Pubmed du 08/04/11

Pubmed du jour

2011-04-08 12:03:50

1. Allman MJ. {{Deficits in temporal processing associated with autistic disorder}}. {Front Integr Neurosci};2011;5:2.

2. Alvarez-Iglesias V, Mosquera-Miguel A, Cusco I, Carracedo A, Perez-Jurado LA, Salas A. {{Reassessing the role of mitochondrial DNA mutations in autism spectrum disorder}}. {BMC Med Genet};2011 (Apr 6);12(1):50.

ABSTRACT: BACKGROUND: There is increasing evidence that impairment of mitochondrial energy metabolism plays an important role in the pathophysiology of autism spectrum disorders (ASD; OMIM number: 209850). A significant proportion of ASD cases display biochemical alterations suggestive of mitochondrial dysfunction and several studies have reported that mutations in the mitochondrial DNA (mtDNA) molecule could be involved in the disease phenotype. METHODS: We analysed a cohort of 148 patients with idiopathic ASD for a number of mutations proposed in the literature as pathogenic in ASD. We also carried out a case control association study for the most common European haplogroups (hgs) and their diagnostic single nucleotide polymorphisms (SNPs) by comparing cases with 753 healthy and ethnically matched controls. RESULTS: We did not find statistical support for an association between mtDNA mutations or polymorphisms and ASD. CONCLUSIONS: Our results are compatible with the idea that mtDNA mutations are not a relevant cause of ASD and the frequent observation of concomitant mitochondrial dysfunction and ASD could be due to nuclear factors influencing mitochondrion functions or to a more complex interplay between the nucleus and the mitochondrion/mtDNA.

3. Eldevik S, Hastings RP, Jahr E, Hughes JC. {{Outcomes of Behavioral Intervention for Children with Autism in Mainstream Pre-School Settings}}. {J Autism Dev Disord};2011 (Apr 7)

We evaluated outcomes for 31 children with autism (2-6 years of age at intake) who received behavioral intervention in mainstream pre-school settings and a comparison group of 12 children receiving treatment as usual. After 2 years, children receiving behavioral intervention had higher IQ scores (Hedges g = 1.03 (95% CI = .34, 1.72) and adaptive behavior composite scores (Hedges g = .73 (95% CI = .05, 1.36). Despite probably fewer intervention hours, these group level outcomes were comparable to studies providing more intensive intervention. Individual child data also showed positive results with 19.4% achieving change at a reliable level for IQ; but a lower percentage than found in recent meta-analysis research. Strengths and weaknesses of the mainstream pre-school delivery model are discussed.

4. Klauck SM, Poustka L, Chiocchetti A. {{[Genetics and animal modeling of autism spectrum disorders : New developments.]}}. {Nervenarzt};2011 (Apr 7)

Autism spectrum disorders (ASD) are pervasive developmental disorders with a complex phenotype in respect to communication, verbal development, and social behavior. Manifold molecular genetic analyses point towards a multifactorial genetic predisposition. For the identification of central key mechanisms large consortia have performed linkage analysis, genome-wide association, and copy number variation (CNV) studies, which led to the characterization of risk factors for ASD like CNV and single nucleotide polymorphisms but also single rare mutations. The so far associated genomic regions and candidate genes impact neuronal development especially the establishment of the synaptic cleft, secretion of surface proteins, or dendritic translation. These findings point towards deficits of translation-dependent cell-cell connectivity and synaptic plasticity for ASD. Animal models are relevant to analyze the pathomechanisms of single genetic risk variants at the cellular, tissue-specific, and behavioral levels.

5. Lopez-Hernandez T, Ridder MC, Montolio M, Capdevila-Nortes X, Polder E, Sirisi S, Duarri A, Schulte U, Fakler B, Nunes V, Scheper GC, Martinez A, Estevez R, van der Knaap MS. {{Mutant GlialCAM Causes Megalencephalic Leukoencephalopathy with Subcortical Cysts, Benign Familial Macrocephaly, and Macrocephaly with Retardation and Autism}}. {Am J Hum Genet};2011 (Apr 8);88(4):422-432.

Megalencephalic leukoencephalopathy with subcortical cysts (MLC) is a leukodystrophy characterized by early-onset macrocephaly and delayed-onset neurological deterioration. Recessive MLC1 mutations are observed in 75% of patients with MLC. Genetic-linkage studies failed to identify another gene. We recently showed that some patients without MLC1 mutations display the classical phenotype; others improve or become normal but retain macrocephaly. To find another MLC-related gene, we used quantitative proteomic analysis of affinity-purified MLC1 as an alternative approach and found that GlialCAM, an IgG-like cell adhesion molecule that is also called HepaCAM and is encoded by HEPACAM, is a direct MLC1-binding partner. Analysis of 40 MLC patients without MLC1 mutations revealed multiple different HEPACAM mutations. Ten patients with the classical, deteriorating phenotype had two mutations, and 18 patients with the improving phenotype had one mutation. Most parents with a single mutation had macrocephaly, indicating dominant inheritance. In some families with dominant HEPACAM mutations, the clinical picture and magnetic resonance imaging normalized, indicating that HEPACAM mutations can cause benign familial macrocephaly. In other families with dominant HEPACAM mutations, patients had macrocephaly and mental retardation with or without autism. Further experiments demonstrated that GlialCAM and MLC1 both localize in axons and colocalize in junctions between astrocytes. GlialCAM is additionally located in myelin. Mutant GlialCAM disrupts the localization of MLC1-GlialCAM complexes in astrocytic junctions in a manner reflecting the mode of inheritance. In conclusion, GlialCAM is required for proper localization of MLC1. HEPACAM is the second gene found to be mutated in MLC. Dominant HEPACAM mutations can cause either macrocephaly and mental retardation with or without autism or benign familial macrocephaly.

6. Pickett J, Xiu E, Tuchman R, Dawson G, Lajonchere C. {{Mortality in Individuals With Autism, With and Without Epilepsy}}. {J Child Neurol};2011 (Apr 6)

Previous studies show higher mortality rates among individuals with autism than the general population. Comorbidity with epilepsy is an assumed, often ill-defined factor in the increased mortality rates of individuals with autism. Data from the Autism Tissue Program, a tissue donation program established to support biomedical research on autism, show that approximately one-third of its brain donors with autism also had epilepsy. Analysis of new data from the California State Department of Developmental Services is consistent with past reports showing that there is a higher than expected rate of mortality in individuals with autism and epilepsy than autism alone. Accurate, complete and accessible records on cause of death are necessary not just for brain research, but also for understanding risk factors that contribute to early death in individuals with autism spectrum disorders. Various national health care and state developmental disability agency initiatives to reduce risk of mortality are described.

7. Ruiz Calzada L, Pistrang N, Mandy WP. {{High-Functioning Autism and Asperger’s Disorder: Utility and Meaning for Families}}. {J Autism Dev Disord};2011 (Apr 7)

We used framework analysis to investigate the utility of pervasive developmental disorder diagnoses, interviewing young people (aged 9-16 years) with high-functioning autistic disorder (AD) and Asperger’s disorder (AsD), and their parents. Twenty two participants from ten families described both gains and costs resulting from diagnosis. Perceived advantages of AD and AsD diagnosis were increased understanding and practical support, and parental empowerment. Disadvantages included the effects of stigma and concerns about validity. Participants tended to consider AsD and AD as interchangeable terms. Findings suggest that the utility of AD and AsD depends upon both their validity and how these diagnoses are received in their cultural, economic and legislative context. Improvement of post-diagnostic services will improve the utility of AD and AsD.

8. Schumann G, Coin LJ, Lourdusamy A, Charoen P, Berger KH, Stacey D, Desrivieres S, Aliev FA, Khan AA, Amin N, Aulchenko YS, Bakalkin G, Bakker SJ, Balkau B, Beulens JW, Bilbao A, de Boer RA, Beury D, Bots ML, Breetvelt EJ, Cauchi S, Cavalcanti-Proenca C, Chambers JC, Clarke TK, Dahmen N, de Geus EJ, Dick D, Ducci F, Easton A, Edenberg HJ, Esk T, Fernandez-Medarde A, Foroud T, Freimer NB, Girault JA, Grobbee DE, Guarrera S, Gudbjartsson DF, Hartikainen AL, Heath AC, Hesselbrock V, Hofman A, Hottenga JJ, Isohanni MK, Kaprio J, Khaw KT, Kuehnel B, Laitinen J, Lobbens S, Luan J, Mangino M, Maroteaux M, Matullo G, McCarthy MI, Mueller C, Navis G, Numans ME, Nunez A, Nyholt DR, Onland-Moret CN, Oostra BA, O’Reilly PF, Palkovits M, Penninx BW, Polidoro S, Pouta A, Prokopenko I, Ricceri F, Santos E, Smit JH, Soranzo N, Song K, Sovio U, Stumvoll M, Surakk I, Thorgeirsson TE, Thorsteinsdottir U, Troakes C, Tyrfingsson T, Tonjes A, Uiterwaal CS, Uitterlinden AG, van der Harst P, van der Schouw YT, Staehlin O, Vogelzangs N, Vollenweider P, Waeber G, Wareham NJ, Waterworth DM, Whitfield JB, Wichmann EH, Willemsen G, Witteman JC, Yuan X, Zhai G, Zhao JH, Zhang W, Martin NG, Metspalu A, Doering A, Scott J, Spector TD, Loos RJ, Boomsma DI, Mooser V, Peltonen L, Stefansson K, van Duijn CM, Vineis P, Sommer WH, Kooner JS, Spanagel R, Heberlein UA, Jarvelin MR, Elliott P. {{Genome-wide association and genetic functional studies identify autism susceptibility candidate 2 gene (AUTS2) in the regulation of alcohol consumption}}. {Proc Natl Acad Sci U S A};2011 (Apr 6)

Alcohol consumption is a moderately heritable trait, but the genetic basis in humans is largely unknown, despite its clinical and societal importance. We report a genome-wide association study meta-analysis of approximately 2.5 million directly genotyped or imputed SNPs with alcohol consumption (gram per day per kilogram body weight) among 12 population-based samples of European ancestry, comprising 26,316 individuals, with replication genotyping in an additional 21,185 individuals. SNP rs6943555 in autism susceptibility candidate 2 gene (AUTS2) was associated with alcohol consumption at genome-wide significance (P = 4 x 10(-8) to P = 4 x 10(-9)). We found a genotype-specific expression of AUTS2 in 96 human prefrontal cortex samples (P = 0.026) and significant (P < 0.017) differences in expression of AUTS2 in whole-brain extracts of mice selected for differences in voluntary alcohol consumption. Down-regulation of an AUTS2 homolog caused reduced alcohol sensitivity in Drosophila (P < 0.001). Our finding of a regulator of alcohol consumption adds knowledge to our understanding of genetic mechanisms influencing alcohol drinking behavior.

9. Stroganova TA, Posikera IN, Prokof’ev AO, Morozov AA, Grachev VV, Obukhov Iu V. {{[Phase-locked alpha oscillations evoked by illusory contour perception in boys in norm and with autism]}}. {Zh Vyssh Nerv Deiat Im I P Pavlova};2011 (Jan-Feb);61(1):47-60.

We examined temporal dynamics of EEG phase-locked alpha oscillations during perception of illusory (Kanizsa square) and non-illusory images in boys with autism and age-matched typically developing boys. In typically developing boys the illusory contour (IC) as compared to the control stimulus provoked an increased alpha response at the parietal scalp areas. This IC effect demonstrated continuity within the time window of 133-267 ms after the stimulus onset. Although boys with autism did not display this effect at the group level, part of the sample showed an atypical two-stage pattern of illusory contour effect. The first early stage of IC effect (50-133 ms) was pronounced at the midline occipital electrode localized in the vicinity of the primary visual cortex. The localization and the early onset time suggest that this early IC effect is related to abnormally enhanced « low-level » locally-oriented processes of contour completion in autism. The second stage of IC effect (267-400 ms) was observed at the left parietal region only, and was delayed comparatively to that in healthy boys, suggesting the deficit of « intermediate » processes of perceptual grouping linked to the higher-order visual areas.