Identification of genes predisposing to atherosclerosis

描述（由申请人提供）：冠心病（CHD）是一种复杂的疾病，构成了西方社会的主要健康问题。我们的目的是通过研究最常见的家族性血脂异常，家族性合并高脂血症（FCHL），来评估冠心病未知的遗传背景。据估计，FCHL的人群患病率为1- 2%，这种疾病影响了10- 20%的早产儿冠心病家庭。FCHL患者血清胆固醇、甘油三酯或两者均升高。环境因素和遗传因素都可能影响FCHL的复杂表型。由于FCHL的分子基础是未知的，大量的遗传易感个体仍然未被识别并暴露于早期冠心病。我们将使用来自芬兰遗传隔离人群的独特研究样本，并应用分子遗传学工具首先限制我们已确定的遗传位点，然后表征染色体1q21上FCHL疾病的致病基因。具体而言，我们首先旨在通过剖析不同成分特征来进一步限制该区域。我们将利用密集的微卫星标记和单核苷酸多态性对61个FCHL家族的所有可用家族成员进行基因分型，以充分利用精细定位中的精细定量表型信息。其次，我们的目标是在1q21-q23的关键区域建立转录图谱，并在区域候选基因中确定FCHL的致病基因。1q21-q23上的这个区域与小鼠3号染色体上的一个区域同源，在那里发现了一个与合并高脂血症相关的位点（Hyplip 1）。我们分析了Hyplip 1基因的人类同源物，但令人失望的是，人类Hyplip 1基因在距离峰值连锁标记10 Mb处被发现，没有证据表明Hyplip 1是FCHL的致病基因。我们鉴定FCHL基因的目标是目前在连锁峰附近显示最强关联的基因。然后对FCHL基因进行功能表征以证明生物学功能障碍。表征FCHL的一个基因将提高我们对心血管疾病分子机制的理解，并有可能导致更准确的诊断、治疗和预防。

DESCRIPTION (provided by applicant): Coronary heart disease (CHD) is a complex disorder constituting a major health problem in Western societies. We aim to assess the unknown genetic background of CHD by investigating the most common familial dyslipidemia predisposing to CHD, familial combined hyperlipidemia (FCHL). The population prevalence of FCHL is estimated to be 1-2 percent and the disorder affects 10-20 percent of families with premature CHD. In FCHL, serum cholesterol, triglycerides, or both are elevated. Both environmental and genetic factors are suggested to affect the complex FCHL phenotype. Since the molecular basis of FCHL is unknown, a significant number of genetically predisposed individuals remain unidentified and exposed to premature CHD. We will use our unique study samples from the genetically isolated population of Finland and apply molecular genetic tools to first restrict the genetic locus we have identified and then to characterize the causative gene underlying the FCHL disorder on chromosome 1q21. Specifically, we first aim to further restrict the region by dissecting the different component traits. We will genotype an extended study sample consisting of all available family members of 61 FCHL families with dense sets of microsatellite markers and single nucleotide polymorphisms to fully utilize the refined quantitative phenotype information in fine mapping. Second, we aim to build a transcript map over the critical region on 1q21-q23 and to identify the causative FCHL gene among the regional candidate genes. This region on 1q21-q23 is orthologous to a region on mouse chromosome 3, where a locus (Hyplip 1) for combined hyperlipidemia has been identified. We have analyzed the human homolog of the Hyplip 1 gene but disappointingly, the human Hyplip 1 gene was found 10 Mb from the peak linkage markers and no evidence emerged for Hyplip 1 as a causative gene for FCHL. Our targets to identify the FCHL gene are currently the genes showing strongest association near the linkage peak. The FCHL gene will then be functionally characterized to prove the biological dysfunction. Characterizing one gene for FCHL would improve our understanding of molecular mechanisms of cardiovascular disease, and potentially lead to more accurate diagnosis, treatment and prevention.