Molecular Genetics of Age Related Macular Degeneration

描述（由申请人提供）：视网膜相关性黄斑变性（AMD）是发达国家严重视力丧失的最常见原因，仅在美国就影响了1000多万人。75岁以上的人中约有三分之一受到一定程度的影响。这种疾病的很大一部分是遗传性的。在这项研究中，我们将利用这样一个事实，即经验丰富的临床医生可以可靠地识别具有可解释原因的异常结构和功能的模式。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结合起来，以识别新的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，我们将通过将特征良好的AMD患者和人眼供体的基因型与他们的检眼镜和/或组织病理学发现相关联来鉴定新的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DNA测序的新实施来筛选13个已知AMD基因和37个候选AMD基因的致病变异，从而在已知AMD基因中鉴定新的AMD致病基因和新的AMD致病突变。这些基因的整个编码序列和近端启动子将在400名AMD患者和400名老年对照个体中使用焦磷酸测序的新实现进行测序。在患者或对照组中发现的显著偏斜的变化将通过在400名AMD患者和400名对照的第二队列中测定它们来验证。在目标3中，我们将通过表征具有高风险和低风险AMD基因型的人供体眼中视网膜和RPE/脉络膜基因的表达来研究AMD的病理生理机制。具体而言，对于五个不同的AMD基因座中的每一个，我们将分析五个高风险基因型纯合的人眼供体的视网膜和RPE/脉络膜RNA，并将这些结果与从五个低风险基因型纯合的供体获得的结果进行比较。这些研究将为AMD的病理生理机制提供新的见解，这将对开发更特异的诊断方法和更有效的治疗方法具有价值。

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.