An Association Study between the Dopamine D5 Receptor Gene and Korean Schizophrenia / 신경정신의학

OBJECTIVE: This study was performed to define the genetic relationship between the micro-satellite (CT/GT/GA)n polymorphism for the dopamine D5 receptor gene and schizophrenia. An association study in 100 schizophrenic patients and 100 normal controls of Korea was made by means of using polymerase chain reaction. RESULTS: The microsatellite(D5(CT/GT/GA)n) had 11 alleles. There was a significant difference in the allele distribution between schizophrenia and normal controls(p<0.05). In schizophrenic patients, the frequency of allele A10 was decreased. As to the genotype distribution, there was no difference in both groups. CONCLUSIONS: This finding suggests that dopamine D5 gene is likely to be related to the development of schizophrenia in Korea but with only this result, we cannot come to the conclusion that this genetic locus is the genetic determinant of schizophrenia. Further studies of dopamine D5 receptor genetic locus that can confirm this result should be made.

Association Study of the Sequence Mutation(T978C) of the Dopamine D5 Receptor Gene in Korean Schizophrenics / 신경정신의학

OBJECTIVE: This study was performed to assess the possible involvement of the dopamine D5 receptor gene(DRD5) in the etiology of schizophrenia. METHODS: We identified the distribution of the T978C varient of the dopamine D5 receptor gene in 100 schizophrenics and 100 normal controls in Korean population, and evaluated the association between two groups. RESULTS: There were no significant differences in genotype frequency of T978C variation and genotype prevalence of homozygotes between schizophrenic and control groups. There was no significant difference in T978C allele frequencies between schizophrenic and control groups. CONCLUSION: We present evidence of a lack of allelic association between the exonic common polymorphism of the dopamine D5 receptor gene and Korean schizophrenic patients. The assumption that the T978C varient of the dopamine D5 receptor gene has a genetic role in the development of schizophrenia was not examined by this case-control study. However, because it is considered that DRD5 may act as the expression factor for the symptoms of schizophrenia or affect the difference in an individual's susceptibility to the disease, future studies to investigate the influence of other variations of DRD5 are needed.