GRIK4 and psychotic disorder: When comparing a broader neurodevelopmental phenotype, e.g. ASD, psychosis and ID, or a narrower psychosis phenotype with control individuals, we observed a significantly increased burden of LoF and missense variants within all GRIK and NETO genes (broad neurodevelopmental, all allele frequencies, p = 2.97 × 10−10; broad neurodevelopmental, ultra-rare and rare p = 6.02 × 10−7; psychosis, all frequencies; p = 6.17 × 10−7; psychosis, ultra-rare and rare p = 1.83 × 10−7).