Like chromodomain helicase DNA binding protein 8 (CHD8), the most frequently mutated gene in individuals with ASD, the candidate gene <i>AT-rich interaction domain 1B</i> (<i>ARID1B</i>) encodes a chromatin remodeling factor.
As demonstrated in our patients, along with other previously reported studies support that disruption of the CHD8 gene represents a specific genetic sub-type of ASD.
Our findings indicate that CHD8 disruptions define a distinct ASD subtype and reveal unexpected comorbidities between brain development and enteric innervation.
Our data support associations between specific genes and reciprocal subphenotypes (CHD8-macrocephaly and DYRK1A-microcephaly) and replicate the importance of a β-catenin-chromatin-remodeling network to ASD etiology.
Genes associated with ASD were strongly enriched among indirectly down-regulated loci (P < 10(-8)) and CHD8-bound genes (P = 0.0043), which align with previously identified coexpression modules during fetal development.
Because identification of novel CHD7 and CHD8 interacting partners will provide further insights into the pathogenesis of CHARGE syndrome and ASD/NDD, we searched for additional associated polypeptides using the method of stable isotope labeling by amino acids in cell culture (SILAC) in combination with mass spectrometry.
We sequenced 136 microcephaly or macrocephaly (Mic-Mac)-related genes and 158 possible ASD-risk genes in 536 Chinese ASD probands and detected 22 damaging de novo mutations (DNMs) in 20 genes, including CHD8 and SCN2A, with recurrent events.
We characterized sexually dimorphic changes in mice carrying a heterozygous mutation in Chd8 (Chd8<sup>+/N2373K</sup>) that was first identified in human CHD8 (Asn2373LysfsX2), a strong ASD-risk gene that encodes a chromatin remodeler.
Genome-wide DNA methylation (DNAm) was assessed using the Illumina Infinium HumanMethylation450 and MethylationEPIC arrays in blood from individuals with ASD of heterogeneous, undefined etiology (n = 52), and individuals with 16p11.2 deletions (16p11.2del, n = 9) or pathogenic variants in the chromatin modifier CHD8 (CHD8<sup>+/-</sup>, n = 7).
We explore the field through the lens of Chd3, Chd4, and Chd5 proteins, which incorporate into the nucleosome remodeling and deacetylase (NuRD) complex, and the related proteins Chd7 and Chd8, implicated in the pathogenesis of intellectual disability and autism spectrum disorders.
We investigated 25 individuals with CHD8 protein truncating variants (PTVs), including 10 previously unreported patients and found a male to female ratio of 2.7:1 (19:7) and a pattern of common features: macrocephaly (62.5%), tall stature (47%), developmental delay and/or intellectual disability (81%), ASDs (84%), sleep difficulties (50%), gastrointestinal problems (40%), and distinct facial features.
The most interesting genes included in this deletion are CHD8, a chromodomain helicase DNA binding protein that is associated with autism spectrum disorders, and MMP14, a matrix metalloproteinase that has been linked to obesity and type 2 diabetes.
Disruptive mutations in chromatin remodeler CHD8 cause autism spectrum disorders, exhibiting widespread white matter abnormalities; however, the underlying mechanisms remain elusive.
Our data suggest that CHD8 haploinsufficiency represents a specific subtype of ASD where neuropsychiatric symptoms are underpinned by long-range over-connectivity.
Finally, analyses of the CHD8 subnetwork and altered transcript levels from an independent study of CHD8 suppression further confirmed the central role of genes regulating neurogenesis and cell adhesion processes in ASD brain maldevelopment.
Two fetal genomes were found to harbor potentially detrimental variants in chromodomain helicase DNA binding protein 8 (<i>CHD8</i>) and LDL receptor-related protein 1 (<i>LRP1</i>), variations of which have been associated with autism spectrum disorder and keratosis pilaris atrophicans, respectively.
<i>CHD8</i> (chromodomain helicase DNA-binding protein 8), which codes for a member of the CHD family of ATP-dependent chromatin-remodeling factors, is one of the most commonly mutated genes in autism spectrum disorders (ASD) identified in exome-sequencing studies.