TPH2基因单核苷酸多态性与双相情感障碍及其自杀行为的关系

目的 探讨色氨酸羟化酶2(TPH2)基因rs7305115单核苷酸多态性与双相情感障碍及自杀行为的关系.方法 提取205例双相情感障碍患者和225名健康对照者基因组DNA,采用聚合酶链反应(polymerase chain reaction PCR)扩增包括TPH2基因rs7305115位点的312bp基因组DNA片段,PCR产物直接测序.结果 在第7外显子周围未发现其它的单核苷酸多态性.双相情感障碍患者和健康对照者TPH2 rs7305115基因型和等位基因频率无统计学意义的差别(P>0.05),但患者组内有自杀行为的个体携带基因型AA的频率及等位基因A的频率均较低,两组比较差异有统计学意义(P<0.05).结论 TPH2基因rs7305115单核苷酸多态性与双相情感障碍无明显关联,与自杀行为有关联,其可能与双相情感障碍自杀行为易感性相关.

Abstract：

Objective To explore the relation among single nucleotide polymorphism of a novel tryptophan hydroxylase isoform (TPH2) gene rs7305115,bipolar disorder and suicidal behavior. Methods Specimens of peripheral blood were collected from 205 bipolar disorder and 225 controls. A novel tryptophan hydroxylase isoform (TPH2) gene rs7305115 in length 312bp was amplitied by Polvmerase chain reaction (PCR), and the product was analyzed by direct sequencing. Results We did not discover new single nucleotide polymorphism. Compared with Control Group,no significant difference of genotypes and alleles of TPH2 gene rs7305115 single nucleotide polymorphism had been found in patient group(P>0. 05). However,there existed significant differences between suicide behavior and non suicide behavior in bipolar disorder patient in genotypea of TPH2 gene rs7305115A/A. Suicide behavior of bipolar disorder patients in AA genotypes was much lower than non suicide behavior of bipolar disorder patients (P<0. 05). Con-clusion TPH2 gene rs7305115 single nucleotide polymorphism may have no association with the susceptibility of bipolar disorder, but associated with suicide behavior in bipolar disorder. A allele may be one of the risk factors for suicide behavior in bipolar disor-der.     

内皮固有型一氧化氮合酶基因单核苷酸多态性与冠心病的相关性研究

探讨内皮固有型一氧化氮合酶(ecNOS)基因的单核苷酸多态性(SNP)与冠心病(CAD)的相关性.提取107例CAD患者和132名健康对照者外周血有核细胞DNA,应用荧光标记单碱基延伸分型技术及寡核苷酸微阵列芯片杂交技术检测ecNOS基因的2个标签SNP(tag SNP)rs7830和rs3918188.结果发现CAD组rs7830的CC基因型频率和C等位基因频率明显低于健康对照组(P＜0.05).两组rs3918188的基因型频率及等位基因频率无统计学差异(P＞0.05).通过对2个SNP进行单倍型分析发现,CAD组和健康对照组的单倍型频率具有统计学差异(P<0.05).结果提示ecNOS基因 rs7830多态性变异及由rs7830和rs3918188构建的CA、AA单倍型是CAD的遗传危险因素.     

Ⅰ型干扰素通路IRF5 基因多态性与系统性红斑狼疮的关联性研究

目的:研究玉型干扰素通路IRF5 基因rs2004640、rs10954213、rs4728142 位点的单核苷酸多态性与系统性红斑狼疮易感性之间的关联。方法: 运用Taqman 荧光定量PCR 检测218 例SLE 患者及200 例健康对照者IRF5 基因rs10954213、rs4728142、rs2004640 位点基因型,计算等位基因频率,分析其与SLE 的关系;用IIF 法和LIA 法测定218 例SLE 患者血浆中抗核抗体、抗双链DNA 抗体和特异性抗体,并分析其与IRF5 rs2004640、rs10954213 位点基因频率的关系。结果:IRF5 rs2004640 位点等位基因T 频率分布SLE 组高于对照组,差异有统计学意义(字2 =6.809,P =0.009),基因型GG/ TT 分布在两组差异有统计学意义(字2 =5.111,P =0.024,);IRF5 rs10954213 位点等位基因G 频率分布在SLE 组高于对照组,差异有统计学意义(字2 =4.332,P =0.037);基因型GG 在两组的分布差异有统计学意义(字2 =5.805,P =0.016);IRF5 rs4728142 位点等位基因频率及基因型,两组比较差异无统计学意义。SLE 组IRF5 rs2004640 位点等位基因T 和抗Sm 抗体、抗Rib-P 抗体相关(字2 =8.512、4.057;P =0.005、0.048)。218 例SLE 患者中活动期患者特异性抗体主要以Anti-NUC、Anti-His、Ant-Rib-P 为主,两组比较差异有统计学意义(P<0.05)。结论:IRF5 基因rs2004640、rs10954213 基因位点单核苷酸多态性与SLE 易感性相关,rs4728142 基因位点单核苷酸多态与SLE 易感性不相关;IRF5 rs2004640 T 等位基因和抗Sm 抗体、Anti-Rib-P 抗体相关,SLE 活动期患者特异性抗体主要以抗ds-DNA 抗体、抗NUC 抗体、抗His 抗体、抗Rib-P 抗体为主。     

组织型激肽释放酶基因多态性与长沙地区汉族人群脑出血的关联研究

目的 分析长沙地区汉族人群脑出血与组织型激肽释放酶(kallikrein 1,KLK1)基因多态性的关系.方法 收集273例散发性脑出血患者和140名正常对照者的外周血标本.采用多重单碱基延伸单核苷酸多态分型技术和DNA测序法检测KLK1基因rs5516及rs5517多态性位点在两组人群中的分布.结果 (1)脑出血组及对照组KLK1基因rs5516多态和等位基因频率分布差异无统计学意义(P>0.05);脑出血组组织型KLK1基因rs5517多态A等位基因频率显著高于对照组(P<0.05).(2)对照组rs5517多态AA及GA基因型携带者舒张压水平显著高于GG基因型携带者(P<0.05);而rs5516位点各基因型亚组间血压水平差异无统计学意义(P>0.05).结论 组织型激肽释放酶基因rs5516多态性与脑出血无关,而组织型激肽释放酶基因rs5517多态性与脑出血存在关联,可能通过影响血压水平而参与脑出血的发生发展.     

PTPN2基因单核苷酸多态性与中国东北地区人群溃疡性结肠炎的关系

目的探讨我国东北地区人群PTPN2 rs2542151基因多态性与溃疡性结肠炎(ulcerative colitis,UC)遗传易感性、疾病活动性和严重性的关系。方法收集115例UC患者和99例健康对照者全血,应用TAQMAN探针,Realtime-PCR检测PTPN2 rs2542151位点等位基因多态性。结果 UC组PTPN2 rs2542151 T等位基因频率,G等位基因频率分别为79.13%,20.87%;对照组分别为85.35%,14.65%,差异无统计学意义(0.05)。GG纯合子相对于TT纯合子和TG杂合子UC易感性较健康对照组有显著差异(=0.042)。基因型是TG的患者病情为重度的可能性是GG的11.553倍(0.05)。PTPN2 rs2542151位点基因多态性与UC患者的发病年龄、性别、血红蛋白、血沉、C反应蛋白、血小板、临床分型及发病部位无关(0.05)。结论 PTPN2 rs2542151单核苷酸多态性与中国东北地区人群UC易感性相关,PTPN2 rs2542151基因突变可影响UC的病情严重程度。     

AXIN2基因三个位点与先天性巨结肠的关联研究

目的 探讨AXIN2基因单核苷酸多态性(single nucleotide polymorphisms,SNPs)rs2240308、rs8081536和rs9913621 3个位点与先天性巨结肠(Hirschspnmg disease,HSCR)的关联性.方法 对120例HSCR患者和120名正常人群外周血进行基因组DNA抽提,用PCR技术对AXe2基因3个位点(rs2240308、rs8081536和rs9913621)进行PCR扩增,PCR产物用内切酶CviJ I、Dde I和BaN I消化,将SNPs位点进行分型与分析,应用X2检验统计分析病例组和对照组等位基因频率、等位基因型频率及其患病风险;同时将PCR产物进行测序,以进一步确定基因突变位点.结果 HSCR组与对照组AXIN2 rs8081536 CC和CT基因型频率差异无统计学意义(P＞0.05);而HSCR组与对照组AXIN2 rs2240308 GG、AG和从基因型频率及A和G等位基因频率差异有统计学意义(P＜0.05),GC和从基因型及G等位基因的患病风险分别为2.091、0.846和1.703;HSCR组与对照组AXIN2 rs9913621 CC、CT和TT基因型频率及C和T等位基因频率差异有统计学意义(P＜0.05),CC和TT基因型及T等位基因的患病风险分别为0.535、1.113和1.569.测序rs2240308第301位密码子核苷酸GCA→CCA杂合突变;rs913621第199位密码子核苷酸CAC→CAG杂合突变.结论 AXIN2 rs8081536等位基因变异与HSCR的易感性无关;AXIN2 rs2240308和rs9913621与HSCR的发生可能有关联,具有GG基因型与CC基因型患HSCR的危险性相对较高.     

clock基因rs3817444多态性与大学生抑郁症、原发性失眠的关联分析

目的:探讨clock基因与大学生抑郁症、原发性失眠的关联。方法:用Snapshot SNP分型技术对88例(其中抑郁睡眠障碍65例)大学生抑郁症患者、55例原发性失眠患者和110名大学生正常对照进行clock基因rs3817444位点分型,比较三组间该基因多态性基因型和等位基因频率的差异。结果:与对照组相比,抑郁症组rs3817444多态性的基因型和等位基因的频率差异无统计学意义(P0.05);与对照组相比,原发性失眠组rs3817444多态性的等位基因频率差异有统计学意义(P0.05);对rs3817444多态性三种基因型C/C、A/C、A/A抑郁症和原发性失眠大学生的临床资料比较,显示各项没有明显差异(P0.05)。结论:clock基因rs3817444多态性可能与大学生抑郁症的发病无关联,但与大学生原发性失眠可能关联。     

转录因子7类似物2基因rs7903146位点和rs12255372位点多态性与2型糖尿病的关系

目的探讨转录因子7类似物2基因(TCF7L2)rs7903146位点和rs12255372位点多态性与2型糖尿病的关系。方法选取2015年1月-2017年2月期间于我院内分泌科门诊进行就诊的2型糖尿病患者作为病例组(T2DM组),同期于本院体检中心接受体检的300例健康体检者为健康对照组,提取两组研究对象外周静脉血样本DNA,PCR扩增DNA后采用ABI 3730系列高通量基因分析仪对样本DNA进行测序,比较rs7903146位点和rs12255372位点基因型以及等位基因频率在两组研究对象中的分布差异,及其与2型糖尿病的相关性。结果两组研究对象性别构成、平均年龄等一般资料比较,无统计学差异(P0.05),而BMI、SP、DP、FBG、2h PG、HbA1C、TG、TC、HDL以及LDL等实验室指标比较,差异具有统计学意义(P0.05)。此外,rs 7903146位点等位基因频率以及基因型分布在两组具有统计学差异,T2DM组T等位基因频率以及GT基因型频率显著高于对照组(P0.05),提示rs 7903146位点基因多态性与2型糖尿病发病相关,等位基因T为2型糖尿病的风险等位基因;rs 12255372位点等位基因频率和基因型分布差异无统计学意义,提示rs 12255372位点基因多态性与2型糖尿病不相关。结论 TCF7L2基因rs 7903146位点基因多态性与本地区2型糖尿病发病相关,等位基因T为2型糖尿病的风险等位基因;而rs 12255372位点基因多态性与2型糖尿病发生不相关。     

抑郁症患者无抽搐电休克治疗的疗效与脑源性神经营养因子基因多态性

目的:探讨抑郁症患者脑源性神经营养因子(brain-derived neurotrophic factor,BDNF)基因两个单核苷酸多态性位点的多态性与无抽搐电休克治疗(modified electroconvulsive therapy,MECT)疗效的关系。方法:采用病例对照研究,研究组为110例符合美国精神障碍诊断统计手册第4版(Diagnostic and Statistical Manual of Mental Disorders,Fourth Edition,DSM-IV)抑郁症诊断标准的门诊及住院患者,对照组为100名正常人。患者入组后连续接受MECT8次,使用汉密顿抑郁量表(Hamilton Depression Rating Scale for Depression,HRSD)进行抑郁严重程度及疗效评估。运用PCR扩增及测序的方法,分析BD-NF基因rs6265、rs7103411单核苷酸多态性的分布,分析rs6265、rs7103411基因型及等位基因频率分布与MECT疗效的关系。结果:BDNF基因rs6265、rs7103411位点基因型及等位基因频率在对照组与患者组间的差异无统计学意义,MECT后2个位点基因型及rs7103411等位基因频率在不同疗效组间的差异无统计学意义。rs6265位点A等位基因频率和G等位基因频率在减分率≥50%组分别为47.9%、52.1%;在减分率<25%组分别为27.5%、72.5%,两组比较差异有统计学意义(P<0.05),且A等位基因对MECT反应好于G等位基因(OR=1.740,95%CI:1.022~2.963)。结论:病情严重的抑郁症患者BDNF基因rs6265位点A等位基因可能与无抽搐电休克治疗效果有关,A等位基因携带者接受MECT的疗效较G等位基因携带者好。     

TPH2基因多态性与重度抑郁发作治疗反应的关系研究CSCD

目的分析TPH2基因多态性与重度抑郁发作（major depressive disorder,MDD）治疗反应之间的相关性。方法收集304例接受抗抑郁药治疗的MDD患者。用MassArray质谱分析法对TPH2基因的3个单核苷酸多态性（rs1007023、rs1023990和rs4570625）进行基因分型。用HAMD-17量表评估基线和治疗1、2、4和6周后的效果。结果共290名受试者完成了研究,其中rs4570625基因多态性与抗抑郁治疗的效果存在显著的相关性,有效组和无效组的基因型、等位基因分布频率差异具有统计学意义（P=0．013,P=0．007）,经错误发现率校正后,上述差异仍具有统计学意义（P=0．039,P=0．021）,治疗有效的患者中等位基因G和GG基因型的频率更高（OR=1．70,95％CI=1．15～2．51;OR=3．34,95％CI=1．40～7．98）。未发现rs1007023和rs1023990基因多态性和抗抑郁药疗效存在相关性（P〉0．05）。结论TPH2基因rs4570625多态性可能与抗抑郁药疗效存在一定的关联。     

No association between a TPH2 promoter polymorphism and mood disorders or monoamine turnover

BACKGROUND: Tryptophan hydroxylase (TPH) is the rate-limiting enzyme in serotonin synthesis. TPH2 is a recently discovered isoform that is expressed predominantly in serotonin neurons. Associations are reported of TPH2 polymorphisms with MDD, bipolar disorder and suicidal behavior. This study examines a single nucleotide polymorphism in the putative promoter region of the TPH2 gene. METHODS: One hundred nine bipolar, 324 major depressive disorder, and 130 healthy volunteers were genotyped for the rs4131347 (-C8347G) promoter SNP. Association was assessed with diagnosis, suicide attempt status, severity of psychopathology and cerebrospinal fluid monoamine metabolite levels of 5-HIAA, HVA, and MHPG. General linear models and logistic regression tested the effect of genotype*childhood abuse interactions on psychopathology severity and suicide attempt. RESULTS: There was no association between genotype and either mood disorder, suicide attempt status, psychopathology severity or CSF monoamine metabolite levels. CONCLUSIONS: No association was detected between the rs4131347 (-C8347G) SNP in the promoter region of the TPH2 gene and mood disorders, suicidal behavior or monoamine function.     

Case control and family-based studies of tryptophan hydroxylase gene A218C polymorphism and suicidality in adolescents.

The association of suicidality with polymorphism A218C in intron 7 of tryptophan hydroxylase (TPH) gene remains controversial. The aim of this study was to use family-based methods to examine this association in adolescents in order to eliminate the difficulty of sampling a control group from the same ethnic population. Eighty-eight inpatient adolescents who recently attempted suicide were assessed by structured interview for detailed clinical history, diagnoses, suicide intent, suicide risk, impulsivity, aggression, and depression. DNA samples were collected from all subjects, from both biological parents of 40 subjects and from one parent of 9 subjects; TPH allele frequencies were calculated and tested for association to phenotype, stratified by severity, using the haplotype relative risk (HRR) and transmission disequilibrium test (TDT) methods (n = 49). The frequencies were also compared for all the Jewish subjects (n = 84) to the known frequencies of these alleles in healthy Jewish populations. There was no significant allelic association of A218C polymorphism with suicidal behavior or other phenotypic measures according to the HRR method (chi-square = 0.094; P = 0.76), the TDT (chi-square = 0.258; P = 0.61), or association analysis to known population frequencies (chi-square = 1.667, P = 0.19 for Ashkenazi, and chi-square = 0.810, P = 0.37 for non-Ashkenazi). Analysis of variance with the Scheffè test demonstrated a significant difference between CC and AA genotypes in suicide risk and depression among the patients (n = 88). The findings suggest that polymorphism A218C has no major relevance to the pathogenesis of adolescent suicidal behavior, but may have a subtle effect on some related phenotypes.     

Polymorphisms in the neuronal isoform of tryptophan hydroxylase 2 are associated with bipolar disorder in French Canadian pedigrees

OBJECTIVE: Tryptophan hydroxylase is the rate-limiting enzyme in the serotonin biosynthetic pathway and plays an important role in the regulation of serotonin levels. Recently, a brain-specific isoform, tryptophan hydroxylase 2 or n-tryptophan hydroxylase, has been discovered. Some studies reported genetic and functional associations between this isoform and bipolar disorder and/or major depressive disorder. The aim of this study was to investigate further association of genetic variants in French Canadian samples with bipolar disorders. METHODS: Genetic variants in the tryptophan hydroxylase 2 gene were genotyped in a case-control sample consisting of 225 affected individuals (191 bipolar I and 34 bipolar II) and 221 controls and in a collection of extended pedigrees and trios from the same population 357 nuclear families (201 bipolar I, 64 bipolar II, 79 recurrent major depressive disorder). RESULTS: We determined linkage disequilibrium structure in our isolated population and analyzed six tagged single nucleotide polymorphisms in the case-control sample. Whereas no single, single nucleotide polymorphism gave any significant result, a three single nucleotide polymorphism haplotype gave a global P=0.01. Family-based association showed significant association (P=0.004) of one polymorphism (rs4290270) with the major allele overtransmitted to affected offspring. CONCLUSIONS: Case-control and family-based association studies further support the presence of a susceptibility locus for bipolar disorder in tryptophan hydroxylase 2 by showing statistically significant associations with both, single nucleotide polymorphism alone and haplotype of single nucleotide polymorphism markers.     

Variation in tryptophan hydroxylase-2 gene is not associated to male completed suicide in Estonian population

Dysfunction of the central serotonergic system has been related to a spectrum of psychiatric disorders, including suicidal behavior. Tryptophan hydroxylase isoform 2 (TPH2) is the rate-limiting enzyme in the biosynthetic pathway of serotonin, being expressed in serotonergic neurons of raphe nuclei. We investigated genetic variation in TPH2 gene in two samples of male subjects: 288 suicide completers and 327 volunteers, in order to reveal any associations between 14 single nucleotide polymorphisms and completed suicide. No associations were revealed neither on allelic nor haplotype level. Our finding does not support the hypothesis of TPH2 being a susceptibility factor for completed suicide in males of Estonian origin.     

Tryptophan hydroxylase gene 218A/C polymorphism is associated with somatic anxiety in major depressive disorder.

BACKGROUND: Abnormalities in functioning of the central serotonergic system have been implicated in the pathogenesis of depressive illness and suicidal behavior. Tryptophan hydroxylase (TPH) is the rate-limiting enzyme in the biosynthesis of serotonin, therefore, it may play an important role in regulation or control of serotonin functions. The aim of the present investigation was to determine whether there is an association between TPH gene polymorphism and major depression. particularly in patients with suicidal ideation. METHODS: A total of 135 unrelated patients suffering from major depressive disorder and 196 normal unrelated controls were included in the study. All controls and patients were Caucasian. A biallelic polymorphism at the tryptophan hydroxylase locus was genotyped. RESULTS: No significant difference between controls and depressed subjects in TPH gene polymorphism was detected. There was no association between TPH gene polymorphism and suicidal ideation. Total HAMD scores were not different between the genotypes or alleles in patients. However, among the HAMD clusters, somatic anxiety was significantly associated with TPH genotypes and alleles in that patients with 218A/A genotype had a significantly higher somatic anxiety scores compared to other genotypes. LIMITATION: Potential confounding effect of population stratification can not be excluded. The functional relevance of the TPH gene 218A/C polymorphism is, at present, uncertain. CONCLUSION: The polymorphism in serotonergic system related genes may be associated with depressive symptoms in major depressive disorder. The results suggest that analysis of clusters that narrow down the phenotype may be more suitable in genetic studies of major depressive illness.     

Association study of tryptophan hydroxylase 2 gene polymorphisms in panic disorder

Experimental studies on serotonin (5-HT) availability suggest a role for 5-HT synthesis rate in panicogenesis. Recently, it has been discovered that the tryptophan hydroxylase gene isoform 2 (TPH2), rather than TPH1, is preferentially expressed in the neuronal tissue and, therefore, is primarily responsible for the regulation of brain 5-HT synthesis. In the present case-control genetic association study we investigated whether panic disorder (PD) phenotypes are related to two single nucleotide polymorphisms (SNP) of TPH2, rs1386494 A/G and rs1386483 C/T. The study sample consisted of 213 (163 females and 50 males) PD patients with or without affective comorbidity and 303 (212 females and 91 males) matched healthy control subjects. The allelic and genotypic analyses in the total sample did not demonstrate significant association of PD with the studied SNPs, suggesting that these polymorphisms may not play a robust role in predisposition to PD. However, an association with rs1386494 SNP was observed in the subgroup of female patients with pure PD phenotype, indicating a possible gender-specific effect of TPH2 gene variants in PD.     

Case control and family‐based studies of tryptophan hydroxylase gene A218C polymorphism and suicidality in adolescents

The association of suicidality with polymorphism A218C in intron 7 of tryptophan hydroxylase (TPH) gene remains controversial. The aim of this study was to use family‐based methods to examine this association in adolescents in order to eliminate the difficulty of sampling a control group from the same ethnic population. Eighty‐eight inpatient adolescents who recently attempted suicide were assessed by structured interview for detailed clinical history, diagnoses, suicide intent, suicide risk, impulsivity, aggression, and depression. DNA samples were collected from all subjects, from both biological parents of 40 subjects and from one parent of 9 subjects; TPH allele frequencies were calculated and tested for association to phenotype, stratified by severity, using the haplotype relative risk (HRR) and transmission disequilibrium test (TDT) methods (n = 49). The frequencies were also compared for all the Jewish subjects (n = 84) to the known frequencies of these alleles in healthy Jewish populations. There was no significant allelic association of A218C polymorphism with suicidal behavior or other phenotypic measures according to the HRR method (chi‐square = 0.094; P = 0.76), the TDT (chi‐square = 0.258; P = 0.61), or association analysis to known population frequencies (chi‐square = 1.667, P = 0.19 for Ashkenazi, and chi‐square = 0.810, P = 0.37 for non‐Ashkenazi). Analysis of variance with the Scheffè test demonstrated a significant difference between CC and AA genotypes in suicide risk and depression among the patients (n = 88). The findings suggest that polymorphism A218C has no major relevance to the pathogenesis of adolescent suicidal behavior, but may have a subtle effect on some related phenotypes. © 2001 Wiley‐Liss, Inc.     

Common genetic variations in TPH1/TPH2 genes are not associated with schizophrenia in Japanese population

Alteration of serotonin transmission in the brain of patients with schizophrenia has been reported in postmortem brain studies, cerebrospinal fluid studies, and pharmacological challenges. Although a genetic association of tryptophan hydroxylase isoform 1 (TPH1), the rate-limiting enzyme in serotonin synthesis, with schizophrenia has been suggested by recent systematic meta-analyses, the newly identified neuronal isoform TPH2 is more relevant to the central nervous system and the association of TPH2 gene with schizophrenia has been much less explored. We, therefore, explored the association of TPH2 gene with schizophrenia using a case–control study of 720 Japanese populations and also tried to replicate the association of the TPH1 rs1800532 (A218C) single nucleotide polymorphism (SNP) with schizophrenia. We selected 15 tagging SNPs in the TPH2 gene. We found no significant differences in genotypic distributions (uncorrected P = 0.18–0.98) or allelic frequencies (uncorrected P = 0.18–0.98) of the 15 SNPs between the schizophrenia and control groups. Haplotypes constructed with these SNPs were also not associated with schizophrenia (uncorrected P = 0.12–0.97). The genotypic and allelic distribution of the TPH1 rs1800532 SNP was also not different between the case and control groups in our samples. In addition, a subsequent meta-analysis including our results did not showed a significant association with schizophrenia in Asian populations. Our findings suggest that neither common genetic variations of TPH1 nor TPH2 are likely to contribute to the genetic susceptibility to schizophrenia in Japanese population.     

A Tryptophan Hydroxylase 2 Gene Polymorphism is Associated with Panic Disorder

Panic disorder (PD) is a complex and heterogeneous psychiatric condition. Dysfunction within the serotonergic system has been hypothesized to play an important role in PD. The novel brain-specific serotonin synthesizing enzyme, tryptophan hydroxylase 2 (TPH2), which represents the rate-limiting enzyme of serotonin production in the brain, may therefore be of particular importance in PD. We investigated the TPH2 703G/T SNP for association with PD. Patients with PD (n = 108), and control subjects (n = 247), were genotyped for rs4570625 (TPH2 703G/T). Male and female subjects were analyzed separately. The severity of their symptoms was measured using the Spielberger state-trait anxiety inventory (STAI), panic disorder severity scale (PDSS), anxiety sensitivity index (ASI), acute panic inventory (API), and Hamilton’s rating scale for depression (HAMD). The genotype and allele frequencies of the PD patients and controls were analyzed using χ ² statistics. There was a significant difference in the allele frequency in rs4570625 between the PD patients and normal controls. The T allele was significantly less frequent in the PD patients. We also found a significant association with rs4570625 in the female subgroup. There was no difference in symptom severity among the genotypes of this polymorphism. This result suggests that rs4570625 polymorphism may play a significant role in the pathogenesis of PD. Moreover, rs4570625 may have a gender-dependent effect on susceptibility to PD. Further studies are needed to replicate the association that we observed. Edited by Tatiana Foroud.