Discovering Human Birth Defect Genes from Chromosomal Rearrangements

从染色体重排中发现人类出生缺陷基因

• 批准号: 7763960
• 负责人: RICHARD L MAAS
• 金额: $ 40.12万
• 依托单位: BRIGHAM AND WOMEN'S HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-02-05 至 2014-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7763960
• 关键词: A Mouse; Affect; Balanced Chromosomal Translocation; Candidate Disease Gene; Chromosomal Rearrangement; Chromosome abnormality; Complex; Congenital Abnormality; Cytogenetics; DNA Sequence Rearrangement; Development; Developmental Gene; Disease; Environmental Risk Factor; Etiology; Eye; Genes; Genetic; Genetic Heterogeneity; Goals; Grant; Human; Human Chromosomes; Human Genetics; Kidney; Laboratories; Link; Maps; Methods; Mus; Mutate; Mutation; Organogenesis; Patients; Phenotype; Provider; Public Health; Recruitment Activity; Role; System; Testing; Vesico-Ureteral Reflux; cleft lip and palate; cohort; congenital cataract; craniofacial; craniofacial complex; gene discovery; genetic pedigree; interest; outreach; proband

DESCRIPTION (provided by applicant): Although complex diseases represent a critical challenge for human genetics, birth defects represent one class of complex diseases that remain largely unresolved. Because of phenotypic and genetic heterogeneity, the role of environmental factors, and the rarity of extended pedigrees and well-stratified cohorts, birth defects are difficult to study by conventional genetic methods. Nonetheless, the societal burden imposed by birth defects is enormous. This application will take advantage of an efficient, established birth defect gene discovery pipeline that focuses on important birth defects associated with balanced chromosomal rearrangements. In these cases, we will identify genes that are disrupted by the rearrangement breakpoints, and we will test the hypothesis that the genes disrupted by breakpoints are causal for the subject's phenotype. To test the validity of the candidate genes identified, two further strategies will be employed: (1) mutational analysis of phenotypically similar cases that do not involve chromosomal rearrangements, to search for intragenic mutations in the candidate gene, and (2) recapitulation of key aspects of the proband's phenotype in the mouse by targeted mutation or knockdown of the candidate gene. The endpoint for these analyses is to obtain conclusive evidence that the gene disrupted by chromosomal rearrangement in any given case is responsible for the associated birth defects, and to conduct an initial analysis of the gene's developmental function. To accomplish these goals, we will employ a robust accrual system to recruit cases of interest from both national outreach and from major commercial cytogenetic providers. To take maximal advantage of the expertise that already exists within our laboratory, we will restrict our scope to two cases per year (ten overall) and we will focus specifically upon cases that affect organogenesis of the eye, kidney and craniofacial complex. In Aim 1, we will ascertain cases involving balanced chromosomal rearrangements (i.e., translocations and inversions) that are associated with disorders of craniofacial, ocular or renal development, and we will map the rearrangement breakpoints. In Aim 2, we will identify candidate genes disrupted by the breakpoints and determine the relevant mutational mechanisms. In Aim 3, to establish causality for these candidate genes, we will perform mutational analyses of phenotypically related human cases, and in Aim 4 we will further seek to establish causality by using genetic means to recapitulate the phenotype in mouse, and we will also determine the gene's developmental function. This powerful gene discovery approach will identify human genes that are newly linked to medically important birth defects, and help to define their developmental functions. PUBLIC HEALTH REVELANCE: This grant proposes to identify genes that are broken by naturally occurring human chromosome abnormalities associated with congenital birth defects. We will focus on birth defects involving the craniofacial region (e.g., cleft lip and palate), the eye (e.g., congenital cataracts), and the kidney (e.g., vesicoureteral reflux, or VUR). To prove that the broken genes are causally linked to the accompanying birth defect, we will search for mutations in the same gene in other patients with the same birth defect, and we will investigate the consequences of mutating the gene in mice.

描述（由申请人提供）：尽管复杂疾病是人类遗传学面临的重大挑战，但出生缺陷是一类尚未解决的复杂疾病。由于先天缺陷的表型和遗传异质性，环境因素的作用，以及扩展谱系和分层良好的队列的稀缺性，传统的遗传方法难以研究先天缺陷。尽管如此，先天缺陷造成的社会负担是巨大的。这个应用程序将利用一个有效的，建立出生缺陷基因发现管道，重点关注与平衡染色体重排相关的重要出生缺陷。在这些情况下，我们将识别被重排断点破坏的基因，我们将测试被断点破坏的基因是受试者表型的因果关系的假设。为了测试所鉴定的候选基因的有效性，将采用两种进一步的策略：(1)对不涉及染色体重排的表型相似病例进行突变分析，寻找候选基因的基因内突变；(2)通过靶向突变或敲低候选基因，在小鼠中再现先证表型的关键方面。这些分析的目的是获得确凿的证据，证明在任何特定情况下，被染色体重排破坏的基因是导致相关出生缺陷的原因，并对该基因的发育功能进行初步分析。为了实现这些目标，我们将采用一个健全的应计制，从国家外联和主要的商业细胞遗传学提供者那里招募感兴趣的病例。为了最大限度地利用我们实验室现有的专业知识，我们将把研究范围限制在每年2例（总共10例），我们将特别关注影响眼睛、肾脏和颅面复合体器官发生的病例。在目标1中，我们将确定涉及与颅面、眼或肾脏发育障碍相关的平衡染色体重排（即易位和倒位）的病例，并绘制重排断点。在目标2中，我们将确定被断点破坏的候选基因，并确定相关的突变机制。在目标3中，为了建立这些候选基因的因果关系，我们将对与表型相关的人类病例进行突变分析，在目标4中，我们将进一步寻求通过使用遗传手段来概括小鼠的表型来建立因果关系，我们还将确定基因的发育功能。这种强大的基因发现方法将识别与医学上重要的出生缺陷有关的人类基因，并有助于确定它们的发育功能。公共卫生启示：该拨款旨在鉴定与先天性出生缺陷相关的自然发生的人类染色体异常所破坏的基因。我们将重点关注涉及颅面区域（如唇裂和腭裂）、眼睛（如先天性白内障）和肾脏（如膀胱输尿管反流或VUR）的出生缺陷。为了证明破碎的基因与伴随的出生缺陷有因果关系，我们将在其他具有相同出生缺陷的患者中寻找相同基因的突变，我们将研究小鼠基因突变的后果。