基因多态性与复发性自然流产的相关性研究

复发性自然流产（recurrent spontaneous abortions,RSA）是指连续发生2次或2次以上流产者。RSA的病因复杂,包括胚胎染色体异常、免疫功能异常、黄体功能不足、感染、生殖道异常等。但目前仍有部分RSA患者病因及发病机制尚不清楚,遗传背景等因素的改变可能使部分人群易发生RSA[1]。近年来从免疫遗传角度提出了一些新的观点,认为RSA的发生与遗传有关。寻找RSA的易感基因或致病基因,从根本上阐明RSA的发病机理,是RSA治疗和预防的重要途径。     

内皮型一氧化氮合酶基因多态性与原发性高血压

原发性高血压是我国发病率最高的心血管疾病,是一种多基因,多因子病。一氧化氮是重要的内皮衍化的舒张因子,很多生理性的以及药物引起的血管舒张都是通过一氧化氮途径实现的。但内皮型一氧化氮合酶基因的突变与原发性高血压的关系仍有待明确。     

内皮型一氧化氮合酶基因多态性与临床疾病

内皮型一氧化氮合酶 (e NOS)催化生成的一氧化氮 (NO)具有舒张血管、抑制血管平滑肌细胞增殖、抑制血小板和白细胞粘附等功能 ,因此 e NOS基因多态性可能与心血管等疾病的发生发展密切相关。     

内皮型一氧化氮合酶基因多态性与临床疾病

内皮型一氧化氮合酶（eNOS)催化生成的一氧化氮（NO）具有舒张血管、抑制血管平滑肌细胞增殖、抑制血小板和白细胞粘附等功能，因此eNOS基因多态性可能与心血管等疾病的发生发展密切相关。     

内皮型一氧化氮合酶基因多态性与原发性高血压

原发性高血压是我国发病率最高的心血管疾病，是一种多基因，多因子病。一氧化氮是重要的内皮衍化的舒张因子，很多生理性的以及药物引起的血管舒张都是通过一氧化氮途径实现的。但内皮型一氧化氮合酶基因的突变与原发性高血压的关系仍有待明确。     

内皮型一氧化氮合酶基因和凝血因子Ⅶ基因多态性与老年人冠心病的相关性研究

[摘要] 目的 探讨内皮型一氧化氮合酶（endothelial nitric oxide synthase，eNOS）基因外显子7的Glu298Asp和凝血因子Ⅶ（coagulation factor Ⅶ，FⅦ）基因外显子8的R353Q多态性与与汉族人群冠心病（CHD）及老年人CHD发病的关系。方法 选取147例CHD患者和116例正常对照组人群，应用聚合酶链反应-限制性片段长度多态性（PCR-RFLP）分析技术检测eNOS基因Glu298Asp和FⅦ基因R353Q多态性。结果 （1）eNOS基因Glu/Glu、Glu/Asp、Asp/Asp基因型频率CHD组分别为78.9%、20.4%、0.68%和对照组分别为 89.7%、10.3%和0.0%；FⅦ基因型频率CHD组和对照组之间差异无显著性（P>0.05）；（2）Glu/Asp+Asp/Asp型和Asp等位基因频率CHD组(21.1% and 10.9%)显著高于对照组(10.3% and 5.2%)（P<0.05）， Asp等位基因对≥60岁老年人发生CHD的风险增高，OR=2.43，95%CI：1.22～4.86（P<0.05）；（3）携带FⅦ基因RQ+QQ型和Q等位基因个体发生CHD的风险降低，OR=0.77,95%CI:0.33～0.56和OR=0.85,95%CI:0.38～0.53(P>0.05)。结论 eNOS基因Asp等位基因可能是汉族老年人CHD发病的遗传易感因素之一；FVII基因R353Q多态性与CHD发病无关。     

内皮型一氧化氮合酶基因Glu298Asp多态性与原发性高血压的关系

目的探讨中国大连人群eNOs基因Glu298Asp多态性与原发性高血压的关系。方法选取277名高血压患者及547名血压正常者,提取基因组DNA,使用聚合酶链反应(PCR)及限制性片段长度多态性(RFLP)分析确定eNOs Glu298Asp多态性。进行两组问的比较并使用Logistic,回归分析年龄、性别、家族史、TC、TG、BMI及基因型对高血压的影响。结果基因型频率及等位基因频率在高血压和对照组的分布无差异。高血压组氨基酸298位GG、GT、TT基因型频率分别为84．1％、14．4％、1．4％,在对照组为85．6％、13．5％、0．9％(P=O．73)。Asp等位基因的频率在高血压组及对照组分别为8．7％和7．7％,(P=0．50)。对年龄、性别和BMI及有无家族史进行亚组分析也未发现基因型的分布在各组间有差异。采用隐性遗传模型把GG和GT基因型合并,GG GT和TT基因型的分布在两组间仍未发现有显著差异(P=0．49)。Logistic回归显示年龄、BMI、家族史及饮酒是高血压发病的独立危险因素,OR值分别为1．09(P<0．001)、1．28(P<0．001)、9．53(P<0．001)和2．26(P<0．05)。结论本实验显示年龄、BMI、家族史及饮酒是高血压的独立危险因素。eNOs基因Glu298Asp突变可能不是大连人原发性高血压的主要易感基因。     

PAI-1基因和MTHFR基因多态性与复发性早期自然流产的关系

目的探讨纤溶酶原激活剂抑制物1(plasminogenactivatorinhibitor1,PAI1)基因和亚甲基四氢叶酸还原酶(methylenetetrahydrofolatereductase,MTHFR)基因多态性与复发性早期自然流产(recurrentearlyspontaneousabortion,RESA)的相关性。方法选取127例RESA非妊娠患者和117名健康非妊娠妇女,应用聚合酶链反应限制性片段长度多态性分析技术检测PAI1基因-675位4G/5G多态性和MTHFR基因C677T位点多态性。结果(1)患者组PAI1基因4G/4G基因型频率(45.7%)和4G等位基因频率(66.1%)显著高于对照组(17.1%和46.6%)(P<0.01),与5G/5G基因型比较,4G/4G型患者发生RESA的相对风险率的比数比(oddsratio,OR)为4.8,95%的可信区间(confidenceinterval,CI):2.23～10.35;(2)MTHFR基因T/T基因型和T等位基因频率患者组(43.3%和66.5%)显著高于正常对照组(21.4%和52.6%)(P<0.01),与C/C基因型比较,T/T型患者发生RESA的相对风险率为OR=3.2,95%CI:1.40～7.30;(3)RESA患者若同时兼有4G/4G和T/T基因型时,发生自然流产的相对风险率明显增加,OR=6.20,95%CI:2.62～14.67。结论PAI1基因4G/5G多态性和MTHFR基因C677T位点多态性与不明原因RESA密切相关,易感基因型4G/4G型和T/T型对RESA的发生具有协同作用。     

内皮型一氧化氮合酶基因与冠心病的研究进展

由血管内皮产生的一氧化氮（NO）是心血管系统中抗冠状动脉粥样硬化、血栓形成，维持正常血管舒缩反应必不可少的保护因子。一氧化氮合酶作为合成NO的关键酶，其基因发生变异，对NO的生成具有重要的影响。本文将对内皮型一氧化氮合酶基因多态性与冠心病的研究进展作一综述。     

内皮型一氧化氮合酶基因第7外显子894位点多态性与妊娠期高血压疾病

目的探讨内皮型一氧化氮合酶基因(endothelia n itric oxide synthase,eNOS)第7外显子894位点多态性现象与妊娠期高血压疾病(hypertensive d isorder comp licating pregnancy)的相关性及其在发病机制中的作用。方法应用聚合酶链反应-限制性片段长度多态性技术检测妊娠期高血压疾病患者和健康孕妇的eNOS基因第7外显子894位点多态性。对两组之间的基因型和等位基因频率进行比较。采用W estern b lot方法分别检测胎盘中eNOS蛋白含量在正常组和病例组之间、病例组中两种基因型之间是否存在表达水平的差异。结果T等位基因频率在正常孕妇组为6.87%,妊娠期高血压疾病组为23.00%(χ2=14.01,P=0.001,OR=4.05 95%可信区间为1.88~8.74),TG TT基因型频率在两组分别为13.75%和36.00%,χ2=8.79,P=0.003;OR=3.53 95%可信区间为1.49~8.33)差异有统计学意义。病例组中eNOS蛋白表达低于正常组,病例组中GG基因型组表达水平高于TG TT组(P<0.01)。结论eNOS基因第7外显子894位点多态性与妊娠期高血压疾病具有相关性,该位点的突变可引起eNOS蛋白表达降低,是引起妊娠期高血压疾病的可能机制。     

MTHFR基因C677T位点多态性与不明原因重复性自然流产的相关性

目的　检测不明原因重复性流产 (unexplained recurrent spontaneous abortion,URSA)患者亚甲基四氢叶酸还原酶 (methylenetetrahydrofolate reductase,MTH FR)基因 C6 77T位点多态性 ,探讨其与血清同型半胱氨酸、叶酸、维生素 B1 2 及与不同临床特征的关系。　方法　 U RSA非孕期患者 5 7例 ,对照组 5 0名 ,空腹血清总高半胱氨酸 (homocysteine,Hcy)的检测采用高压液相色谱法 ,血清叶酸、维生素 B1 2 的检测采用放射免疫法。MTH FR基因 C6 77T多态性采用聚合酶链反应 -限制性片段长度多态性技术检测。结果　 URSA患者组 C/ C基因型频率显著低于正常对照组者 ,总的突变 T等位基因频率显著高于对照组。MTHFR T/ T基因型患者血清 Hcy水平显著增高 ,血清叶酸水平显著降低 ,MTHFR C6 77T基因型在不同年龄、地区、流产时间、流产性质患者的分布差异无显著性。流产 3次以上 (包括 3次 )的患者 6 77T/ T基因型、携带 T等位基因的 C/ T T/ T基因型频率均大于流产次数少于 3次的患者。　结论　 MTH FRC6 77T基因多态性是 URSA发病的遗传风险因素。     

Endothelial nitric oxide synthase gene polymorphism in women with idiopathic recurrent miscarriage

BACKGROUND: Lack of endothelium-derived nitric oxide is associated with vasospasm and vascular infarction. We investigated the relationship between idiopathic recurrent miscarriage and a polymorphism of the gene encoding endothelial nitric oxide synthase (NOS3). METHOD: In a prospective case-control study, 105 women with idiopathic recurrent miscarriage and 91 healthy controls were investigated. We used the polymerase chain reaction to identify the different alleles of a 27 base pair tandem repeat polymorphism in intron 4 of the NOS3 gene. RESULTS: The wild type B allele was identified on 329 out of 392 chromosomes (frequency 0.84). The polymorphic A allele was present on 63 chromosomes (frequency 0.16). The genotype frequencies were as follows: 68% (B/B), 31% (A/B) and.5% (A/A). The distribution of genotype frequencies was significantly different between the study and control groups for allele A/B heterozygotes (NOS3(A/B)) (36.7 versus 23.8%, P = 0.03, OR 1.6, 95% CI 1.1--3.8). Only one individual was homozygous for the A allele (NOS3(A/A)). She was in the study group. Between women with primary and secondary recurrent miscarriages, no statistically significant difference between the distribution of NOS3(A/B) genotypes (28 versus 34%) was observed. CONCLUSIONS: These data support a role for the NOS3 gene as a genetic determinant of the risk of idiopathic recurrent miscarriage.     

Association of vascular endothelial growth factor gene polymorphisms with recurrent spontaneous abortion in Chinese Han women

Citation Xing X, Yan J, Zhao Y, You L, Bian Y, Chen Z‐J. Association of vascular endothelial growth factor gene polymorphisms with recurrent spontaneous abortion in Chinese Han women. Am J Reprod Immunol 2011; 65: 521–525 Problem An association of polymorphism ?1154G/A (rs1570360) in vascular endothelial growth factor (VEGF) gene with idiopathic recurrent spontaneous abortion (RSA) has been found in Caucasians. The aim of this study was to examine the association of VEGF ?1154 with RSA in a well‐defined group of Chinese Han patients. Method of study The VEGF ?1154G/A genotype was detected by real‐time PCR with TaqMan probes. The products were also subjected to gene sequence analysis to validate the PCR results. Results The allele frequencies of VEGF ?1154G/A showed no significant difference between RSA patients and the normal controls (P = 0.183). The frequencies of VEGF ?1154G/A genotypes were not significantly different between RSA patients and the normal controls (P = 0.228). Conclusion Our study revealed that VEGF ?1154G/A polymorphism was not associated with the susceptibility to RSA in Chinese Han women.     

Prevalence of endothelial nitric oxide synthase gene polymorphisms in patients with atopic asthma

BACKGROUND: Asthma is a common multifactorial disease, the aetiology of which is attributable to both environmental and genetic factors. The endothelial nitric oxide synthase (NOS3) gene has been implicated in asthma pathogenesis. OBJECTIVE: This study investigated associations of 27 base-pair tandem repeat polymorphism in intron 4 and the Glu298Asp (G894T) variant of the NOS3 gene with atopic asthma in a Czech population. METHODS: Polymerase chain reaction was used to determine the NOS3 genotypes in subjects with atopic asthma (n = 163) and random controls (n = 209). RESULTS: The NOS3 allele or genotype distributions did not differ significantly between the control and asthma groups. However, the common genotype (bb) of the NOS3 polymorphism in intron 4 was found to be significantly associated with total IgE levels (P = 0.006), specific IgE levels for feathers (P = 0.0002) and a positive skin prick test for hay (P = 0.004). In one atopic patient, we identified an additional 27-bp repeat in the NOS3 gene (NOS3c), which occurred in heterozygous combination with the NOS3b allele (NOS3b/c genotype). In addition, we describe a new polymorphism (A5495G) in the NOS3 gene, which was in almost complete linkage disequilibrium with the NOS3 repeat polymorphism in intron 4. The Glu298Asp variant was not associated with asthma and/or related atopic phenotypes in our study. CONCLUSION: Neither the NOS3 'b' allele nor the NOS3 'b/b' genotype showed any general association with atopic asthma, but they were associated with atopy-related phenotypes. We conclude that the NOS3 gene polymorphisms may act as disease modifiers in atopic asthma phenotype in our population.     

Endothelial nitric oxide synthase gene polymorphisms and prostate cancer risk in Serbian population

Genome-wide association studies (GWAS) have identified over 46 SNPs associated with human prostate cancer (PCa). Some studies have shown correlation of the nitric oxide synthase (NOS) NOS3 gene polymorphisms with the risk and/or progression of PCa. This study aimed to evaluate the association of NOS3 gene polymorphisms (−786T>C, −764A>G, −714G>T, −690C>T, −649G>A and 894G>T) with PCa risk and progression. 150 patients with PCa, 150 patients with BPH and 100 age-matched healthy controls were recruited in this study. Genotyping of promoter polymorphisms was performed by bi-directional DNA sequencing, and for 894G>T by RFLP analysis. There was no significant association between the alleles and genotypes of these genetic variants and PCa risk. For −786T>C polymorphism, we found that C allele is associated with absence of metastases, assuming dominant genetic model (P = 0.049; OR, 0.50; 95% CI, 0.25–1.00). It was found that, compared with NOS3 −690C>T variant CC genotype, CT and TT genotypes confer decreased risk of developing metastases (dominant model, P = 0.015, OR, 0.24; 95% CI, 0.07–0.88) and show association with low clinical tumour stage, compared with stages T₃ and T₄ (dominant model, P = 0.046, OR, 0.20; 95% CI, 0.04–1.02). Genetic variants −764A>G, −714G>T, −649G>A were not detected in our study group. There is evidence of an inverse correlation of the NOS3 894G>T minor allele with high serum PSA (>20 ng/ml) (dominant model, P = 0.013, OR, 0.37; 95% CI, 0.17–0.82). Our results suggest that NOS3 gene polymorphisms are genetic susceptibility factors for the progression of PCa and patient outcome.     

No association of C677T methylenetetrahydrofolate reductase and an endothelial nitric oxide synthase polymorphism with recurrent pregnancy loss

PROBLEM: It is controversial whether polymorphisms of methylenetetrahydrofolate reductase (MTHFR) and the endothelial nitric oxide synthase (eNOS) are associated with recurrent pregnancy loss. METHOD OF STUDY: We studied the frequency of the C677T polymorphism of MTHFR and a eNOS gene polymorphism, as well as the plasma levels of homocysteine and NO, in 85 cases with a history of two or more unexplained embryonal losses, 40 patients suffering fetal loss and 76 controls. RESULTS: The frequency of the MTHFR gene T allele, which has been reported to be associated with miscarriages, in patients suffering fetal loss was rather significantly lower than in controls whereas there was no difference in the frequency of the eNOS gene A allele. There were no differences in the plasma homocysteine levels among the three groups. However, the NO concentrations in the embryonal loss and fetal loss groups were significantly higher than that in controls. CONCLUSION: We conclude that the NO concentration but not the polymorphism of MTHFR and eNOS gene and hyperhomocysteinemia are associated with recurrent pregnancy loss in Japanese.     

Gene polymorphisms of endothelial nitric oxide synthase and angiotensin-converting enzyme in patients with asthma

BACKGROUND: Nitric oxide, including that produced by endothelial constitutive nitric oxide synthase (ecNOS), may regulate vascular and airway tone in the lungs and may influence various aspects of airway homeostasis. Angiotensin-converting enzyme (ACE) is expressed at high levels in the lungs and plays a role in the metabolism of angiotensin II, bradykinin, and substance P, all of which are potentially involved in the pathogenesis of asthma. An insertion-deletion polymorphism of the ACE gene has been shown to be associated with enzyme activity levels of ACE. To examine the possible involvement of the ecNOS and/or ACE genes as the genetic basis of bronchial asthma, we investigated whether there was any association between bronchial asthma and polymorphisms of the ecNOS and/or ACE genes. METHODS: A total of 310 patients with bronchial asthma and 121 healthy subjects took part in this study. The ecNOS and ACE genotypes were determined in all subjects by polymerase chain reaction. RESULTS: 1) The distribution of one genotype (bb) of ecNOS was significantly higher in the asthma group than in the control population. 2) The ACE genotype distribution was not significantly different between the control and the asthma groups. 3) In asthmatic patients, the ACE and ecNOS genotype distribution did not differ significantly among groups of patients with different severities of asthma. CONCLUSIONS: These results suggest that polymorphisms of the ecNOS gene, but not the ACE gene, may be associated with the development of asthma. However, the severity of asthma may not be influenced by polymorphisms of the ecNOS and ACE genes.     

HLA-G polymorphisms in couples with recurrent spontaneous abortions

The etiology of a fraction of recurrent spontaneous abortions (RSA) may involve immunological mechanisms. Aberrant profiles of Th1 and Th2 cytokines have been observed which are not present in uncomplicated pregnancies. Studies of classical HLA class I and II antigens in relation to RSA have not been conclusive. Furthermore, these antigens are not expressed in the placenta with the exception of HLA-C. However, HLA-G is expressed on especially invasive cytotrophoblasts and exists in both membrane and soluble forms. HLA-G may be involved in materno-fetal tolerance. Therefore, 61 RSA couples (with three or more spontaneous abortions) and 47 fertile control couples were HLA-G genotyped by direct DNA sequencing and analyzed for specific polymorphisms. No statistically significant differences were observed in the distribution of HLA-G alleles between controls and RSA couples, however, 15% of the RSA women carried the HLA-G*0106 allele compared to 2% of the control women. The 14 bp deletion polymorphism in exon 8 was investigated separately. There were a greater number of heterozygotes for the 14 bp polymorphism in the group of fertile control women than expected, according to Hardy-Weinberg equilibrium. Furthermore, the HLA-G alleles without the 14 bp sequence were prominent in the RSA males in contrast to the RSA women in whom alleles including the 14 bp sequence were frequently observed, especially as homozygotes. These results are discussed in relation to two hypotheses concerning HLA-G and RSA. A hypothesis of HLA-G histo-incompatibility between fetus/placenta and the mother was not supported by the data. Another hypothesis concerned certain HLA-G alleles associated with an altered expression profile of HLA-G isoforms or reduced expression of certain HLA-G isoforms.     

MTHFR、MTRR基因多态性与反复流产的相关性分析

目的探讨叶酸代谢相关基因5,10-亚甲基四氢叶酸还原酶(MTHFR)、甲硫氨酸合成酶还原酶(MTRR)多态性与反复流产的关系,分析基因多态性对红细胞叶酸水平的影响。方法选取2016年12月至2018年6月来唐山市妇幼保健院遗传咨询门诊,要求进行常规孕前检查,汉族非妊娠健康女性424例为研究对象。依据不良孕产史分为两组,其中病例组216例和对照组218例。采集静脉血,提取DNA,荧光定量PCR法进行MTHFR、MTRR基因多态性检测。化学发光法进行红细胞叶酸定量检测。采用SPSS19.0软件进行统计学分析。比较两组MTHFR、MTRR基因多态性分布频率、不同基因类型红细胞叶酸水平。探讨基因多态性、红细胞叶酸水平与反复流产的关系。结果MTHFR A1298C和MTRR A66G两位点多态性在病例组和对照组间的分布,差异无统计学意义。MTHFR C677T位点多态性,在病例组中的分布频率明显高于对照组,差异具有统计学意义。病例组中MTHFR C667T位点TT型基因突变的患者红细胞叶酸水平远低于正常和杂合型。结论MTHFR C677T基因突变与反复流产的密切相关,MTHFR C667T位点TT型基因突变影响机体红细胞叶酸代谢水平。