Harnessing EHR-linked Genomics Data to Study Clonal Hematopoiesis and its Evolution to Inflammatory Phenotypes

项目摘要 克隆性造血(CH)，一种在造血干/祖细胞获得后发生的遗传嵌合体 一个或多个突变是与衰老有关的常见现象，影响10%-30%的 年龄在70岁及以上的个人。尽管在CH中看到的突变与那些 在血液病癌症中，CH患者的血细胞计数通常正常。然而，窝藏克隆人 并不是无害的--越来越多的研究表明，CH与1)增加的ALL- 导致死亡，2)白血病转化率增加10倍，3)缺血风险增加一倍 心血管事件，独立的小鼠模型已证明与CH介导的增加有关 在炎症中。只有一部分CH患者会继续发生心肌梗死或发展 白血病提出了一个问题，即种系和环境因素如何塑造克隆生长和表型 后果。这一建议试图通过以下方式研究特定的种系-体细胞-表型相互作用 范德比尔特大学医学中心独特资源中的CH鉴定：一个大型遗传数据库 (BioVU)链接到患者电子健康记录(EHR)的完整、未识别版本。这一点的基础 这项工作取决于BioVU内90,000多名在同一个人身上进行了基因分型的人 核苷酸多态(SNP)阵列。本提案提供的初步数据表明，这一点 胚系基因分型阵列可用于检测体细胞变异JAK2V617F，这是一种在两种先天性心脏病中常见的突变 和骨髓增生性肿瘤(MPN)，对变异等位基因片段(VAFs)和GT；5%具有高度的准确性。 拟议研究的目标1将把这种计算方法扩展到识别体细胞突变到其他 常见的CH病变部位，验证其有效性。现有数组数据将用于定义特定于SNP的 和广义截止值，以区分假定的体细胞突变体和生殖系突变体。数字聚合酶链式反应 然后用来确定该方法的准确性，并确定其对JAK2V617F和 其他CH突变。这些研究的目标2将试图通过调查来证明这些方法的实用性 胚系SNP与较高的体细胞JAK2V617F突变率相关的可能机制 影响向JAK2V617F阳性MPN的进展。提案中提供的数据确定了一种免疫- 相关蛋白预计在具有这些JAK2V617F相关生殖系SNPs的细胞中高表达。 这些研究将通过体外过表达研究阐明靶标在炎症中的作用 人类细胞系和原代造血细胞，并将靶蛋白表达与MPN诊断相关 和通过复习图表的进度。总之，这些研究将描述生殖系的贡献-- 诱导JAK2V617F克隆性生长的促炎状态，为研究其影响奠定了基础 生殖系和环境暴露对CH的获取、进展、相关的共病以及 死亡率。

Project Summary Clonal hematopoiesis (CH), a genetic mosaicism which occurs after hematopoietic stem/progenitor cells acquire one or more mutations, is a common phenomenon associated with aging, affecting between 10-30% of individuals aged 70 and older. Although there is substantial overlap between the mutations seen in CH and those seen in hematologic cancers, individuals with CH often have normal blood counts. However, harboring a clone is not harmless – a growing body of research has demonstrated that CH is associated with 1) increased all- cause mortality, 2) a ten-fold higher rate of leukemic transformation, and 3) a doubling of the risk of ischemic cardiovascular events, which independent mouse models have shown to be linked to a CH-mediated increase in inflammation. That only a subset of individuals with CH go on to have a myocardial infarction or develop leukemia raises the question of how germline and environmental factors shape clonal outgrowth and phenotypic consequences. This proposal seeks to investigate a specific germline-somatic-phenotype interaction through identification of CH within a unique Vanderbilt University Medical Center resource: a large genetic database (BioVU) linked to a complete, de-identified version of patients’ electronic health records (EHR). The basis for this work rests on the more than 90,000 individuals within BioVU who have been genotyped on the same single nucleotide polymorphism (SNP) array. In preliminary data presented in this proposal, it is shown that this germline genotyping array can be used to detect the somatic variant JAK2V617F, a mutation common in both CH and myeloproliferative neoplasia (MPN), with a high degree of accuracy for variant allele fractions (VAFs) > 5%. Aim 1 of the proposed studies will expand this computational approach to identify somatic mutations to other common CH lesion sites and validate its effectiveness. Existing array data will be used to define SNP-specific and generalized cutoff values to differentiate putative somatic mutants from germline variants. Digital PCR will then be used to determine the accuracy of this approach and to define its limit of detection for JAK2V617F and other CH mutations. Aim 2 of these studies will seek to demonstrate the utility of these methods by investigating a possible mechanism by which germline SNPs associated with higher rates of somatic JAK2V617F mutations influence the progression to JAK2V617F-positive MPN. Data presented in the proposal identify an immune- associated protein predicted to be highly expressed in cells with these JAK2V617F-associated germline SNPs. These studies will elucidate the target’s contribution to inflammation via in vitro overexpression studies utilizing human cell lines and primary hematopoietic cells and will correlate target protein expression with MPN diagnosis and progression through chart review. Together, these studies will characterize the contribution of a germline- induced proinflammatory state to JAK2V617F clonal outgrowth and will establish a tool for studying the influence of germline and environmental exposures on CH acquisition, progression, associated comorbidities, and mortality.