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.
Deletions and point mutations in the neurexin 1 (NRXN1) gene are associated with a broad spectrum of neuropsychiatric and neurodevelopmental disorders, including autism, intellectual disability, epilepsy, developmental delay, and schizophrenia.
Single cell analysis of autism patient with bi-allelic NRXN1-alpha deletion reveals skewed fate choice in neural progenitors and impaired neuronal functionality.
Mutations in neurexin 1 (NRXN1) as well as two other members of the neuroligin family, NLGN3 and NLGN4, have been associated with autism and mutations in NLGN4 have also been associated with intellectual disability, seizures, and EEG abnormalities.
Interestingly, there was a statistically significant association of neurexin-1 SNP P300P (rs2303298) with risk of autism (26.2% vs. 13.8%; χ(2) = 22.487; p = 3.45E-006; OR = 2.152 (1.559-2.970)).
Despite the challenge posed by such models, results from de novo events and a large parallel case-control study provide strong evidence in favour of CHD8 and KATNAL2 as genuine autism risk factors.
2p16.3 deletions, involving heterozygous NEUREXIN1 (NRXN1) deletion, dramatically increase the risk of developing neurodevelopmental disorders, including autism and schizophrenia.
This case report supports the association of CHD8 mutations with classical autism, macrocephaly, infantile hypotonia, speech delay, lack of major ID, and psychopathology in late adolescence caused by insufficient dosage of CHD8.
Heterozygous mutations of the NRXN1 gene, which encodes the presynaptic cell-adhesion molecule neurexin-1, were repeatedly associated with autism and schizophrenia.
Three additional subjects with NRXN1 deletions and autism were identified through the Homozygosity Mapping Collaborative for Autism, and this deletion segregated with the phenotype.
CHD8 has been reported as an autism susceptibility/intellectual disability gene but emerging evidence suggests that it additionally causes an overgrowth phenotype.
Autistic patients also presented overexpression of genes regulated by androgen receptor (AR), and AR itself, which in turn interacts with CHD8 (chromodomain helicase DNA binding protein 8), a gene recently shown to be associated with the cause of autism and found to be upregulated in some patients tested here.