1. Abu-Akel AM, Wood SJ, Hansen PC, Apperly IA. {{Perspective-taking abilities in the balance between autism tendencies and psychosis proneness}}. {Proc Biol Sci};2015 (Jun 7);282(1808)
Difficulties with the ability to appreciate the perspective of others (mentalizing) is central to both autism and schizophrenia spectrum disorders. While the disorders are diagnostically independent, they can co-occur in the same individual. The effect of such co-morbidity is hypothesized to worsen mentalizing abilities. The recent influential ‘diametric brain theory’, however, suggests that the disorders are etiologically and phenotypically diametrical, predicting opposing effects on one’s mentalizing abilities. To test these contrasting hypotheses, we evaluated the effect of psychosis and autism tendencies on the perspective-taking (PT) abilities of 201 neurotypical adults, on the assumption that autism tendencies and psychosis proneness are heritable dimensions of normal variation. We show that while both autism tendencies and psychosis proneness induce PT errors, their interaction reduced these errors. Our study is, to our knowledge, the first to observe that co-occurring autistic and psychotic traits can exert opposing influences on performance, producing a normalizing effect possibly by way of their diametrical effects on socio-cognitive abilities. This advances the notion that some individuals may, to some extent, be buffered against developing either illness or present fewer symptoms owing to a balanced expression of autistic and psychosis liability.
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2. Ambridge B, Bannard C, Jackson GH. {{Is Grammar Spared in Autism Spectrum Disorder? Data from Judgments of Verb Argument Structure Overgeneralization Errors}}. {J Autism Dev Disord};2015 (Jun 6)
Children with Autism Spectrum Disorder (ASD) aged 11-13 (N = 16) and an IQ-matched typically developing (TD) group aged 7-12 (N = 16) completed a graded grammaticality judgment task, as well as a standardized test of cognitive function. In a departure from previous studies, the judgment task involved verb argument structure overgeneralization errors (e.g., *Lisa fell the cup off the shelf) of the type sometimes observed amongst typically developing children, as well as grammatical control sentences with the same verbs (e.g., The cup fell off the shelf). The ASD group showed a smaller dispreference for ungrammatical sentences (relative to the control sentences) than did the TD group. These findings are indicative of a subtle grammatical impairment in even relatively high-functioning children with ASD.
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3. Borreca A, Gironi K, Amadoro G, Ammassari-Teule M. {{Opposite Dysregulation of Fragile-X Mental Retardation Protein and Heteronuclear Ribonucleoprotein C Protein Associates with Enhanced APP Translation in Alzheimer Disease}}. {Mol Neurobiol};2015 (Jun 6)
Amyloid precursor protein (APP) is overexpressed in familiar and sporadic Alzheimer Disease (AD) patients suggesting that, in addition to abnormalities in APP cleavage, enhanced levels of APP full length might contribute to the pathology. Based on data showing that the two RNA binding proteins (RBPs), Fragile-X Mental Retardation Protein (FMRP) and heteronuclear Ribonucleoprotein C (hnRNP C), exert an opposite control on APP translation, we have analyzed whether expression and translation of these two RBPs vary in relation to changes in APP protein and mRNA levels in the AD brain at 1, 3, and 6 months of age. Here, we show that, as expected, human APP is overexpressed in hippocampal total extract from Tg2576 mice at all age points. APP overexpression, however, is not stable over time but reaches its maximal level in 1-month-old mutants in association with the stronger (i) reduction of FMRP and (ii) augmentation of hnRNP C. APP levels then decrease progressively as a function of age in close relationship with the gradual normalization of FMRP and hnRNP C levels. Consistent with the mouse data, expression of FMRP and hnRNP C are, respectively, decreased and increased in hippocampal synaptosomes from sporadic AD patients. Our findings identify two RBP targets that might be manipulated for reducing abnormally elevated levels of APP in the AD brain, with the hypothesis that acting upstream of amyloidogenic processing might contribute to attenuate the amyloid burden.
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4. Chi OZ, Wu CC, Liu X, Rah KH, Jacinto E, Weiss HR. {{Restoration of Normal Cerebral Oxygen Consumption with Rapamycin Treatment in a Rat Model of Autism-Tuberous Sclerosis}}. {Neuromolecular Med};2015 (Jun 6)
Tuberous sclerosis (TSC) is associated with autism spectrum disorders and has been linked to metabolic dysfunction and unrestrained signaling of the mammalian target of rapamycin (mTOR). Inhibition of mTOR by rapamycin can mitigate some of the phenotypic abnormalities associated with TSC and autism, but whether this is due to the mTOR-related function in energy metabolism remains to be elucidated. In young Eker rats, an animal model of TSC and autism, which harbors a germ line heterozygous Tsc2 mutation, we previously reported that cerebral oxygen consumption was pronouncedly elevated. Young (4 weeks) male control Long-Evans and Eker rats were divided into control and rapamycin-treated (20 mg/kg once daily for 2 days) animals. Cerebral regional blood flow (14C-iodoantipyrine) and O2 consumption (cryomicrospectrophotometry) were determined in isoflurane-anesthetized rats. We found significantly increased basal O2 consumption in the cortex (8.7 +/- 1.5 ml O2/min/100 g Eker vs. 2.7 +/- 0.2 control), hippocampus, pons and cerebellum. Regional cerebral blood flow and cerebral O2 extractions were also elevated in all brain regions. Rapamycin had no significant effect on O2 consumption in any brain region of the control rats, but significantly reduced consumption in the cortex (4.1 +/- 0.3) and all other examined regions of the Eker rats. Phosphorylation of mTOR and S6K1 was similar in the two groups and equally reduced by rapamycin. Thus, a rapamycin-sensitive, mTOR-dependent but S6K1-independent, signal led to enhanced oxidative metabolism in the Eker brain. We found decreased Akt phosphorylation in Eker but not Long-Evans rat brains, suggesting that this may be related to the increased cerebral O2 consumption in the Eker rat. Our findings suggest that rapamycin targeting of Akt to restore normal cerebral metabolism could have therapeutic potential in tuberous sclerosis and autism.
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5. Ginevra MC, Nota L, Stokes MA. {{The differential effects of Autism and Down’s syndrome on sexual behavior}}. {Autism Res};2015 (Jun 7)
Although sexuality plays a major role in the socialization of people, few studies have examined the sexual behaviors of individuals with developmental disabilities. Because of this, we decided to investigate sexuality in adolescents with autism spectrum disorder (ASD) and Down’s syndrome (Ds) and to compare them with typically developing adolescents, by surveying their parents. Specifically, it was hypothesized that young people with ASD would display lower levels over five domains: social behavior, privacy, sex education, sexual behavior, and parental concerns, than peers with Ds and typically developing young people. In addition, we sought to verify developmental trends in five domains with age for each group. Overall, 269 parents participated; 94 parents of typically developing adolescents, 93 parents of adolescents diagnosed with Ds, and 82 parents of adolescents diagnosed with ASD. Participants were surveyed with a Sexual Behavior Scale developed by Stokes and Kaur [] that assesses parents’ reports of their child’s: social behavior, privacy awareness, sex education, sexual behavior and parental concerns about the child’s behaviors. It was found that three groups were significantly different on all five domains, adolescents with ASD reportedly displaying lower levels than other groups. Moreover, there was a significant improvement in knowledge of privacy and parental concerns with age for adolescents with ASD and a decline in sex education for adolescents with Ds. The results obtained emphasize the need to train adolescents with developmental disability, and especially for adolescents with ASD through sex education programs. Autism Res 2015. (c) 2015 International Society for Autism Research, Wiley Periodicals, Inc.
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6. Kaiser MD, Yang DY, Voos AC, Bennett RH, Gordon I, Pretzsch C, Beam D, Keifer C, Eilbott J, McGlone F, Pelphrey KA. {{Brain Mechanisms for Processing Affective (and Nonaffective) Touch Are Atypical in Autism}}. {Cereb Cortex};2015 (Jun 5)
C-tactile (CT) afferents encode caress-like touch that supports social-emotional development, and stimulation of the CT system engages the insula and cortical circuitry involved in social-emotional processing. Very few neuroimaging studies have investigated the neural mechanisms of touch processing in people with autism spectrum disorder (ASD), who often exhibit atypical responses to touch. Using functional magnetic resonance imaging, we evaluated the hypothesis that children and adolescents with ASD would exhibit atypical brain responses to CT-targeted touch. Children and adolescents with ASD, relative to typically developing (TD) participants, exhibited reduced activity in response to CT-targeted (arm) versus non-CT-targeted (palm) touch in a network of brain regions known to be involved in social-emotional information processing including bilateral insula and insular operculum, the right posterior superior temporal sulcus, bilateral temporoparietal junction extending into the inferior parietal lobule, right fusiform gyrus, right amygdala, and bilateral ventrolateral prefrontal cortex including the inferior frontal and precentral gyri, suggesting atypical social brain hypoactivation. Individuals with ASD (vs. TD) showed an enhanced response to non-CT-targeted versus CT-targeted touch in the primary somatosensory cortex, suggesting atypical sensory cortical hyper-reactivity.
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7. Kiykim E, Zeybek CA, Zubarioglu T, Cansever S, Yalcinkaya C, Soyucen E, Aydin A. {{Inherited metabolic disorders in Turkish patients with autism spectrum disorders}}. {Autism Res};2015 (Jun 7)
Autism spectrum disorders (ASDs) are a major health problem because of their high prevalence in the general population. The pathophysiology of ASD remains unclear, although genetic defects may be detected in 10-20% of affected patients. Among these cases, the prevalence of inherited metabolic disorders (IMD) has not been extensively evaluated. IMDs responsible for ASDs are usually identified via clinical manifestations such as microcephaly, dysmorphic features, convulsions, and hepatosplenomegaly. Infrequently, patients with no additional clinical symptoms suggestive of an IMD may be diagnosed as having an idiopathic ASD. High consanguinity rates have resulted in an increased prevalence of IMDs in the Turkish population. The aim of this study was to explore the benefits of systematic screening for IMD among Turkish patients with ASDs. In our study, data were retrospectively collected for 778 children with ASDs. In all cases, the metabolic investigations included an arterial blood gas analysis, serum ammonia and lactate levels, a quantitative plasma amino acid analysis, a whole blood acylcarnitine profile via tandem mass spectrometry and a urine organic acid profile. Urinary glycosaminoglycan levels and homocysteine levels were screened in selected cases; 300 of the 778 patients with ASDs whose physical and metabolic investigations were complete and met this study’s criteria were enrolled. Among the 300 children with autism, IMD were diagnosed in nine patients as follows: two patients were diagnosed with phenylketonuria, and one patient was diagnosed with partial biotinidase deficiency; one patient was diagnosed with mucopolysaccharidosis type III, and one patient was diagnosed with classical homocystinuria; one patient was diagnosed with glutaric acidemia type 1, and one patient was diagnosed with short chain acyl-CoA dehydrogenase deficiency; one patient was diagnosed with argininemia, and one patient was diagnosed with L-2-hydroxyglutaric aciduria. Autism Res 2015. (c) 2015 International Society for Autism Research, Wiley Periodicals, Inc.
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8. Machado C, Estevez M, Rodriguez R, Leisman G, Melillo R, Chinchilla M, Portela L. {{ANATOMIC AND FUNCTIONAL CONNECTIVITY RELATIONSHIP IN AUTISTIC CHILDREN DURING THREE DIFFERENT EXPERIMENTAL CONDITIONS}}. {Brain Connect};2015 (Jun 7)
A group of 21 autistic children was studied for determining the relationship between the anatomic (AC) vs. functional (FC) connectivity, considering short-range and long-range brain networks. AC was assessed by the DW-MRI technique and FC by EEG coherence calculation, in three experimental conditions: basal, watching a popular cartoon with audio (V-A), and with muted audio track (VwA). For short-range connections, basal records, statistical significant correlations were found for all EEG bands in the left hemisphere, but no significant correlations were found for fast EEG frequencies in the right hemisphere. For the V-A condition, significant correlations mainly diminished for the left hemisphere; for the right hemisphere, no significant correlations were found for the fast EEG frequency bands. For the VwA condition, significant correlations for the rapid EEG frequencies mainly disappeared for the right hemisphere. For long-range connections, basal records showed similar correlations both hemispheres. For the right hemisphere, significant correlations incremented to all EEG bands for the V-A condition, but these significant correlations disappeared for the fast EEG frequencies in the VwA condition. It appears that in a resting-state condition, AC is better associated with functional connectivity for short-range connections in the left hemisphere. V-A experimental condition enriches AC and FC association for long-range connections in the right hemisphere. This might be related to an effective connectivity improvement due to full video stimulation (visual and auditory). An impaired audio-visual interaction in the right hemisphere might explain why significant correlations disappeared for the fast EEG frequencies in the VwA experimental condition.
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9. Patel S, Roncaglia P, Lovering RC. {{Using Gene Ontology to describe the role of the neurexin-neuroligin-SHANK complex in human, mouse and rat and its relevance to autism}}. {BMC Bioinformatics};2015;16(1):186.
BACKGROUND: People with an autistic spectrum disorder (ASD) display a variety of characteristic behavioral traits, including impaired social interaction, communication difficulties and repetitive behavior. This complex neurodevelopment disorder is known to be associated with a combination of genetic and environmental factors. Neurexins and neuroligins play a key role in synaptogenesis and neurexin-neuroligin adhesion is one of several processes that have been implicated in autism spectrum disorders. RESULTS: In this report we describe the manual annotation of a selection of gene products known to be associated with autism and/or the neurexin-neuroligin-SHANK complex and demonstrate how a focused annotation approach leads to the creation of more descriptive Gene Ontology (GO) terms, as well as an increase in both the number of gene product annotations and their granularity, thus improving the data available in the GO database. CONCLUSIONS: The manual annotations we describe will impact on the functional analysis of a variety of future autism-relevant datasets. Comprehensive gene annotation is an essential aspect of genomic and proteomic studies, as the quality of gene annotations incorporated into statistical analysis tools affects the effective interpretation of data obtained through genome wide association studies, next generation sequencing, proteomic and transcriptomic datasets.
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10. Rajab A, Schuelke M, Gill E, Zwirner A, Seifert F, Morales Gonzalez S, Knierim E. {{Recessive DEAF1 mutation associates with autism, intellectual disability, basal ganglia dysfunction and epilepsy}}. {J Med Genet};2015 (Jun 5)
BACKGROUND: Various genetic defects cause autism associated with intellectual disability and epilepsy. Here, we set out to identify the genetic defect in a consanguineous Omani family with three affected children in whom mutations in known candidate genes had been excluded beforehand. METHODS: For mutation screening, we combined autozygosity mapping and whole exome sequencing. Segregation of potential disease variants with the phenotype was verified by Sanger sequencing. A splice-site mutation was confirmed and quantified by qPCR. RESULTS: We found an autosomal recessive splice acceptor mutation in DEAF1 (c.997+4A>C, p.G292Pfs*) in all affected individuals, which led to exon skipping, and reduced the normal full-length mRNA copy number in the patients to 5% of the wild-type level. Besides intellectual disability and autism, two of three affected siblings suffered from severe epilepsy. All patients exhibited dyskinesia of the limbs coinciding with symmetric T2 hyperintensities of the basal ganglia on cranial MRI. CONCLUSIONS: A recent report has shown dominant DEAF1 mutations to occur de novo in patients with intellectual disability. Here, we demonstrate that a DEAF1-associated disorder can also be inherited as an autosomal recessive trait with heterozygous individuals being entirely healthy. Our findings expand the clinical and genetic spectrum of DEAF1 mutations to comprise epilepsy and extrapyramidal symptoms.
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11. van Bakel MM, Delobel-Ayoub M, Cans C, Assouline B, Jouk PS, Raynaud JP, Arnaud C. {{Low but Increasing Prevalence of Autism Spectrum Disorders in a French Area from Register-Based Data}}. {J Autism Dev Disord};2015 (Jun 6)
Register-based prevalence rates of childhood autism (CA), Asperger’s syndrome (AS) and other autism spectrum disorders (ASD) were calculated among children aged 7 years old of the 1997-2003 birth cohorts, living in four counties in France. The proportion of children presenting comorbidities was reported. 1123 children with ASD were recorded (M/F ratio: 4.1), representing an overall prevalence rate of 36.5/10,000 children (95 % CI 34.4-38.7): 8.8/10,000 for CA (95 % CI 7.8-9.9), 1.7/10,000 for AS (95 % CI 1.3-2.3) and 25.9/10,000 for other ASD (95 % CI 24.2-27.8). ASD prevalence significantly increased (p < 0.0001) during the period under study. The proportion of children with an intellectual disability was 47.3 %, all other comorbidities were present in less than 5 % of the cases.
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12. Wiggins LD, Levy SE, Daniels J, Schieve L, Croen LA, DiGuiseppi C, Blaskey L, Giarelli E, Lee LC, Pinto-Martin J, Reynolds A, Rice C, Rosenberg CR, Thompson P, Yeargin-Allsopp M, Young L, Schendel D. {{Autism Spectrum Disorder Symptoms Among Children Enrolled in the Study to Explore Early Development (SEED)}}. {J Autism Dev Disord};2015 (Jun 6)
This study examined the phenotypic profiles of children aged 30-68 months in the Study to Explore Early Development (SEED). Children classified as autism spectrum disorder (ASD), developmental delay (DD) with ASD symptoms, DD without ASD symptoms, and population comparison (POP) differed significantly from each other on cognitive, adaptive, behavioral, and social functioning and the presence of parent-reported conditions. Children with ASD and DD with ASD symptoms had mild to severe ASD risk on several measures compared to children with other DD and POP who had little ASD risk across measures. We conclude that children in SEED have varying degrees of ASD impairment and associated deficits. SEED thus provides a valuable sample to explore ASD phenotypes and inform risk factor analyses.
