Human exomics genotyping-driven discovery and characterization of proteins related to clinical thrombosis, blood coagulation and thrombin generation

7.项目摘要/摘要 增进有关血栓形成的基础和临床知识是该项目的主要目标。凝血酶过多 代发导致血栓形成，包括静脉血栓栓塞症(VTE)，这是一种复杂的 疾病。基于基因组学的研究应该是发现静脉血栓栓塞症危险因素的有力工具，但GWAS 几乎没有添加新的见解。与以常见基因变异为中心的GWA不同，新的外显子组 基因分型阵列允许对整个基因组中罕见的功能变异进行询问。种族特定的因果关系 在高加索人、日本人和中国人中，VTE的因素涉及凝血蛋白的罕见变异。 静脉血栓栓塞症风险的缺失遗传性可能部分归因于罕见或低频变异。外显子 基因分型可以询问&gt；25万个变异，寻找可能改变蛋白质的罕见错义变异 功能性活动。我们将外显子组阵列技术初步应用于一群欧美人和 一组非裔美国人产生了令人惊讶的发现，这一发现将得到证实并得到推广 项目。而与VTE相关的新遗传变异的鉴定代表着重要和有价值的遗传 协会，关键是要确定是否以及如何新牵连的生物活动 候选基因的产物可能导致血栓形成。我们最初的外显子组基因分型显示 与VTE风险相关的结构蛋白基因，包括一些肌球蛋白重链基因。令人惊讶的是 这一发现导致了一些肌球蛋白具有促凝血活性的发现。我们建议将其描述为 肌球蛋白通过与凝血因子相互作用促进凝血酶生成的机制。我们也 建议澄清构成血浆蛋白，即血清淀粉样蛋白A4，通过其与 促进凝血酶生成的凝血因子。这个项目的一个主要目标是发现新的稀有基因 研究不足、无遗传风险的非裔美国人人群中与静脉血栓栓塞症相关的变异 这一因素尚未得到广泛认可。我们最初的外显子组基因分型数据显著识别了一组VTE- 非裔美国人独有的链接稀有变体和另一组独有的VTE稀有变体 高加索美国人。在这个项目中，我们建议研究来自主要协作中心的七个队列 其中这些研究将包括大约3000名高加索人和2000名非裔美国人。这些队列将 使我们最初基于外显子组基因分型的发现能够复制，并将促进进一步的努力 发现与静脉血栓栓塞症相关的外源稀有变异。如果成功，这个项目的新知识将包括 血栓形成相关罕见基因变异的发现和可能参与血栓形成的新蛋白的发现 血栓风险。这种关于新基因和以前未被识别的蛋白质的新知识将显著 扩展我们关于VTE病理生理学的概念，并将对新的诊断或 治疗应用。

7. PROJECT SUMMARY/ABSTRACT Advancing basic and clinical knowledge about thrombosis is the major goal of this Project. Excessive thrombin generation causes thrombosis, including venous thromboembolism (VTE) which is a complex disease. Genomics-based research should be a powerful tool for discovery of VTE risk factors, but GWAS had added few new insights. In contrast to GWAS that is centered on common gene variations, new exome genotyping arrays permit interrogation of rare functional variants throughout the genome. Race-specific causal factors for VTE in Caucasian, Japanese and Chinese populations involve rare variants in coagulation proteins. The missing heritability of VTE risk may be attributed, in part, to rare or low frequency variants. Exome genotyping can interrogate > 250,000 variations for rare missense variants that might alter a protein's functional activity. Our initial application of exome array technology to one cohort of European Americans and one cohort of African Americans yielded surprising findings which will be confirmed and extended by this project. While identification of new genetic variants linked to VTE represents significant and valuable genetic associations, it is critical to determine whether and how the biological activities of the newly implicated candidate gene's product may contribute to thrombosis. Our initial exome genotyping implicated certain structural protein genes as being linked to VTE risk, including some myosin heavy chain genes. This surprising discovery led to the discovery that some myosins have procoagulant activity. We propose to characterize the mechanisms by which myosin promotes thrombin generation by its interactions with clotting factors. We also propose to clarify mechanisms by which the constitutive plasma protein, serum amyloid A 4, interacts with clotting factors to promote thrombin generation. A major goal of this project is to discover new genetic rare variants that are linked to VTE among the understudied African American population for whom no genetic risk factor has yet been widely recognized. Our initial exome genotyping data significantly identified a set of VTE- linked rare variants unique to African Americans and another set of VTE-linked rare variants unique to Caucasian Americans. For this project, we propose to study seven cohorts from key collaborating centers wherein these studies will include circa 3,000 Caucasians and 2,000 African Americans. These cohorts will enable replication of our initial exome genotyping-based discoveries and will facilitate efforts for further discoveries of exomic rare variants linked to VTE. If successful, new knowledge from this project will include discovery of thrombosis-related rare genetic variants and revelation of new proteins that may contribute to thrombosis risks. This new knowledge about new genes and previously unrecognized proteins will significantly extend our concepts about VTE pathophysiology and will have potential implications for new diagnostic or therapeutic applications.