GRIA2 and Neurodevelopmental delay: Consistent with the role of GluA2 channels in synapse development and plasticity19, phenotypic analysis of patients carrying de-novo GRIA2 variants demonstrated an NDD spectrum including ID/DD, developmental regression, ASD, speech impairment, RTT-like features, and seizures or DEE (Fig. 1b; Supplementary Videos 1–5).