Exome sequencing and functional studies in familial CHD

描述（由申请人提供）： 大规模并行测序技术的发展可能是个性化医疗的关键，因为它允许识别使人易患疾病的功能性遗传变异。要实现这一点，必须确定致病基因。该提案集中于非综合征性先天性心脏病（CHD）。作为最常见的出生缺陷类型，CHD不仅影响儿童，而且影响越来越多的成年幸存者。流行病学研究已经证明了遗传因素，但很少有致病基因已被确定。在克服这一知识差距之前，潜在的分子原因将仍然隐藏，并阻碍新疗法的开发和长期并发症的潜在预测。我们的长期目标是确定潜在的遗传原因，并阐明导致冠心病的分子机制。本申请的总体目标是发现导致CHD的遗传变异。中心假设是CHD致病基因可以通过全基因组测序的方法，利用表现出孟德尔遗传模式的家族来鉴定。提出这项研究的理由是，发现冠心病的遗传原因有可能提供更好的风险咨询，并为导致死亡的畸形提供新的治疗方法 从婴儿期到成年期。在支持这一前提和拥有独特家族队列的最新文献的指导下，将通过追求两个特定目标来测试中心假设：1）扩展我们目前的CHD多重家族和散发病例队列; 2）通过外显子组和全基因组测序的传递不平衡测试，在表现出CHD孟德尔分离的家族和三人组中鉴定致病基因。将专门开发方法来测试三重数据中的罕见变异关联，这些数据在基因区域内聚集变异，并根据频率和功能对这些变异进行加权。这些方法也将允许对有家族史的无关个体进行联合分析 CHD和Trio数据。将通过体外和体内非洲爪蟾试验研究推定的因果变体功能效应。然后将对一个更大的CHD队列进行筛选，以确定基因中的突变。我们的方法是创新的，不仅因为它采用了新技术，而且还通过使用家庭来解决复杂疾病的遗传基础，增加了孟德尔遗传学的力量。该应用程序侧重于NHLBI战略计划目标和挑战的一部分，以确定与特定疾病相关的人群中的关键遗传变异。这一提议的成功将为人类疾病基因鉴定方法带来范式转变。这项拟议中的研究意义重大，因为它有望通过识别CHD的致病基因来垂直推进人类遗传学，发育生物学和心血管医学领域。在目前的胎儿诊断和干预时代，这些知识将用于改善预防措施，子宫内诊断，遗传咨询和治疗。

DESCRIPTION (provided by applicant): The development of massively parallel sequencing technologies may hold the key to personalized medicine as it allows for the identification of functional genetic variants that rende a person susceptible to disease. For this to become reality, disease-causing genes must be identified. This proposal concentrates on non-syndromic congenital heart defects (CHDs). Representing the most common type of birth defect, CHDs affect not only children but also a growing population of adult survivors. Epidemiologic studies have demonstrated genetic contributors, but few etiologic genes have been identified. Until this knowledge gap is overcome, the underlying molecular cause will remain hidden and hinder the development of new therapies and potentially prediction of long-term complications. Our long-term goal is to identify the underlying genetic causes and elucidate the molecular mechanisms leading to CHDs. The overall objective of this application is to discover the genetic variation that results in CHDs. Th central hypothesis is that CHD-causing genes can be identified by a genome-wide sequencing approach, using families exhibiting Mendelian inheritance patterns. The rationale for the proposed research is that the discovery of genetic causes of CHDs has the potential to provide better risk counseling and result in novel therapies for malformations that contribute to mortality from infancy to adulthood. Guided by recent literature supporting this premise and possession of a unique cohort of families, the central hypothesis will be tested by pursuing two Specific Aims: 1) Expand our current cohort of multiplex families and sporadic cases of CHDs; 2) Identify disease-causing genes in families exhibiting Mendelian segregation for CHDs and in trios via transmission disequilibrium tests by exome and whole genome sequencing. Methods will be developed specifically to test for rare variant associations in trio data, which aggregate over variants within a gene region and weight these variants based upon frequency and functionality. These methods will also allow for the joint analysis of unrelated individuals with a family history of CHD and trio data. The putative causal variants functional effects will be investigated by in vitro and in vivo Xenopus assays. A larger cohort with CHD will then be screened for mutations in identified genes. Our approach is innovative not only because it employs new technologies but also adds the power of Mendelian genetics through the use of families to tackle the genetic basis of a complex disease. This application focuses on part of the NHLBI Strategic Plan goals and challenges to identify key genetic variants in the human population that are associated with specific diseases. Success of this proposal will create a paradigm shift in the approach for human disease gene identification. The proposed research is significant because it is expected to vertically advance the fields of human genetics, developmental biology and cardiovascular medicine by identifying causal genes for CHDs. In the current era of fetal diagnosis and intervention, this knowledge will be used to improve prevention measures, in utero diagnosis, genetic counseling and therapy.