Genes encoding NMDAR subunits (such as GRIN1, GRIN2A, and GRIN2B) have been identified to be associated with broad-spectrum phenotypes, including epilepsies, epilepsies with NDD, and NDD without seizures (Endele et al., 2010; Charron et al., 2022). The gene discussed is GRIN1; the disease is Neurodevelopmental delay.