Project I - Human genetics of meningomyelocele and risk mitigation by folic acid

摘要-项目I：人类脑膜脊膜膨出的遗传学和叶酸降低风险 本项目的重点是人类脑膜脊膜膨出患者的基因组变异特征。 (Mm)，最常见的中枢神经系统出生缺陷，遗传率估计为70%-75%1，2，累积发病率 每万名美国活产儿中有3.72人出生。MM是一种使人衰弱的结构性出生缺陷，是NTD最常见的形式 与生活相适应，并与大量相关的发病率和死亡率相关联。国家叶酸(FA) 补充剂使发病率降低了3倍，但对其机制知之甚少。 基因-环境互作(GxE)。在这里，我们建议通过一种新的方法研究人类多发性骨髓瘤的分子基础。 以严格定义的纳入/排除标准在世界范围内招募三人组，按产前FA分层 曝光。我们假设从头基因突变(DNM)对多发性骨髓瘤的风险有重要贡献，并且 FA增加了表型表达所需的突变负担。MM与其他公司共享功能 严重的儿童疾病，表现出强烈的DNM贡献，如先天性结构障碍和 自闭症。我们的初步数据表明，DNM对MM有很大的贡献，但像自闭症一样，这些DNM增加 风险，但可能会与其他因素一起行动来确定风险。我们建议仔细确定总共2000个 表型MM三人组，在世界各地招募，根据国家膳食FA补充状况进行分层 受孕时(+FA：强化VS-FA：非强化)。三人组将接受全基因组测序 (WGS)，然后分析从头开始和遗传突变作为危险因素，并与对照三人组进行比较。结果 来自项目I的数据将被合并到项目II和项目III的工作流程中，以建立突变模型，其结果来自 项目II和项目III将用于完善项目I中的WGS分析。项目I将依靠核心B来确定 来自表观遗传特征变化的候选FA反应基因，以及在核心C上的生物信息学 分析。项目I已经：1]成立了脊柱裂测序联盟，并招募了一批 使用社交媒体和历史队列的1500 MM三人组，分层为+FA或-FA。2]提取DNA并进行质量控制 来自这三人中的&gt；700。3]成功竞争NICHD Gabriella Miller-Kids首次计划访问权限 1000个WGS样本。4]对600个三元组进行了排序，并对算法进行了优化，以达到一致 突变呼唤。5]确定了12个MM候选基因，其中包括3个重复突变基因和1个 重复拷贝数变异(CNV)。6]发现+FA三重奏而不是-FA三重奏表现出惊人的 与对照相比，有害DNMS的积累。我们将测试从头开始并继承的模型 突变与FA相互作用，以确定风险。该应用程序建议完成招聘，识别出 MM中的Novo和遗传基因突变与母亲FA暴露相关，并揭示了MM的机制 临床范围内的疾病。

Abstract – Project I: Human genetics of meningomyelocele and risk mitigation by folic acid This project focuses on the characterization of genomic variation in human patients with Meningomyelocele (MM), the most common CNS birth defect, with heritability estimated at 70-75% 1,2, and a cumulative incidence of 3.72/10,000 live US births. MM is a debilitating structural birth defect, the most common form of NTD compatible with life, and with substantial associated morbidity and mortality. National folic acid (FA) supplementation has reduced incidence >3-fold, but there is little understanding of the mechanism of this Gene-Environment interaction (GXE). Here we propose to study the molecular basis of human MM through a world-wide recruitment of trios with narrowly defined inclusion/exclusion criteria, stratified by prenatal FA exposure. We hypothesize that de novo mutations (DNMs) make a critical contribution to the risk of MM, and that FA increases the mutational burden required for phenotypic expressivity. MM shares features with other severe childhood diseases that show strong DNM contributions such as congenital structural disorders and autism. Our preliminary data point to a strong DNM contribution to MM, but like autism, these DNM increase risk but likely act with other factors to determine risk. We propose to ascertain a total of 2000 carefully phenotyped MM trios, recruited worldwide, stratified based upon national dietary FA supplementation status at the time of conception (+FA:fortified vs -FA:nonfortified). Trios will undergo whole genome sequencing (WGS), then analyzed for de novo and inherited mutations as risk factors, compared with control trios. Results from Project I will be incorporated into workflow of Project II and III to model mutations, and results from Project II and III will be used to refine WGS analysis in Project I. Project I will rely on Core B to identify candidate FA-responsive genes from changes in epigenetic signatures, and on Core C for bioinformatic analysis. Project I has already: 1] Founded the Spina Bifida Sequencing Consortium and enrolled a cohort of >1500 MM trios using social media, and historic cohorts, stratified as +FA or -FA. 2] Extracted and QC’d DNA from >700 of these trios. 3] Competed successfully for NICHDs Gabriella Miller-Kids First program access for 1000 WGS samples. 4] Performed sequencing on 600 trios, as well as optimized algorithms to achieve uniform mutation calling. 5] Identified 12 MM candidate genes, including 3 recurrently mutated genes, and one recurrent copy number variant (CNV). 6] Found that +FA trios but not -FA trios demonstrate a striking accumulation of damaging DNMs compared with controls. We will test the model that de novo and inherited mutations interact with FA to determine risk. The application proposes to complete recruitment, identify de novo and inherited gene mutations in MM, correlate with maternal FA exposure, and uncover mechanisms of disease within a clinical context.