Pubmed du 19/03/10

Pubmed du jour

2010-03-19 12:03:50

1. Auber B, Burfeind P, Thiels C, Alsat EA, Shoukier M, Liehr T, Nelle H, Bartels I, Salinas-Riester G, Laccone F. {{An unbalanced translocation resulting in a duplication of Xq28 causes a Rett syndrome-like phenotype in a female patient}}. {Clin Genet} (Mar 1)

2. Chien WH, Gau SS, Wu YY, Huang YS, Fang JS, Chen YJ, Soong WT, Chiu YN, Chen CH. {{Identification and molecular characterization of two novel chromosomal deletions associated with autism}}. {Clin Genet} (Feb 11)

Chien W-H, Gau SS-F, Wu Y-Y, Huang Y-S, Fang J-S, Chen Y-J, Soong W-T, Chiu Y-N, Chen C-H. Identification and molecular characterization of two novel chromosomal deletions associated with autism. Autism is a childhood-onset neurodevelopmental disorder with a strong genetic basis in its etiology. Conventional karyotype analysis has revealed that chromosomal structural aberrations such as translocation, inversion, deletion, and duplication play a role in causing autism spectrum disorders (ASD). In addition, recent array-based comparative genomic hybridization (array CGH) studies discovered that submicroscopic deletion and duplication of DNA segments also contributed significantly to the genetic etiology of ASD. Together, these studies indicate that genomic rearrangement is an important genetic mechanism of ASD. Using karyotyping analysis and array CGH technology, we identified a subtelomeric deletion of approximately 6.8 Mb at 4q35.1-35.2 and a terminal deletion of approximately 2.4 Mb at 8p23.2-pter in two autistic boys, respectively. These two deletions were further validated using fluorescent in situ hybridization and real-time quantitative polymerase chain reaction, and their breakpoints were delineated using high-resolution array CGH. The 4q deletion is a rare de novo mutation, while the transmission of 8p deletion is unknown, because the father of the patient was unavailable for study. These two deletions are rare mutations and were not found in the additional 282 patients with ASD and in the 300 control subjects in our population. The identification of these two chromosomal deletions contribute to our understanding of the genetic basis of ASD, and the haploinsufficiency of several genes located at the deleted regions of chromosome 8p and 4q may contribute to the clinical phenotypes of autism.

3. Morsanyi K, Handley SJ, Evans JS. {{Decontextualised Minds: Adolescents with Autism are Less Susceptible to the Conjunction Fallacy than Typically Developing Adolescents}}. {J Autism Dev Disord} (Mar 17)

The conjunction fallacy has been cited as a classic example of the automatic contextualisation of problems. In two experiments we compared the performance of autistic and typically developing adolescents on a set of conjunction fallacy tasks. Participants with autism were less susceptible to the conjunction fallacy. Experiment 2 also demonstrated that the difference between the groups did not result from increased sensitivity to the conjunction rule, or from impaired processing of social materials amongst the autistic participants. Although adolescents with autism showed less bias in their reasoning they were not more logical than the control group in a normative sense. The findings are discussed in the light of accounts which emphasise differences in contextual processing between typical and autistic populations.

4. Paakki JJ, Rahko J, Long X, Moilanen I, Tervonen O, Nikkinen J, Starck T, Remes J, Hurtig T, Haapsamo H, Jussila K, Kuusikko-Gauffin S, Mattila ML, Zang Y, Kiviniemi V. {{Alterations in regional homogeneity of resting-state brain activity in autism spectrum disorders}}. {Brain Res} (Mar 19);1321:169-179.

Measures assessing resting-state brain activity with blood oxygen level dependent (BOLD) functional magnetic resonance imaging (fMRI) can reveal cognitive disorders at an early stage. Analysis of regional homogeneity (ReHo) measures the local synchronization of spontaneous fMRI signals and has been successfully utilized in detecting alterations in subjects with attention-deficit hyperactivity disorder (ADHD), depression, schizophrenia, Parkinson’s disease and Alzheimer’s dementia. Resting-state brain activity was investigated in 28 adolescents with autism spectrum disorders (ASD) and 27 typically developing controls being imaged with BOLD fMRI and analyzed with the ReHo method. The hypothesis was that ReHo of resting-state brain activity would be different between ASD subjects and controls in brain areas previously shown to display functional alterations in stimulus or task based fMRI studies. Compared with the controls, the subjects with ASD had significantly decreased ReHo in right superior temporal sulcus region, right inferior and middle frontal gyri, bilateral cerebellar crus I, right insula and right postcentral gyrus. Significantly increased ReHo was discovered in right thalamus, left inferior frontal and anterior subcallosal gyrus and bilateral cerebellar lobule VIII. We conclude that subjects with ASD have right dominant ReHo alterations of resting-state brain activity, i.e., areas known to exhibit abnormal stimulus or task related functionality. Our results demonstrate that there is potential in utilizing the ReHo method in fMRI analyses of ASD.

5. Ploog BO. {{Stimulus Overselectivity Four Decades Later: A Review of the Literature and Its Implications for Current Research in Autism Spectrum Disorder}}. {J Autism Dev Disord} (Mar 18)

This review of several topics related to « stimulus overselectivity » (Lovaas et al., J Abnormal Psychol 77:211-222, 1971) has three main purposes: (1) To outline the factors that may contribute to overselectivity; (2) to link the behavior-analytical notion of overselectivity to current nonbehavior-analytical research and theory; and (3) to suggest remedial strategies based on the behavior-analytical approach. While it is clear that overselectivity is not specific to autism spectrum disorder (ASD) and also that not all persons with ASD exhibit overselectivity, it is prevalent in ASD and has critical implications for symptoms, treatment, research, and theory. Weak Central Coherence and Enhanced Perceptual Functioning theories are briefly considered. The research areas addressed here include theory of mind, joint attention, language development, and executive function.

6. Vignoli A, Fabio RA, La Briola F, Giannatiempo S, Antonietti A, Maggiolini S, Canevini MP. {{Correlations between neurophysiological, behavioral, and cognitive function in Rett syndrome}}. {Epilepsy Behav} (Mar 15)

Rett syndrome, a neurodevelopmental disorder affecting mainly females, is caused by a mutation of the MeCP2 gene. Girls with Rett syndrome manifest diverse behavioral and cognitive phenotypes, and the reasons for this variability remain unknown. In addition, girls with Rett syndrome often have epileptic seizures and abnormal EEGs, the characteristics of which differ with the patient. The aim of the study was to verify if neurophysiological and epileptological characteristics could be correlated with cognitive measures, obtained using eye tracker technology, and behavioral scores (Vineland Adaptive Behavior Scales and Rett Assessment Rating Scale) in 18 patients with Rett syndrome (mean age 13.7years) at clinical stages III and IV. Age at epilepsy onset and seizure frequency were strictly correlated with neuropsychological outcome, as were EEG stage and distribution of paroxysmal abnormalities. Our findings demonstrate that neurophysiological features should be considered prognostic of cognitive and behavioral outcome in the clinical management of Rett syndrome.