In the brain, ADAR2-mediated A-to-I editing recodes the transcripts encoding glutamate (eg, GRIA2, GRIK1) and serotonin (eg, HTR2C) receptor subunits, modulating their functions.1 7 8 Consequently, deregulation of A-to-I editing of these transcripts has been associated with a wide range of neurological and psychiatric disorders.20 21 Of note, the viability of Adar2 null mice is restored on insertion of the pre-edited Gria2 R sequence into the mouse genome.22 The same lethal phenotype was observed in mice with the editing-incompetent allele of Gria2. Here, GRIK1 is linked to psychiatric disorder.