1. Adachi M, Autry AE, Covington HE, 3rd, Monteggia LM. {{MeCP2-mediated transcription repression in the basolateral amygdala may underlie heightened anxiety in a mouse model of Rett syndrome}}. {J Neurosci};2009 (Apr 1);29(13):4218-4227.
Rett syndrome (RTT) is an X-linked neurodevelopmental disorder that results from loss of function mutations in the methyl-CpG binding protein 2 (MECP2) gene. Using viral-mediated basolateral amygdala (BLA)-specific deletion of Mecp2 in mice, we show that intact Mecp2 function is required for normal anxiety behavior as well as some types of learning and memory. To examine whether these behavioral deficits are the result of impaired transcriptional repression, because Mecp2 is believed to act as a transcriptional repressor in complex with histone deacetylases (HDACs), we infused a HDAC inhibitor chronically into the BLA of wild-type mice. We found that HDAC inhibition produces behavioral deficits similar to those observed after the deletion of Mecp2 in the BLA. These results suggest a key role for Mecp2 as a transcriptional repressor in the BLA in mediating behavioral features of RTT.
2. Baron-Cohen S. {{Autism: the empathizing-systemizing (E-S) theory}}. {Ann N Y Acad Sci};2009 (Mar);1156:68-80.
The mind-blindness theory of autism spectrum conditions has been successful in explaining the social and communication difficulties that characterize these conditions but cannot explain the nonsocial features (the narrow interests, need for sameness, and attention to detail). A new theory, the empathizing-systemizing (E-S) theory, is summarized, which argues two factors are needed to explain the social and nonsocial features of the condition. This is related to other cognitive theories such as the weak central coherence theory and the executive dysfunction theory. The E-S theory is also extended to the extreme male brain theory as a way of understanding the biased sex ratio in autism. Etiological predictions are discussed, as are the clinical applications arising from the E-S theory.
3. Eran A, Graham KR, Vatalaro K, McCarthy J, Collins C, Peters H, Brewster SJ, Hanson E, Hundley R, Rappaport L, Holm IA, Kohane IS, Kunkel LM. {{Comment on « Autistic-like phenotypes in Cadps2-knockout mice and aberrant CADPS2 splicing in autistic patients »}}. {J Clin Invest};2009 (Apr);119(4):679-680; author reply 680-671.
4. Levitt P, Campbell DB. {{The genetic and neurobiologic compass points toward common signaling dysfunctions in autism spectrum disorders}}. {J Clin Invest};2009 (Apr);119(4):747-754.
Autism spectrum disorder (ASD) is a common neurodevelopmental disorder with high heritability. Here, we discuss data supporting the view that there are at least two distinct genetic etiologies for ASD: rare, private (de novo) single gene mutations that may have a large effect in causing ASD; and inherited, common functional variants of a combination of genes, each having a small to moderate effect in increasing ASD risk. It also is possible that a combination of the two mechanisms may occur in some individuals with ASD. We further discuss evidence from individuals with a number of different neurodevelopmental syndromes, in which there is a high prevalence of ASD, that some private mutations and common variants converge on dysfunctional ERK and PI3K signaling, which negatively impacts neurodevelopmental events regulated by some receptor tyrosine kinases.
5. Lombardo MV, Chakrabarti B, Baron-Cohen S. {{The amygdala in autism: not adapting to faces?}} {Am J Psychiatry};2009 (Apr);166(4):395-397.
6. Noor A, Gianakopoulos PJ, Fernandez B, Marshall CR, Szatmari P, Roberts W, Scherer SW, Vincent JB. {{Copy number variation analysis and sequencing of the X-linked mental retardation gene TSPAN7/TM4SF2 in patients with autism spectrum disorder}}. {Psychiatr Genet};2009 (Mar 31)
7. Ryburn B, Anderson V, Wales R. {{Asperger syndrome: how does it relate to non-verbal learning disability?}} {J Neuropsychol};2009 (Mar);3(Pt 1):107-123.
The syndrome of non-verbal learning disabilities (NLD) is associated with prominent non-verbal deficits such as reduced perceptual and spatial abilities, against a background of relatively intact verbal abilities. Asperger syndrome is one of the several developmental disorders for which Byron Rourke has claimed that almost all the signs and symptoms of NLD are present. This study investigated the claim utilizing a battery of neuropsychological tests that were found to be sensitive to NLD in the original learning disordered populations used to describe the syndrome. Children aged between 8 and 14 were recruited to form two groups: (1) children with Asperger syndrome (N=14) and (2) normal healthy schoolchildren (N=20). By contrast to the main principle outlined in the NLD model, children with Asperger syndrome did not display a relative difficulty with spatial- or problem-solving tasks; indeed, they displayed significantly higher performance on some non-verbal tasks in comparison with verbal tasks. It was only in relation to their high levels of psychosocial and interpersonal difficulties, which are also predicted on the basis of their psychiatric diagnosis, that the children with Asperger syndrome were clearly consistent with the NLD model in this study. These results raise questions about the relevance of the syndrome of NLD for children with Asperger syndrome.
8. Shattuck PT, Grosse S, Parish S, Bier D. {{Utilization of a Medicaid-funded intervention for children with autism}}. {Psychiatr Serv};2009 (Apr);60(4):549-552.
OBJECTIVE: The study examined utilization of Wisconsin’s Medicaid funding for autism intervention before and after a major shift in program administration. METHODS: Medicaid enrollment data were analyzed for 1,822 children with autism from 2000 through 2006, as were geocoded demographic data and decennial census data. Enrollees’ data were compared with demographic data for Wisconsin’s general population. RESULTS: Compared with averages for all Wisconsin families, new Medicaid enrollees in 2000 were more likely to be from census tracts with a high proportion of white families with high socioeconomic status. These disparities decreased by 2006, two years after a change from a Medicaid fee-for-service structure to a Medicaid home- and community-based services waiver. CONCLUSIONS: As more states consider carve-out benefits for children with autism, close attention needs to be paid to the potential for disparities and the influence of mode of administration on utilization.
9. Whitehouse AJ, Watt HJ, Line EA, Bishop DV. {{Adult psychosocial outcomes of children with specific language impairment, pragmatic language impairment and autism}}. {Int J Lang Commun Disord};2009 (Mar 19):1-18.
Background: The few studies that have tracked children with developmental language disorder to adulthood have found that these individuals experience considerable difficulties with psychosocial adjustment (for example, academic, vocational and social aptitude). Evidence that some children also develop autistic symptomatology over time has raised suggestions that developmental language disorder may be a high-functioning form of an autism spectrum disorder (ASD). It is not yet clear whether these outcomes vary between individuals with different subtypes of language impairment. Aims: To compare the adult psychosocial outcomes of children with specific language impairment (SLI), pragmatic language impairment (PLI) and ASD. Methods & Procedures: All participants took part in research as children. In total, there were 19 young adults with a childhood history of Specific Language Impairment (M age = 24;8), seven with PLI (M age = 22;3), 11 with high functioning ASD (M age = 21;9) and 12 adults with no history of developmental disorder (Typical; n = 12; M age = 21;6). At follow-up, participants and their parents were interviewed to elicit information about psychosocial outcomes. Outcomes & Results: Participants in the SLI group were most likely to pursue vocational training and work in jobs not requiring a high level of language/literacy ability. The PLI group tended to obtain higher levels of education and work in ‘skilled’ professions. The ASD participants had lower levels of independence and more difficulty obtaining employment than the PLI and SLI participants. All groups had problems establishing social relationships, but these difficulties were most prominent in the PLI and ASD groups. A small number of participants in each group were found to experience affective disturbances. The PLI and SLI groups showed lower levels of autistic symptomatology than the ASD group. Conclusions & Implications: The between-group differences in autistic symptomatology provide further evidence that SLI, PLI, and ASD are related disorders that vary along qualitative dimensions of language structure, language use and circumscribed interests. Childhood diagnosis showed some relation to adult psychosocial outcome. However, within-group variation highlights the importance of evaluating children on a case-by-case basis.
