Among these genes, it is affirmative that TBR1 is a causative gene for intellectual disability; however, the pathogenic genes of other phenotypes remain unclear.
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.
TBR1, a transcription factor involved in early cortical development, is a strong candidate for the intellectual disability phenotype seen in our patient and in patients with larger deletions in this region of the genome.