CLONING THE MCRD1 GENE--NORTH CAROLINA MACULAR DYSTROPHY

描述（改编自申请人摘要）：最近对Stargardt病基因的成功研究表明，一种罕见的黄斑疾病如何导致对常见的老年性黄斑变性（AMD）的深入了解。这一承诺的持续进展和成功也将导致更好地了解黄斑功能和功能障碍以及AMD。北卡罗莱纳黄斑营养不良症（MCDR1）是一种先天性黄斑营养不良症，由Small等人于1992年通过连锁定位到6号染色体。最初（先前）提议的主要目标是针对MCDR1基因的精细定位和克隆。除了MCDR1基因的实际鉴定和突变的鉴定外，所有这些先前的目标都已实现。目前的提案将通过继续使用位置克隆策略来实现这一目标。具体目标1是继续确定北卡罗莱纳黄斑营养不良（MCDR1）家族，以便进一步缩小遗传间隔。研究者的实验室已经将当前的间隔缩小到600 kb。具体目标2是继续鉴定和表征MCDR1候选基因。该小组最近从他们的基因组区域的PACs （P1人工染色体）中确定了27个新的候选基因。具体目标3是在MCDR1家族中对这些基因进行突变筛选。如果片段大小为300-1,000 bp，则主要通过蛋白质截断测试（PTT）或片段小于300 bp的单链构象多态性（SSCP）来完成。如果在这些候选基因中没有发现突变，则将识别并优先考虑其他基因。具体目标4：一旦MCDR1基因被确定，AMD患者将被筛查MCDR1基因的突变，以评估其在AMD中的作用以及该突变在普通人群中的流行程度。预计上述具体目标将在三年内实现。然而，由于MCDR1基因的鉴定时间难以预测，因此讨论了该基因发现的未来目标。这些未来的目标和方向是确定MCDR1的功能，并确定与MCDR1基因产物相互作用的其他蛋白质，因为它们也可能参与黄斑疾病，包括AMD。最后，将创建转基因、敲除和敲入小鼠，以更好地了解MCDR1的功能，并为未来的治疗尝试创建动物模型。

DESCRIPTION (Adapted from applicant's abstract): The recent success with the Stargardt disease gene shows how a rare macular disease can lead to insight into the common age-related macular degeneration (AMD). This promise that continued progress and success will also lead to a better understanding of macular function and dysfunction as well as AMD. North Carolina macular dystrophy (MCDR1) is a congenital macular dystrophy that was mapped by linkage to chromosome 6 in 1992 by Small et al. The major goals from the original (previous) proposal were directed towards the fine mapping and cloning of the MCDR1 gene. All of these previous goals have been achieved except for the actual identification of the MCDR1 gene and identification of the mutations(s). The current proposal will accomplish this by continuing the ongoing efforts with positional cloning strategies. Specific aim 1 is to continue to ascertain North Carolina macular dystrophy (MCDR1) families in order to try to narrow the genetic interval even further. The current interval has been narrowed to 600 kb by the investigator's laboratory. Specific aim 2 is to continue the identification and characterization of the MCDR1 candidate genes. The group has recently identified 27 new candidate genes from their PACs (P1 artificial chromosomes) within the genomic region. Specific aim 3 is to perform mutations screening of these genes in MCDR1 families. This will be accomplished primarily by protein truncation testing (PTT) if the fragments are 300-1,000 bp in size or by single strand conformation polymorphism (SSCP) if the fragment is less than 300 bp. If no mutations are found in these candidate genes, additional ones will be identified and prioritized. Specific aim 4: Once the MCDR1 gene is identified, AMD patients will be screened for mutations in the MCDR1 gene in order to evaluate its role in AMD and the prevalence of the mutation in the general population. It is expected that the above specific aims will be accomplished within three years. However, because the timing of the identification of the MCDR1 gene is difficult to predict, the future aims of this proposal are discussed in case the gene is found sooner. These future aims and directions are to determine the function of the MCDR1 and to identify other proteins that interact with the MCDR1 gene product since they may also be involved in macular diseases including AMD. Finally, a transgenic, a knockout, and a knock in mouse will be created to better understand MCDR1 function and to create an animal model for future therapeutic attempts.