The dysbindin gene (DTNBP1) and schizophrenia: no support for an association in the Korean population.

The dysbindin gene (DTNBP1) is located in chromosome 6p22.3, one of the regions of positive linkage for schizophrenia. A strong genetic association between DTNBP1 and schizophrenia has been replicated through many recent studies. In particular, dysbindin protein has been found to play a role in the glutamate neural transmission in the brain. In this study, we attempted to replicate the previously reported positive association between DTNBP1 and schizophrenia in the Korean population. Our sample included 194 patients with schizophrenia based on DSM-IV and 351 normal controls. We genotyped five SNPs including SNP A in promoter region of DTNBP1. The allele and genotype association were analyzed and the simulated haplotype was investigated as well. As the result, we could not find a significant association of DTNBP1 with schizophrenia in this Korean sample. Additional analysis of the subgroup of schizophrenia having familial loading of major psychiatric disorders did not show association, either. In summary, DTNBP1 is not likely to be a major susceptibility gene for schizophrenia in this Korean population. This result of no association also implies possible genetic heterogeneity of schizophrenia. Further studies with more dense SNPs of the whole gene sequence for various populations will be necessary to understand the genetic contribution of DTNBP1 for the development of schizophrenia.