Assessing the Impact of Rare Polymorphism at CRP on CRP Levels & Atherosclerosis

描述（由申请人提供）：血浆c反应蛋白（CRP）水平是预测未来心血管疾病（CVD）风险的生物标志物。我们最近证明了CRP基因中几个常见的单核苷酸多态性（snp）的等位基因与血浆CRP水平相关，并在功能上改变了CRP启动子的调节。然而，CRP水平的大部分个体间差异仍未得到解释。常见的snp往往比罕见的snp更古老，因此暴露在更长期的自然选择中。因此，与已知的常见snp相比，罕见snp对血浆CRP的影响更大，这并非不可能，这些罕见snp可能解释了血浆CRP剩余差异的重要部分。本应用程序的目的是发现CRP基因中罕见的snp，这些snp与血浆CRP水平和动脉粥样硬化发病机制具有功能相关性。

DESCRIPTION (provided by applicant): Plasma C-Reactive Protein (CRP) level is a biomarker that predicts future risk of cardiovascular disease (CVD). We recently demonstrated that alleles at several common single nucleotide polymorphisms (SNPs) in the CRP gene correlate with plasma CRP levels, and functionally alter the regulation of the CRP promoter. However, the majority of the inter-individual variance in CRP levels remains unexplained. Common SNPs tend to be older than rare SNPs, and therefore have been exposed to longer term natural selection. Thus, it is not unlikely that rare SNPs exist with larger effects on plasma CRP than the known, common SNPs, and these rare SNPs might explain a significant fraction of the remaining variance in plasma CRP. The goal of this application is to discover rare SNPs in the CRP gene, which are of functional relevance in relation to plasma CRP levels and atherosclerotic pathogenesis. Aim 1: We will identify rare SNPs likely to alter CRP levels by resequencing two panels: A. the high (N=376) and low (N=376) tails of the CRP distribution (and age/gender matched controls) in the CARDIA cohort, a cohort of more than 4000 individuals, ages 38 to 50, and B. Severely stenosed cases (N=500) and controls (N=500) from a study of carotid atherosclerotic disease. Aim 2: We will functionally characterize putatively functional SNPs identified in Aim 1, using site-directed mutagenesis of a plasmid containing a CRP-GFP fusion gene to generate allelic constructs, and transient transfection analysis of expression from the allelic constructs to assess functional impacts on protein and RNA levels.