Next Generation Mendelian Genetics

描述（由申请人提供）：本申请涉及医学测序发现项目的NHGRI RFA-OD-09-004。该提案的最终目标是通过外显子组重测序来确定人类罕见孟德尔疾病的候选基因和突变的新方法。几十年来，连锁分析一直是人类遗传学的支柱。然而，对于罕见的孟德尔疾病，家庭收集是困难的或谱系是小的，这种方法是不太有用的。虽然已经通过连锁作图或候选基因方法确定了2,600多种孟德尔疾病的分子基础，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，致病基因的识别仍然是棘手的连锁图谱或详尽的候选基因分析。外显子组重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，在整个人类基因组中选择性捕获蛋白质编码序列，再加上大规模并行重测序以定义编码变异，可以准确地识别单基因疾病的基因。在这个例子中，对来自少至两个受疾病影响的不相关个体的外显子组变异数据的比较分析将候选基因的列表减少到少于10个。候选名单进一步减少到一个单一的基因与外显子组数据少至四个无关的情况下。一旦确定，每个候选基因将通过常规方法在更大的病例集中筛选致病变异。迄今为止，发现大量罕见疾病的遗传基础将大大扩展我们对人类基因组生物学的理解，促进这些疾病的准确诊断和改善管理，并为开发新疗法提供所需的信息。如果成功的话，这种方法很可能取代连锁分析作为研究疾病的主要范式展示孟德尔遗传模式，并将提供一个新的路径医学遗传学。 公共卫生相关性：随着我们进入个性化医疗时代，DNA测序将对公共卫生越来越重要，有助于我们了解人类疾病的遗传基础。人类基因组（外显子组）中所有蛋白质编码区的靶向捕获和大规模平行测序有可能显着加速人类遗传学研究，作为在全基因组范围内识别高度渗透变体的有效方法。该项目将应用和评估外显子组重测序作为一种新的工具，以快速确定人类数十种罕见遗传疾病的原因。

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.