Termed the broader autism phenotype (BAP), these traits suggest a genetic liability for autism-related traits in families. Genetic influence in autism is strong, with identical twins showing high concordance for the diagnosis and related traits and approximately 20% of all ASD cases having an identified genetic mechanism. This paper highlights the studies conducted to date regarding the BAP and considers the implications of these findings for the etiology and treatment of ASD.

Autism spectrum disorders--a genetics review

Autism is an etiologically and clinically heterogeneous group of disorders, diagnosed solely by the complex behavioral phenotype. On the basis of the high-heritability index, geneticists are confident that autism will be the first behavioral disorder for which the genetic basis can be well established. Although it was initially assumed that major genome-wide and candidate gene association studies would lead most directly to common autism genes, progress has been slow. Rather, most discoveries have come from studies of known genetic disorders associated with the behavioral phenotype. New technology, especially array chromosomal genomic hybridization, has both increased the identification of putative autism genes and raised to approximately 25%, the percentage of children for whom an autism-related genetic change can be identified. Incorporating clinical geneticists into the diagnostic and autism research arenas is vital to the field. Interpreting this new technology and deciphering autism's genetic montage require the skill set of the clinical geneticist including knowing how to acquire and interpret family pedigrees, how to analyze complex morphologic, neurologic, and medical phenotypes, sorting out heterogeneity, developing rational genetic models, and designing studies. The current emphasis on deciphering autism spectrum disorders has accelerated the field of neuroscience and demonstrated the necessity of multidisciplinary research that must include clinical geneticists both in the clinics and in the design and implementation of basic, clinical, and translational research.

Attachment security in infants at-risk for autism spectrum disorders

Little is known about attachment security and disorganization in children who are at genetic risk for an Autism Spectrum Disorder (ASD) prior to a possible diagnosis. The present study examined distributions of attachment security and disorganization at 15-months of age in a sample of infant siblings of older children with (ASD-sibs; n = 51) or without (COMP-sibs; n = 34) an ASD. ASD-sibs were not more or less likely to evince attachment insecurity or disorganization than COMP-sibs. However, relative to COMP-sibs, the rate of B1-B2 secure subclassifications was disproportionately larger in the ASD-sib group. Results suggest that ASD-sibs are not less likely to form secure affectional bonds with their caregivers than COMP-sibs, but may differ from COMP-sibs in their expression of attachment security.

Pragmatic language and school related linguistic abilities in siblings of children with autism

Siblings of probands with autism spectrum disorders are at higher risk for developing the broad autism phenotype (BAP). We compared the linguistic abilities (i.e., pragmatic language, school achievements, and underling reading processes) of 35 school-age siblings of children with autism (SIBS-A) to those of 42 siblings of children with typical development. Results indicated lower pragmatic abilities in a subgroup of SIBS-A identified with BAP related difficulties (SIBS-A-BAP) whereas school achievements and reading processes were intact. Furthermore, among SIBS-A-BAP, significant negative correlations emerged between the severity scores on the Autism Diagnostic Observation Schedule and full and verbal IQ scores. These results are discussed in the context of the developmental trajectories of SIBS-A and in relation to the BAP.

Sowing the seeds of the autism field: Leo Kanner (1943)

More than 65 years after Leo Kanner published his seminal article, research on autism continues to be an area of increasing interest. Although much progress has been made, this field is still in its infancy, and many avenues of research are just beginning to be pursued. Despite the time that has passed, the syndrome Kanner identified and his comments about the children he observed continue to have meaning today, and although some of his suggestions about the etiology and presentation of autism were grounded in the thinking of his day, many of his observations were quite prescient. In this paper we explore Kanner's contributions to the field of autism, discuss how the field has changed, and suggest ways that research on autism spectrum disorders can continue to move forward.

Autism spectrum disorders in siblings of children with a developmental language disorder

Little is known about the familial characteristics of children diagnosed during childhood as having a developmental language disorder (DLD). This study aimed to investigate the prevalence of autism spectrum disorders (ASD) in siblings of probands diagnosed during childhood as having a DLD. In order to estimate the prevalence of ASD, 908 siblings of 469 probands diagnosed during childhood as having a DLD, and 3,802 siblings of 2,345 controls from the general population, without a known history of DLD, were screened for ASD through the nationwide Danish Psychiatric Central Register (DPCR). The mean length of observation was 35.2 years and 34.8 years, respectively, and the mean age at follow-up 38.4 years and 37.4 years, respectively. At follow-up one sibling (0.1%) in the DLD case group and eight siblings (0.2%) in the comparison group were known in the DPCR with a diagnosis of any ASD (P = 0.53; OR = 0.52; 95%CI 0.07-4.19). Thus our results provide no support for a familial association between DLD and ASD.

Co-morbidity of autism and SLI: kinds, kin and complexity

There has been a long-standing interest in the relationship between specific language impairment (SLI) and autism spectrum disorder (ASD). In the last decade Tager-Flusberg and colleagues have proposed that this relationship consists of a partial overlap between the two. Therefore, among children with ASD there exists a subgroup who have SLI and ASD which has been called 'ALI'. Tager-Flusberg's laboratory has presented several papers showing similar language profiles and brain structure abnormalities in both SLI and ALI. Others (Bishop, Whitehouse, Botting, Williams) have been less convinced that these ALI children have both ASD and SLI. Although they generally agree that the two groups are grossly similar, careful inspection of the data shows that there are differences. I will argue that many of the problems in this debate stem from a view of SLI that represents a particular kind of language learner and therefore a particular and unique profile can be assumed. I argue for recognizing that SLI is not likely to be a unique kind of language learner. Many of the features reported to be characteristic of SLI are also found in other forms of neurodevelopmental disorders. Other features are the outgrowth of studying clinically identified children with SLI and thus the profile appears to reflect biases and practices in the clinical service system. As a result it may be more reasonable to conclude that there is a large group of children with ASD who have poor language skills. The question then remains why are there so many children with ASD who also have poor language? There are several factors that collectively are strong candidates for answers to this question.

Impaired ability to organize information in individuals with autism spectrum disorders and their siblings

Despite rigorous research on disturbances of executive function and social cognition in autism spectrum disorders (ASD), little information has been available concerning higher cognitive functions, such as the ability to focus and associate relevant features to form categories, or 'organizing of information'. The purpose of this study was to investigate this issue by using the Wisconsin Card Sorting Test (WCST) and the Verbal Learning Task (VLT). Cognitive assessments were conducted in 22 individuals with ASD, 14 non-affected siblings, and 15 age-matched control subjects. Overall, individuals with ASD performed significantly worse on the WCST and VLT compared to their siblings and normal control subjects. Although siblings performed generally well on both tasks, they exhibited similar degree of perseverative responses in the WCST compared to the probands. A linear increase of the memory organization score in the VLT was also absent in siblings as well as the ASD group. These results suggest an impaired ability to organize information is one of the cognitive endophenotypes for ASD.