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）是造血干/祖细胞获得造血干/祖细胞后发生的一种遗传嵌合现象。 一个或多个突变，是与衰老相关的常见现象，影响10-30%的 70岁及以上的人。虽然在CH中观察到的突变和那些在其他人中观察到的突变之间存在大量重叠， 在血液系统癌症中，CH患者的血细胞计数通常正常。然而，窝藏克隆人 不是无害的-越来越多的研究表明，CH与1）增加所有- 导致死亡，2）白血病转化率高出十倍，3）缺血性风险增加一倍 心血管事件，独立的小鼠模型已显示与CH介导的增加有关 炎症。只有一部分CH患者会继续发生心肌梗死或发展为 白血病提出了生殖系和环境因素如何塑造克隆生长和表型的问题， 后果该建议旨在通过以下途径研究特定的生殖系-体细胞-表型相互作用： 在一个独特范德比尔特大学医学中心资源中鉴定CH：一个大型遗传数据库 （BioVU）链接到一个完整的，去识别版本的病人的电子健康记录（EHR）。其基础 这项工作依赖于BioVU内的90，000多名个体，他们已经在同一个单一的基因型上进行了基因分型。 核苷酸多态性（SNP）阵列。在本提案中提出的初步数据中， 种系基因分型阵列可用于检测体细胞变异JAK 2 V617 F，这是一种在两种CH 和骨髓增生性肿瘤（MPN），对于> 5%的变异等位基因分数（VAF）具有高准确度。 拟议研究的目标1将扩展这种计算方法，以确定体细胞突变， 常见的CH病变部位，并验证其有效性。现有阵列数据将用于定义SNP特定 和广义的截止值来区分推定的体细胞突变体和种系变异体。数字PCR将 然后用于确定该方法的准确性，并定义JAK 2 V617 F的检测限， 其他CH突变这些研究的目的2将试图通过调查来证明这些方法的实用性。 生殖系SNP与较高的体细胞JAK 2 V617 F突变率相关的可能机制 影响JAK 2 V617 F阳性MPN的进展。提案中提出的数据确定了一种免疫- 预测在具有这些JAK 2 V617 F相关生殖系SNP的细胞中高度表达的JAK 2 V617 F相关蛋白。 这些研究将通过体外过表达研究阐明靶点对炎症的作用， 人细胞系和原代造血细胞，并将靶蛋白表达与MPN诊断相关联 并通过图表审查进行进展。总之，这些研究将描述生殖系的贡献- 诱导的促炎状态对JAK 2 V617 F克隆生长的影响，并将建立一个研究影响的工具 生殖系和环境暴露对CH获得、进展、相关合并症的影响， mortality.

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.