抑郁症患者脑源性神经营养因子Val66Met多态性与血清浓度的关系

目的探讨脑源性神经营养因子（BDNF）基因Val66Met多态性与抑郁症之同的关系以及Val66Met多态性是否影响血清BDNF浓度。方法对76例未经药物治疗的抑郁症患者和50例正常人,用限制性片段长度多态性方法分析Val66Met多态性,采用酶联吸附反应方法对血清BDNF浓度进行检测。结果（1）抑郁症患者血清BDNF浓度（24．7±12．7）ng／m1显著低于正常对照组（36．6±16．4）pg／m｜,差异有统计学意义（P〈0．01）;（2）抑郁症组和对照组之间的Val66Met多态性位点的等位基因频率和基因型分布差异无统计学意义（P〉0．05）;（3）在抑郁症组和对照组,Val／Met＋Met／Met基因型组与Val／Val基因型相比,血清BDNF浓度差异无统计学意义（P〉0．05）。结论抑郁症患者存在较低的血清BDNF水平,BDNF基因Val66Met多态性与抑郁症之间无相关性,Val66Met多态性对血清BDNF水平浓度无明显影响。     

脑源性神经营养因子基因Val66Met多态性与重性抑郁障碍患者认知功能的关系

目的:探讨脑源性神经营养因子(BDNF)基因Val66Met多态性与重性抑郁障碍认知功能的关系。方法:对100例重性抑郁障碍患者进行认知功能测验和事件相关电位P300检查,同时检测BDNF基因多态性。结果:Val/Val基因型患者大部分认知测验成绩优于Met/Met基因型,差异均有统计学意义(P均<0.01);Met/Met基因型患者P3潜伏期(LATP3)长于Val/Val基因型[分别(304.3±11.8)ms和(293.3±15.7)ms],P3波幅(AMPP3)低于Val/Val基因型[分别(5.9±1.9)μV和(7.4±2.1)μV],差异均有统计学意义(P<0.05或P<0.01)。结论:BDNF基因Val66Met多态性可能与重性抑郁障碍患者认知功能损害有关。     

抑郁症患者脑源性神经营养因子Va166Met多态性与血清浓度的关系

目的 探讨脑源性神经营养因子(BDNF)基因Va166Met多态性与抑郁症之间的关系以及Va166Met多态性是否影响血清BDNF浓度.方法 对76例未经药物治疗的抑郁症患者和50例正常人,用限制性片段长度多态性方法分析Va166Met多态性,采用酶联吸附反应方法对血清BDNF浓度进行检测.结果 (1)抑郁症患者血清BDNF浓度(24.7±12.7)ng/ml显著低于正常对照组(36.6±16.4)pg/ml,差异有统计学意义(P＜0.01);(2)抑郁症组和对照组之间的Va166Met多态性位点的等位基因频率和基因型分布差异无统计学意义(P＞0.05);(3)在押郁症组和对照组,Val/Met+Met/Met基因型组与Val/Val基因型相比,血清BDNF浓度差异无统计学意义(P＞0.05).结论 抑郁症患者存在较低的血清BDNF水平,BDNF基因Val66Met多态性与抑郁症之间无相关性,Va166Met多态性对血清BDNF水平浓度无明显影响.     

脑卒中后抑郁与脑源性神经营养因子基因Val66Met单核苷酸多态性的相关性研究

目的探讨脑卒中后抑郁(PSD)与脑源性神经营养因子(BDNF)基因Val66Met单核苷酸多态性(SNP)的相互关系。方法选择86例PSD患者为PSD组,68例脑卒中无PSD患者为无PSD组,另选择46名健康者为对照组。3组研究对象年龄及性别基本匹配。采用酶联免疫吸附法检测BDNF浓度和等位基因特异性聚合酶链反应(A-S PCR)技术检测BDNF基因Val66Met位点SNP的分布。结果 PSD组和无PSD组间BDNF表达差异有统计学意义(t=-2.038,P=0.043);两组间基因型频率(χ2=0.340,P=0.844)和等位基因频率(χ2=0.036,P=0.849)差异均无统计学意义。结论 BDNF表达与PSD发生相关,但BDNF基因Val66Met位点SNP与PSD未发现有相关关系。     

脑源性神经营养因子基因多态性与重性抑郁障碍认知功能的关系

目的 探讨脑源性神经营养因子(BDNF)基因Va166Met多态性与重性抑郁障碍认知功能的关系.方法 以100例重性抑郁障碍患者(患者组)与100名健康志愿者(对照组)为研究对象,采用1组神经心理学检测评估认知功能,并检测BDNF基因多态性;分别按照总智商(FIQ)、威斯康星卡片分类测验改良版(M-WCST)分类数、正确数、持续错误数、河内塔测试(TOH)计划时间、执行时间及总分的测验成绩由好到差排序,将患者组分为组1(成绩前50例,认知功能较好的患者)和组2(成绩后50例,认知功能较差的患者),检测组1与组2 BDNF基因型频率分布.结果 (1)对照组:除数字广度外,其他神经心理学测验成绩在BDNF基因型间的差异均无统计学意义(P>0.05).(2)患者组:中国修订韦氏成人智力量表(WAIS-RC)FIQ[(102.1±11.5)分vs(92.5±10.2)分]、M-WCST分类数[(5.6±1.7)分vs(2.9±1.2)分]和正确数[(36.5±6.0)分vs(26.8±5.6)分]、TOH总分[(50.8±9.6)分vs(40.4±9.3)分]及各项测验成绩,连线测验(TMT)A耗时数和B耗时数的成绩在患者组Val/Val基因型均优于Met/Met基因型,差异有统计学意义(P均<0.01).(3)组1Met/Met基因型频率分布显著低于组2,差异均有统计学意义(P均<0.01);除FIQ和TOH执行时间外,其他各项组1 Val/Val基因型频率显著高于组2,差异有统计学意义(P均<0.05).结论 BDNF基因Va166Met多态性与重性抑郁障碍患者认知功能损害可能有关.

Abstract：

objective To investigate relationship between brain-derived neurotrophic factor (BDNF)gene Va166Met polymorphism and cognitive function in patients with major depressive disorder.Methods One hundred patients with major depressive disorder and 100 healthy volunteers were included.The cognitive function was assessed by a series of neuropsychology tests,and BDNF gene polymorphism was detected.Results (1)In control group,the achievements of all neuropsychology tests except for digit span were not significantly different among ones with different BDNF genotypes(P>0.05).(2)In patient group,the achievements of neuropsychology tests such as WAIS-RC(102.1±1 1.5 vs.92.5±10.2),M-WCST(5.6±1.7 vs.2.9±1.2,36.5±6.0 vs.26.8±5.6),TOH(50.8±9.6 vs.40.4±9.3),time for TMT-A and TMT-B,were significantly better in ones with Val/Val genotype than in ones with Met/Met genotype(P≤0.01).(3)The Val/Val genotype frequency in patients with better cognitive function was higher than that in patients with worse cognitive function,while Met/Met genotype frequency was in the opposite direction(P<0.05 or P<0.01).Conclusion The BDNF gene Va166Met polymorphism is possibly correlated with impairment of cognitive function in patients with major depressive disorder.     

儿童精神分裂症患者脑源型神经营养因子基因VaL66Met多态性与颅脑结构关系的研究

目的分析脑源性神经营养因子(brain-derived neurotrophic factor,BDNF)基因VaL66Met多态性与儿童精神分裂症及其脑结构之间的关系。方法采用限制性片段长度多态性技术测定199例儿童精神分裂症患者与和200名健康儿童的BDNF基因VaL66Met多态性,用磁共振成像对104例患者进行检测,并采用计算机软件测量颅腔结构。结果患者组与对照组的BDNF VaL66Met基因型(A/A,A/G,G/G)和等位基因(A,G)频率的差异均无统计学意义(掊2=1.22,P>0.05;掊2=0.24,P>0.05)。BDNF基因VaL66Met不同基因型之间患者比较,左外侧裂脑沟根部宽(F=8.11,P<0.01)、右外侧裂脑沟根部宽(F=10.25,P<0.00)、顶叶脑沟宽(F=8.23,P<0.01)、右颞角宽度(F=5.13,P<0.05)差异具有统计学意义。且各基因型两两比较显示,A/A型的患者的顶叶脑沟宽(3.77±1.36)cm、右外侧裂脑沟根部宽(6.44±2.75)cm显著高于A/G型[(3.19±0.74)cm,(5.19±1.16)cm]、G/G型[(3.15±0.60)cm,(4.92±1.83)cm];A/A型的患者的左外侧裂脑沟根部宽(6.28±1.79)cm显著高于A/G型(5.11±1.56)cm;A/A型患者的右颞角宽度(5.05±1.36)cm显著高于G/G型(4.05±2.13)cm,均具有统计学意义(P<0.05)。结论儿童精神分裂症易感性与BDNF基因VaL66Met多态性无显著相关;儿童精神分裂症患者中携带BDNF基因(VaL66Met)A/A基因型的患者存在显著的脑室扩大、右颞角宽度增大。     

高压氧联合奥拉西坦对脑外伤后患者的认知功能及相关细胞因子的影响

目的探讨高压氧联合奥拉西坦对外伤后认知障碍患者的认知功能及相关细胞因子的影响。 方法选取徐州市中心医院神经外科自2017年1月至2018年10月住院治疗的脑外伤后认知障碍的患者60例,随机分为对照组和治疗组各30例,对照组给予传统的常规疗法治疗,治疗组在常规治疗的基础上给予高压氧联合奥拉西坦治疗,疗程3周。治疗前、治疗3周行血清血管形成素-1（Ang-1）、血管内皮生长因子（VEGF）和脑源性神经营养因子（BDNF）浓度测定,采用中文版蒙特利认知评分量表（MOCA）评估认知功能。 结果2组患者治疗前的血清Ang-1、VEGF、BDNF水平比较,差异无统计学意义（P>0.05）。治疗3周后,2组患者的血清Ang-1、VEGF、BDNF水平均较治疗前增加,治疗组血清Ang-1、VEGF、BDNF水平较对照组增加明显,差异有统计学意义（P<0.05）。2组患者治疗前MOCA评分比较,差异无统计学意义（P>0.05）。治疗3周后,治疗组的MOCA评分较对照组高,差异具有统计学意义（P<0.05）。 结论高压氧联合奥拉西坦治疗脑外伤后认知障碍患者较常规治疗可促进血清Ang-1、VEGF和BDNF的分泌,从而改善急脑外伤后认知障碍患者的认知功能。     

整体身心调节干预对颅脑损伤认知障碍患者血清脑源性神经营养因子的影响

目的整体身心调节干预对颅脑损伤认知障碍患者血清脑源性神经营养因子(BDNF)的影响。方法采用投掷硬币随机分组法将85例认知障碍的颅脑损伤患者分为对照组(42例)和身心调节干预组(43例)。对照组给予针对性的认知康复训练,身心调节干预组在此基础上给予身心调节干预训练。采用执行缺陷综合征的行为评价(BADS)和洛文斯顿作业疗法认知评定测验(LOTCA)量表进行执行功能及认知能力评测;酶联免疫吸附试验(ELISE)检测血清BDNF的浓度。结果治疗前,两组患者的BADS各项指标评分以及LOTCA评分差异无统计学意义(P>0.05),BDNF浓度变化差异无统计学意义(P>0.05);治疗后,身心调节干预组BADS各项指标评分以及LOTCA评分优于对照组,BDNF血清浓度较对照组升高,差异有统计学意义(P<0.05)。结论整体身心调节行为干预可改善颅脑损伤患者执行功能障碍,与提高血清脑源性生长因子的浓度有关。     

脑源性神经营养因子Val66Met功能基因多态性与抗抑郁剂疗效

目的：探讨脑源性神经营养因子（BDNF）Val66Met功能基因多态性与抗抑郁剂临床疗效的相关性。方法：302例抑郁症患者给予抗抑郁剂治疗8周。于治疗前和治疗2、4、6、8周后采用汉密尔顿抑郁量表（HAMD）评定抑郁严重程度和疗效。以治疗后HAMD总分≤7分为临床痊愈,将302例患者分为痊愈组160例和未痊愈组142例,抽取患者静脉血,采用Illumina GoldenGate定制芯片分析BDNFVal66Met基因多态性并进行基因分型。结果：痊愈组基因型分布A/A31例（19.4%）、A/G92例（57.5%）和G/G37例（23.1%）,未痊愈组分别为28例（19.7%）、78例（54.9%）和36例（25.4%）（χ2=0.054,P=0.817）;痊愈组等位基因频率分布A154例（48.1%）和G166例（51.9%）,未痊愈组分别为134例（47.2%）和150例（52.8%）（χ2=0.247,P=0.884）。3种BDNFVal66Met基因型患者间在性别、年龄、受教育年限、病程、发病次数、有无精神疾病家族史、HAMD基线及减分率上差异均无统计学意义（P均〉0.05）。结论：BDNFVal66Met基因多态性不是影响抗抑郁剂治疗近期疗效的主要因素。     

天津地区汉族人群COMT基因多态性与脑梗死相关性研究

研究背景儿茶酚胺氧位甲基转移酶(COMT)是儿茶酚胺的主要代谢酶,催化儿茶酚胺第3位羟基甲基化,降解儿茶酚胺,同时亦是雌激素的主要代谢酶。COMT基因在rs4680位点存在鸟嘌呤腺嘌呤(G-A)点突变,使其编码的第108和(或)158位氨基酸由缬氨酸(Val)变为蛋氨酸(Met),导致儿茶酚胺氧位甲基转移酶活性降低。已知COMT基因多态性与精神疾病、酒精依赖、药物不良反应等有关,而与脑梗死之间的关系尚不明确,本研究旨在探讨COMT基因多态性与脑梗死之间的关系。方法通过聚合酶链反应限制性酶切片段长度多态性方法检测181例天津地区汉族脑梗死患者COMT Val及Met基因型,以及不同基因型脑梗死患者血糖、总胆固醇、甘油三酯、低密度脂蛋白胆固醇、高密度脂蛋白胆固醇,以及载脂蛋白A和B水平。结果脑梗死组Val等位基因频率(78.45%)及Val/Val纯合子基因型(61.33%)均高于正常对照组(68.24%和45.95%),差异具有统计学意义(P<0.05);进一步分析显示男性Val等位基因频率(82.52%)与正常对照组(66.67%)之间差异亦存在统计学意义(P<0.01),而女性患者组间差异(69.83%对69.07%)无统计学意义(P>0.05)。脑梗死组Val/Val型与Val/Met+Met/Met型比较,血糖、血脂水平及高血压患病率差异无统计学意义(均P>0.05)。结论 COMT Val等位基因频率和Val/Val纯合子基因型是男性脑梗死患者的遗传学危险因素,COMT对脑梗死的影响与血糖、血脂及血压无明显相关性。     

Prefrontal cognition in schizophrenia and bipolar illness in relation to Val66Met polymorphism of the brain-derived neurotrophic factor gene

The measures of prefrontal cognition have been used as endophenotype in molecular-genetic studies. Brain-derived neurotrophic factor (BDNF) has been implicated in cognitive functions and in the pathogenesis of major psychoses. This study investigates the relationship between Val66Met polymorphisms of the BDNF gene and prefrontal cognitive function in 129 patients with schizophrenia and 111 patients with bipolar mood disorder. Cognitive tests included the Wisconsin Card Sorting Test (WCST), with such domains as number of perseverative errors, non-perseverative errors, completed corrected categories, conceptual level responses, and set to the first category, and the N-back test, where mean reaction time and percent of correct reactions were measured. Genotyping for Val66Met BDNF polymorphism was done by polymerase chain reaction method. In schizophrenia, no relationship between Val66Met polymorphism of the BDNF gene and the results of the WCST was observed. Patients with Val/Val genotype had a higher percentage of correct reactions in the N-back test than those with the remaining genotypes. Bipolar patients with Val/Val genotype obtained significantly better results on three of five domains of the WCST. No relationship between BDNF polymorphism and the results of the N-back test was found in this group. A limitation to the results could be variable psychopathological state and medication during cognitive testing and lack of Hardy-Weinberg equilibrium in schizophrenia group. Val66Met polymorphism of the BDNF gene may be associated with cognitive performance on the WCST in bipolar mood disorder but not in schizophrenia. An association of this polymorphism with performance on the N-back test in schizophrenia and not in bipolar illness may suggest that in schizophrenia, the BDNF system may be connected with early phases of information processing.     

Brain-Derived Neurotrophic Factor Gene Val66Met Polymorphism Is a Risk Factor for Attention-Deficit Hyperactivity Disorder in a Turkish Sample

ObjectiveAttention-deficit hyperactivity disorder (ADHD) is a neurodevelopmental disorder that negatively affects different areas of life. We aimed to evaluate the associations between the Val66Met polymorphism of brain-derived neurotrophic factor (BDNF) and ADHD and to assess the effect of the BDNF polymorphism on the neurocognitive profile and clinical symptomatology in ADHD.MethodsTwo hundred one ADHD cases and 99 typically developing subjects (TD) between the ages of 8 and 15 years were involved in the study. All subjects were evaluated using a complete neuropsychological battery, Child Behavior Checklist, the Teacher''s Report Form (TRF) and the DSM-IV Disruptive Behavior Disorders Rating Scale-teacher and parent forms.ResultsThe GG genotype was significantly more frequent in the patients with ADHD than in the TD controls, and the GG genotype was also significantly more frequent in the ADHD-combined (ADHD-C) subtype patients than in the TDs. However, there were no significant associations of the BDNF polymorphism with the ADHD subtypes or neurocognitive profiles of the patients. The teacher-assessed hyperactivity and inattention symptom count and the total score were higher, and the appropriately behaving subtest score of the TRF was lower in the GG genotypes than in the GA and AA (i.e., the A-containing) genotypes.ConclusionWe found a positive association between the BDNF gene Val66Met polymorphism and ADHD, and this association was observed specifically in the ADHD-C subtype and not the ADHD-predominantly inattentive subtype. Our findings support that the Val66Met polymorphism of BDNF gene might be involved in the pathogenesis of ADHD. Furthermore Val66Met polymorphism of BDNF gene may be more closely associated with hyperactivity rather than inattention.     

Is the Val66Met polymorphism of the brain‐derived neurotrophic factor gene associated with panic disorder? A meta‐analysis

Although emerging evidence has suggested an association between the Val66Met (rs6265) polymorphisms in brain‐derived neurotrophic factor (BDNF) gene and the panic disorder, the conclusion is inclusive given the mixed results. This meta‐analysis reviewed and analyzed the recent studies addressing the potential association between the Val66Met polymorphisms and panic disorder susceptibility. Related case–control studies were retrieved by database searching and selected according to established inclusion criteria. Six articles were identified, which explored the association between the BDNF Val66Met polymorphism and panic disorder. Statistical analyses revealed no association for the allele contrast and the dominant model. However, the recessive model showed a significant association between the BDNF Val66Met polymorphism and panic disorder (odds ratio = 1.26, 95% confidence interval = 1.04–1.52, z = 2.39, P = 0.02). Despite of some limitations, this meta‐analysis suggests that the Val66Met polymorphism of BDNF gene is a susceptibility factor for panic disorder.     

The BDNF Val66Met polymorphism impairs synaptic transmission and plasticity in the infralimbic medial prefrontal cortex

The brain-derived neurotrophic factor (BDNF) Val66Met polymorphism is a common human single nucleotide polymorphism (SNP) that affects the regulated release of BDNF, and has been implicated in affective disorders and cognitive dysfunction. A decreased activation of the infralimbic medial prefrontal cortex (IL-mPFC), a brain region critical for the regulation of affective behaviors, has been described in BDNF(Met) carriers. However, it is unclear whether and how the Val66Met polymorphism affects the IL-mPFC synapses. Here, we report that spike timing-dependent plasticity (STDP) was absent in the IL-mPFC pyramidal neurons from BDNF(Met/Met) mice, a mouse that recapitulates the specific phenotypic properties of the human BDNF Val66Met polymorphism. Also, we observed a decrease in NMDA and GABA receptor-mediated synaptic transmission in the pyramidal neurons of BDNF(Met/Met) mice. While BDNF enhanced non-NMDA receptor transmission and depressed GABA receptor transmission in the wild-type mice, both effects were absent in BDNF(Met/Met) mice after BDNF treatment. Indeed, exogenous BDNF reversed the deficits in STDP and NMDA receptor transmission in BDNF(Met/Met) neurons. BDNF-mediated selective reversal of the deficit in plasticity and NMDA receptor transmission, but its lack of effect on GABA and non-NMDA receptor transmission in BDNF(Met/Met) mice, suggests separate mechanisms of Val66Met polymorphism upon synaptic transmission. The effect of the Val66Met polymorphism on synaptic transmission and plasticity in the IL-mPFC represents a mechanism to account for this impact of SNP on affective disorders and cognitive dysfunction.     

The brain-derived neurotrophic factor Val66Met polymorphism and rate of decline in Alzheimer's disease

It is largely unknown why some patients with Alzheimer's disease (AD) decline cognitively more rapidly than others. Genetic differences among patients could influence rate of decline. Brain-derived neurotrophic factor (BDNF) is a neurotrophin important in the survival neurons and in memory function. BDNF levels are reduced in the brain in AD. The Val66Met polymorphism in the BDNF gene modifies neuronal BDNF secretion, and affects hippocampal function and memory performance. We tested the hypothesis that the BDNF Val66Met polymorphism influences rate of cognitive decline in AD. In a sample of 149 AD patients followed for an average of 3.9 years, we found no effect of BDNF Val66Met genotype on rate of change in the Mini Mental State Examination. Results were similar when we excluded patients taking an acetylcholinesterase inhibitor, those placed in a nursing home during the study, or those with a neuropathological diagnosis that included AD plus an entity other than AD. We also found no evidence that the effects of the BDNF Val66Met genotype depend on APOE genotype, which itself had no effect on rate of cognitive change. These findings suggest that the functional BDNF Val66Met variant is not a major determinant of rate of cognitive decline in AD.     

Brain-derived neurotrophic factor (BDNF) Val66Met polymorphism and post-stroke dementia: a hospital-based study from northern Iran

Brain-derived neurotrophic factor (BDNF) Val66Met polymorphism is associated with functional and cognitive outcomes of stroke and plays a key role in preventing neuronal death. This study aimed to answer the following question: does BDNF Val66Met polymorphism prognosticate survival status and risk of post-stroke dementia (PSD)? In a retrospective cohort study, 206 patients with ischemic stroke (IS) entered the study. They were consecutively being admitted to the neurology clinic in Poursina Hospital (northern Iran) from 2012 to 2014. The diagnosis of PSD was based on DSM-5 criteria. The current and the premorbid cognitive statuses of the patients were respectively assessed through the third edition of Addenbrooke’s Cognitive Examination and the Informant Questionnaire on Cognitive Decline in the Elderly. BDNF Val66Met gene polymorphism was determined by PCR–RFLP. On average, 48 patients (23.3 %) developed PSD 6 months after IS. Log-rank test showed that the survival rate of at least one Val-allele carriers was significantly lower than that of Met/Met homozygotes (P = 0.0005), and the former developed PSD sooner than the latter (375, 492 days, respectively). Cox model showed that heterozygous carriers of Val/Met were at greater risk of PSD over time (HR 2.280, 95 % CI 1.566–4.106, P = 0.006). However, the risk ratio of patients with PSD among different BDNF genotypes decreased after adjusting demographic, clinical, and vascular risk factors, and was no longer statistically significant (AHR 2.434, 95 % CI 0.597–9.926, P = 0.215). Val-allele carriers or Val/Met genotypes were more quickly diagnosed as having dementia after IS. However, this genetic vulnerability became more destructive when it was added to demographic, clinical, and vascular risk factors.     

Sex-specific association of brain-derived neurotrophic factor (BDNF) Val66Met polymorphism and plasma BDNF with attention-deficit/hyperactivity disorder in a drug-naïve Han Chinese sample

A functional polymorphism of the brain derived neurotrophic factor gene (BDNF) (Val66Met) has been suggested to be involved in the pathogenesis of attention-deficit/hyperactivity disorder (ADHD). It also has an impact on peripheral BDNF levels in psychiatric disorders. This study examined the association of Val66Met with plasma BDNF level of ADHD in Han Chinese children (170 medication – naïve ADHD patients and 155 unaffected controls, aged 6–16 years). The Val allele was showed a higher frequency in females with ADHD (n=84) than controls (P=0.029) from the case-control association study. The analysis of covariance (ANCOVA) indicated that the mean plasma BDNF levels of ADHD patients were significantly higher than that of controls (P=0.001). We performed both total sample and sex stratified analyses to investigate the effect of Val66Met genotype on the plasma BDNF levels, but only a trend of association was found in females with ADHD (n=84), with a tendency of lower plasma BDNF level in Val allele carriers than Met/Met genotype carriers (P=0.071). Our results suggested a sex-specific association between BDNF and ADHD. Furthermore, there was a possible sex-specific relationship between the BDNF Val66Met genotype and plasma BDNF levels. However, further studies are required to elucidate the role of BDNF in ADHD.     

Genetic Role of BDNF Val66Met and 5-HTTLPR Polymorphisms on Depressive Disorder

Objective

We investigated possible association between depressive disorders and BDNF Val66Met and 5-HTTLPR. Brain derived neurotrophic factor (BDNF) gene and serotonin transporter (SLC6A4) gene are promising candidate genes for depressive disorders. It has been suggested that BDNF promotes the survival and differentiation of serotonergic neurons and that serotonergic transmission exerts powerful control over BDNF gene expression.

Methods

Final analyses were performed on 186 patients with depressive disorders and 1032 controls. Val66Met polymorphism of BDNF gene and 5-HTTLPR polymorphism of serotonin transporter gene were genotyped and allele and genotypic associations on the diagnosis of depression and age at onset of depression were analyzed.

Results

The 5-HTTLPR was positively associated with depressive affected status in the total sample and in females (p=0.038 for allelewise, p=0.015 for genotype-wise associations), but, not in males. The BDNF Val66Met showed no association with depression. BDNF Val66Met and 5-HTTLPR alone were not associated with age at onset of depression. Additional analysis on the interaction between BDNF Val66Met and 5-HTTLPR found a significant association with age at onset of depression in the entire patient group. This association was also found in the female but not in the male patient group. None of the positive results survived Bonferroni correction for multiple testing.

Conclusion

This result suggested that BDNF Val66Met and 5-HTTLPR may contribute to depressive disorders in a complex way and that the genetic effect could differ by gender. Further studies with large number of patients will be necessary.