Association between a promoter polymorphism in the dopamine D2 receptor gene and schizophrenia.

Genetic factors and dopamine receptor dysfunction have been implicated in the pathophysiology of schizophrenia. Recently, an association between a putative functional promoter polymorphism (-141C Ins/Del) in the dopamine D2 receptor gene and schizophrenia was reported. We investigated unrelated Swedish schizophrenic patients (n = 129) and control subjects (n = 179) for the same polymorphism. Similarly to a previous Japanese report, the - 141C Del allele frequency was significantly lower in patients than controls (chi2=4.4, 1 df, p<0.05; odds ratio 0.49, 95% confidence interval 0.26-0.91). The present and previous results may indicate that the -141C Ins/Del dopamine D2 receptor gene polymorphism affects susceptibility to schizophrenia.     

多巴胺D3受体基因多态性与精神分裂症

目的:探讨沈阳地区汉族人群中多巴胺D3受体基因(DRD3)第一外显子第9密码子A→G单核苷酸置换多态性(Ser9Gly多态)与精神分裂症的关联。方法:采用聚合酶链反应-限制性内切酶片断长度多态性(PCR-RFLP)技术对70例精神分裂症患者、94名健康对照者进行基因分型鉴定。比较患者组与对照组DRD3多态性分布频率、精神分裂症早发组与非早发组基因分布频率差异,并与其他国家人群进行比较。结果:患者组与对照组之间等位基因分布无明显差异,早发组与非早发组亦未发现明显差异,而该位点等位基因分布频率与巴西、英国人群有明显差异。结论:研究人群中未发现DRD3基因Ser9Gly多态与精神分裂症存在明显关联。     

多巴胺D2受体基因的TaqI A多态性与迟发性运动障碍的关联分析

目的　研究多巴胺D2受体 (DRD2 )基因TaqIA多态性与精神分裂症伴迟发性运动障碍 (TD)的相关性。方法　使用异常不自主运动量表 (AIMS)评定精神分裂症患者有无TD及TD严重程度 ,并采用简明精神病评定量表 (BPRS)评定患者精神症状 ;应用聚合酶链反应 (PCR)—限制性片段长度多态性 (RFLP)法分析TD组和非TD组的DRD2基因的TaqIA等位基因频率和基因型分布。结果　DRD2基因TaqIA的等位基因频率和基因型分布在TD组与非TD组之间均无显著性差异 ,且不同基因型间的AIMS总分值也无显著性差异。结论　在中国汉族男性精神分裂症患者中DRD2基因的TaqIA多态性可能不是影响TD发生的主要危险因素。     

Association between dopamine receptor D1 A-48G polymorphism and methamphetamine abuse

Several lines of evidence have suggested that substance abuse is mediated by the dopaminergic rewarding system, primarily through the activity of the dopamine receptor D1 (DRD1). The purpose of the present study was to evaluate the association of DRD1 A-48G polymorphism with methamphetamine (MAP) abusers and MAP-induced psychosis patients. A total of 363 MAP abusers and 425 healthy normal controls were enrolled. The structural Diagnostic Interview for Genetic Study was used to evaluate all MAP abusers. The MAP abusers were classified into psychosis (n = 135) and non-psychosis (n = 228) groups. A-48G polymorphism was determined by polymerase chain reaction-restriction fragment length polymorphism. The results show that male sex and a higher frequency of MAP abuse were the predisposing factors in the development of MAP psychosis. The DRD1 -48G allele frequency in the MAP psychosis group, non-psychosis group and the healthy normal controls was 0.14, 0.18 and 0.16, respectively. No association was found between DRD1 A-48G polymorphism and MAP abuse and MAP psychosis. However, the data provided additional evidence of ethnicity-related differences in the distribution of polymorphism in comparison to previous studies.     

Association between the dopamine D2 receptor (DRD2) polymorphism and the personality traits of healthy Japanese participants

Background

Dopamine neurotransmitter systems have been associated with reward-related and novelty-seeking personality traits. We investigated the possible relationship between the personality traits measured by the Temperament and Character Inventory (TCI) and the TaqI A and − 141C Ins/Del polymorphisms in the dopamine D2 receptor gene (DRD2).

Methods

The sample consisted of 1084 healthy Japanese medical students and medical staff (age = 29.0 ± 9.7 years), each of whom completed the TCI. Their genomic DNA was isolated from whole blood and genotyped using the TaqMan allele-specific assay method. The associations between gene polymorphisms and the scores for TCI were statistically analyzed by one-way analysis of covariance (ANCOVA) adjusting age. Males and females were analyzed separately. Epstatis was assesses using two-way ANCOVA between the DRD2 and ANKK1 genes.

Results

Men with the Ins/Del genotype of the − 141C Ins/Del polymorphism had significantly higher self-directedness scores than those with the Ins/Ins genotype (p = 0.021). None of the TCI scores differed among women with regard to the three genotype groups of the − 141C Ins/Del polymorphism. The DRD2/ANKK1 Taq1 A polymorphism did not affect any TCI factor for either men or women. An epistatic analysis did not reveal main effects of the two genes with regard to TCI scores, but an ANKK1 × DRD2 interaction significantly predicted TCI scores.

Conclusion

These findings suggest the possibility that the − 141C Ins/Del polymorphism and the DRD2/ANKK1 Taq1 A polymorphism are not strongly linked to personality traits directly, but influences them under the interaction between the DRD2 and ANKK1 genes.     

多巴胺D4受体基因与精神分裂症质量性状和数量性状的关联分析

目的探讨多巴胺D4受体(DRD4)基因第3外显子48 bp可变重复序列(VNTR)多态性与精神分裂症疾病表型的质量性状和数量性状的关系.方法应用聚合酶链反应(PCR)、变性聚丙烯酰胺凝胶电泳结合银染技术检测162例精神分裂症患者(患者组)及162名正常人(对照组)的DRD4基因48 bp VNTR多态性;利用阳性与阴性症状量表(PANSS)来评定精神分裂症疾病表型的数量性状.用χ2检验和单因素方差分析(one way-ANOVA)分析DRD4基因与精神分裂症疾病表型的质量性状和数量性状的关系.结果 (1)患者组与对照组间DRD4基因的基因型及等位基因的频率分布的差异无统计学意义 (P＞0.05).按性别比较,3/5基因型在女性患者(47%)中的频率明显高于男性患者(29%)和女性对照者(32%),差异有统计学意义(P<0.05).(2)患者组DRD4基因3种基因型间PANSS总分及其分量表分差异无统计学意义(P＞0.05);但患者组长片段基因型"思维障碍"的因子分明显高于中片段基因型者,差异有统计学意义(P<0.05);女性患者长片段基因型者概念紊乱条目分明显高于中片段基因型者(P=0.01)和短片段基因型者,差异有统计学意义(P<0.05).结论 (1)DRD4基因48 bp VNTR与精神分裂症疾病表型的质量性状和数量性状可能无关联;(2)DRD4基因48 bp VNTR与精神分裂症疾病表型中的"思维障碍"和"概念紊乱"的数量性状可能存在关联,长片段基因型患者的症状可能较严重.     

多巴胺D3受体基因多态性与精神分裂症亚型及利培酮疗效相关性分析

目的探讨多巴胺D3受体(dopamine D3 receptor,DRD3)基因第一外显子丝氨酸9甘氨酸(Ser9Gly)多态性与精神分裂症临床亚型、药物疗效的关联.方法 241 例汉族首发精神分裂症患者,采用限制性片段长度多态性(restriction fragment length polymorphism,RFLP)技术测定基因型.分析判断基因多态性与精神分裂症的临床亚型、药物疗效的关联. 结果精神分裂症各亚型Ser9Gly等位基因分布存在显著性差异(p <0.05).利培酮疗效不同的患者间Ser9Gly等位基因多态性均无显著性差异. 结论 DRD3受体基因第一外显子Ser9Gly多态性可能与精神分裂症亚型相关,而与患者对药物的反应不相关.     

多巴胺D2受体基因多态性与脑出血的相关性研究

目的 探讨多巴胺D2受体（DRD2）基因TaqI位点多态性与中国湖南地区汉族人群脑出血发病的相关性.方法 本研究筛选121例脑出血患者,匹配103例正常体检人群为对照,PCR-RFLP检测DRD2 TaqI基因多态性.结果 DRD2 TaqI三种基因型（A1A1,A1 A2,A2A2）频率及两种等位基因（A1,A2）频率在脑出血组和正常对照组分布的差异无统计学意义（P＞0.05）.脑出血组中高血压亚组、非高血压亚组及对照组三者两两比较DRD2 TaqI基因型频率分布的差异无统计学意义（P＞0.05）.Logistic回归调整了脑出血环境因素的影响后,DRD2 TaqI基因多态性仍与脑出血的无相关性（P＞0.05）.结论 DRD2 TaqI基因多态性可能与中国湖南地区汉族人群脑出血无关.     

The -141C Ins/Del and Taq1A polymorphism in the dopamine D2 receptor gene may confer susceptibility to schizophrenia in Asian populations

It has been reported that two single nucleotide polymorphisms (SNP) Taq1A and -141C Ins/Del in the DRD2 gene may be associated with susceptibility to schizophrenia. Due to inconclusive and mixed results, a meta-analysis was conducted to further clarify the relationship between the two SNP and schizophrenia susceptibility. A systematic literature search for the association of these two SNP with schizophrenia susceptibility was conducted using PubMed, ScienceDirect, Chinese Biomedical Literature Database, and Chinese National Knowledge Infrastructure. Odds ratios (OR) with 95% confidence intervals (CI) were used to assess the strength of the associations reported. A total of 5558 schizophrenic patients and 6792 healthy controls from 31 articles were included in this study. Evidence regarding the association between -141C Ins/Del polymorphism and schizophrenia was found in the allele frequency comparison (Ins versus Del: OR 1.29, 95% CI 1.06–1.57; p = 0.01, P_raw = 0.1, P_{False Discovery Rate} = 0.023). In ethnic subgroup analysis, the result revealed that the 141C Ins/Del polymorphism was associated with schizophrenia in all genetic models in Asians, but not in Caucasians. For Taq1A polymorphism, a significant association was found in the allele frequency (A1 versus A2: OR 0.71, 95% CI 0.52–0.98, p = 0.03). Stratification by ethnicity indicated an association between the Taq1A polymorphism and schizophrenia in Asians, but not Caucasians. The present study suggests that the -141C Ins/Del polymorphism carries a significantly increased risk of schizophrenia, while the Taq1A polymorphism carries a significantly decreased risk of schizophrenia susceptibility in Asians.     

Association between dopamine D3 receptor gene polymorphisms and schizophrenia in an isolate population

There are several lines of evidence implicating the dopamine D3 receptor in the pathophysiology of schizophrenia. The Ser9Gly polymorphism of the dopamine D3 receptor gene (DRD3) has been the most extensively investigated DRD3 variant in connection with the disease but results have been inconclusive. Recent reports indicate that the Ser9Gly polymorphism is in linkage disequilibrium with other markers, but association studies between DRD3 haplotypes and schizophrenia have had mixed results. Genetic heterogeneity may be one of the causes of contradicting results. In order to clarify the role of DRD3 alterations in the aetiology of disease, we have investigated three D3 genetic variants (Ser9Gly, -205-G/A, -7685-G/C) in a sample of patients with schizophrenia or schizoaffective disorder (N=118) and controls (N=162) recruited from a human isolate from Navarra (Northern Spain) of Basque origin. Although no association was found between the Ser9Gly or the -205-A/G polymorphisms and disease, an excess of allele -7685-C was observed in patients (p=0.002 after correction for multiple analyses). Haplotype analysis shows the three markers to be in strong linkage disequilibrium (p<0.0001) and strongly associated with disease (p<1x 10(-5)). These results may suggest that these polymorphisms exert a combined or synergistic effect on susceptibility to schizophrenia, or are in linkage with an unknown causative factor. However, further replication in independent samples is required.     

Association in Japanese patients between neuroleptic malignant syndrome and functional polymorphisms of the dopamine D(2) receptor gene

A genetic predisposition to the development of neuroleptic malignant syndrome (NMS) has been suggested by clinical studies. Although the molecular basis of NMS is unclear, a dopaminergic blockade mechanism has been considered the main cause. We therefore investigated the association between NMS and three functional polymorphisms of the dopamine D(2) receptor (DRD(2)) gene: TaqI A, -141C Ins/Del, and Ser311Cys. Subjects included 32 Japanese patients, previously diagnosed with NMS, and 132 schizophrenic patients treated with neuroleptics without occurrence of NMS. Polymerase chain reaction and restriction fragment length polymorphism analyses were performed to determine each genotype. We found significant differences in genotypic and allelic frequencies of the -141C Ins/Del polymorphism between patients with and without NMS. The -141C Del allele was significantly more frequent in the NMS group (23.4 vs 11.7%, P=0.026). Similarly, the proportion of -141C Del allele carriers was significantly higher in the NMS group (40.6 vs 20.5%, P=0.022). No significant differences between the two groups were seen for allelic and genotypic frequencies of the TaqI A and Ser311Cys polymorphisms. This result suggests that the -141C Ins/Del polymorphism is likely to predispose toward the development of NMS, probably together with other unidentified factors.     

No linkage between D2 dopamine receptor gene region and schizophrenia

The dopamine hypothesis is one of the major etiological hypotheses of schizophrenia. The well-established role of genetic factors in schizophrenia together with reports of increased D2 dopamine receptor densities in untreated schizophrenic patients support the D2 dopamine receptor gene as a strong candidate gene for schizophrenia. The recent cloning of the D2 dopamine receptor gene made it possible to test the involvement of the D2 dopamine receptor locus (DRD2) in a large Swedish and a smaller Californian schizophrenia pedigree. Using multipoint linkage analysis between schizophrenia and a genetic map that includes the DRD2 locus and assuming a dominant mode of inheritance, we were able to exclude the DRD2 locus with a lod score of -4.14 for the penetrance of 0.72 and with a lod score of -3.05 for the lower bound penetrance of 0.56. The area of exclusion (lod score, less than -2.00) extended 27 centimorgans. These results provide strong evidence against linkage of the D2 dopamine receptor gene region to schizophrenia in the two pedigrees investigated. We conclude that the genetic predisposition to schizophrenia in these pedigrees is not due to aberrations in the DRD2 locus or the porphobilinogen deaminase locus. Our results do not support the D2 dopamine receptor hypothesis of schizophrenia. However, they cannot exclude the possibility that other genes regulating aspects of D2 dopamine expression might be involved in the etiology of schizophrenia, such as the expression of two D2 dopamine receptor subtypes by alternative RNA splicing.     

Extrastriatal dopamine D2 receptor occupancy in olanzapine-treated patients with schizophrenia

Olanzapine is described as a multi-acting receptor-targeted antipsychotic agent. Although regional differences of dopamine D₂ receptor occupancy, i.e., limbic selectivity, were reported for olanzapine, contradictory results were also reported. We measured dopamine D₂ receptor occupancy of olanzapine in extrastriatal regions in patients with schizophrenia using positron-emission tomography with [¹¹C]FLB457 and the plasma concentrations of olanzapine. Ten patients with schizophrenia taking 5–20 mg/day of olanzapine participated. Dopamine D₂ receptor occupancy in the temporal cortex ranged from 61.1 to 85.8%, and plasma concentration was from 12.7 to 115.4 ng/ml. The ED₅₀ value was 3.4 mg/day for dose and 10.5 ng/ml for plasma concentration. The ED₅₀ values obtained in this study were quite similar to those previously reported in the striatum. In conclusion, although the subjects and methods were different from previous striatal occupancy studies, these results suggest that limbic occupancy by olanzapine may not be so different from that in the striatum.     

精神分裂症患者多巴胺D1受体基因-48A/G多态性与认知功能的关系

目的探讨精神分裂症患者多巴胺D1受体基因-48A／G多态性与认知功能的关系。方法应用聚合酶链反应-限制性片段长度多态性方法(PCR-RFLP),检测103例精神分裂症患者多巴胺D1受体基因-48A／G多态性。采用威斯康星卡片分类测验(Wiscosin Card Sorting Test,WCST)和韦氏成人智力量表修订版(Wechsler Adult Intelligence Scale-RC,WAIS-RC)评估患者的认知功能。结果其中分类数、错误应答数、持续应答数、非持续错误数、算术、数字广度(顺)、数字符号及木块图得分在AA基因型和AG+GG基因型两组患者间均无显著性差异(P>0．05),但持续错误数(t=2．321,P<0．05)和数字广度(逆)(t=3．042,P<0．01)在两组间有显著性差异,AA基因型患者持续错误数和数字广度(逆)得分明显高于AG+GG基因型患者。结论精神分裂症患者D1受体基因-48A／G多态性与持续性错误数及数字广度(逆)相关,AA基因型精神分裂症患者较AG+GG基因型患者工作记忆受损更严重,但短时记忆能力要强于后者。     

Association between chromogranin A gene polymorphism and schizophrenia in the Japanese population

It has been reported that expression of the chromogranin A (CHGA) gene is reduced in the prefrontal cortex and cerebrospinal fluid of patients with schizophrenia. Single-marker and haplotype analyses of SNPs within the CHGA gene were performed in 633 subjects with schizophrenia and 589 healthy controls. A significant association with schizophrenia was observed to one SNP marker, rs9658635 (p=0.0269), and with a 2 marker haplotype (p=0.0016). Significant association of rs9658635 was then replicated in a second independent cohort (377 schizophrenia and 338 control samples) (p=0.007). These results suggest that the CHGA gene is associated with the risk of developing schizophrenia in the Japanese population.