GENETICS OF CEREBROVASCULAR DISEASE

拟议研究的长期目标是确定 致病基因及其致病特征 高血压性脑血管病的发病机制。高血压 脑血管疾病是中风的主要原因，也是第三大主要原因 我们社会中死亡和残疾的原因。当血液升高时 压力是一个重要的风险因素，越来越多的证据表明 另外，不受血压影响的遗传因素也起着重要作用 探讨脑血管疾病的发病机制。流行病学数据表明 这种疾病是作为多基因、数量性状遗传的，类似于 到原发性高血压。人类多基因疾病的复杂性， 因其异质性和多因素的性质而突出，令人沮丧 旨在识别人类中与疾病相关的基因或基因的尝试。 或者，近亲繁殖的动物品系表现出感兴趣的特征，作为一种 基因决定表型，代表了一个有用的近似值， 对其进行研究可能会揭示随后可以应用于 人类疾病。因此，我们建议使用容易中风的， 自发性高血压大鼠(SHRSP)，是一种实验动物， 遗传性易患高血压脑血管病 一种非常类似人类病理学的方式，作为一种允许研究的模型 其中一些总是存在于人类身上的混杂因素可以 会被避开。遵循共同隔离分析的范式，对 解剖与疾病相关的遗传基因座，我们将建立F2 SHRSP与自发性高血压患者的杂交队列研究 大鼠(SHR)，另一种高血压动物品系，但不 发展中风。这一策略消除了血压，这是一种重要的 来自分析的混杂变量，并提供了混合种群 其中中风的倾向根据他的不同而表现出变化 特定个体具有的中风相关基因的相对剂量 由于等位基因的自由分离而收到的，而血压， 相反，显示了最小的变化，如我们在初步报告中所示 学习。该算法提供了一种强大的搜索方法 致病重要基因，而且，与比较的 研究，唯一确定基因和基因之间因果关系的 表型。拟议的研究将追求以下具体目标； (I)初步研究表明，当喂食自发性高血压综合征时， 特定饮食(其元素也已在流行病学中显示 增加男性中风风险的研究表明，早期中风风险很高 中风的发病率，然而血压与自发性高血压是相同的。An F2 由这两个菌株杂交制备的杂交队列将 表现出关于中风的特征，使用潜伏期直到 卒中作为主要的区分表型参数。(Ii)此外 已经被鉴定为多态的中等数量的遗传标记 在SHR和SHRSP中，将使用以下工具生成更广泛的地图面板 几种相辅相成的方法，包括开发新的 微卫星、点突变多态和随机扩增多态性DNA分型。在……里面 此外，有限数量的候选基因的多态标记将 被开发出来。(3)从SHRSP/SHR杂交中制备的DNA将 利用制备的一组多态标记和连锁进行基因分型 进行了分析。(4)如已建立与标记的连锁，品种 分子遗传方法和经典遗传方法的结合， 包括在该区域开发新的、间隔更密集的标志 感兴趣的(例如，通过染色体跳跃)和培育同源基因 台词。

The long term objectives of the proposed research are athe identification of disease-causing genes an the characterization of their pathogenetic mechanism in hypertensive cerebrovascular disease. Hypertensive cerebrovascular disease is a major cause of stroke, and the third leading cause of death and disability in our society. While elevated blood pressure is an important risk factor, there is increasing evidence that other, blood pressure-independent, genetic factors play an significant role int he pathogenesis of cerebrovascular disease. Epidemiologic data suggest that the disease is inherited as a polygenic, quantitative trait, similar to primary hypertension. The complexity of polygenic diseases in man, accentuated by their heterogeneous and multifactorial nature, discourages attempts aimed at identifying disease-related genes or loci in humans. Alternatively, inbred animal strains showing the trait of interest as a genetically determine phenotype, represent a useful approximation, the study of which may reveal information that subsequently can be applied to human disease. We propose, therefore, to use the stroke-prone, spontaneously hypertensive rat (SHRSP), an experimental animal that is genetically predisposed to develop hypertensive cerebrovascular disease in a manner closely resembling human pathology, as a model that allows studies in which some of the confounding factors invariably present in humans can be avoided. Following the paradigm of cosegregation analysis for the dissection of disease-relevant genetic loci, we will establish an F2 intercross cohort by breeding the SHRSP with the spontaneously hypertensive rat (SHR), another hypertensive animal strain that, however, does not develop stroke. This strategy removes blood pressure, an important confounding variable, from the analysis, and provides a hybrid population in which the tendency towards stroke shows variation according tot he relative dosage of stroke-relevant genes that a given individual has received as a result of free segregation of alleles, while blood pressure, in contrast, shows minimal variation, as we have shown in preliminary studies. This algorithm provides a powerful approach to search for pathogenetically important genes, and also, in contrast to comparative studies, the only one that establishes causality between gene and phenotype. The proposed studies will pursue the following specific aims; (i) Preliminary studies demonstrate the SHRSP, but not SHR, when fed a specific diet (elements of which have also been shown in epidemiologic studies to increase the risk for stroke in man, show a high, early incidence of stroke, yet blood pressures are identical to SHR. An F2 hybrid cohort prepared by crossbreeding the two strains will be phenotypically characterized with regard to stroke, using latency until stroke as the major discriminating phenotype parameter. (ii) In addition to a moderate number of genetic markers already identified as polymorphic among SHR and SHRSP, a broader mapping panel will be generated using several complimentary approaches, including the development of new microsatellites, point mutation polymorphisms, and RAPD typing. In addition, polymorphic markers for a limited number of candidate genes will be developed. (iii) DNA prepared from the SHRSP/ SHR cross will be genotyped using the panel of polymorphic markers prepared and linkage analysis performed. (iv) If linkage to a marker is established, a variety of molecular and classical genetic approaches will be entertained, including the development of new, more densely spaced markers in the region of interest (e.g. by chromosome jumping) and the breeding of congenic lines.