Association between serotonin transporter gene polymorphism and anxiety-related traits.

BACKGROUND: Polymorphism in the serotonin transporter promoter gene has been recently reported to be associated with the personality trait known as anxiety-related traits. We have attempted to replicate these findings in 101 healthy Japanese subjects. METHODS: The personality traits of the subjects were assessed with the tridimensional personality questionnaire. RESULTS: An association was observed in the present study between individuals grouped according to the transporter gene and harm avoidance scores. CONCLUSIONS: These data supported that there was an association between the serotonin transporter gene and anxiety.     

Association and linkage of anxiety-related traits with a functional polymorphism of the serotonin transporter gene regulatory region in Israeli sibling pairs

A functional polymorphism in the regulatory region of the serotonin transporter gene (5-HTTLPR) has been reported to be both associated and linked to anxiety-related personality measures, although other studies have not replicated these findings. The current study examines both association and linkage of the gene to two major anxiety-related personality measures, the harm avoidance scale on the Tridimensional Personality Questionnaire and the neuroticism scale of the NEO-PI-R, in a sample of 148 Israeli subjects comprising 74 same-sex sibling pairs. We replicated the reported association between the short allele and higher scores on the TPQ harm avoidance scale (P = 0.03), including the subscale of shyness (P = 0.02), and also found association in the same direction between the short allele and the NEO-PI-R neuroticism subscales of anxiety (P = 0.03) and depression (P = 0.04). Sib-pair linkage analysis, using the regression method, further supported a role of the 5-HTTLPR in anxiety-related personality traits.     

No association of a functional polymorphism in the serotonin transporter gene promoter and anxiety-related personality traits

Serotonergic neurotransmission, which is involved in many psychiatric disorders, is mediated by the serotonin transporter protein. Gene coding for the serotonin transporter protein is designated SLC6A4, which has been differentially associated with anxiety-related behavioral traits and neuroticism in healthy subjects. To confirm the association between the serotonin transporter (5-HTT) gene-linked polymorphic region (5-HTTLPR) and anxiety-related personality traits, we examined 228 healthy unrelated participants (age 38.6 +/- 12.8 years; 115 male, 113 female) of German origin, who were carefully examined with respect to psychiatric health. The self-ratable State-Trait Anxiety Inventory (STAI) and the NEO Five Factor Inventory (NEO-FFI) were performed. No significant association was observed between the 5-HTTLPR genotype and STAI 1 (state, chi2 = 0.82, p < 0.66, d.f. = 2), STAI 2 (trait, chi2 = 2.7, p < 0.25, d.f. = 2) and NEO-FFI scores of any of the 5 major axes, including neuroticism (chi2 = 3.35, p < 0.18, d.f. = 2) in all subjects. Given the small effect of this 5-HTT polymorphism on behaviour in previous studies, a lack of significant genotype differences in these tests could be due to considerable individual variability in these measures.     

Association study of a functional serotonin transporter gene polymorphism with schizophrenia, psychopathology and clozapine response

Serotonin is implicated in the pathogenesis of schizophrenia. Following serotonin release, the serotonin transporter (5-HTT) is the major determinant of serotonin inactivation. The present study tested the hypothesis that a biallelic polymorphism in the 5' regulatory region of the 5-HTT gene (5-HTTLPR) confers susceptibility to schizophrenia, association with the clinical manifestations of schizophrenia or clozapine response. 90 treatment-resistant schizophrenic patients were assessed using the Brief Psychiatric Rating Scale before and after clozapine treatment. The results demonstrated that the 5-HTTLPR variants did not play a major role in the susceptibility, clinical manifestations or clozapine response in schizophrenia.     

5-羟色胺基因多态性与抑郁症的相关性研究

目的：探讨5-羟色胺转运体(5-HTT)基因启动子区多态性(5-HTTLPR)与抑郁症的相关性及其对抗抑郁药疗效的影响。方法：运用聚合酶链反应技术(PCR)检测51例抑郁症患者(患者组)和60名健康对照者(对照组)5-HTTLPR的分布频率；并予文拉法辛治疗，用汉密尔顿抑郁量表(HAMD)观察疗效。结果：患者组5-HTTLPR的短重复序列／短重复序列(short／short，S／S)基因型和短重复序列(short，S)等位基因频率分别为71％和81％，对照组为45％和69％差异显著。治疗4周后，长重复序列／长重复序列(long／long，L／L)基因型患者的减分率显著高于其他两型。结论：5-HTTLPR的S／S基因型可能是抑郁症的易感基因之一，L／L基因型可能和更好的选择性5-羟色胺受体阻滞剂类(SSRIs)疗效有关。     

5-羟色胺转运体基因功能性多态与强迫症的关联研究

目的 探讨中国汉族人群中5-羟色胺转运体基因启动子区域多态(5-HTTLPR)功能性3等位基因L_A、L_G和S与强迫症(OCD)的关系.方法 采用聚合酶链反应-限制性片段长度多态技术测定138例OCD患者(OCD组)和199名健康人(对照组)的5-HTTLPR功能性3等位基因多态性.结果 OCD组5-HTTLPR功能性基因型及等位基因频率与对照组间的差异有统计学意义(χ~2=8.396,P＜0.05;χ~2=8.483,P＜0.01);L_A/L_A因型和L_A等位基因与OCD存在显著正关联[比值比分别为3.361(P＜0.05)和1.771(P＜0.01)].结论在中国汉族人群中5-HTTLPR功能性3等位基因可能与OCD存在遗传关联,L_A/L_A基因型和等位基因L_A可能是OCD的风险因子.     

Association of a functional polymorphism in the serotonin transporter gene with abnormal emotional processing in ecstasy users

OBJECTIVE: The long-term effects of the use of 3,4-methylenedioxymethamphetamine (MDMA, or Ecstasy) in humans are controversial and unclear. The authors' goal was to assess the contribution of a functional polymorphism in the gene encoding serotonin transporter to changes in emotional processing following chronic Ecstasy use. METHOD: They investigated Beck Depression Inventory scores and performance on the Affective Go/No-Go test, a computerized neuropsychological test sensitive to emotional processing, in Ecstasy users and comparison subjects, stratifying the results by serotonin transporter genotype. RESULTS: Ecstasy use was associated with higher Beck Depression Inventory score and abnormalities in the Affective Go/No-Go test in individuals with the ss and ls genotype but not those with the ll genotype. CONCLUSIONS: Ecstasy users carrying the s allele, but not comparison subjects carrying the s allele, showed abnormal emotional processing. On the basis of a comparison with acute tryptophan depletion, the authors hypothesize that chronic Ecstasy use may cause long-term changes to the serotonin system, and that Ecstasy users carrying the s allele may be at particular risk for emotional dysfunction.     

Association of the serotonin transporter gene with smoking behavior

OBJECTIVE: In an ongoing molecular genetic study of temperament, participants were genotyped to examine the association of smoking with two polymorphisms of the serotonin transporter gene (SERT): the promoter region, 5-HTTLPR, and an intronic variable-number-of-tandem-repeats region (VNTR). METHOD: Full information was available for 330 families, and 244 "ever smokers" were identified (54 past smokers, 190 current smokers). The average number of cigarettes smoked per day was 13.12, and the mean Fagerstrom Tolerance Questionnaire score was 4.79. Associations of genotype, Tridimensional Personality Questionnaire scores, and smoking phenotype were tested by using a robust family design with a variance-components framework and by case-control analysis. RESULTS: There was a significant excess of the 5-HTTLPR long allele with the 12-repeat VNTR in current smokers, past smokers, and ever smokers, compared to participants who had never smoked. The results from the population design were confirmed in the family-based analysis. No association was observed between two quantitative measures of smoking and the polymorphisms. A weak association was observed between novelty seeking and the VNTR polymorphism and between reward and 5-HTTLPR. Smokers, regardless of gender, scored significantly higher on novelty seeking and did not differ on harm avoidance or reward. CONCLUSIONS: There was a highly significant association between SERT and the categorical definition of smoking, irrespective of dependence level, suggesting that this gene influences the initiation of smoking. Mediation analysis failed to substantiate the hypothesis that novelty seeking partially mediates the effect of SERT on smoking. SERT appears to independently contribute to novelty seeking and smoking.     

Association study for a functional serotonin transporter gene polymorphism and late-onset Alzheimer's disease for Chinese patients.

Two recent studies have demonstrated an association for a deletion/insertion polymorphism within the promoter region of the serotonin transporter gene (5-HTTLPR), and Alzheimer's disease (AD). According to these studies, subjects with the short variant of the 5-HTTLPR gene are at increased risk for AD; however, this finding has not been confirmed by other workers. To evaluate the role of the 5-HTTLPR gene in susceptibility for AD, we conducted an association study for this polymorphism in a Chinese population. No significant differences were determined for genotype distribution or allele frequencies, comparing AD patients and normal controls. Even dividing the population into subgroups according to the presence of the APOE epsilon4 allele, no differences for genotype or allele frequencies were determined, comparing patients and controls. These results suggest that it is unlikely that the 5-HTTLPR polymorphism plays a substantial role in conferring susceptibility to AD.     

Association of a functional polymorphism in the serotonin transporter gene with personality traits in females in a Polish population

The aim of our study was to determine whether the 5-HTTLPR polymorphism is related to temperamental traits measured using the Formal Characteristics of Behavior - Temperament Inventory (FCB-TI) and personality traits assessed by the NEO Five-Factor Inventory (NEO-FFI) questionnaire. The sample comprised 200 unrelated females, aged 18-29 years. DNA of the subjects was isolated from buccal epithelial cells, and 5-HTTLPR polymorphism was genotyped using PCR. The subjects were divided into SS, SL and LL groups according to their genotype. The differences in results on the endurance scale (F = 11.29, p = 0.001), measured using FCB-TI and neuroticism measured using NEO-FFI (F = 15.32, p = 0.000) between the S group (short-form allele; genotypes SS and SL) and the L group (long-form allele; genotype LL) were statistically significant. Additionally, statistically significant differences between the LL and SS groups, and between the SL and SS groups with respect to 'activity' (FCB-TI) were found (F = 4.5, p = 0.012). These findings support a role of the 5-HTTLPR polymorphism in the modulation of personality and temperamental traits.     

Association of the serotonin transporter gene polymorphism with Korean male alcoholics

This study investigated the association between the serotonin transporter polymorphism (5-HTTLPR) and alcoholism in the Korean population. In addition, in order to reduce the clinical heterogeneity, sub-analysis was carried out according to some clinical variables such as a family history of alcoholism, aggressive/violent behavior and the age of onset of alcoholism. One hundred and forty-five patients meeting the DSM-VI criteria for alcohol dependence and 201 healthy controls were examined. Genotyping was performed using a polymerase chain reaction (PCR)-based method. The frequency of the L-allele of 5-HTTLPR was significantly higher in the alcohol dependent patients than in the normal controls (chi(2)=19.11, df=1, p<0.001). Furthermore, there was a significant difference in the allelic distribution between the subgroups defined by a family history of alcoholism (chi(2)=4.005, df=1, p=0.045). This study suggests a putative role of the 5-HTTLPR for alcoholism in the Korean population. However, a replication study with larger different ethnic samples and a refinement of the subtype of alcoholism is needed.     

中国大学生焦虑相关人格特质与5-羟色胺转运体基因多态性的相关性分析

目的调查5-羟色胺转运体基因上游调控区多态性位点(5-HTTLPR)与第二内含子多态性位点(5-HTTStin2)在中国汉族人群中的基因频率，比较这2个多态位点在种族间的差异，并且首次在中国大学生人群中对这2个多态位点与焦虑相关人格特质进行相关性研究。方法利用聚合酶链反应(PCR)等方法对222名随机健康汉族中国人中的这2个多态性位点进行了群体遗传学研究。并在148名大学生中对这2个位点与焦虑相关人格特质进行了相关分析。结果对于5-HTTLPR多态信息含量为0．352；5-HTTStin2多态信息含量为0．153。等位片段频率在中国汉族人与美国黑人及白人、西欧人、土耳其人有着显著差异，而与日本人相似。在148名大学生中进行的这2个位点与焦虑相关分析未能得出阳性结论。结论5-HTTLPR及5-HTTStin2这2个多态位点在不同种族和人群中的分布有差异；相关分析结果不支持在中国汉族人群中这2个多态位点与焦虑相关人格特质有关。     

强迫症与5-羟色胺转运体基因多态的关联分析

目的 探索汉族人群中5-羟色胺转运体SLC6A4基因多态与强迫症发病的关系。方法采用聚合酶链反应扩增片段长度多态技术测定120例强迫症患者(强迫症组)和130名健康人(对照组)的SLC6A4基因型。结果 强迫症组SLC6A4第2内含子及启动子的基因型多态分布与对照组间的差异有显著性(X2=6.70,P=0.035;X2=6.35,P=0.042);第2内含子等位基因频数分布与对照组之间的差异有非常显著性(X2=7.54,P=0.006);第2内含子的等位基因10,12/10基因型和启动子的L/L基因型与强迫症存在显著正关联[比数比(OR)值分别为2.24,2.12和3.57,P<0.05];强迫症组及对照组内不同性别间基因型分布的差异均无显著性(P>0.05)。结论 在汉族人群中SLC6A4基因可能与强迫症存在遗传关联,第2内含子的等位基因10和12/10基因型、启动子的L/L基因型可能是强迫症的风险因子。     

5-羟色胺转运体基因多态性与青少年抑郁症的关联研究

目的 探讨中国汉族青少年抑郁症与5-羟色胺转运体（5-HTY）基因的启动子区多态（5-HTTLPR）之间的关系。方法 应用聚合酶链式反应（PCR）扩增技术对84例青少年抑郁症患者和85例健康者进行基因型分析。结果 5-HTYLPR基因的3种基因型S／S,L／S和L/L在青少年抑郁症组的分布分别为57．1％,36．9％,6．0％;在对照组分别为57．6％,34．1％,8．2％,两组间差异无显著性（P〉0．05）。抑郁症组中S／S基因型患者HAMD自杀因子评分明显高于L／L和L／S型患者（P〈0.01）。结论 5-HTT基因多态性与青少年抑郁症无明显关联。抑郁症中携带S／S基因型患者的自杀风险相对比L／L型、L／S型患者高。     

Association analysis of serotonin transporter promoter gene polymorphism with ADHD and related symptomatology

Attention deficit hyperactivity disorder (ADHD) is one of the most common childhood behavioral disorders. Genetic factors contribute to the underlying liability to develop attention deficit hyperactivity disorder. Several investigations have reported associations between ADHD and serotonin transporter promoter polymorphisms, but the results have been inconsistent. The present study did not find significant association between ADHD and serotonin transporter promoter polymorphisms, but did find an effect of serotonin transporter promoter polymorphisms on some ADHD symptomatology. Patients homozygous for the short allele showed more Withdrawn or Somatic complaint scores than subjects with the long allele.     

Association between serotonin transporter gene promoter polymorphism and suicide: results of a meta-analysis.

BACKGROUND: There is strong evidence supporting a role for serotonin system dysfunction in the pathology of suicidal behavior. Many studies have examined the association between a functional polymorphism of the serotonin transporter gene promoter (5-HTTLPR) and suicide but have yielded inconsistent results. Our goal here, by analyzing the cumulative data from primary literature, was to determine conclusively whether there is an association. METHODS: Three meta-analyses were performed. One compared the 5-HTTLPR polymorphism between suicidal subjects and normal control subjects; another compared suicide attempters with nonattempters of the same psychiatric diagnoses; the last one compared either violent or nonviolent suicidal subjects with normal control subjects. RESULTS: We found no association between 5-HTTLPR polymorphism and suicidal behavior (p =.379). When we compared subjects with the same psychiatric diagnoses, the genotypes carrying the s allele were significantly more frequent in suicide attempters than in nonattempters (p =.004). In addition, the s allele was associated with violent suicide (p =.0001) but not with nonviolent suicide (p = 1.00). CONCLUSIONS: Our results provide significant evidence supporting the association of the s allele of 5-HTTLPR polymorphism with suicidal behavior in the psychiatric population, also with violent suicide. These support a role for decreased serotonin transporter function in the vulnerability to suicide in a select population.     

Allelic variation of a functional polymorphism in the serotonin transporter gene and depression in Parkinson's disease

A genetic susceptibility to depression in PD, acting via the serotonergic system, has been suggested. We examined the influence of allelic variation (L/S) in a functional polymorphism in the serotonin transporter (5-HTTLPR) gene upon mood in 108 PD patients and 82 controls. Using a logistic regression model we found no evidence for an association between 5-HTTLPR genotypes, or the presence of the S allele, and depression.     

Association study of functional polymorphisms in serotonin transporter gene with temporal lobe epilepsy in Han Chinese population

Background and purpose: Serotoninergic dysfunction was reported to be involved in aetiology of temporal lobe epilepsy (TLE). Serotonin (5‐HT) is actively cleared from synaptic cleft by serotonin transporter (5‐HTT). We investigated the association between three common polymorphisms of 5‐HTT gene, which may influence gene expression or function, and risk for TLE. Methods: Three hundred and thirty‐four patients with TLE and four hundred and eighty‐seven non‐epileptic control subjects from Han Chinese origin were enrolled for the present study. Polymerase chain reaction‐restriction fragment length polymorphism (PCR‐RFLP) method was used for genotyping. Results: 10‐repeat allele frequency of 17 bp variable number of tandem repeats in the second intron (5‐HTTVNTR) was moderately higher in patients with TLE than in controls (9.1% vs. 6.1%, P = 0.0187, OR = 1.55, 95%CI = 1.07–2.26). Conclusion: Our study suggested 10‐repeat allele of 5‐HTTVNTR may be associated with TLE susceptibility.