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 MAOA-uVNTR gene polymorphism and personality traits in Chinese young females

Monoamine oxidase A (MAOA), a mitochondrial outer membrane enzyme, degrades biogenic amines including norepinephrine, dopamine and serotonin, which have been implicated in the expression of personality traits. We tested the associations between functional MAOA-uVNTR genetic variants and personality traits in a cohort of 370 healthy young Chinese females. Subjects who were homozygous for the 4-repeat allele of the MAOA-uVNTR gene tended to have a higher total score on the Harm Avoidance (HA) dimension of the Tridimensional Personality Questionnaire (TPQ) (p = 0.056), and had a significantly higher score on subdimension 4 of HA (p = 0.020) compared with the 3-repeat carriers. No significant association was demonstrated for MAOA-uVNTR polymorphism and the other two dimensions (Novelty Seeking and Reward Dependence) of TPQ. These results suggest that genetic variants of the MAOA gene may play a role in HA, but not in Novelty Seeking or Reward Dependence.     

Serotonin transporter gene polymorphism and personality traits in a Korean population

Recently, there has been growing enthusiasm for exploring biological approaches to personality, especially in the area of genetic research into the identification of those genes responsible for particular personality traits. The aim of this study was to investigate the association between the serotonin transporter-linked promoter region (5-HTTLPR) polymorphism and personality traits. We recruited 211 unrelated, normal subjects. The Korean version of the Temperament and Character Inventory (TCI) was used to assess certain personality traits. From blood samples taken from the subjects, DNA was isolated using standard techniques and the 5-HTTLPR polymorphism was genotyped by means of polymerase chain reaction and electrophoresis. We classified the subject into the s/s, s/l, and l/l groups according to their genotype. The differences in the temperament factors of the TCI between group S (s/s genotype) and group L (s/l + l/l genotype) were assessed, after the inclusion of gender and age as covariates in the analysis of variance. After controlling for gender and age, there were no associations between the harm avoidance, novelty seeking, and reward dependence scores and the genotypes. However, the persistence score of group S was significantly higher than that of group L. Our results suggest that the 5-HTTLPR polymorphism may be associated with the persistence score of the TCI in a normal Korean population.     

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.     

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.     

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。     

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.     

Association between a serotonin transporter promoter polymorphism (5HTTLPR) and personality disorder traits in a community sample

Background

The serotonin transporter (SERT) polymorphism (5HTTLPR) has been reported to be associated with several psychiatric conditions. Specific personality disorders could be intermediate factors in the known relationship between 5HTTLPR and psychiatric disorders. This is the first study to test the association between this polymorphism and dimensions of all DSM-IV personality disorders in a community sample.

Methods

374 white participants were assessed by clinical psychologists using the International Personality Disorder Examination (IPDE). Associations between dimensions of each DSM-IV personality disorder and the long (l) and short (s) alleles of the 5HTTLPR were evaluated using non-parametric tests and regression models.

Results

The s allele of the 5HTTLPR polymorphism was significantly associated with higher avoidant personality trait scores in the whole sample. Males with the s allele had a significantly lower likelihood of higher obsessive-compulsive personality disorder (OCPD) trait scores, whereas females with the s allele were likely to have higher OCPD personality trait scores.

Conclusion

This paper provides preliminary data on the relationship between personality disorders and the 5HTTLPR polymorphism. The relationship of the s allele and avoidant PD is consistent with findings of a nonspecific relationship of this polymorphism to anxiety and depressive disorders. Concerning the unusual sexual dimorphic result with OCPD, several hypotheses are presented. These findings need further replication, including a more detailed study of additional variants in SERT.     

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.     

Association between serotonin transporter gene and borderline personality disorder

Borderline personality disorder (BPD) is characterized by a pervasive pattern of instability in regulation of emotion, interpersonal relationships, self-image, and impulse control beginning in early adulthood. BPD affects about 1-2% of the general population and has a high mortality rate as a result of suicide and impulsive behaviour. The serotonin transporter gene (5-HTT) is considered as a candidate gene for BPD as multiple lines of evidence have suggested that it plays an important role in suicide, impulsive behaviour, and emotional liability. To test for an association between 5-HTT and BPD, we genotyped three common polymorphisms: the serotonin transporter linked promoter region (5-HTTLPR); a variable number of tandem repeat (VNTR) in intron 2, and a single nucleotide variant (A/G) within the LPR region. Eighty-nine Caucasian patients with BPD and 269 Caucasian healthy controls were analyzed. The program UNPHASED was used to compare allele and haplotype frequencies between cases and controls. Significant differences in allele frequencies of the VNTR marker (p=0.012) and haplotype frequencies (p=0.002) between patients and controls were found. Compared with healthy controls, patients with BPD showed higher frequencies of the 10 repeat of the VNTR marker and the S-10 haplotype, and lower 12 repeat and L(A)-12 haplotype. Our results suggest that the serotonin transporter gene may play a role in the aetiology of borderline personality disorder.     

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。     

Anxiety- and novelty seeking-related personality traits and serotonin transporter gene polymorphisms

The affection of human personality by the promoter and the intron 2 polymorphism in the serotonin transporter gene (SERT) is inconsistently reported. We aimed to clarify this situation by gender-specific haplotype-phenotype association. 98 women and 97 men completed the personality inventories NEO-PI-R and TPQ. The subjects were genotyped for the two SERT polymorphisms and the haplotypes were calculated. The short (S) and long (L) promoter alleles and the 12 and 10 repeat intron 2 alleles formed the haplotypes S 12, S 10, L 12 and L 10. In men, scores in the anxiety-related dimensions were higher in S 12 than in L 12 carriers. Opposite in direction, scores tended to be lower in S 10 than in L 10 carriers. In the novelty seeking-related dimensions, scores were higher in S 10 than in S 12 carriers. No association was observed in women. In conclusion, anxiety- and novelty seeking-related personality dimensions are differentially associated with different SERT haplotypes; the consistent restriction to men suggests common androgen regulation. Opposite trends with haplotypes including the same promoter alleles suggest contribution of group stratification to earlier inconsistent findings and call to further differentiate the molecular function and clinical implications of the SERT promoter polymorphism.     

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.     

A functional serotonin transporter gene polymorphism is associated with migraine with aura

An association study was performed in 197 migraineurs with regard to a functional serotonin (5-HT) transporter (5-HTT) gene promoter polymorphism that leads to low or high 5-HT uptake activity. The frequency of the less active short allele was increased in migraineurs with aura but not in migraineurs without aura in comparison with the control population (p < 0.001). This indicates that the 5-HTT may be involved in the polygenic etiology of migraine with aura.     

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。     

Serotonin transporter gene polymorphism and personality traits in primary alcohol dependence.

We tested the hypothesis of an association between the serotonin transporter (5-HTT) gene regulatory region polymorphism and the Temperament and Character Inventory (TCI) personality dimension of Harm Avoidance. For the study, 124 subjects seeking inpatient treatment for primary alcohol dependence were grouped by their 5-HTT genotype and assessed with the TCI. Genotypes differed statistically significantly in Harm Avoidance but not in any other personality trait. This gives support to the hypothesis that the TCI temperament Harm Avoidance is associated with serotonergic neurotransmission in primary alcohol dependence.     

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.