GRIK2 and Neurodevelopmental delay: The majority of disease-causing genes encoding the proteins interacting with the DLG3 protein are associated with neurological diseases, including five causative genes of both epilepsy and NDD (GRIN1, GRIN2A, GRIN2B, GRIK2, and NBEA), eleven causative genes of NDD with seizures (GRIA1, GRIA2, CASK, NRXN1, NLGN3, NEDD4L, SHANK3, GPSM2, DLG4, SYNGAP1, and UBE3A), and four causative genes of NDD without seizures (NLGN4X, CACNG2, SHANK2, and NLGN1) (Figure 6).