Association analysis of the genetic variants of the N-methyl D-aspartate receptor subunit 2b (NR2b) and treatment-refractory schizophrenia in the Chinese

Several pieces of evidence showed that N-methyl D-aspartate (NMDA)-receptor-mediated decreases in function may be a causative factor for schizophrenia. The NMDA receptors are composed of a common glutamate receptor, an ionotropic NMDA 1 (GRIN1) subunit and one of four GRIN2 subunits (GRIN2A-GRIN2D), combined in an undetermined ratio to make up the receptor complex. In this study, we tested the hypothesis of whether the GRIN2B 366C/G and 2664C/T genetic polymorphisms are related to Chinese treatment-refractory schizophrenic patients. 193 treatment-refractory schizophrenic patients and 176 normal subjects were recruited for this study. The results demonstrated that the genotype distribution was similar between schizophrenic patients and control subjects in 366C/G (p = 0.88) and 2664C/T (p = 0.336), but we found a higher mean clozapine dosage in 2664C/C genotype patients. These results show that GRIN2B genetic variations were not a major risk factor for treatment-refractory schizophrenic patients, but may influence the effect of clozapine during treatment. Copyright (C) 2003 S. Karger AG, Basel.