We provide support for three previous findings in schizophrenia, as we identified one deletion in a case at 1q21.1, one deletion within NRXN1, and four duplications in cases and one in a control subject at 16p13.1, a locus first implicated in autism and later in schizophrenia.
Here, we identified deletions of the NRXN1 region in affected cohorts, confirming a strong association with the autism spectrum and other neurodevelopmental disorders.
Deletions at 2p16.3 involving exons of NRXN1 are associated with susceptibility for autism and schizophrenia, and similar deletions have been identified in individuals with developmental delay and dysmorphic features.
Previous analyses of neurexin 1α (Nrxn1α) knockout (KO) mouse as a model of these disorders have revealed impairments in synaptic transmission but failed to reveal defects in social behaviour, one of the core symptoms of autism.
Because TBR1 is critical for glutamate receptor, ionotropic, <i>N</i>-methyl-D-aspartate receptor subunit 2B (<i>Grin2b</i>) expression and is a causative gene for autism and intellectual disability, we then generated CASK T740A (corresponding to rat CASK T724A) mutant mice using a gene-targeting approach.
While the Wilms tumor/genitourinary anomalies and aniridia are caused by deletion of WT1 and PAX6 respectively, the genomic cause of mental retardation and autism in WAGR syndrome remains unknown.
Copy-number variants and truncating mutations in SHANK genes were present in ∼1% of patients with ASD: mutations in SHANK1 were rare (0.04%) and present in males with normal IQ and autism; mutations in SHANK2 were present in 0.17% of patients with ASD and mild intellectual disability; mutations in SHANK3 were present in 0.69% of patients with ASD and up to 2.12% of the cases with moderate to profound intellectual disability.
Mutations in <i>SHANK1-3</i> are prevalent in patients with autism spectrum disorders (ASD), and loss of one copy of <i>SHANK3</i> causes Phelan-McDermid Syndrome, a syndrome in which Autism occurs in >80% of cases.
The discovery of apparent reduced penetrance of ASD in females bearing inherited autosomal SHANK1 deletions provides a possible contributory model for the male gender bias in autism.
These results suggest an overlapping pathway of gene dysregulation within 15q11-q13 in Rett, Angelman and autism and implicate MeCP2 in the regulation of UBE3A and GABRB3 expressions in the postnatal mammalian brain.
One such gene is CNTNAP2 encoding contactin-associated protein 2 (CASPR2), which harbours mutations associated to autism, schizophrenia, and intellectual disability.
Slack activity is enhanced by interaction with the Fragile-X-Mental-Retardation-Protein (FMRP) and loss of FMRP leads to decreased sodium-activated potassium currents in medial nucleus of the trapezoid body neurons of the Fmr1-knockout (KO) mouse representing a mouse model of the human Fragile-X-Syndrome (FXS) and autism.