1. Alsaeed I, Al-Somali F, Sakhnini L, Aljarallah OS, Hamdan RM, Bubishate SA, Sarfaraz ZK, Kamal A. {{Autism-relevant social abnormalities in mice exposed perinatally to extremely low frequency electromagnetic fields}}. {Int J Dev Neurosci};2014 (Jun 23)
The incidence of autism spectrum disorders (ASD) has been rising, but the causes of ASD remain largely unidentified. Collective data have implicated the increased human exposure to electromagnetic fields (EMF) in the increasing incidence of ASD. There are established biological effects of extremely low-frequency (ELF) EMF, but the relation to ASD is not investigated enough. In this study we examined the effects of perinatal exposure to ELF EMF on some ASD-relevant behavioral parameters in mice. The EMF was delivered via a Helmholtz coil pair. Male BALB/C mice were used and divided into exposed and control groups (n=8 and n=9, respectively). Tests were used to assess sociability, preference for social novelty, locomotion, anxiety, exploratory behavior, motor coordination, and olfaction. The examined mice were all males and exposed to EMF during the last week of gestation and for 7 days after delivery. The exposed mice demonstrated a lack of normal sociability and preference for social novelty while maintaining normal anxiety-like behavior, locomotion, motor coordination, and olfaction. Exposed mice also demonstrated decreased exploratory activity. We concluded that these results are supportive of the hypothesis of a causal link between exposure to ELF-EMF and ASD; however, replications of the study with further tests are recommended.
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2. Bruno JL, Garrett AS, Quintin EM, Mazaika PK, Reiss AL. {{Aberrant Face and Gaze Habituation in Fragile X Syndrome}}. {Am J Psychiatry};2014 (Jun 27)
Objective: The authors sought to investigate neural system habituation to face and eye gaze in fragile X syndrome, a disorder characterized by eye-gaze aversion, among other social and cognitive deficits. Method: Participants (ages 15-25 years) were 30 individuals with fragile X syndrome (females, N=14) and a comparison group of 25 individuals without fragile X syndrome (females, N=12) matched for general cognitive ability and autism symptoms. Functional MRI (fMRI) was used to assess brain activation during a gaze habituation task. Participants viewed repeated presentations of four unique faces with either direct or averted eye gaze and judged the direction of eye gaze. Results: Four participants (males, N=4/4; fragile X syndrome, N=3) were excluded because of excessive head motion during fMRI scanning. Behavioral performance did not differ between the groups. Less neural habituation (and significant sensitization) in the fragile X syndrome group was found in the cingulate gyrus, fusiform gyrus, and frontal cortex in response to all faces (direct and averted gaze). Left fusiform habituation in female participants was directly correlated with higher, more typical levels of the fragile X mental retardation protein and inversely correlated with autism symptoms. There was no evidence for differential habituation to direct gaze compared with averted gaze within or between groups. Conclusions: Impaired habituation and accentuated sensitization in response to face/eye gaze was distributed across multiple levels of neural processing. These results could help inform interventions, such as desensitization therapy, which may help patients with fragile X syndrome modulate anxiety and arousal associated with eye gaze, thereby improving social functioning.
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3. Germani T, Zwaigenbaum L, Bryson S, Brian J, Smith I, Roberts W, Szatmari P, Roncadin C, Sacrey LA, Garon N, Vaillancourt T. {{Brief Report: Assessment of Early Sensory Processing in Infants at High-Risk of Autism Spectrum Disorder}}. {J Autism Dev Disord};2014 (Jun 27)
This study assessed sensory processing differences between 24-month infants at high-risk of autism spectrum disorder (ASD), each with an older sibling with ASD, and low-risk infants with no family history of ASD. Sensory processing differences were assessed using the Infant/Toddler Sensory Profile, a parent-reported measure. Groups were compared based on 3-year outcomes: (a) high-risk infants subsequently diagnosed with ASD; (b) high-risk infants without an ASD diagnosis; and (c) low-risk infants without an ASD diagnosis. Analyses showed that high-risk infants diagnosed with ASD have more difficulty with auditory processing (i.e., responses to auditory stimuli) and lower registration (i.e., lacking sensation awareness) compared to controls. Thus, behavioral responses to sensory input represent early risk markers of ASD, particularly in high-risk infants.
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4. Granader Y, Wallace GL, Hardy KK, Yerys BE, Lawson RA, Rosenthal M, Wills MC, Dixon E, Pandey J, Penna R, Schultz RT, Kenworthy L. {{Characterizing the Factor Structure of Parent Reported Executive Function in Autism Spectrum Disorders: The Impact of Cognitive Inflexibility}}. {J Autism Dev Disord};2014 (Jun 28)
Parents of children with autism spectrum disorders (ASD) consistently report executive functioning (EF) deficits. This study investigates the factor structure of the Behavior Rating Inventory of Executive Function (BRIEF) as reported by parents of children with ASD and typically developing children (TDC). BRIEFs for 411 children with ASD and 467 TDC were examined. Confirmatory factor analysis of a nine-factor model met thresholds for goodness-of-fit in TDC, but not in the ASD sample. We found globally elevated EF problems in the ASD sample, especially on the Shift scale. These findings confirm that children with ASD exhibit significant EF deficits. Further investigation is needed to understand the pervasive nature of cognitive inflexibility in children with ASD.
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5. Heckman LD, Chahrour MH, Zoghbi HY. {{Rett-causing mutations reveal two domains critical for MeCP2 function and for toxicity in MECP2 duplication syndrome mice}}. {Elife};2014 (Jun 26):e02676.
Loss of function of the X-linked gene encoding methyl-CpG binding protein 2 (MeCP2) causes the progressive neurological disorder Rett syndrome (RTT). Conversely, duplication or triplication of Xq28 causes an equally wide-ranging progressive neurological disorder, MECP2 duplication syndrome, whose features overlap somewhat with RTT. To understand which MeCP2 functions cause toxicity in the duplication syndrome, we generated mouse models expressing endogenous Mecp2 along with a RTT-causing mutation in either the methyl-CpG binding domain (MBD) or the transcriptional repression domain (TRD). We determined that both the MBD and TRD must function for doubling MeCP2 to be toxic. Mutating the MBD reproduces the null phenotype and expressing the TRD mutant produces milder RTT phenotypes, yet both mutations are harmless when expressed with endogenous Mecp2. Surprisingly, mutating the TRD is more detrimental than deleting the entire C-terminus, indicating a dominant-negative effect on MeCP2 function, likely due to the disruption of a basic cluster.
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6. Koelkebeck K, Riedel A, Ohrmann P, Biscaldi M, Tebartz van Elst L. {{[High-functioning autism spectrum disorders in adulthood.]}}. {Nervenarzt};2014 (Jun 27)
The prevalence of autism spectrum disorders in the general population is approximately 1 %. Some individuals with high-functioning autism graduate from regular schools without autism having been diagnosed and problems only occur when the demands for social competence increase. Then patients often present with secondary psychiatric symptoms, such as depression, anxiety or interpersonal problems. At this time, typical autistic features, such as social interaction deficits, restricted interests and stereotypic behavior can be camouflaged by high compensatory skills, particularly in highly intelligent patients. Therefore, missed or wrong diagnoses are frequent. Interviews, questionnaires and neuropsychological tests might be used to support the diagnosis. In cases where there is evidence for a secondary cause of autistic symptoms, somatic disorders should be excluded. Pharmacological treatment should be symptom-oriented. Individualized psychotherapeutic approaches are becoming increasingly more available; however, pragmatic solutions often need to be deployed.
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7. Plumet MH, Veneziano E. {{Typical and Atypical Pragmatic Functioning of ASD Children and Their Partners: A Study of Oppositional Episodes in Everyday Interactions}}. {J Autism Dev Disord};2014 (Jun 27)
Pragmatic functioning of autism spectrum disorder (ASD) children is rarely examined in socially-meaningful contexts. This study investigates the way oppositional episodes are handled in such contexts by 25 families, 10 with ASD and 15 with typically-developing children. Oppositions occur whenever someone protests, refuses or denies someone else’s action, request or statement. The analysis focuses on justifications accounting for the opposition and on their immediate persuasive effect. Analyses of 1,065 oppositional episodes show no differences in justifications among partners and children, except for ASD children with a verbal age 3-4 years, who justify less than their matched controls. The persuasive effect of justifications on children and on partners differs according to their group and verbal age. Implications of the study and future perspectives are discussed.
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8. Poslawsky IE, Naber FB, Bakermans-Kranenburg MJ, De Jonge MV, Van Engeland H, Van IMH. {{Development of a Video-feedback Intervention to promote Positive Parenting for Children with Autism (VIPP-AUTI)}}. {Attach Hum Dev};2014 (Aug);16(4):343-355.
In this paper we describe the development and content of Video-feedback Intervention to promote Positive Parenting for Children with Autism (VIPP-AUTI). VIPP-AUTI is an adapted version of the evidence-based intervention VIPP. The lack of social responsiveness in children with autism often lowers the quality of the parent-child interaction. A wide range of early interventions exist to cope with the disorder. The majority of early interventions for children with autism focus on their deficits of (social) skills, but the number of evidence-based interventions to improve early parent-child interaction patterns is limited. The aim of VIPP-AUTI is to enhance parental sensitivity to children’s autistic characteristics, in order to improve child developmental outcome by increased parental support.
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9. Risch N, Hoffmann TJ, Anderson M, Croen LA, Grether JK, Windham GC. {{Familial Recurrence of Autism Spectrum Disorder: Evaluating Genetic and Environmental Contributions}}. {Am J Psychiatry};2014 (Jun 27)
Objective: This study was designed to examine the pattern of familial recurrence of autism spectrum disorder (ASD) in terms of genetic and environmental contributions related to timing of birth. Method: The authors linked California Department of Developmental Services records with state birth certificates to identify all siblings and half siblings of individuals affected with ASD born between 1990 and 2003. A total of 6,616 full siblings, 644 maternal half siblings, and 299 paternal half siblings born after ASD index cases were used to calculate recurrence risks. Control families, identified through matching to cases, were included for comparison (a total of 29,384 siblings). Results: The overall sibling recurrence risk was 10.1%, compared with a prevalence of 0.52% in siblings of controls. The recurrence risk in second-born children was higher (11.5%) than in later-born siblings (7.3%); a similar pattern was observed for maternal half siblings (6.5% for second-born compared with 3.0% for later-born siblings; 4.8% overall). The recurrence risk was significantly higher for siblings who immediately followed the index case in birth order compared with those later in birth order. The recurrence risk for paternal half siblings (2.3%) was half the overall recurrence risk for maternal half siblings but was similar to that for later-born maternal half siblings. An exponential effect of short interbirth interval was observed, with the recurrence risk reaching 14.4% for an interbirth interval of 18 months or less, compared with 6.8% for an interval of 4 years or more. An identical phenomenon was observed in maternal half siblings. Conclusions: The results support genetic susceptibility in the familial recurrence of ASD along with factors related to timing of birth.
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10. Schaaf RC, Case-Smith J. {{Sensory interventions for children with autism}}. {J Comp Eff Res};2014 (May);3(3):225-227.