Project description:Autism spectrum disorders (ASD) are common, heritable neurodevelopmental conditions. The genetic architecture of ASD is complex, requiring large samples to overcome heterogeneity. Here we broaden coverage and sample size relative to other studies of ASD by using Affymetrix 10K single nucleotide polymorphism (SNP) arrays and 1168 families with = 2 affected individuals to perform the largest linkage scan to date, while also analyzing copy number variation (CNV) in these families. Linkage and CNV analyses implicate chromosome 11p12-p13 and neurexins, respectively, amongst other candidate loci. Neurexins team with previously-implicated neuroligins for glutamatergic synaptogenesis, highlighting glutamate-related genes as promising candidates for ASD. Keywords: Autism spectrum disorder, Affymetrix SNP genotyping, linkage analysis, copy number analysis, chromosomal rearrangements.
Project description:Individualized outcome prediction classifiers were successfully constructed through expression profiling of 91 up-regulated and 67 down-regulated miRNAs in 5 autism spectrum disorder (ASD) cases and 5 controls. In the study presented here, a well-defined cohort of 5 autism spectrum disorder cases and 5 controls was used to acquire expression profiles of 91 up-regulated and 67 down-regulated miRNAs, leading to the first global miRNA expression profile of ASD in China.
Project description:We performed aCGH analysis using a custom Agilent oligonucleotide array to analyze 288 probands with idiopathic autism spectrum disorder (ASD) from the Simons Simplex Collection (SSC) of autism samples. The array is customized to high resolution coverage of exons for genes identified as encoding proteins included in a detailed protein interaction network for autism.
Project description:Gene expression in blood of children with autism spectrum disorder (ASD) was studied. Transcriptional profiles were compared with age and gender matched, typically developing children from the general population (GP) or IQ matched children with mental retardation or developmental delay (MR/DD). Keywords: autism analysis
Project description:Autism Spectrum Disorder (ASD) is a common pediatric cognitive disorder with high heritability. Yet no single genetic variant has accounted for more than a small fraction of cases. We sought to determine whether we could classify patients as having ASD vs. controls solely based on a multi-gene expression profiling of their peripheral blood cells.
Project description:Autism spectrum disorder (ASD) is a common, highly heritable neuro-developmental condition characterized by marked genetic heterogeneity. Thus, a fundamental question is whether autism represents an etiologically heterogeneous disorder in which the myriad genetic or environmental risk factors perturb common underlying molecular pathways in the brain. Here, we demonstrate consistent differences in transcriptome organization between autistic and normal brain by gene co-expression network analysis. Remarkably, regional patterns of gene expression that typically distinguish frontal and temporal cortex are significantly attenuated in the ASD brain, suggesting abnormalities in cortical patterning. We further identify discrete modules of co-expressed genes associated with autism: a neuronal module enriched for known autism susceptibility genes, including the neuronal specific splicing factor A2BP1/FOX1, and a module enriched for immune genes and glial markers. Using high-throughput RNA-sequencing we demonstrate dysregulated splicing of A2BP1-dependent alternative exons in ASD brain. Moreover, using a published autism GWAS dataset, we show that the neuronal module is enriched for genetically associated variants, providing independent support for the causal involvement of these genes in autism. In contrast, the immune-glial module showed no enrichment for autism GWAS signals, indicating a non-genetic etiology for this process. Collectively, our results provide strong evidence for convergent molecular abnormalities in ASD, and implicate transcriptional and splicing dysregulation as underlying mechanisms of neuronal dysfunction in this disorder. Total RNA was extracted from approximately 100mg of postmortem brain tissue representing Cerebellum (C), Frontal cortex (F), and Temporal cortex (T), from autistic and control individuals.
Project description:Autism spectrum disorder (ASD) and mental retardation (MR) represent clinically distinct neurodevelopmental disorders with a complex genetic etiology. Using microarrays we identified de novo copy number variations in the SHANK2 synaptic scaffolding gene in two unrelated ASD and MR patients; DNA sequencing of SHANK2 revealed additional variants including a de novo nonsense mutation and 7 rare inherited changes. Our findings further link common genes between ASD and intellectual disability.