GRM2 and schizophrenia: A total of 45 polymorphisms in the genes GRIN1, GRIN2A, GRIN2B, GRIN3A,GRIA1, GRIK2, GRM2, GRM3, GRM5, GRM8, SLC1A1, SLC1A3 and GAD1 were genotypedin 258 patients with schizophrenia.