本文關(guān)鍵詞： 亞甲基四氫葉酸還原酶 基因分型 單核苷酸多態(tài)性 同型半胱氨酸 熒光偏振　出處：《第四軍醫(yī)大學(xué)》2005年碩士論文　論文類型：學(xué)位論文

【摘要】：同型半胱氨酸(Homocysteine,Hcy)是轉(zhuǎn)甲基和轉(zhuǎn)硫基代謝過程中產(chǎn)生的一種氨基酸,血漿Hcy增高增加多種疾病危險(xiǎn)性,包括血管病、冠心病、血栓形成、中風(fēng)、神經(jīng)管發(fā)育不全及糖尿病腎病等。 亞甲基四氫葉酸還原酶(MTHFR)是Hcy代謝的一個(gè)關(guān)鍵酶,MTHFR可催化5,10—亞甲基四氫葉酸還原成5—甲基四氫葉酸的不可逆反應(yīng)。MTHFR基因最常見多態(tài)性為677位核苷酸C→T置換(C677T),使酶活性區(qū)的丙氨酸(Ala)置換為纈氨酸(Val)生成不耐熱酶,妨礙5—甲基四氫葉酸的合成,后者為Hcy生成蛋氨酸的甲基供體,并導(dǎo)致血漿Hcy水平升高,TT基因型個(gè)體的Hcy水平較CC或CT基因型可升高約25%。 C677T分布頻率存在種族及地區(qū)差異,在非洲撒哈拉地區(qū)及加拿大北部人群T等位基因頻率最低,而南歐及南美人群分布頻率最高。C677T多態(tài)性是多種疾病的獨(dú)立風(fēng)險(xiǎn)因子。如:阿滋海默病、心血管疾病、血栓及栓子形成、腫瘤等,與神經(jīng)管閉合不全及其它先天發(fā)育缺陷及妊娠綜合癥相關(guān),還可能影響某些藥物代謝,可能由于合成S-腺苷蛋氨酸所需的5—甲基四氫葉酸的不足,TT基因型者外周淋巴細(xì)胞DNA甲基化水平低于CC基因型個(gè)體,因而與腫瘤發(fā)生相關(guān)。
[Abstract]:Homocysteine homocysteine homocysteine (homocysteine) is an amino acid produced during the metabolism of transmethylated and transthiocarbamate. The increase of plasma Hcy increases the risk of many diseases, including vascular diseases. Coronary heart disease, thrombosis, stroke, neural tube dysplasia and diabetic nephropathy. Methylene tetrahydrofolate reductase (MTHFR) is a key enzyme in the metabolism of Hcy. Irreversible reaction of 10-methylenetetrahydrofolic acid reduction to 5-methyltetrahydrofolic acid. MTHFR gene is the most common polymorphism of 677 nucleotides. 鈫扵 replacement of C677TN, the alanine of the active region of the enzyme was replaced by valine valine (Vala) to produce thermostable enzyme, which obstructed the synthesis of 5-methyltetrahydrofolic acid (5-methyltetrahydrofolic acid). The latter was a methyl donor to produce methionine from Hcy and increased the level of plasma Hcy. The Hcy level of individuals with TT genotype was about 25% higher than that of CC or CT genotypes. There were ethnic and regional differences in the distribution of C677T, and the frequency of T allele was the lowest in sub-Saharan Africa and northern Canada. In southern Europe and South America, the highest frequency of .C677T polymorphism is an independent risk factor for many diseases, such as Alzheimer's disease, cardiovascular disease, thrombosis and embolus formation, tumor and so on. Associated with neural tube insufficiency and other congenital developmental defects and pregnancy syndrome, it may also affect the metabolism of certain drugs, possibly due to a lack of 5-methyl-tetrahydrofolic acid necessary for the synthesis of S-adenosylmethionine. The DNA methylation level of peripheral lymphocytes in TT genotype was lower than that in CC genotype individuals, so it was associated with tumorigenesis.
【學(xué)位授予單位】：第四軍醫(yī)大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2005
【分類號(hào)】：R346

【共引文獻(xiàn)】

相關(guān)期刊論文 前10條

1 姚華;丁麗麗;王先敏;徐菲麗;;男性高尿酸血癥與亞甲基四氫葉酸還原酶C677T多態(tài)性的關(guān)系[J];癌變.畸變.突變;2007年01期

2 陸建偉,高長(zhǎng)明,吳建中,孫小峰,王麗,馮繼鋒;亞甲基四氫葉酸還原酶基因C677T多態(tài)性與胃癌患者對(duì)5-FU化療敏感性的關(guān)系[J];癌癥;2004年08期

3 劉炬;徐兵河;;單核苷酸多態(tài)與乳腺癌治療反應(yīng)相關(guān)研究進(jìn)展[J];癌癥進(jìn)展;2006年05期

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6 孫全昌;李旭強(qiáng);鄭紀(jì)寧;;MTHFR基因多態(tài)性及其與大腸癌的相關(guān)性研究[J];承德醫(yī)學(xué)院學(xué)報(bào);2012年01期

7 徐菲莉;姚華;丁麗麗;王先敏;;男性高尿酸血癥與MTHFR基因C677T、β_3-AR基因T190C、ACE基因I/D和AGT基因T704C多態(tài)性關(guān)系的研究[J];地方病通報(bào);2006年06期

8 麥W，

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