1. English MCW, Kitching ES, Maybery MT, Visser TAW. {{Modulating attentional biases of adults with autistic traits using transcranial direct current stimulation: A pilot study}}. {Autism Res}. 2017.
While neurotypical individuals over-attend to the left-side of centrally-presented visual stimuli, this bias is reduced in individuals with autism/high levels of autistic traits. Because this difference is hypothesized to reflect relative reductions in right-hemisphere activation, it follows that increasing right-hemisphere activation should increase leftward bias. We administered transcranial direct current stimulation (tDCS) over the right posterior parietal cortex to individuals with low levels (n = 19) and high levels (n = 19) of autistic traits whilst they completed a greyscales task. Anodal tDCS increased leftward bias for high-trait, but not low-trait, individuals, while cathodal tDCS had no effect. This outcome suggests that typical attentional patterns driven by hemispheric lateralization could potentially be restored following right-hemisphere stimulation in high-trait individuals. Autism Res 2017. (c) 2017 International Society for Autism Research, Wiley Periodicals, Inc. LAY SUMMARY: Attentional differences between individuals with and without autism may reflect differences in underlying activation of the left and right hemispheres. In this study, we combine an attentional task that reflects relative hemispheric activation with non-invasive cortical stimulation, and show that attentional differences between healthy individuals with low and high levels of autistic-like traits can be reduced. This outcome is encouraging, and suggests that other aspects of attention in autism (e.g., face processing) may stand to benefit from similar stimulation techniques.
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2. Esposito G, Tremolaterra MR, Savarese M, Spiniello M, Patrizio MP, Lombardo B, Pastore L, Salvatore F, Carsana A. {{Unraveling unusual X-chromosome patterns during fragile-X syndrome genetic testing}}. {Clin Chim Acta}. 2017.
BACKGROUND: Fragile X syndrome (FXS) is the most common form of inherited intellectual disability (ID). Together with fragile X-associated tremor and ataxia (FXTAS) and fragile X-associated premature ovarian failure (POF)/primary ovarian insufficiency (POI), depends on dysfunctional expression of the FMR1 gene on Xq27.3. In most cases, FXS is caused by a >200 CGG repeats in FMR1 5′-untranslated region (UTR) and by promoter hypermethylation that results in gene silencing. Males and females with unmethylated premutated alleles (repeats between 55 and 200) are at risk for FXTAS and POF/POI. METHODS: FXS molecular testing relied on PCR and methylation-specific Southern blot analysis of the FMR1 5’UTR. Atypical Southern blot patterns were studied by X-chromosome microsatellite analysis, copy number dosage at DMD locus, amelogenin gender-marker analysis and array-comparative genomic hybridization (array-CGH). RESULTS: Six men affected by ID and three women affected by ID and POF/POI underwent FXS molecular testing. They had normal FMR1 CGG repeats, but atypical X chromosome patterns. Further investigations revealed that the six males had Klinefelter syndrome (XXY), one female was a Turner mosaic (X0/XX) and two women had novel rearrangements involving X chromosome. CONCLUSIONS: Diagnostic investigation of atypical patterns at FMR1 locus can address patients and/or their relatives to further verify the condition by performing karyotyping and/or array-CGH.
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3. Fordyce TA, Leonhard MJ, Chang ET. {{A critical review of developmental exposure to particulate matter, autism spectrum disorder, and attention deficit hyperactivity disorder}}. {J Environ Sci Health A Tox Hazard Subst Environ Eng}. 2017: 1-31.
Autism spectrum disorder (ASD) and attention deficit (hyperactivity) disorder (ADD/ADHD) are key focuses of current health research due to their increasing prevalence. The objective of this systematic literature search and critical review was to evaluate whether the human epidemiologic data indicate a pattern of association between ASD or ADD/ADHD and developmental exposure to particulate matter (PM), with a focus on exposures encountered before the age of three. A MEDLINE and EMBASE search was conducted; following preliminary and full-text screening, 14 relevant articles were identified for review. Three of the 14 studies were prospective cohort studies evaluating exposure to PM10; 11 studies had a case-control design. There was no consistent association between developmental PM exposure and ASD across the three of the cohort studies. Seven of the case-control studies examined the relationship between PM2.5 and/or PM10 and ASD; four examined the relationship between developmental diesel PM exposure and ASD. Overall, there was low external consistency in results among studies of PM2.5/PM10 and ASD, with some reporting high internal consistency without significant associations, others showing associations with high internal consistency for specific exposure windows only (e.g., third trimester), and still others showing high consistency for moderate to strong associations between PM and ASD. The majority of studies reporting significant results had low effect sizes in conjunction with small sample sizes. The four studies of diesel PM and ASD also had low external consistency of results. Only one study evaluated associations with ADD/ADHD, and it found no significant associations with PM10. The inconsistent findings across studies of developmental exposure to PM and ASD may be attributed to differences in the study populations, exposure assessments, outcome assessments, or chance. Further research is needed to understand the underlying biological mechanisms that lead to ASD and ADD/ADHD and how PM might be involved in those mechanisms, if at all. High-quality epidemiologic studies are also needed to conclusively determine whether developmental PM exposure is a causal factor for ASD or ADD/ADHD, with focus on a well-developed exposure assessment.
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4. Kaushik G, Xia Y, Pfau JC, Thomas MA. {{Dysregulation of autism-associated synaptic proteins by psychoactive pharmaceuticals at environmental concentrations}}. {Neurosci Lett}. 2017; 661: 143-8.
Autism Spectrum Disorders (ASD) are complex neurological disorders for which the prevalence in the U.S. is currently estimated to be 1 in 50 children. A majority of cases of idiopathic autism in children likely result from unknown environmental triggers in genetically susceptible individuals. These triggers may include maternal exposure of a developing embryo to environmentally relevant minute concentrations of psychoactive pharmaceuticals through ineffectively purified drinking water. Previous studies in our lab examined the extent to which gene sets associated with neuronal development were up- and down-regulated (enriched) in the brains of fathead minnows treated with psychoactive pharmaceuticals at environmental concentrations. The aim of this study was to determine whether similar treatments would alter in vitro expression of ASD-associated synaptic proteins on differentiated human neuronal cells. Human SK-N-SH neuroblastoma cells were differentiated for two weeks with 10muM retinoic acid (RA) and treated with environmentally relevant concentrations of fluoxetine, carbamazepine or venlafaxine, and flow cytometry technique was used to analyze expression of ASD-associated synaptic proteins. Data showed that carbamazepine individually, venlafaxine individually and mixture treatment at environmental concentrations significantly altered the expression of key synaptic proteins (NMDAR1, PSD95, SV2A, HTR1B, HTR2C and OXTR). Data indicated that psychoactive pharmaceuticals at extremely low concentrations altered the in vitro expression of key synaptic proteins that may potentially contribute to neurological disorders like ASD by disrupting neuronal development.
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5. Marton K, Kovi Z, Egri T. {{Is interference control in children with specific language impairment similar to that of children with autistic spectrum disorder?}}. {Res Dev Disabil}. 2017; 72: 179-90.
AIMS: The purpose of the study was to examine resistance to proactive interference, which is strongly associated with working memory (WM) performance and language processing, in children with specific language impairment (SLI), with autism spectrum disorder (ASD), and with typical development (TD). METHODS: Sixty children (eight to ten years; matched in age and nonverbal IQ) participated in the study. Resistance to proactive interference was measured using a verbal conflict paradigm. RESULTS: Children with SLI and ASD show a deficit in resistance to proactive interference compared to their TD peers, but the source of the problem appears to be different for the two clinical groups. The interference problem exhibited by the children with SLI is related to a more complex deficit involving different cognitive-linguistic functions, whereas the children with ASD show a specific problem in cognitive flexibility. IMPLICATIONS: The theoretical implications are that poor resistance to interference may be caused by weaknesses in different WM functions, such as a deficit in updating or responses based on familiarity rather than recollection. The clinical implications are that children with SLI and ASD show distinct patterns of performance; therefore they need different types of intervention to strengthen their resistance to proactive interference.
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6. Naaijen J, Zwiers MP, Forde NJ, Williams SC, Durston S, Brandeis D, Glennon JC, The Tactics C, Franke B, Lythgoe DJ, Buitelaar JK. {{Striatal structure and its association with N-Acetylaspartate and glutamate in autism spectrum disorder and obsessive compulsive disorder}}. {Eur Neuropsychopharmacol}. 2017.
Autism spectrum disorders (ASD) and obsessive compulsive disorder (OCD) are often comorbid and are associated with changes in striatal volumes and N-Acetylaspartate (NAA) and glutamate levels. Here, we investigated the relation between dorsal striatal volume and NAA and glutamate levels. We additionally compared striatal volume and shape between ASD, OCD and controls. T1-weighted magnetic resonance (MR) images, proton spectra (1H-MRS) in the left striatum, and phenotypic information were collected from 54 children with ASD, 32 with OCD, and 56 controls (aged 8-13 years) in a four-site study. Dorsal striatal volume and shape were determined using the FMRIB integrated registration and segmentation tool (FIRST). Spectra were processed with Linear Combination Model. The relationship of left striatal volume with NAA and glutamate was investigated, and group comparisons were performed for NAA levels and for bilateral striatal volume and shape. NAA levels were lower in subjects with ASD compared with controls (t=2.86, p=0.005) and were associated with striatal volume (beta=0.37, t=2.78, p=0.008). Glutamate levels were also associated with volume in the ASD group (beta=0.38, t=2.46, p=0.018). No group differences were found for striatal volume or shape, but a post-hoc diagnosis-by-hemisphere interaction (F(2,129)=3.86, p=0.024) revealed greater asymmetry (right>left) in striatal volume for the disorder-groups compared with controls. Our findings show involvement of NAA and glutamate in striatal volume in ASD and suggest greater asymmetry in paediatric ASD and OCD compared with controls, pointing to overlapping subcortical abnormalities. The lower NAA in ASD reflects reduced neuronal integrity or impaired neuronal functioning.
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7. Odom SL, Cox A, Sideris J, Hume KA, Hedges S, Kucharczyk S, Shaw E, Boyd BA, Reszka S, Neitzel J. {{Assessing Quality of Program Environments for Children and Youth with Autism: Autism Program Environment Rating Scale (APERS)}}. {J Autism Dev Disord}. 2017.
The purpose of this study was to examine the psychometric properties of the Autism Program Environment Rating Scale (APERS), an instrument designed to assess quality of program environments for students with autism spectrum disorder. Data sets from two samples of public school programs that provided services to children and youth with autism spectrum disorder were utilized. Cronbach alpha analyses indicated high coefficients of internal consistency for the total APERS and moderate levels for item domains for the first data set, which was replicated with the second data set. A factor analysis of the first data set indicated that all domain scores loaded on one main factor, in alignment with the conceptual model, with this finding being replicated in the second data set. Also, the APERS was sensitive to changes resulting from a professional development program designed to promote program quality.
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8. Orlando M. {{Double Voicing and Personhood in Collaborative Life Writing about Autism: the Transformative Narrative of Carly’s Voice}}. {J Med Humanit}. 2017.
Collaborative memoirs by co-writers with and without autism can enable the productive interaction of the voices of the writers in ways that can empower rather than exploit the disabled subject. Carly’s Voice, co-written by Arthur Fleischmann and his autistic daughter Carly, demonstrates the capacity for such life narratives to facilitate the relational interaction between writers in the negotiation of understandings of disability. Though the text begins by focusing on the limitations of life with autism, it develops into a collaboration which helps both writers move toward new ways of understanding disability and their own and one another’s life stories.
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9. Rubenstein E, Schieve L, Bradley C, DiGuiseppi C, Moody E, Thomas K, Daniels J. {{The prevalence of gluten free diet use among preschool children with autism spectrum disorder}}. {Autism Res}. 2017.
Our objective was to estimate prevalence of current or ever use of a gluten free diet (GFD) in children aged 30-68 months with autism spectrum disorder (ASD) and population controls (POP); and to identify characteristics associated with ever having used GFD among children with ASD. We used data from the Study to Explore Early Development (SEED), a multi-site, case-control study of children with ASD. Caregivers reported GFD use by their children through structured questionnaires about diet patterns, gastrointestinal (GI) issues, and ASD-specific treatments. Prevalence was estimated and compared using log-Poisson regression, adjusting for confounders. In children with ASD, we examined whether child or mother’s GI conditions or child’s phenotypic traits were associated with ever trying a GFD. In SEED, 71 children with ASD (11.1% prevalence after adjustment) were on a GFD at time of the study and 130 (20.4%) had ever used a GFD, a greater percentage than in POP children (N = 11, 0.9% current use). Of current users with ASD, 50.7% had a dietary intervention that was prescribed by a medical professional. Among children with ASD, child GI conditions and developmental regression were positively and independently associated with having ever used a GFD. Current use and ever use of a GFD were prevalent in children with ASD identified in SEED. GFD usage was associated with GI issues and child phenotype. Clinicians may consider advising parents on how best to use these diets in the context of the child’s GI presentation and current scientific knowledge about effectiveness in relation to ASD symptoms. Autism Res 2017. (c) 2017 International Society for Autism Research, Wiley Periodicals, Inc. LAY SUMMARY: Gluten free diets (GFDs) are commonly used as an alternative therapy for autism spectrum disorder (ASD); however, the effectiveness is still uncertain which makes it important to know who tries this type of diet. We found that one in five preschool aged children with ASD had ever used a GFD. Children with gastrointestinal conditions and developmental regression were more likely to have tried a GFD.
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10. Zhang Y, Liu Y, Zarrei M, Tong W, Dong R, Wang Y, Zhang H, Yang X, MacDonald JR, Uddin M, Scherer SW, Gai Z. {{Association of IMMP2L deletions with autism spectrum disorder: A trio family study and meta-analysis}}. {Am J Med Genet B Neuropsychiatr Genet}. 2017.
IMMP2L, the gene encoding the inner mitochondrial membrane peptidase subunit 2-like protein, has been reported as a candidate gene for Tourette syndrome, autism spectrum disorder (ASD) and additional neurodevelopmental disorders. Here we genotyped 100 trio families with an index proband with autism spectrum disorder in Han Chinese population and found three cases with rare exonic IMMP2L deletions. We have conducted a comprehensive meta-analysis to quantify the association of IMMP2L deletions with ASD using 5,568 cases and 10,279 controls. While the IMMP2L deletions carried non-recurrent breakpoints, in contrast to previous reports, our meta-analysis found no evidence of association (P > 0.05) between IMMP2L deletions and ASD. We also observed common exonic deletions impacting IMMP2L in a separate control (5,971 samples) cohort where subjects were screened for psychiatric conditions. This is the first systematic review and meta-analysis regarding the effect of IMMP2L deletions on ASD, but further investigations in different populations, especially Chinese population may be still needed to confirm our results.
