Genes with DNMs overlapped with genes implicated in autism (for example, AUTS2, CHD8 and MECP2) and intellectual disability (for example, HUWE1 and TRAPPC9), supporting a shared genetic etiology between these disorders.
Recently, disruptive CHD8 mutations were described in patients with similar phenotypes further showing pivotal role of CHD8 gene in the pathogenesis of DD/ID or ASDs.
To better understand the phenotype associated with CHD8 mutations, we genotyped all CHD8 exons in carefully assessed cohorts of autism (n = 142), schizophrenia (SCZ; n = 143), and intellectual disability (ID; n = 94).
As expected, individuals with ADNP disruptions had higher rates of ID but less severe social affect symptoms compared to the CHD8 and Idiopathic ASD groups.
Mutations in the CHD2 gene have been linked to developmental delay, intellectual disability, autism and seizures, CHD8 mutations to autism and intellectual disability, whereas haploinsufficiency of CHD7 is associated with executive dysfunction and intellectual disability.
These results suggest that, in addition to its established link with autism and intellectual disability, CHD8 causes an overgrowth phenotype, and should be considered in the differential diagnosis of patients presenting with increased height and/or head circumference in association with intellectual disability.
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.
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.