GRM7 and schizophrenia: GRM7 was first associated with schizophrenia in a study of Japanese patients with schizophrenia in a case-control study of 2293 Japanese patients and 2382 control subjects, examining the influence of one polymorphism associated with schizophrenia on the expression of GRM7 in a dual-luciferase assay (in transfected cells, mutations in all the exons, exon/intron junctions, and promoter regions); the results suggested a potential association of a synonymous polymorphism (371T/C, rs3749380) in exon 1 with schizophrenia [126].