青海藏族人群ADH3、ALDH2基因多态性及其与饮酒行为的关系

目的 了解青海藏族男性乙醇脱氢酶3(ADH3)和乙醛脱氢酶2(ALDH2)基因多态性分布及其与饮酒行为的关系.方法 采用聚合酶链式反应-限制性片段长度多态性(PCR-RFLP)方法对ADH3和ALDH2基因型进行检测;采用回顾性问卷调查研究对象的饮酒行为.结果 等位基因ADH3*2和ALDH2*2在藏族人群中的比例分别为7.79％和22.21％;不饮酒组中等位基因ALDH2*2、ADH3*1频率高于饮酒者;危险饮酒组中等位基因ALDH2*2、ADH3*1频率低于安全饮酒者.结论 ADH3、ALDH2基因与青海藏族男性人群饮酒行为有关.     

慢性苯中毒遗传易感性与细胞色素P4502E1基因多态性关系的初步探讨

为探讨细胞色素P45 0 2E1(CYP2E1)基因多态性与苯中毒遗传易感性的关系 ,应用PCR RFLP方法对 35例苯中毒病例、44例苯作业工人及 2 6例正常对照组的细胞色素P45 0 2E1(CYP2E1)基因RsaⅠ和DraⅠ多态进行检测。结果显示 ,CYP2E1基因RsaⅠ位点基因型 (c1 c1、c1 c2和c2 c2 )及等位基因 (c1、c2 )和DraⅠ位点基因型 (DD、CD和CC)及等位基因 (D、C)在三组间的分布频率均无统计学意义。提示CYP2E1基因RsaⅠ和DraⅠ多态位点与苯中毒遗传易感性可能无关     

醛、醇脱氢酶基因多态性与三氯乙烯药疹样皮炎易感性的关系

目的研究醛脱氢酶、醇脱氢酶基因多态性与三氯乙烯药疹样皮炎易感性的关系。方法应用聚合酶链反应-限制性片段长度多态性(PCR-RFLP)方法,比较108例三氯乙烯药疹样皮炎病人和145例健康三氯乙烯接触工人醛脱氢酶2(ALDH2)、醇脱氢酶2(ADH2)和醇脱氢酶3(ADH3)的基因多态性分布,并计算相对危险度(OR)。结果ADH2和ADH3基因型分布在病人与接触对照工人中无显著性差异;ALDH2变异型基因(ALDH2*1/*2+ALDH2*2/*2)频率在病人中显著低于接触对照工人(分别为27·8%和43·4%,P=0·011),使三氯乙烯药疹样皮炎的危险性显著降低(OR=0·50,95%CI=0·29~0·85)。结论高活性ALDH2可能是导致三氯乙烯药疹样皮炎个体易感性差异的原因之一。     

湖北地区心血管疾病患者CYP2C19基因多态性分布情况及临床意义

目的了解湖北地区心血管疾病患者细胞色素P4502C19(CYP2C19)基因多态性分布情况及其对临床的指导意义,为个体化治疗提供依据。方法选取2015年1月—2016年3月在武汉大学人民医院住院的心血管疾病患者900例,采用基因芯片法检测患者CYP2C19基因型,同时收集其临床资料,包括年龄、性别、体重及诊断等相关指标进行分析。结果 900例患者,其中男性594例(66%),女性306例(34%);共检出6种CYP2C19基因型,其中*1/*2(636 GG,681 GA)基因型患者最多,占42.3%;其余依次为*1/*1(636 GG,681 GG)基因型患者(36.6%)、*2/*2(636 GG,681 AA)基因型患者(13.0%)、*1/*3(636 GA,681 GG)基因型患者(5.1%)、*2/*3(636 GA,681 GA)基因型患者(2.8%)和*3/*3(636 AA,681 GG)基因型患者(0.2%)。表型中IM型最高,占47.4%;其次为EM型和PM型,分别占36.6%和16.0%。等位基因CYP2C19*1的频率最高,占60.3%,等位基因CYP2C19*2和CYP2C19*3的频率分别为35.6%和4.2%。结论湖北地区心血管疾病患者CYP2C19基因型以*1/*2(636 GG,681 GA)基因型为主,表型IM型最多,等位基因以CYP2C19*1最常见。     

细胞色素P450 2E1基因多态性与胃癌易患性

目的研究与前致癌物亚硝胺类代谢活化有关的细胞色素P450 2E1(cytochromeP450 2E1,CYP2E1)基因多态性与胃癌易患性的关系,探讨环境因素与遗传因素在胃癌发病中的作用.方法采用病例-对照分子流行病学方法,调查原发性胃癌患者和对照各48例,以聚合酶链反应-限制性片段长度多态(PCR-RFLP)检测被调查者的CYP2E1基因RsaⅠ位点的多态性,条件Logistic回归模型进行资料分析.结果 CYP2E1 A、B和C 3种基因型在病例组中的构成比分别为68.8%,29.2%和2.1%,对照组分别为45.83%,47.92%和6.25%,2组差异无统计学意义(x2=5.389,P=0.068).而病例和对照组CYP2E1基因Rsa Ⅰ位点等位基因c1和c2频率分别为83.3%,16.7%和69.8%,30.2%,差异有统计学意义(x2=5.241,P＜0.05).环境因素中食盐、香肠和熟食的过多摄入以及肿瘤家庭史和c1等位基因作为胃癌的危险因素进入回归模型,而经常喝茶作为保护性因子可能降低胃癌的发生危险.结论 CYP2E1基因Rsa Ⅰ位点等位基因c1与胃癌易感性相关联;某些饮食因素与胃癌的发生有关.     

华法林抗凝治疗患者CYP2C9基因多态性的研究

[目的]研究深圳地区口服华法林抗凝治疗患者细胞色素P4502C9(CYP2C9)基因CYP2C9*1、 CYP2C9*2、 CYP2C9*3多态性的特点.[方法]应用聚合酶链反应-限制性片段长度多态性分析方法(PCR-RFLP)检测151例口服华法林抗凝治疗患者CYP2C9基因CYP2C9*1、 CYP2C9*2、 CYP2C9*3的多态性.[结果]151例口服华法林抗凝治疗患者中未检测出CYP2C9*2等位基因,CYP2C9*1、 CYP2C9*3等位基因的频率分别为92.7%和7.3%, CYP2C9*1*1、 CYP2C9*1*3、 CYP2C9*3*3基因型频率分别为85.4%(129)、14.6%(22)、0(0).[结论]深圳地区口服华法林抗凝治疗病人中存在CYP2C9*3突变基因,使用华法林抗凝治疗时应检测患者CYP2C9的基因型.     

CYP2E1和CYP1A1及白细胞介素-4基因多态性与三氯乙烯药疹样皮炎的关系

目的 研究代谢酶基因CYP2E1和CYP1A1以及白细胞介素(IL)-4的基因多态性与三氯乙烯(TCE)药疹样皮炎易感性的关系.方法 选择35例TCE药疹样皮炎病例作为病例组,选无皮肤损害的35名健康工人作为对照组.应用实时荧光定量聚合酶链反应(PCR)和TaqMan MGB探针技术,检测病例组和对照组CYP2E1、CYP1A1和IL-4基因的单核苷酸多态性(SNP),计算病例组和对照组的基因型与等位基因型频率.结果 CYP1A1基因(rs1048943)的SNP多态性检测结果显示,病例组G等位基因频率(37.1%)明显高于对照组,差异有统计学意义(P＜0.01);检测发现,病例组CYP2E1基因-1053 C→岬位点T等位基因频率(41.4%)明显高于对照组,差异有统计学意义(P＜0.01);对IL4基因588 C→岬位点(rs2243250)检测发现,病例组TT纯合突变频率(75.0%)明显高于对照组,差异有统计学意义(P＜0.01),T等位基因频率(87.5%)明显高于对照组,差异有统计学意义(P＜0.01).结论 CYP1A1、CYP2E1和IL-4基因的某些位点的改变可能与少数TCE敏感个体对接触TCE引起的超敏反应存在密切关系,CYP1A1、CYP2E1和IL-4的基因多态性可能是TCE药疹样皮炎患者易感性差异相关的遗传学因素之一.     

衢州地区冠心病患者CYP2C19基因多态性分析

目的 探讨衢州地区冠心病患者CYP2C19基因多态性的分布情况。方法 采用PCR荧光探针法对浙江省衢州市人民医院306例冠心病患者进行CYP2C19基因检测。结果 在306例冠心病患者中,CYP2C19基因型的分布频率由高到低为*1/*2、*1/*1、*2/*2、*1/*3、*2/*3、*3/*3,所占比例分别为39.87%、38.56%、10.13%、8.17%、3.27%、0.00%。快代谢型(*1/*1)占38.56%,中间代谢型(*1/*2、*1/*3)占48.04%,慢代谢型(*2/*2、*2/*3、*3/*3)占13.40%,不同性别、不同年龄患者CYP2C19基因型和代谢型差异均无统计学意义(P> 0.05)。结论 衢州地区冠心病患者CYP2C19功能缺失型等位基因所占比例较高,患者用药前应进行CYP2C19基因检测,制定个体化治疗方案,实现精准治疗。     

ADH1B与ALDH-2基因多态性与中国人群食管癌发病风险的Meta分析

目的探讨中国人乙醇脱氢酶1B(ADH1B)和乙醛脱氢酶-2(ALDH-2)的基因多态性与食管癌发病风险的关系。方法检索中外文数据库,获得有关ADH1B和ALDH-2位点的多态性与食管癌发病风险的病例-对照研究资料,对各位点以及与饮酒的交互作用进行Meta分析,得到合并的OR值及其95%CI。结果等位基因ADH1B*1和ALDH-2*2可增加食管癌的发病风险。基因型ADH1B*1/*2和ADH1B*1/*1的OR值分别为1.24(95%CI 1.10-1.41)和3.05(95%CI 1.94-4.77);基因型ALDH-2*1/*2和ALDH-2*2/*2的OR值分别为1.6(95%CI 1.01-2.03)和0.77(95%CI 0.28-2.09)。在饮酒人群中,与基因型ADH1B*2/*2相比,ADH1B*1/*2+*2/*2的OR=3.13(95%CI 2.17-4.51);与基因型ALDH-2*1/*1相比,ALDH-2*1/*2+*2/*2的OR=4.12(95%CI 1.98-8.56)。结论在中国人群中,等位基因ADH1B*1和ALDH-2*2均能增加食管癌患病的风险,且饮酒可以增加这一风险。     

ALDH2和CYP2E1基因多态性及饮酒习惯与肝细胞癌易感性的关系

目的研究乙醛脱氢酶2(ALDH2)和细胞色素P4502E1(CYP2E1)基因多态性与饮酒因素交互作用在广西原发性肝细胞癌发生中的作用。方法对广西壮族自治区300例肝细胞癌和292例正常对照进行流行病学调查研究,并用PCR-RFLP方法检测ALDH2和CYP2E1基因型。结果病例和对照组中ALDH2和CYP2E1变异基因型携带者分别占50.3%、48.0%和32.3%、32.9%(P0.05)。饮酒频度每周≥3次(高频饮酒)且携带变异基因ALDH2和CYP2E1者发生肝癌的危险度分别是饮酒频度每周3次(低频饮酒)且携带野生基因型者的3.334倍(95%CI=1.746～6.406)和1.803倍(95%CI=0.974～3.336),同时携带两变异基因型者患肝癌风险为1.200倍(95%CI=0.730～1.972),且饮酒增加两变异基因型携带者的肝癌发病风险(OR=1.816,95%CI=0.985～3.348)。结论单一ALDH2或CYP2E1基因型与肝细胞癌易感性无关;但高频饮酒且携带变异基因ALDH2或CYP2E1者患肝癌风险增加,且两变异基因型单倍体增加肝癌发病风险。提示乙醇在增加肝癌发病风险的过程中存在基因-环境和基因-基因相互作用。     

Bayesian implementation of a genetic model-free approach to the meta-analysis of genetic association studies

A genetic model-free method for the meta-analysis of genetic association studies is described that estimates the mode of inheritance from the data rather than assuming that it is known. For a bi-allelic polymorphism, with G as risk allele and g as wild-type, the genetic model depends on the ratio of the two log odds ratios, lambda = log OR(Gg)/log OR(GG), where OR(GG) compares GG with gg and OR(Gg) compares Gg with gg. Modelling log OR(GG) as a random effect creates a hierarchical model that can be implemented within a Bayesian framework.In Bayesian modelling, vague prior distributions have to be specified for all unknown parameters when no external information is available. When the data are sparse even supposedly vague prior distributions may have an influence on the posterior estimates. We investigate the impact of different vague prior distributions for the between-study standard deviation of log OR(GG) and for lambda, by considering three published meta-analyses and associated simulations. Our results show that depending on the characteristics of the meta-analysis the results may indeed be sensitive to the choice of vague prior distribution for either parameter.Genetic association studies usually use a case-control design that should be analysed by the corresponding retrospective likelihood. However, under some circumstances the prospective likelihood has been shown to produce identical results and it is usually preferred for its simplicity. In our meta-analyses the two likelihoods give very similar results.     

Ⅰ、Ⅱ相代谢酶基因多态性与肺癌易感性关系的研究

目的探讨Ⅰ相代谢酶CYPlA1、2E1、2D6和Ⅱ相GSTM1基因多态性与肺癌遗传易感性的关系及吸烟与基因之间的交互作用。方法 采用病例对照研究和聚合酶链反应-限制性片段长度多态性等技术,检测217例肺癌患者和200例对照CYPlA1、2E1、2D6和GSTM1基因型频率分布以及与吸烟的关系。结果 肺癌组GSTM1缺陷型频率为58.5％,与对照组(47.5％)比较差异有统计学意义(P=0.02);CYPlA1、2E1、2D6在肺癌组和对照组分布差异无统计学意义(P>0.05)。吸烟与GSTM1有协同作用,与CYPlA1、2E1、2D6未见明显的协同作用。结论 吸烟和GSTM1缺陷型均是肺癌的危险因素,GSTM1缺陷型有吸烟行为的人更易患肺癌,是肺癌的高危人群。     

Steering a course around the genetic iceberg

A US company is now marketing worldwide, via the Internet, genetic testing for predisposition to breast and ovarian cancer. This paper explores some of the divergent concerns about the implications of private genetic testing for the United States and United Kingdom, with their differing health care systems. As the UK National Health Service faces calls for expansion in its genetic services to meet growing demand, there is now a need for evaluation of the costs and effectiveness of such services so that they may be efficiently targeted to those women who can benefit most from them. In the cases of breast and ovarian cancer, it is relatively straightforward to calculate the benefits in terms of added life expectancy and health-related quality of life resulting from earlier diagnosis and treatment of affected women, but these women are likely to be a small proportion of the total number of women who are referred or self-refer to genetic services. This paper asks how we are to measure and value the benefits of information about risk of cancer to a particular woman or to members of her family; how we are to measure and value the benefits of effective counselling, which encourages autonomous, informed decision-making about whether or not to undergo genetic testing, and which facilitates comprehension of complex results; and ultimately, in the face of advances in genetic science, how we are to steer the NHS around the genetic iceberg.     

Contending visions in the evolution of genetic medicine: the case of cancer genetic services in Ontario, Canada

Growth in genetic medicine has provoked debate about how new and emerging genetic services should be provided, and specifically, what roles non-genetic clinicians should assume. We address this question through a qualitative interview based case study of the program in genetic testing for the hereditary cancer syndromes (breast/ovarian and colorectal) in Ontario, Canada. We argue that two communities offer parallel visions of cancer genetic care: one "genetic," the other "oncologic." Both communities argue from precedent that cancer genetics is a natural extension of their work: it is "what we do." Both communities also highlight the importance of their own expertise in providing core elements of cancer genetic care: it requires "what we know." Further, both communities perceive the need for leadership by their own (or a related) community as genetic medicine expands to include a broader array of more common and complex diseases: it is expanding "where we're leading." Yet, the "we's" articulating these visions are not reducible to professional identity; rather, both represent distinctive "communities of practice and discourse" that are constructed in relation to institutionalized professional roles, and interactions with the genetic technologies (both tests and counselling) themselves. Available literature on the role of diverse health care professionals in the provision of genetic health care presumes a fixed identity and set of approaches for each professional group that might play a role. Further, existing models tend to assume that genetic technologies are given as tools, and that service organization concerns primarily questions of who will have access to these tools and their powers, as well as the consequent professional and ethical responsibilities. Yet questions about who will control genetic technologies are not simply turf battles between the professions: they are also inescapably questions about what the genetic technologies should and will accomplish clinically.     

First attempts in preimplantation genetic diagnosis: genetic analysis]

Preimplantation genetic diagnosis is a new approach for the prevention of genetic disorders, which provides a healthy pregnancy avoiding the need for its possible termination. The combination of in vitro fertilization techniques and single cell molecular genetic diagnosis allows only unaffected embryos to be selected for transfer to the uterus. It is an acceptable alternative of prenatal diagnosis for certain couples. Here we report our first attempts in the application of fluorescent PCR for sex determination and the detection of the delta-F508 mutation in human blastomeres. We modelled clinical PGD situations as we performed sex determination on 23 preembryos. Sex determination was successful is 20 preembryos (83%). We performed the detection of the delta-F508 mutation on 23 preembryos, which was successful in 20 preembryos (87%). Our experience suggests, that the established fluorescent PCR analysis is a reliable method for PGD, which enables us to apply it for clinical preimplantation genetic diagnosis.