GRIA2 and brain disorder: For example, editing at the Q/R site of glutamate ionotropic receptor AMPA type subunit 2 (GluA2) by ADAR2 affects trafficking and limits calcium permeability, with reduced GluA2 editing promoting excitotoxicity and seizures.7 Dysregulation of A-to-I editing has been associated with several brain diseases.8,9