第10号染色体缺失的磷酸酶张力蛋白同源物基因多态性与脑膜瘤易感性关联研究

目的 研究中国人群中第10号染色体缺失的磷酸酶张力蛋白同源物基因（PTEN）单核苷酸多态性与脑膜瘤发病风险的关系。方法 选取2017年10月—2018年1月在北京天坛医院神经外科手术治疗的200例脑膜瘤患者为研究对象,应用SNaPshot基因分型技术对PTEN基因多态位点rs2735343、rs701848和rs1234214检测,分析PTEN基因多态性与脑膜瘤的易感性。结果 PTEN基因多态位点rs2735343、rs701848和rs1234214基因频率在脑膜瘤组和对照组基因型和等位基因频率分布无差异（P＞0.05）。单体型分析结果显示CTC单体型频率在脑膜瘤组和对照组之间差异有统计学意义（P＜0.05）,CTC单体型携带者发生脑膜瘤的风险增加（OR=1.366,95%CI=1.034~1.805,P=0.028）。结论 PTEN基因多态性可能与脑膜瘤发病无关联,但PTEN基因rs2735343、rs701848和rs1234214构成的CTC单体型可能是中国人群脑膜瘤发病的危险因素。     

代谢型谷氨酸受体3基因多态性与中国北方汉族男性酒依赖关系的研究

目的探讨中国北方汉族人群代谢型谷氨酸受体3(GRM3)基因多态性与酒依赖的相关性。方法采用聚合酶链反应(PCR)和连接酶检测反应(LDR)方法,检测248例酒依赖患者和235例对照组的GRM3组基因上10个位点的单核苷酸多态性。结果酒依赖组与对照组相比较,rs6465084位点的A等位基因和A/A基因型频率明显增高(P0.05)。单体型TAATATT、CAGTATT、TCGTATT、CAATAGC、TAATATC频率在酒依赖组和对照组中具有统计学显著差异(P0.05),其中单体型TAATATT频率较对照组明显增高(P0.001),且频率≥5%。结论GRM3基因可能是酒依赖发生的候选基因之一。     

精神分裂症患者谷氨酸受体基因多态性及与奥氮平疗效的关系

目的:探讨奥氮平治疗精神分裂症的疗效与代谢型谷氨酸受体-3(m GluR3)基因多态性的关系。方法:给予268例精神分裂症患者奥氮平单药治疗12周;应用阳性与阴性症状量表(PANSS)、临床总体印象量表-严重程度和改善程度量表(CGI-SI)分别于治疗前和治疗1、2、4、8、12周对患者进行疗效评定。采用DNA测序技术检测上述患者及272名正常对照者m GluR3基因单核苷酸多态性rs1335042和rs6465084的基因型及等位基因频率,并对精神分裂症患者的奥氮平疗效与m GluR3基因多态性进行关联分析。结果:rs1335042基因型患者PANSS总分从治疗2周起开始下降(P0.05或P0.01),rs6465084基因型患者PANSS总分下降不明显,奥氮平疗效对多态性位点的等位基因和基因型频率分布有影响作用(P均0.05)。结论:奥氮平治疗精神分裂症的疗效可能与谷氨酸受体基因的多态性有关。     

精神分裂症患者脑源性神经营养因子基因多态性与临床症状的关系

背景 神经发育学说是精神分裂症发病机制的研究重点,脑源性神经营养因子（BDNF）在神经元发育过程中起重要作用,可能是精神分裂症的生物标志物之一。BDNF水平及其基因多态性在精神分裂症的发病机制中具有重要作用,但尚存争议。目的 分析精神分裂症患者BDNF水平与健康对照人群的差异,探讨BDNF单核苷酸多态性（SNPs）位点（rs11030101、rs2030324、rs6265）与BDNF水平的关系,并分析其与临床症状的关系,为精神分裂症的治疗提供参考。方法 采用病例对照研究,纳入2019年1月-2020年12月在中山市第三人民医院就诊的、符合《精神障碍诊断与统计手册（第5版）》（DSM-5）精神分裂症诊断标准的55例精神分裂症患者为研究对象,同期在中山市第三人民医院工作人员和社会人群中招募健康对照组31名。使用阳性和阴性症状量表（PANSS）评定精神分裂症患者的临床症状。采用酶联免疫吸附法（ELISA法）经酶标仪定标检测精神分裂症患者和对照组血清BDNF水平,采用聚合酶链式反应产物直接测序确定患者组和对照组BDNF的rs11030101、rs2030324、rs6265位点基因型。结果 患者组血清BDNF水平低于对照组,差异有统计学意义（t=-3.804,P<0.01）。临床症状方面,BDNF rs11030101位点不同基因型的患者PANSS总评分、兴奋敌对因子评分和抑郁焦虑因子评分差异均有统计学意义（t=2.022、Z=-2.696、-2.467,P<0.05或0.01）。不同位点的各基因型患者血清BDNF水平差异均无统计学意义（Z=1.483、F=2.584、0.417,P均>0.05）。结论 精神分裂症患者BDNF水平偏低。BDNF的rs11030101、rs2030324、rs6265位点多态性与血清BDNF水平水平无关,BDNF的rs11030101位点多态性可能会导致精神分裂症患者兴奋敌对、抑郁焦虑等临床症状。血清BDNF水平可能更多地取决于诊断效果而非基因多态性效应。     

GluR-6和GABRG2基因多态性与精神分裂症患者精神症状的关系

目的探讨谷氨酸受体6基因（GluR6）和γ－氨基丁酸γ2受体基因（GABRG2）基因多态性与精神分裂症患者精神症状的关系。方法以聚合酶链式反应－限制性片段长度多态性（PCR--RFLP）方法对600名研究对象的GluR6基因rs2227283（G／A碱基改变）和GABRG2基因rs211014（T／G碱基改变）单核苷酸多态性（SNP）进行检测。同时采用阳性与阴性症状量表（PANSS）、修订版外显攻击量表（MOAS）以及自制的一般情况调查表对研究组和对照组1的研究对象进行测查。使用SPSS13．0对数据进行统计分析。结果（1）GluR6基因的rs2227283位点等位基因分布与精神分裂症的阳性症状被害妄想相关（F=4．641,P=0．032）;（2）rs2227283等位基因A与兴奋、情绪退缩、关注身体健康以及不合作等阴性症状相关联（P〈0．05）,rs211014等位基因G与幻觉行为、兴奋、自罪感、动作迟缓以及不寻常思维内容等阳性症状相关（P〈0．05）。结论GluR6基因rs2227283位点多态性可能与攻击行为及阴性症状有关联,GABRG2基因rs211014位点多态性可能与攻击行为及阳性症状有关联。     

PPP1R3A基因多态性与中国维吾尔族人群精神分裂症关联性研究

目的探索蛋白磷酸酶1调节亚基3A(protein phosphatase 1 regulatory subunit 3A, PPP1R3A)基因外显子区域基因位点多态性与中国维吾尔族人群精神分裂症的关联性。方法利用多重PCR靶向捕获二代测序技术对528例维吾尔族精神分裂症患者及576名维吾尔族正常对照进行PPP1R3A基因外显子区域DNA扩增,Illumina HiSeq X Ten平台进行高通量测序,用阳性与阴性症状量表(positive and negative symptoms scale,PANSS)评估患者病情严重程度。结果患者组与对照组之间PPP1R3A基因rs1800000位点等位基因和基因型频率差异有统计学意义(P0.05);rs1799999位点基因型频率在女性患者组与对照组间差异有统计学意义(P0.05);rs8192686位点在男性患者组与对照组间等位基因频率差异有统计学意义(P0.05)。结论PPP1R3A基因rs1800000位点多态性可能与中国维吾尔族人群精神分裂症的发生发展存在关联性;rs1799999位点多态性可能与中国维吾尔族女性精神分裂症的发病有关联性;rs8192686位点C等位基因可能与中国维吾尔族男性精神分裂症发病有关联性。     

精神分裂症锚蛋白重复序列3基因多态性及表达研究

目的探讨锚蛋白重复序列3(ankyrin repeat 3,ANK3)基因多态性和基因表达与精神分裂症的关系。方法采用Taq Man探针等位基因分型技术对456例中国汉族精神分裂症患者(患者组)和495名正常对照者(对照组)ANK3基因多态性位点rs10994336、rs10994359进行基因分型,并对基因型、等位基因、单体型频率进行比较;然后采用Taq Man探针及实时荧光定量PCR方法检测另外30例急性期精神分裂症患者和26名正常对照外周血ANK3基因m RNA的表达水平。结果患者组与对照组rs10994336和rs10994359基因型、等位基因频率分布的差异无统计学意义(P0.05)。单体型分析显示,由rs10994336-rs10994359组成单体型C-C、C-T、T-C的频率分布在患者组与对照组间差异无统计学意义(P0.05)。与对照组相比,急性期精神分裂症患者外周血ANK3基因的m RNA表达水平略高,但差异无统计学意义(P0.05)。结论本研究未发现ANK3基因位点rs10994336、rs10994359多态性与精神分裂症的关联,急性期精神分裂症患者外周血中ANK3基因的表达水平未见异常。     

精神分裂症和2型糖尿病与胞浆型磷脂酶A2基因和断裂基因1的关联分析

目的 探讨精神分裂症与2型糖尿病间是否存在遗传相关性.方法 纳入首发精神分裂症患者133例、正常一级亲属79名、2型糖尿病患者125例和正常对照88名,采用限制性片段长度多态性技术(PCR-RFLP)检测胞浆型磷脂酶A2(cPLA2)基因BanI多态性与断裂基因1(DISCl)rs821616多态性.比较上述4组间BanI与rs821616基因多态分布频率的差异.结果 ①精神分裂症组和2型糖尿病组BanI多态性的A2/A2基因型频率与正常对照组间的差异均有统计学意义(P=0.047,OR=2.419;P=0.043,OR=2.472),A2/A2基因型频率分别为精神分裂症组(17.29%)、一级亲属(13.93%)、2型糖尿病(17.60%)、对照组(7.96%);A1/A2、A1/A1基因型和A1、A2等位基因频率组间比较差异均无统计学意义(P＞0.05);②4组间rs821616多态性的基因型和等位基因分布频率差异均无统计学意义(P＞0.05).结论 cPLA2基因BanI多态性与精神分裂症和2型糖尿病均可能存在关联,提示cPLA2基因可能与两种疾病均相关;未发现rs821616多态性与精神分裂症或2型糖尿病关联.     

中国新疆维吾尔族人群中ANK3基因rs10761482多态性与精神分裂症关联性的病例对照研究(英文)

背景:ANK3基因rs10761482多态性已被发现与精神分裂症的发生相关联。目的:评估新疆维吾尔族人群ANK3基因和精神分裂症之间的关联。方法:使用Taqman探针技术对630例新疆维吾尔族精神分裂症患者和535名新疆维吾尔族健康人群进行ANK3基因rs10761482位点的基因分型。采用SHEsis和SPSS17.0软件进行数据分析。结果:病例组和对照组之间的基因型和等位基因频率无显著差异。在病例组,性别或精神分裂症发病年龄与基因型或等位基因频率之间没有显著关联。将男性和女性单独分析,病例组与对照组之间的等位基因和基因型频率均未发现显著差异,青春期发病与成年后发病的精神分裂症患者之间的等位基因和基因型频率也无显著差异。结论:我们的研究结果不支持以往ANK3基因与精神分裂症有关联的报告。本研究招募的维吾尔族人群中,ANK3基因rs10761482多态性与精神分裂症之间没有显著关联。如果这些结果在进一步的研究中得到证实,那么研究重点将转而了解为什么在这个特定的族群中不存在上述已经被广泛认可的关联。     

GSK3B基因启动子区多态性与中国北方汉族人群阿尔茨海默病的相关分析

目的研究中国北方汉族人群中糖原合成酶激酶38基因（GSK3B）启动子区rs334558位点基因多态性与阿尔茨海默病（AD）易感性的相关性。方法采用直接测序的方法,对403例AD病例及369名对照外周血DNA的GSK3B基因多态位点rs334558进行基因分型。结果AD组与对照组rs334558位点等位基因和基因型分布相似,等位基因T的频率在AD组和对照组分别为38．8％和37．9％,差异无统计学意义（y。一0．130,P〉0．05）。按照性别或者是否携带AopF~4等位基因分别进行分层分析,发现AD组和对照组之间等位基因频率和基因型分布的差异无统计学意义（,分别为0．331,0．565;P〉0．05）。结论GSK3B基因启动子区多态性位点rs334558可能与中国汉族人群AD发病无关。     

Effect of metabotropic glutamate receptor 3 genotype on N-acetylaspartate measures in the dorsolateral prefrontal cortex

OBJECTIVE: This study was carried out to confirm prior evidence of an effect of a single nucleotide polymorphism (SNP) in the metabotropic glutamate receptor 3 (GRM3) gene (a putative risk factor for schizophrenia) on measures of N-acetylaspartate in healthy comparison subjects. METHOD: Fifty-four carefully screened healthy volunteers genotyped at SNP rs6465084 underwent magnetic resonance spectroscopic imaging (MRSI) at 3 T and selected neuropsychological testing. RESULTS: The A/A genotype group exhibited a significant reduction of N-acetylaspartate/creatine levels in the right dorsolateral prefrontal cortex compared to the G carriers. A tendency in the same direction was seen in the left dorsolateral prefrontal cortex and in the white matter adjacent to the prefrontal cortex. CONCLUSIONS: These findings provide further evidence that GRM3 affects prefrontal function and that variation in GRM3, monitored by SNP rs6465084, affects GRM3 function.     

Effect of metabotropic glutamate receptor 3 genotype on N-acetylaspartate levels and neurocognition in non-smoking, active alcoholics

ABSTRACT: BACKGROUND: We studied the effects of single nucleotide polymorphisms (SNPs) in the metabotropic glutamate receptor 3 (GRM3) gene on brain N-acetylaspartate (NAA) concentrations and executive function (EF) skills in non-smoking, active alcoholics, and evaluated associations between these variables. METHODS: SNPs (rs6465084, rs1468412, and rs2299225) in GRM3 were genotyped in 49 male, non-smoking, alcohol-dependent patients and 45 healthy control subjects using ligase detection reactions. NAA/creatine (Cr) ratios in left prefrontal gray matter (GM) and white matter (WM), left parietal GM, left parietal WM, and cerebellar vermis regions were measured by Proton 1 H Magnetic resonance spectroscopy (MRS). EF was measured by the Wisconsin Card Sorting Test (WCST). RESULTS: Compared to controls, alcoholics had lower NAA/Cr ratios in prefrontal GM and WM regions and performed more poorly on all EF tests (P < 0.001). Alcoholics with the A/A genotype for SNP rs6465084 had lower NAA/Cr ratios in prefrontal GM and WM regions and had poorer EF skills than alcoholics who were G-carriers for this SNP (P < 0.01). Non-alcoholics with the A/A genotype for rs6465084 also had lower NAA/Cr levels in prefrontal GM and made more random errors in the WCST than G-carriers (P < 0.01). The A/A genotype group for SNP rs6465084 was significantly different from the G carriers for the variables of NAA/Cr ratios and WCST scores in both alcoholics and controls (P < 0.05). Alcoholics who were T-carriers for rs1468412 had lower NAA/Cr ratios in prefrontal GM and showed poorer EF skills (P < 0.05). No effects of rs2299225 genotype on NAA/Cr or executive skills were observed. NAA/Cr in left prefrontal regions correlated with certain parameters of EF testing in both alcoholics and controls (P < 0.05), but the significance of this correlation among alcoholics disappeared after adjustment for the effects of genotype. CONCLUSIONS: Our results provide evidence that glutamate system dysfunction may play a role in the prefrontal functional abnormalities seen in alcohol dependence. It is possible that certain GRM3 SNP genotypes (the A/A genotype of rs6465084 and the T allele of rs1468412) may further lower NAA/Cr levels and EF skills in addition to the effect of alcohol.     

Association analysis of Group II metabotropic glutamate receptor genes (GRM2 and GRM3) with mood disorders and fluvoxamine response in a Japanese population

Background

Several lines of evidence implicate abnormalities in glutamate neural transmission in the pathophysiology of mood disorders, including major depressive disorder (MDD) and bipolar disorder (BP). Preclinical antidepressant effects were also reported for group II metabotropic glutamate receptor (Group II mGluRs) antagonists show dose-dependent antidepressant-like effects in murine models of depression. Also, it has been suggested that abnormalities in the hypothalamic-pituitary-adrenal axis and serotonergic neural transmission are important mechanisms in the pathophysiology of mood disorders. Group II mGluRs play an important role in regulating the function of these mechanisms. From these results, it has been suggested that abnormalities in Group II mGluRs might be involved in the pathophysiology of mood disorders, including MDD) and BP, and may influence the clinical response to treatment with SSRIs in MDD. Therefore, we studied the association between Group II mGluR genes (GRM2 and GRM3) and mood disorders and the efficacy of fluvoxamine treatment in Japanese MDD patients.

Materials and methods

Using three tagging SNPs in GRM2 and an SNP (rs6465084) reported functional variant in GRM3, we conducted a genetic association analysis of case-control samples (325 MDD patients, 155 BP patients and 802 controls) in the Japanese population. In addition, we performed an association analysis of GRM2 and GRM3 and the efficacy of fluvoxamine treatment in 117 Japanese patients with MDD. The MDD patients in this study had scores of 12 or higher on the 17 items of the Structured Interview Guide for Hamilton Rating Scale for Depression (SIGH-D). We defined a clinical response as a decrease of more than 50% in baseline SIGH-D within 8 weeks, and clinical remission as an SIGH-D score of less than 7 at 8 weeks.

Results

We found an association between rs6465084 in GRM3 and MDD in the allele-wise analysis after Bonferroni's correction (P-value = 0.0371). However, we did not find any association between GRM3 and BP or the fluvoxamine therapeutic response in MDD in the allele/genotype-wise analysis. We also did not detect any association between GRM2 and MDD, BP or the fluvoxamine therapeutic response in MDD in the allele/genotype-wise or haplotype-wise analysis.

Discussion

We detected an association between only one marker (rs6465084) in GRM3 and Japanese MDD patients. However, because we did not perform an association analysis based on LD and a mutation scan of GRM3, a replication study using a larger sample and based on LD may be required for conclusive results.     

Effects of common <Emphasis Type="Italic">GRM5</Emphasis> genetic variants on cognition,hippocampal volume and mGluR5 protein levels in schizophrenia

GRM5 (coding for metabotropic glutamate receptor 5, mGluR5) is a promising target for the treatment of cognitive deficits in schizophrenia, but there has been little investigation of its association with cognitive and brain phenotypes within this disorder. We examined the effects of common genetic variation in GRM5 with cognitive function, hippocampal volume, and hippocampal mGluR5 protein levels in schizophrenia patients relative to healthy controls. Two independent GRM5 variants rs60954128 [C>T] and rs3824927 [G>T] were genotyped in a schizophrenia case/control cohort (n=249/261). High-resolution anatomical brain scans were available for a subset of the cohort (n=103 schizophrenia /78 control). All participants completed a standard set of neuropsychological tests. In a separate postmortem cohort (n=19 schizophrenia/20 controls), hippocampal mGluR5 protein levels were examined among individuals of different GRM5 genotypes. Schizophrenia minor allele carriers of rs60954128 had reduced right hippocampal volume relative to healthy controls of the same genotype (?12.3%); this effect was exaggerated in males with schizophrenia (?15.6%). For rs3824927, compared to major allele homozygotes, minor allele carriers with schizophrenia had lower Intelligence Quotients (IQ). Examination in hippocampal postmortem tissue showed no difference in mGluR5 protein expression according to genotype for either rs60954128 or rs3824927. While these genetic variants in GRM5 were associated with cognitive impairments and right hippocampal volume reduction in schizophrenia, they did not affect protein expression. Further study of these mechanisms may help to delineate new targets for the treatment of cognitive deficits in schizophrenia, and may be relevant to other disorders.     

Genetic susceptibility to tardive dyskinesia in chronic schizophrenia subjects: III. Lack of association of CYP3A4 and CYP2D6 gene polymorphisms

Recent studies of the association between the metabotropic glutamate receptor 3 gene (GRM3) and schizophrenia have produced conflicting results, although GRM3 is a promising candidate gene. Fujii et al. found a single nuclear polymorphism (SNP) for within this gene, rs1468412 to have a positive association to schizophrenia in Japanese patients. To investigate this further, we genotyped 7 SNPs around GRM3 including rs1468412, in 752 Chinese patients with schizophrenia and 752 controls using Taqman technology. We did not detect any association between rs1468412 and schizophrenia, however we found differences in the allele frequency distribution of SNP rs2299225 (p=0.0297, odds ration [OR]=1.44, 95% confidence interval 1.05-1.99) between cases and controls. Moreover, the overall frequency of haplotypes constructed from three SNPs including rs2299225 showed significant differences between cases and controls (p=0.0017). Our results partially support the previous studies in other ethnic groups and indicate that the GRM3 gene may play an important role in the etiology of schizophrenia in the Han Chinese.     

An exploratory model for G × E interaction on hippocampal volume in schizophrenia; obstetric complications and hypoxia-related genes

Background

Smaller hippocampal volume has repeatedly been reported in schizophrenia patients. Obstetric complications (OCs) and single nucleotide polymorphism (SNP) variation in schizophrenia susceptibility genes have independently been related to hippocampal volume. We investigated putative independent and interaction effects of severe hypoxia-related OCs and variation in four hypoxia-regulated schizophrenia susceptibility genes (BDNF, DTNBP1, GRM3 and NRG1) on hippocampal volume in schizophrenia patients and healthy controls.

Methods

Clinical assessment, structural MRI scans, and blood samples for genotyping of 32 SNPs were obtained from 54 schizophrenia patients and 53 control subjects. Information on obstetric complications was collected from original birth records.

Results

Severe OCs were related to hippocampal volume in both patients with schizophrenia and healthy control subjects. Of the 32 SNPs studied, effects of severe OCs on hippocampal volume were associated with allele variation in GRM3 rs13242038, but the interaction effect was not specific for schizophrenia. SNP variation in any of the four investigated genes alone did not significantly affect hippocampal volume.

Conclusions

The findings suggest a gene–environment (G × E) interaction between GRM3 gene variants and severe obstetric complications on hippocampus volume, independent of a diagnosis of schizophrenia. Due to the modest sample size, the results must be considered preliminary and require replication in independent samples.     

The SNP rs1625579 in miR-137 gene and risk of schizophrenia in Chinese population: A meta-analysis

BackgroundSchizophrenia is a severe psychiatric disorder with a high heritability. A single nucleotide polymorphism (SNP) rs1625579 (G/T; T is the common and presumed risk allele) within an intron of miR-137 gene has been recently suggested to contribute to the susceptibility to schizophrenia by a large-scale genome-wide association study (GWAS) in a sample of predominantly European ancestry. However, subsequent genetic association studies in Chinese population yielded inconsistent results.MethodsA meta-analysis reporting the association between rs1625579 and schizophrenia in Chinese population was carried out, pooling 4 eligible case–control studies involving 2847 patients and 3018 controls.ResultsThis meta-analysis demonstrated a significant association between rs1625579 and schizophrenia under the allele model [T versus G, odds ratio (OR):1.20, 95% confidence interval (CI): 1.06–1.36] and the recessive model (TT versus GT + GG; OR: 1.19; 95% CI: 1.04–1.37). Additionally, a marginal significant association under the additive model (TT versus GG; OR: 1.64; 95% CI: 1.00–2.69) was observed. However, no significant association was observed under the dominant model (TT + GT versus GG; OR: 1.58; 95% CI: 0.97–2.59).ConclusionsThis meta-analysis suggested that the SNP rs1625579 in miR-137 gene might be involved in schizophrenia susceptibility in Chinese Han population.     

The AKT1 gene is associated with attention and brain morphology in schizophrenia

Abstract

Objectives. A meta-analysis of the associations between genetic variants in the AKT1 gene and schizophrenia found that a single nucleotide polymorphism (SNP5; rs2494732) was associated with schizophrenia in Asian populations. Methods. In this study, we investigated the effects of this SNP on memory and attentional performance and brain structure using magnetic resonance imaging in a Japanese population (117 patients with schizophrenia and 189 healthy subjects). Results. The memory performance, particularly attention/concentration score, measured by the Wechsler Memory Scale-Revised in A carriers of SNP5, which was found to be enriched in patients with schizophrenia, was lower than that in individuals with the G/G genotype. We confirmed the association of the SNP with attentional performance using the Continuous Performance Test, which assessed sustained attention and vigilance of attentional function. Patients with A allele demonstrated lower attentional performance than patients with the G/G genotype. Patients with the A allele had smaller gray matter volumes in the right inferior parietal lobule related to attentional processes and in the frontostriatal region related to different SNPs in AKT1 than patients with the G/G genotype. Conclusions. Our results suggest that a genetic variant of AKT1 might be associated with attentional deficits and brain morphological vulnerability in patients with schizophrenia.     

Impact of schizophrenia‐risk gene dysbindin 1 on brain activation in bilateral middle frontal gyrus during a working memory task in healthy individuals

Working memory (WM) dysfunction is a hallmark feature of schizophrenia. Functional imaging studies using WM tasks have documented both prefrontal hypo‐ and hyperactivation in schizophrenia. Schizophrenia is highly heritable, and it is unclear which susceptibility genes modulate WM and its neural correlates. A strong linkage between genetic variants in the dysbindin 1 gene and schizophrenia has been demonstrated. The aim of this study was to investigate the influence of the DTNBP1 schizophrenia susceptibility gene on WM and its neural correlates in healthy individuals. Fifty‐seven right‐handed, healthy male volunteers genotyped for DTNBP1 SNP rs1018381 status were divided in heterozygous risk‐allele carriers (T/C) and homozygous noncarriers (C/C). WM was assessed by a 2‐back vs. 0‐back version of the Continuous Performance Test (CPT), while brain activation was measured with fMRI. DTNBP1 SNP rs1018381 carrier status was determined and correlated with WM performance and brain activation. Despite any differences in behavioral performance, risk‐allele carriers exhibited significantly increased activation of the bilateral middle frontal gyrus (BA 9), a part of the dorsolateral prefrontal cortex (DLPFC), compared to noncarriers. This difference did not correlate with WM performance. The fMRI data provide evidence for an influence of genetic variation in DTNBP1 gene region tagged by SNP rs1018381 on bilateral middle frontal gyrus activation during a WM task. The increased activation in these brain areas may be a consequence of “inefficient” or compensatory DLPFC cognitive control functions. Hum Brain Mapp, 2010. © 2009 Wiley‐Liss, Inc.