1. Ben-Yosef D, Anaki D, Golan O. {{Context processing in adolescents with autism spectrum disorder: How complex could it be?}}. {Autism Res};2016 (Aug 3)
The ability of individuals with Autism Spectrum Disorder (ASD) to process context has long been debated: According to the Weak Central Coherence theory, ASD is characterized by poor global processing, and consequently-poor context processing. In contrast, the Social Cognition theory argues individuals with ASD will present difficulties only in social context processing. The complexity theory of autism suggests context processing in ASD will depend on task complexity. The current study examined this controversy through two priming tasks, one presenting human stimuli (facial expressions) and the other presenting non-human stimuli (animal faces). Both tasks presented visual targets, preceded by congruent, incongruent, or neutral auditory primes. Local and global processing were examined by presenting the visual targets in three spatial frequency conditions: High frequency, low frequency, and broadband. Tasks were administered to 16 adolescents with high functioning ASD and 16 matched typically developing adolescents. Reaction time and accuracy were measured for each task in each condition. Results indicated that individuals with ASD processed context for both human and non-human stimuli, except in one condition, in which human stimuli had to be processed globally (i.e., target presented in low frequency). The task demands presented in this condition, and the performance deficit shown in the ASD group as a result, could be understood in terms of cognitive overload. These findings provide support for the complexity theory of autism and extend it. Our results also demonstrate how associative priming could support intact context processing of human and non-human stimuli in individuals with ASD. Autism Res 2016. (c) 2016 International Society for Autism Research, Wiley Periodicals, Inc.
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2. Chiocchetti AG, Haslinger D, Stein JL, de la Torre-Ubieta L, Cocchi E, Rothamel T, Lindlar S, Waltes R, Fulda S, Geschwind DH, Freitag CM. {{Transcriptomic signatures of neuronal differentiation and their association with risk genes for autism spectrum and related neuropsychiatric disorders}}. {Transl Psychiatry};2016;6(8):e864.
Genes for autism spectrum disorders (ASDs) are also implicated in fragile X syndrome (FXS), intellectual disabilities (ID) or schizophrenia (SCZ), and converge on neuronal function and differentiation. The SH-SY5Y neuroblastoma cell line, the most widely used system to study neurodevelopment, is currently discussed for its applicability to model cortical development. We implemented an optimal neuronal differentiation protocol of this system and evaluated neurodevelopment at the transcriptomic level using the CoNTeXT framework, a machine-learning algorithm based on human post-mortem brain data estimating developmental stage and regional identity of transcriptomic signatures. Our improved model in contrast to currently used SH-SY5Y models does capture early neurodevelopmental processes with high fidelity. We applied regression modelling, dynamic time warping analysis, parallel independent component analysis and weighted gene co-expression network analysis to identify activated gene sets and networks. Finally, we tested and compared these sets for enrichment of risk genes for neuropsychiatric disorders. We confirm a significant overlap of genes implicated in ASD with FXS, ID and SCZ. However, counterintuitive to this observation, we report that risk genes affect pathways specific for each disorder during early neurodevelopment. Genes implicated in ASD, ID, FXS and SCZ were enriched among the positive regulators, but only ID-implicated genes were also negative regulators of neuronal differentiation. ASD and ID genes were involved in dendritic branching modules, but only ASD risk genes were implicated in histone modification or axonal guidance. Only ID genes were over-represented among cell cycle modules. We conclude that the underlying signatures are disorder-specific and that the shared genetic architecture results in overlaps across disorders such as ID in ASD. Thus, adding developmental network context to genetic analyses will aid differentiating the pathophysiology of neuropsychiatric disorders.
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3. Denman K, Smart C, Dallos R, Levett P. {{How Families Make Sense of Their Child’s Behaviour When on an Autism Assessment and Diagnosis Waiting List}}. {J Autism Dev Disord};2016 (Aug 1)
Families waiting for an Autism Spectrum Condition assessment often experience difficulties explaining, or making sense of, the referred young person’s behaviour. Little is known about this sense making, or how clinicians might support this ambiguity. This paper explored finite details of how five families do ‘sense-making’ in conversations with each other, while on the waiting list for an ASC assessment. A Discursive Psychology analysis of these conversations found that sense making was affected by (1) an interactional pattern of interruptions impeding the progress of sense making narratives; (2) face saving to maintain positive identities and shared understanding; and (3) difficulties in word finding within sense making narratives. These practices challenged the production of a coherent family sense making narrative.
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4. Domingues VF, Nasuti C, Piangerelli M, Correia-Sa L, Ghezzo A, Marini M, Abruzzo PM, Visconti P, Giustozzi M, Rossi G, Gabbianelli R. {{Pyrethroid Pesticide Metabolite in Urine and Microelements in Hair of Children Affected by Autism Spectrum Disorders: A Preliminary Investigation}}. {Int J Environ Res Public Health};2016 (Apr);13(4):388.
The number of children affected by Autism Spectrum Disorders (ASD) is dramatically increasing as well as the studies aimed at understanding the risk factors associated with the development of ASD. Since the etiology of ASD is partly genetic and partly environmental, factors (i.e., heavy metals, pesticides) as well as lifestyle seem to have a key role in the development of the disease. ASD and Control (CTR) children, aged 5-12 years, were compared. Gas chromatography coupled with trap mass detector was used to measure the level of 3-PBA, the main pyrethroid metabolite in urine in a group of ASD patients, while optical emission spectrometry analysis was employed to estimate the level of metals and microelements in hair in a different group of ASD children. The presence of 3-PBA in urine seems to be independent of age in ASD children, while a positive correlation between 3-PBA and age was observed in the control group of the same age range. Urine concentration of 3-BPA in ASD children had higher values than in the control group, which were marginally significant (p = 0.054). Mg results were significantly decreased in ASD with respect to controls, while V, S, Zn, and Ca/Mg were marginally increased, without reaching statistical significance. Results of Principal Component (PC) analysis of metals and microelements in hair were not associated with either age or health status. In conclusion, 3-PBA in urine and Mg in hair were changed in ASD children relative to control ones.
5. Hamada N, Ito H, Nishijo T, Iwamoto I, Morishita R, Tabata H, Momiyama T, Nagata K. {{Essential role of the nuclear isoform of RBFOX1, a candidate gene for autism spectrum disorders, in the brain development}}. {Sci Rep};2016;6:30805.
Gene abnormalities in RBFOX1, encoding an mRNA-splicing factor, have been shown to cause autism spectrum disorder and other neurodevelopmental disorders. Since pathophysiological significance of the dominant nuclear isoform in neurons, RBFOX1-isoform1 (iso1), remains to be elucidated, we performed comprehensive analyses of Rbfox1-iso1 during mouse corticogenesis. Knockdown of Rbfox1-iso1 by in utero electroporation caused abnormal neuronal positioning during corticogenesis, which was attributed to impaired migration. The defects were found to occur during radial migration and terminal translocation, perhaps due to impaired nucleokinesis. Axon extension and dendritic arborization were also suppressed in vivo in Rbfox1-iso1-deficient cortical neurons. In addition, electrophysiology experiments revealed significant defects in the membrane and synaptic properties of the deficient neurons. Aberrant morphology was further confirmed by in vitro analyses; Rbfox1-iso1-konckdown in hippocampal neurons resulted in the reduction of primary axon length, total length of dendrites, spine density and mature spine number. Taken together, this study shows that Rbfox1-iso1 plays an important role in neuronal migration and synapse network formation during corticogenesis. Defects in these critical processes may induce structural and functional defects in cortical neurons, and consequently contribute to the pathophysiology of neurodevelopmental disorders with RBFOX1 abnormalities.
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6. Hoogenhout M, Malcolm-Smith S. {{Theory of mind predicts severity level in autism}}. {Autism};2016 (Aug 3)
We investigated whether theory of mind skills can indicate autism spectrum disorder severity. In all, 62 children with autism spectrum disorder completed a developmentally sensitive theory of mind battery. We used intelligence quotient, Diagnostic and Statistical Manual of Mental Disorders (4th ed.) diagnosis and level of support needed as indicators of severity level. Using hierarchical cluster analysis, we found three distinct clusters of theory of mind ability: early-developing theory of mind (Cluster 1), false-belief reasoning (Cluster 2) and sophisticated theory of mind understanding (Cluster 3). The clusters corresponded to severe, moderate and mild autism spectrum disorder. As an indicator of level of support needed, cluster grouping predicted the type of school children attended. All Cluster 1 children attended autism-specific schools; Cluster 2 was divided between autism-specific and special needs schools and nearly all Cluster 3 children attended general special needs and mainstream schools. Assessing theory of mind skills can reliably discriminate severity levels within autism spectrum disorder.
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7. Newschaffer CJ, Schriver E, Berrigan L, Landa R, Stone WL, Bishop S, Burkom D, Golden A, Ibanez L, Kuo A, Lakes KD, Messinger DS, Paterson S, Warren ZE. {{Development and validation of a streamlined autism case confirmation approach for use in epidemiologic risk factor research in prospective cohorts}}. {Autism Res};2016 (Aug 3)
The cost associated with incorporating standardized observational assessments and diagnostic interviews in large-scale epidemiologic studies of autism spectrum disorders (ASD) risk factors can be substantial. Streamlined approaches for confirming ASD case status would benefit these studies. We conducted a multi-site, cross-sectional criterion validity study in a convenience sample of 382 three-year olds scheduled for neurodevelopmental evaluation. ASD case classification as determined by three novel assessment instruments (the Early Video-guided Autism Screener E-VAS; the Autism Symptom Interview, ASI; the Screening Tool for Autism in Toddlers Expanded, STAT-E) each designed to be administered in less than 30 minutes by lay staff, was compared to ADOS scores and DSM-based diagnostic assessment from a qualified clinician. Sensitivity and specificity of each instrument alone and in combination were estimated. Alternative cutpoints were identified under different criteria and two-stage cross validation was used to avoid overfitting. Findings were interpreted in the context of a large, prospective pregnancy cohort study utilizing a two-stage approach to case identification. Under initial cutpoints, sensitivity ranged from 0.63 to 0.92 and specificity from 0.35 to 0.70. Cutpoints giving equal weight to sensitivity and specificity resulted in sensitivity estimates ranging from 0.45 to 0.83 and specificity ranging from 0.49 to 0.86. Several strategies were well-suited for application as a second-stage case-confirmation. These included the STAT-E alone and the parallel administration of both the E-VAS and the ASI. Use of more streamlined methods of case-confirmation in large-scale prospective cohort epidemiologic investigations of ASD risk factors appears feasible. Autism Res 2016. (c) 2016 International Society for Autism Research, Wiley Periodicals, Inc.
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8. Park HJ, Kim SK, Kang WS, Park JK, Kim YJ, Nam M, Kim JW, Chung JH. {{Association between IRS1 Gene Polymorphism and Autism Spectrum Disorder: A Pilot Case-Control Study in Korean Males}}. {Int J Mol Sci};2016;17(8)
The insulin-like growth factor (IGF) pathway is thought to play an important role in brain development. Altered levels of IGFs and their signaling regulators have been shown in autism spectrum disorder (ASD) patients. In this study, we investigated whether coding region single-nucleotide polymorphisms (cSNPs) of the insulin receptor substrates (IRS1 and IRS2), key mediators of the IGF pathway, were associated with ASD in Korean males. Two cSNPs (rs1801123 of IRS1, and rs4773092 of IRS2) were genotyped using direct sequencing in 180 male ASD patients and 147 male control subjects. A significant association between rs1801123 of IRS1 and ASD was shown in additive (p = 0.022, odds ratio (OR) = 0.66, 95% confidence interval (CI) = 0.46-0.95) and dominant models (p = 0.013, OR = 0.57, 95% CI = 0.37-0.89). Allele frequency analysis also showed an association between rs1801123 and ASD (p = 0.022, OR = 0.66, 95% CI = 0.46-0.94). These results suggest that IRS1 may contribute to the susceptibility of ASD in Korean males.
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9. Watanabe T, Rees G. {{Anatomical imbalance between cortical networks in autism}}. {Sci Rep};2016;6:31114.
Influential psychological models of autism spectrum disorder (ASD) have proposed that this prevalent developmental disorder results from impairment of global (integrative) information processing and overload of local (sensory) information. However, little neuroanatomical evidence consistent with this account has been reported. Here, we examined relative grey matter volumes (rGMVs) between three cortical networks, how they changed with age, and their relationship with core symptomatology. Using public neuroimaging data of high-functioning ASD males and age-/sex-/IQ-matched controls, we first identified age-associated atypical increases in rGMVs of the regions of two sensory systems (auditory and visual networks), and an age-related aberrant decrease in rGMV of a task-control system (fronto-parietal network, FPN) in ASD children. While the enlarged rGMV of the auditory network in ASD adults was associated with the severity of autistic socio-communicational core symptom, that of the visual network was instead correlated with the severity of restricted and repetitive behaviours in ASD. Notably, the atypically decreased rGMV of FPN predicted both of the two core symptoms. These findings suggest that disproportionate undergrowth of a task-control system (FPN) may be a common anatomical basis for the two ASD core symptoms, and relative overgrowth of the two different sensory systems selectively compounds the distinct symptoms.
