Next Generation Mendelian Genetics

描述(由申请人提供)：本申请针对医学测序发现项目的NHGRI RFA-OD-09-004。这项提议的最终目标是扩大一种新的方法，通过外显子组重新测序来识别人类罕见孟德尔疾病背后的候选基因和突变。几十年来，连锁分析一直是人类遗传学的支柱。然而，对于家系收集困难或家系较小的罕见孟德尔疾病，这种方法就不那么有用了。尽管2600多种孟德尔疾病的分子基础已经通过连锁图谱或候选基因方法确定，但仍有几乎相同数量的疾病有待解决(OMIM)。我们收集了一组罕见的儿童和成人孟德尔疾病，这些疾病代表了这一未解决的问题。在每一种情况下，因果基因的识别对于连锁作图或详尽的候选基因分析来说都是困难的。外显子组重新测序为剖析罕见孟德尔疾病的根本原因提供了一条新的途径。在我们的初步研究中，我们表明，选择性捕获人类基因组中的蛋白质编码序列，结合大规模并行重测序来定义编码变异，可以准确地识别单基因疾病的基因。在这个例子中，对比分析了两个与疾病无关的个体的外显子组变异数据，将候选基因列表减少到不到10个。候选名单被进一步缩减为单基因，只有四个不相关案例的外显子数据。一旦确定，每个候选基因将在更大的一组病例中通过传统方法筛选致病变异。大量罕见疾病的遗传学基础的发现将极大地扩展我们对人类基因组生物学的理解，促进对这些疾病的准确诊断和改进管理，并提供开发新疗法所需的信息。如果成功，这种方法很可能取代连锁分析，成为研究表现孟德尔遗传模式的疾病的主导范式，并将为医学遗传学提供一条新的前进道路。 公共卫生相关性：随着我们进入个性化医学时代，DNA测序对公共健康将变得越来越重要，有助于我们理解人类疾病的遗传基础。对人类基因组中所有蛋白质编码区(外显子组)的定向捕获和大规模并行测序具有显著加快人类遗传学研究的潜力，是在全基因组范围内识别高渗透性变异的有效方法。该项目将应用和评估外显子组重新测序作为一种新的工具，以快速确定人类数十种罕见遗传病的原因。

DESCRIPTION (provided by applicant): This application addresses NHGRI RFA-OD-09-004 for Medical Sequencing Discovery Projects. The ultimate goal of this proposal is to scale a new approach to identify the candidate genes and mutations that underlie rare Mendelian diseases in humans by exome resequencing. For decades, linkage analysis has been the mainstay of human genetics. However, for rare Mendelian diseases where family collection is difficult or pedigrees are small, this approach is less useful. Although the molecular bases of more than 2,600 Mendelian diseases have been determined by linkage mapping or a candidate gene approach, a nearly equal number remain to be solved (OMIM). We have assembled a collection of rare pediatric and adult Mendelian diseases that are representative of this unsolved set. In every instance, the identification of the causal gene remains intractable to either linkage mapping or exhaustive candidate gene analysis. Exome resequencing offers a new way forward for dissecting the underlying causes of rare Mendelian diseases. In our preliminary studies, we show that selective capture of protein coding sequences across the human genome coupled with massively parallel resequencing to define coding variation can accurately identify the gene underlying a monogenic disorder. In this example, comparative analysis of exome variation data from as few as two unrelated individuals affected with the disease reduced the list of candidate genes to less than ten. The candidate list was further reduced to a single gene with exome data from as few as four unrelated cases. Once identified, each candidate gene will be screened for disease-causing variants by conventional methods in a larger set of cases. Discovery of the genetic basis of a large collection of rare disorders that have, to date, been unyielding to traditional analysis will substantially expand our understanding of the biology of the human genome, facilitate accurate diagnosis and improved management of these diseases, and provide the information needed for the development of novel therapeutics. If successful, this approach is likely to replace linkage analysis as the dominant paradigm for studying diseases exhibiting Mendelian inheritance patterns and will provide a new path forward for medical genetics. PUBLIC HEALTH RELEVANCE: As we enter an era of personalized medicine, DNA sequencing will be increasingly important to public health, contributing to our understanding of the genetic basis of human disease. The targeted capture and massively parallel sequencing of all protein coding regions in the human genome (the exome) has the potential to markedly accelerate human genetics research as an efficient method for identifying highly penetrant variants at a genome-wide scale. This project will apply and evaluate exome resequencing as a new tool to rapidly identify the causes of dozens of rare genetic diseases in humans.