Genomic studies of secundum atrial septal defects

描述(由申请人提供)： 我们寻求与组成儿科心脏基因组学联盟的其他中心合作，以加快研究先天性心脏病(CHD)的遗传原因和贡献的临床方案。我们提议的中心将是一个迷你联合体，从两个中等规模的纽约市大都市区CHD项目中吸引潜在的受试者，每个项目都由儿科心脏病专家在当地监督，他们将与研究协调员合作，并将利用现有的基础设施，从之前NHLBI资助的SCCOR项目中招募CHD患者。该中心的拟议临床方案将重点放在继发孔型房间隔缺损(2？ASD)的遗传学上。ASD约占CHD的10%，可以综合征和非综合征的形式发生；已知有几种致病基因。《特殊目的1》将检验以下假设：大拷贝数变异(CNV)导致2个ASD伴心外异常，而罕见的小拷贝数CNV导致孤立的2个ASD。将使用阵列比较基因组杂交(ACGH)来检测CNV，并使用比较定量PCR来确认它们。在特定的AIM 2中，我们假设通过罕见的大规模基因组事件参与2？ASD发病的基因更常见地通过单碱基对替换而突变。为了测试这一点，我们将集中在从针对特定AIM 1的研究中发现的新的从头丢失CNV所识别的候选基因上。进一步，我们假设迄今未知的2个ASD基因编码的蛋白质在功能上与那些已被识别为在突变时导致2个ASD的基因编码的蛋白质联网。我们将探索使用系统生物学方法，播种目前已知的2ASD基因，以产生蛋白质相互作用网络。来自两种方法的候选基因列表将通过对2名ASD受试者和对照的编码外显子的重新排序进行测试。在特定的AIM 3中，我们假设躯体获得性2？ASD基因的点突变与这些缺陷的发病有关。为了验证这一想法，我们将使用从患有两个ASD的受试者的外周血白细胞和房间隔原始活检组织中提取的匹配基因组DNA样本，并对目前已知的两个ASD基因集进行重新排序。我们还将对相同数量的无关基因进行重新测序，以确定体细胞嵌合体的背景率。作为一个整体，我们正在利用基因组学技术的进步来描绘导致2？ASD的基因突变和遗传机制的范围。成功完成后，这些发现将对临床护理和临床试验具有重要意义，并可能为如何找到其他形式CHD的遗传原因提供见解。相关性(见说明)：先天性心脏缺陷是最常见的出生缺陷形式，尽管在护理方面取得了实质性进展，但仍会导致重大疾病和过早死亡。对于大多数心脏缺陷来说，原因尚不清楚，但遗传学被认为是一个关键因素。在这里，我们将参与一个致力于揭示儿童心血管疾病遗传原因的研究网络，并特别建议研究心脏上腔之间的异常开口，即所谓的房间隔缺陷。

DESCRIPTION (provided by applicant): We seek to collaborate with other centers forming the Pediatric Cardiac Genomics Consortium in order to accelerate clinical protocols investigating the genetic causes and contributions to congenital heart disease (CHD). Our proposed center will be a mini-consortium, drawing potential subjects from two moderate-sized New York city metropolitan area CHD programs, each overseen locally by pediatric cardiologists who will work with research coordinators, and will leverage existing infrastructure for CHD patient recruitment from a previous NHLBI-funded SCCOR program. The proposed clinical protocol for this center will focus on the genetics of secundum atrial septal defects (2¿ ASDs). 2¿ ASDs constitute roughly 10% of CHD and can occur in syndromic and non-syndromic forms; several causative genes are known. SPECIFIC AIM 1 will test the hypotheses that large copy number variants (CNVs) cause 2¿ ASDs with extra-cardiac abnormalities and that rare small de novo CNVs cause isolated 2¿ ASDs. Array comparative genomic hybridization (aCGH) will be used to detect CNVs and comparative quantitative PCR used to confirm them. In SPECIFIC AIM 2, we hypothesize that genes implicated in the pathogenesis of 2¿ ASDs through rare large-scale genomic events are more commonly mutated through single-base pair substitutions. To test this, we will focus on candidate genes identified by novel de novo loss CNVs from the studies for SPECIFIC AIM 1. Further, we hypothesize that as-yet-unknown 2¿ ASD genes encode proteins that are functionally networked with those encoded by genes already identified as causing 2¿ ASDs when mutated. We will explore that using a systems biology approach, seeding with currently known 2¿ ASD genes, to generate protein interaction networks. Candidate gene lists from both approaches will be tested using resequencing of coding exons In 2¿ ASD subjects and controls. In SPECIFIC AIM 3, we hypothesize that somatically acquired point mutations in 2¿ ASD genes contribute to the pathogenesis of those defects. To test this idea, we will use matched genomic DNA samples extracted from peripheral blood leucocytes and atrial septum primum biopsies from subjects with 2¿ ASDs and resequence the set of currently known 2¿ ASD genes. We will also resequence a comparable number of unrelated genes in order to determine the background rate of somatic mosaicism. Taken as a whole, we are leveraging advances in genomics technology to delineate the range of gene mutations and genetic mechanisms that lead to 2¿ ASD. Successfully completed, the findings will be important for clinical care and clinical trials, and may provide insights into how to find genetic causes for other forms of CHD. RELEVANCE (See instructions): Congenital heart defects are the commonest form of birth defects and, despite substantial progress in care, continue to result in significant illness and premature death. For most heart defects, the cause is unknown but genetics is believed to be a critical one. Here, we will participate in a research network devoted to uncovering genetic causes of cardiovascular disease in children and specifically propose to study abnormal openings between the upper chambers of the heart, known as atrial septal defects.