色氨酸羟化酶基因-T457C位点遗传多态性与抑郁症的相关性及法医学意义

发布时间：2018-05-31 12:01

本文选题：5-羟色胺 + 色氨酸经化酶　；参考：《中国医科大学》2008年硕士论文

【摘要】： 前言 5-羟色胺(5-hydroxytrptamine,5-HT)广泛分布于体内各组织,作为中枢神经递质之一,参与多种中枢神经活动,如情绪控制,睡眠调节,焦虑,酒精中毒,摄食,性行为等。5-HT代谢失调可导致多种精神紊乱症状,多种酶类、受体、载体等,都会影响5-HT的生理代谢过程及其在中枢神经系统的正常调控作用;其中,色氨酸羟化酶能否正常表达具有重要的意义。色氨酸羟化酶(Tryprophan hydroxylase,TPH)是5-HT合成的限速酶,催化色氨酸生成5-羟色氨酸。TPH基因表达状况决定5-HT的生物合成,增强或减弱5-HT及其代谢物的作用强度,进而影响它在中枢神经系统的功能。 TPH基因位于常染色体11p15.3-p14,全长29kbp,有13个外显子,编码由444个氨基酸组成的TPH。基因序列内存在多个遗传多态性位点,分布于上游启动区、内含子1B区、IC区、内含子7、内含子8及内含子9区。本研究选择位于TPH基因第八内含子的-T457C位点调查其在中国汉族、藏族群体中的遗传多态性,并探讨在法医学个人识别中的意义及与抑郁症的相关性。材料与方法根据文献订购引物,应用PCR技术扩增TPH基因第八内含子的-T457C位点,采用限制性片段长度多态性(RFLP)分析法,以NlaⅢ限制性内切酶消化PCR产物,聚丙烯酰胺凝胶电泳分离并结合银染显带的方法,对284例中国北方汉族个体、142例藏族个体、111例抑郁症个体进行-T457C位点基因分型,并选择部分样本进行测序分析,以验证RFLP分型结果的准确性。结果 TPH基因-T457C位点PCR产物经NlaⅢ限制性内切酶消化、电泳后,共检出三种谱型,分别为TT型、CT型、CC型,DNA测序分析证实分型结果准确。在中国北方汉族群体中,TT型60例(0.211),CT型148例(0.521),CC型76例(0.268);T等位基因的频率为0.472,C等位基因的频率为0.528。142例藏族个体中,TT型30例(0.211),CT型64例(0.451),CC型48例(0.338);T等位基因的频率为0.437,C等位基因的频率为0.563。111例抑郁症患者中TT型31例(0.279),CT型51例(0.460),CC型29(0.261);T等位基因的频率为0.509,C等位基因的频率为0.491。讨论 TPH基因-T457C位点在中国北方汉族、藏族群体中的遗传多态性分布符合Hardy—Weinberg平衡定律。其DP值分别为0.612、0.638,H值分别0.521、0.451,EPP值分别为0.187、0.185。该位点在汉族、藏族群体中隶属高等鉴别能力的遗传标记系统。抑郁症患者与中国北方汉族健康人群相比,二者的等位基因频率和基因型频率分布没有统计学差异(P＞0.05)。但是,患者组T等位基因及TT纯合子频率均明显高于对照组;而且,健康对照组女性与患者女性相比,TT纯合子频率分布有显著差异(P=0.029),提示TPH基因-T457C位点的等位基因T可能与抑郁症有关。汉族与藏族相比,等位基因频率无显著性差异(P＞0.05);二者分别与法国人群比较,则均表现出统计学差异(P=0.001,P=0.050),提示TPH基因座-T457C位点的遗传多态性分布存在种族差异。结论 TPH基因-T457C位点在中国北方汉族、藏族群体中具有较好的遗传多态性,在法医学个人识别和亲子鉴定中具有较高的应用价值;该位点可作为人类遗传学研究的重要遗传标记;推测该位点等位基因T可能与抑郁症有关。
[Abstract]:Preface
5- hydroxytryptamine (5-hydroxytrptamine, 5-HT) is widely distributed in various tissues in the body. As one of the central neurotransmitters, it participates in a variety of central nervous activities, such as emotional control, sleep regulation, anxiety, alcoholism, feeding, sexual behavior and other.5-HT disorders that can lead to a variety of seminal disorders, many enzymes, receptors, carriers, and so on, which affect 5-HT Physiological metabolism process and its normal regulation role in central nervous system, and whether tryptophan hydroxylase can be expressed normally is of great significance.
Tryptophan hydroxylase (Tryprophan hydroxylase, TPH) is a speed limiting enzyme in 5-HT synthesis. The catalytic activity of tryptophan to 5- hydroxytryptophan.TPH gene expression determines the biosynthesis of 5-HT, strengthens or weakens the action strength of 5-HT and its metabolites, and then affects its function in the central nervous system.
The TPH gene is located in the autosomal 11p15.3-p14, full length 29kbp, with 13 exons, and the sequence of TPH. genes encoding 444 amino acids is stored in multiple genetic polymorphic loci, distributed in the upstream promoter region, the intron 1B region, the IC region, the intron 7, the intron 8 and the intron 9 regions.
In this study, we chose the -T457C site of the intron eighth of the TPH gene to investigate the genetic polymorphism in the Han and Tibetan population in China, and to explore the significance of the personal identification in forensic medicine and the correlation with depression.
Materials and methods
The -T457C loci of the intron eighth of TPH gene were amplified by PCR, and the restriction fragment length polymorphism (RFLP) analysis was used to digest PCR products with Nla III restriction endonuclease, polyacrylamide gel electrophoresis was used to separate and combine silver staining bands, and 284 cases of Han nationality in northern China, 142 cases of Tibetan individuals, 1. The -T457C locus genotyping was performed in 11 individuals with depression, and some samples were selected for sequencing analysis to verify the accuracy of RFLP typing results.
Result
The PCR product of the TPH gene -T457C was digested by Nla III restriction endonuclease. After the electrophoresis, three spectral types were detected, which were TT, CT, CC, DNA sequencing, and confirmed that the classification results were accurate. In the Han population of northern China, 60 cases (0.211), CT 148 cases (0.521), CC 76 cases (0.268), and the frequency of T alleles were 0.472 and frequency alleles frequency Among the Tibetan individuals of 0.528.142, 30 cases (0.211), 64 cases (0.451) of CT and 48 cases of CC (0.338); the frequency of T allele was 0.437, and the frequency of C allele was TT 31 (0.279) in 0.563.111 cases, 51 cases (0.460), CC 29 (0.261), T allele frequency was 64, C alleles were frequency
discuss
The genetic polymorphism distribution of the TPH gene -T457C loci in the Han and Tibetan population in northern China is in accordance with the Hardy - Weinberg equilibrium law. The DP values are 0.612,0.638, H value 0.521,0.451 respectively, and EPP values are 0.187,0.185. this loci in the Han and Tibetan populations, which belong to the higher differential genetic marker system.
The allele frequency and genotype frequency distribution of the two depressive patients were not significantly different from those of the Han people in northern China (P > 0.05). However, the T allele and TT homozygous frequency of the patients were significantly higher than those in the control group, and the frequency distribution of the TT homozygote in the healthy control women was significantly lower than that of the women. The difference (P=0.029) suggests that allele T of TPH gene -T457C locus may be associated with depression.
There was no significant difference in allele frequency between the Han and the Tibetans (P > 0.05). Compared with the French population, the two were statistically different (P=0.001, P=0.050), suggesting that the genetic polymorphisms of the -T457C locus of the TPH locus had racial differences.
conclusion
The TPH gene -T457C locus has a good genetic polymorphism in the Han and Tibetan population in northern China. It has high application value in personal identification and parent-child identification in forensic medicine. This loci can be used as an important genetic marker in human genetics research. It is presumed that the allele T of the loci may be related to depression.
【学位授予单位】：中国医科大学
【学位级别】：硕士
【学位授予年份】：2008
【分类号】：D919

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