Molecular Genetics of Age Related Macular Degeneration

描述（由申请人提供）：在发达国家，年龄相关性黄斑变性（AMD）是导致严重视力丧失的最常见原因，仅在美国就有超过1000万人受到影响。大约三分之一的75岁以上的人在某种程度上受到影响。这种疾病很大一部分是遗传的。在这项研究中，我们将利用经验丰富的临床医生能够可靠地识别出具有可发现原因的异常结构和功能模式这一事实。我们将把这种临床专业知识与先进的分子和组织病理学方法相结合，以鉴定新的AMD基因，并更好地了解以前发现的AMD基因的疾病机制。在目标1中，我们将通过将具有良好特征的AMD患者和人眼供体的基因型与其眼科检查和/或组织病理学结果相关联，确定新的AMD基因座和基因座特异性AMD表型。在目标2中，我们将通过使用焦磷酸盐DNA测序的新实现筛选13个已知AMD基因和37个候选AMD基因的致病变异，在已知AMD基因中鉴定新的AMD致病基因和新的AMD致病突变。我们将对400名AMD患者和400名老年对照者的整个编码序列和这些基因的近端启动子进行测序，使用一种新的焦磷酸盐测序方法。在患者或对照组中发现的明显偏斜的变异将通过在第二组400名AMD患者和400名对照组中进行分析来验证。在目标3中，我们将通过表征高风险和低风险AMD基因型的人供眼视网膜和RPE/脉络膜基因表达来研究AMD的病理生理机制。具体来说，对于5个不同的AMD基因座，我们将分析5个高风险基因型纯合的人眼供体的视网膜和RPE/脉络膜RNA，并将这些结果与5个低风险基因型纯合的供体的结果进行比较。这些研究将为AMD的病理生理机制提供新的见解，这将对开发更具体的诊断方法和更有效的治疗方法有价值。

DESCRIPTION (provided by applicant): Age-related macular degeneration (AMD) is the most common cause of severe visual loss in the developed world, affecting more than 10 million people in the United States alone. Approximately 1 in 3 people over the age of 75 are affected to some degree. A significant fraction of this disease is genetic. In this study, we will take advantage of the fact that experienced clinicians can reliably recognize patterns of abnormal structure and function that have discoverable causes. We will couple this clinical expertise with advanced molecular and histopathologic methods to identify new AMD genes and to better understand the disease mechanisms of AMD genes that have been previously discovered. In aim 1, we will identify novel AMD loci and locus-specific AMD phenotypes by correlating the genotypes of well-characterized AMD patients and human eye donors with their ophthalmoscopic and/or histopathologic findings. In aim 2, we will identify new AMD-causing genes and new AMD-causing mutations in known AMD genes by using a novel implementation of pyrophosphate DNA sequencing to screen 13 known AMD genes and 37 candidate AMD genes for disease-causing variations. The entire coding sequence and proximal promoter of these genes will be sequenced in 400 AMD patients and 400 aged control individuals using a novel implementation of pyrophosphate sequencing. Variations found to be significantly skewed in patients or controls will be validated by assaying them in a second cohort of 400 AMD patients and 400 controls. In aim 3, we will investigate the pathophysiologic mechanisms of AMD by characterizing retinal and RPE/choroid gene expression in human donor eyes with both high risk and low risk AMD genotypes. Specifically, for each of five different AMD loci, we will analyze the retinal and RPE/choroidal RNA of five human eye donors who are homozygous for the high-risk genotype and compare these results to those obtained from five donors who are homozygous for the low-risk genotype. These studies will provide new insight into the pathophysiologic mechanisms of AMD that will be valuable for the development of more specific diagnostic methods and more effective therapies. PUBLIC HEALTH RELEVANCE: Age-related macular degeneration (AMD) is the most common cause of blindness in the developed world and this disease is often caused by mutations in genes. In this research study we will discover new genes and new disease-causing mutations that cause AMD. We will also investigate the mechanism by which genetic mutations cause AMD so that more specific diagnostic methods and better treatments can be developed.