Pubmed du 19/01/14

Pubmed du jour

2014-01-19 12:03:50

1. Bockler A, Timmermans B, Sebanz N, Vogeley K, Schilbach L. {{Effects of Observing Eye Contact on Gaze Following in High-Functioning Autism}}. {J Autism Dev Disord};2014 (Jan 19)

Observing eye contact between others enhances the tendency to subsequently follow their gaze and has been suggested to function as a social signal that adds meaning to an upcoming action or event. The present study investigated effects of observed eye contact in high-functioning autism (HFA). Two faces on a screen either looked at or away from each other before providing congruent or incongruent gaze cues to one of two target locations. In contrast to control participants, HFA participants did not depict enhanced gaze following after observing eye contact. Individuals with autism, hence, do not seem to process observed mutual gaze as a social signal indicating the relevance of upcoming (gaze) behaviour. This may be based on the reduced tendency of individuals with HFA to engage in social gaze behavior themselves, and might underlie some of the characteristic deficiencies in social communicative behaviour in autism.

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2. Waltes R, Duketis E, Knapp M, Anney RJ, Huguet G, Schlitt S, Jarczok TA, Sachse M, Kampfer LM, Kleinbock T, Poustka F, Bolte S, Schmotzer G, Voran A, Huy E, Meyer J, Bourgeron T, Klauck SM, Freitag CM, Chiocchetti AG. {{Common variants in genes of the postsynaptic FMRP signalling pathway are risk factors for autism spectrum disorders}}. {Hum Genet};2014 (Jan 19)

Autism spectrum disorders (ASD) are heterogeneous disorders with a high heritability and complex genetic architecture. Due to the central role of the fragile X mental retardation gene 1 protein (FMRP) pathway in ASD we investigated common functional variants of ASD risk genes regulating FMRP. We genotyped ten SNPs in two German patient sets (N = 192 and N = 254 families, respectively) and report association for rs7170637 (CYFIP1; set 1 and combined sets), rs6923492 (GRM1; combined sets), and rs25925 (CAMK4; combined sets). An additional risk score based on variants with an odds ratio (OR) >1.25 in set 1 and weighted by their respective log transmitted/untransmitted ratio revealed a significant effect (OR 1.30, 95 % CI 1.11-1.53; P = 0.0013) in the combined German sample. A subsequent meta-analysis including the two German samples, the « Strict/European » ASD subsample of the Autism Genome Project (1,466 families) and a French case/control (541/366) cohort showed again association of rs7170637-A (OR 0.85, 95 % CI 0.75-0.96; P = 0.007) and rs25925-G (OR 1.31, 95 % CI 1.04-1.64; P = 0.021) with ASD. Functional analyses revealed that these minor alleles predicted to alter splicing factor binding sites significantly increase levels of an alternative mRNA isoform of the respective gene while keeping the overall expression of the gene constant. These findings underpin the role of ASD candidate genes in postsynaptic FMRP regulation suggesting that an imbalance of specific isoforms of CYFIP1, an FMRP interaction partner, and CAMK4, a transcriptional regulator of the FMRP gene, modulates ASD risk. Both gene products are related to neuronal regulation of synaptic plasticity, a pathomechanism underlying ASD and may thus present future targets for pharmacological therapies in ASD.

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