• 생물정신의학
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• 제12권2호
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• pp.107-113
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• 2005

Purpose:In an attempt to predict the interpersonal differences of therapeutic response to antipsychotic drugs on pharmaco-genetic bases, this study was designed to investigate the relationship between the therapeutic response to antipsychotic drugs and Taq I A dopamine $D_2$ receptor polymorphism in schizophrenic patients. Methods:The subjects were 158 patients diagnosed with schizophrenia(DSM-IV). The therapeutic response to antipsychotic drugs was evaluated using the Treatment Response Scale(TRS) retrospectively. Patients were divided into two groups, dopamine receptor antagonist responders, and serotonin-dopamine antagonist responders. The patients' Taq I A dopamine $D_2$ receptor polymorphism was determined by polymerase chain reaction(PCR) and restriction fragment length polymorphism(RFLP). Results:The dopamine receptor antagonist responders had the A1 allele in significantly higher incidences (${\chi}^2$(1)=4.875, p=0.027, two-tailed). No significant difference was found among the serotonin-dopamine antagonist responders between those with or without the A1 allele. Conclusions:The patients with the A1 allele responded better to dopamine receptor antagonists than those with no A1 allele. Based on these results, it is suggested that the pharmacological effect of dopamine receptor antagonists can be predicted depending on the presence of the A1 allele in schizophrenic patients.

• 생물정신의학
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• 제4권2호
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• pp.218-224
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• 1997

The results regarding an association between the polymorphism sites in the dopamine $D_1$ receptor gene and schizophrenia compelled us to study the distribution of the polymorphism in Korean schizophrenia and controls. Eighty-eight schizophrenic patients and normal controls were examined by case-control study for distribution of the polymorphism of the dopamine $D_1$ receptor gene in Korean popualtion to minimize the effect of racial differencies in gene frequencies. The frequencies of the $B_1$ and $B_2$ in schizophrenic patients were 0.11 and 9.89, respectively. And 0.10 and 0.90 in normal control. Ther was no significant differences in the frequencies in the allele $B_1$ and $B_2$between schizophrenic patients and normal controls. The author present here the evidence of a lack of alleic association between the polymorphism of the dopamine $D_1$ receptor gene and Korean schizophrenic patients. The assumption that the dopamine $D_1$ receptor gene has a genetic role in the development of schizophrenia was not suppoorted by this case-control study.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• 제19권1호
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• pp.19-27
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• 2008

Objectives : The aim of this study was to examine the association of attention-deficit hyperactivity disorder (ADHD) in Korean populations with functional polymorphisms of six genes dopamine receptors (Ser311/Cys311 polymorphism, Taq1 A polymorphism, and Taq1 B polymorphism in DRD2, BalI polymorphism in DRD3, and promoter -521 C/T polymorphism and exon III 48 bp repeat polymorphism in DRD4) and one gene in dopamine transporter (DAT1). Methods : Participants were 58 children with ADHD and 110 control children. The genotypes were determined by PCR. Results : There was a statistically significant difference in genotype frequency of -521 C/T polymorphism within the promoter region of the DRD4 between two groups. Furthermore, in the male group, both genotype and allele frequencies showed statistically significant differences. Conclusion : Findings of the study indicate that -521 C/T polymorphism in promoter region of DRD4 appears to be a possible candidate gene for ADHD in Korean population.

• 생물정신의학
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• 제7권2호
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• pp.159-163
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• 2000

Background : Dopamine receptors are strong candidates for involvement in schizophrenia and are target of a wide variety of antipsychotics. Dopamine $D_5$ receptor(DRD5) gene polymorphisms may be associated with various treatment response. The purpose of our study was define to what significance can be held as a predictor of treatment response in this polymorphism. Method : The total number of 116 Korean chronic schizophrenic patients was assessed after 48 weeks treatment. The Positive and Negative Syndrome Scale(PANSS) was rated for the clinical response to various antipsychotics. With the use of polymerase chain reaction amplification, we assessed this dopamine $D_5$ receptor polymorphism in schizophrenic patients who had been treated with antipsychotics, and related genotype with treatment response, to test the hypothesis that DRD5 polymorphism may lead to varying response to antipsychotics. Result : DRD5 polymorphism was not associated with treatment response to a variety of antipsychotics in chronic schizophrenic patients. Conclusion : Genetic variation of $D_5$ receptors do not predict treatment response to antispychotics.

• 생물정신의학
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• 제2권2호
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• pp.237-247
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• 1995

도파민 $D_3$ 수용체 유전자와 정신분열증 병인과의 연관성을 밝히고자 본 연구에서는 한국에서의 정신분열증환자 66명과 정상대조군 76명에서 다형성의 분포를 PCR을 이용하여 환자대조연구 방법으로 조사하였다. 정신분열증환자에서 대립유전자 1의 빈도는 0.66이었고, 정상 대조군에서는 0.76이었다. 즉, 두군간에 대립유전자 1의 빈도에는 유의한 차이가 없었고, 양성 및 음성 증상군 척도평가에 의한 정신분열증의 양성아형과 음성아형간에도 유의한 차이가 없었다. 정신분열증 환지에서는 전체 66명중 동형 접합체가 43명으로 65.1%. 이형 접합체는 23명으로 34.9%였다. 정상 대조군에서는 전체 76명중 동형접합체가 54명으로 71.1%. 이형접합체는 28.9%였다. 이러한 결과는 이전의 정신분열증과 도파민 $D_3$ 수용체 유전자간의 연관관계를 연구한 외국의 연구결과와 일치하며 도파민 $D_3$ 수용체 유전자가 정신분열증 병인의 원인일 것이라는 가설을 뒷받침하지는 못하였다.

• Animal cells and systems
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• 제12권2호
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• pp.77-83
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• 2008

The canine fearfulness is a behavioral trait known to have a genetic basis. This research analyzed genetic effects of the dopamine D4 receptor polymorphism on this behavior by postulating a mixed model of inheritance. Genotyping for the three different repeat polymorphism found in the third exon of the receptor gene was carried out for the population of the Korean native dogs. Four hundred fifty eight dogs with known pedigree were genotyped, and 264 individuals were tested for their fear responses to an experimenter, in which four different behavioral paradigms were adopted. Since the results assessed by principal factor analysis revealed a major factor explaining 69% of the total phenotypic variance, the subsequent analyses were conducted for this quantity. Analyses of the factor scores by estimating their posterior means indicated that there is a fixed effect exerted by the three different repeat polymorphism found in the D4 receptor as well as sex, in addition to unidentified polygenic effects. The phenotypic contribution of the D4 genotype was roughly estimated to be about 2%, which is a fraction of the total genetic effects responsible for more than 20% of the total phenotypic variance.

• 대한불안의학회지
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• 제4권2호
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• pp.142-147
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• 2008

Objective : Evidence from recent studies supports the role of genetic factors in the development of Posttraumatic Stress Disorder (PTSD). The primary aim of this study is to investigate the association between the dopamine D2 receptor (DRD2) TaqI A polymorphism and PTSD. The second aim is to examine the association between the DRD2 TaqI A polymorphism and clinical symptoms in patients with PTSD. Methods : We recruited 189 Vietnam veterans for participation in this study, among whom 99 were PTSD patients and 90 were control subjects. The presence of the DRD2 TaqI A polymorphism was determined by polymerase chain reaction (PCR). Several standardized research scales were used in the clinical assessment of PTSD, including the Combat Exposure Scale (CES), Clinician Administered PTSD Scale (CAPS), Beck Depression Inventory (BDI), and Clinical Global Impression (CGI). Results : There was no significant difference in the distribution of the DRD2 genotype, frequency and prevalence of the A1 allele, or the frequency of heterozygotes between the patients with PTSD and the controls. In the PTSD group, the patients with the A1 allele (A1A1, A1A2) scored higher on the CAPS-total (p=0.044), CAPS-avoidance symptoms (p=0.016) and BDI (p=0.024) than those without the A1 allele (A2A2). Conclusion : We could not find an association between the dopamine D2 receptor (DRD2) TaqI A polymorphism and PTSD. However, the A1 allele of DRD2 seemsto influence avoidance symptoms in patients with PTSD.

• 생물정신의학
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• 제4권1호
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• pp.43-47
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• 1997

The author attempted to examine the allelic association between the A1 allele of Dopamine $D_2$ receptor and alcoholism in Koreans. The allelic distribution of Taq I polymorphism of the $D_2$ dopamine receptor gene with alcoholism was examined in 67 Korean alcoholics and compared with 100 Korean controls. In alcoholics, the numbers of alcoholics with A1A1, A1A2 and A2A2 were 11(16.4%), 30(44.8%) and 26(38.8%) respectively and in controls with A1A1, A1A2 and A2A2 were 17(17.0%), 42(42.0%) and 41(41.0%), respectively. The prevalence of the A1 allele in alcoholics was 61.2% and 59.0% in controls. And the frequency of the A1 allele in alcoholics and controls were 0.39 and 0.38, respectively. There was not significant difference in the frequency of the A1 allele between alcoholics and controls. This data suggest that the A1 allele is not associated with alcoholism in Koreans. The author conclude that our data do not support an allelic association between the A1 allele at Dopamine $D_2$ receptor and alcoholism. Further systemized studies will be necessary to determine whether the role of allele of Dopamine $D_2$receptor is major effect gene or modifying effect gene in the pathogenesis of alcoholism.

• 생물정신의학
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• 제9권1호
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• pp.15-24
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• 2002

Even though alcoholism is a multi-factorial psychiatric disorder, it is reasonable to suppose that genetic factors play a substantial role in the manifestation of this disorder. Because alcohol is the reinforcing substance which manifests its effects through activation of the mesolimbic dopaminergic reward pathway of the brain, the gene encoding dopamine receptor subtypes can be a major natural candidate gene. Since 1990, many association studies have identified strong evidence implicating the dopamine D2 receptor(DRD2) gene in alcoholism, specifically TaqI A minor(A1) allele. Association studies have also been conducted on other dopamine receptor(DRD3 & DRD4) polymorphisms but the results have yet to be confirmed. Through a number of other approaches, each dopamine receptor gene has been investigated in association with different phenotypes in alcoholism, but further researches will be needed. In conclusion, studies in the past decade have shown that the TaqI A1 allele of the DRD2 gene is associated with alcoholism in various subject groups. Other dopamine receptor genes have since been added to the list but yet to be identified. Thus, the knowledge of these genes and their functional significance will enhance the understanding of the underlying biological mechanisms of alcoholism. Furthermore, it could lead to more helpful prevention and treatment approaches to alcoholism.

• 생물정신의학
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• 제18권3호
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• pp.119-125
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• 2011

Objective It has been suggested that the dopamine D2 receptor gene (DRD2) is associated with pathological gambling (PG). We investigated the association of the DRD2 Taq1A polymorphism and the temperament in PG using Cloninger's temperament and characteristic inventory (TCI). Methods 104 PG patients and 114 control subjects were recruited. Tests for DRD2 Taq1A polymorphism were conducted in both PG patients and controls. PG patients were requested to complete the TCI. Results There were no significant differences in frequencies of the genotype (${\chi}^2$ = 0.77, p = 0.681), allele (${\chi}^2$ = 0.52, p = 0.469), and allele (A1) carrier (${\chi}^2$ = 0.15, p = 0.695) between the PG patients and the control group. When we compared the TCI profile in the PG patients according to genotypes, there were significant differences in harm-avoidance (HA, p = 0.033), and self-directedness (SD, p = 0.012) among genotypes. These difference were more evident between A1 allele carriers and non-carriers (HA, p = 0.009 and SD, p = 0.004). Conclusion Present results suggest Taq1A polymorphism may not play an important role in the susceptibility to pathological gambling in our population. However, Taq1A polymorphism might be associated with some temperament in Korean PG patients.