CLONING THE MCRD1 GENE--NORTH CAROLINA MACULAR DYSTROPHY

描述(摘自申请者的摘要)：Stargardt病基因最近的成功表明，一种罕见的黄斑疾病可以导致对常见的老年性黄斑变性(AMD)的深入了解。持续的进步和成功也将带来对黄斑功能和功能障碍以及AMD的更好的理解。北卡罗来纳州黄斑营养不良症(North Carolina macular dystrophy，MCDR1)是一种先天性黄斑营养不良症，1992年Small等人将其定位于6号染色体。最初(先前)提案的主要目标是对MCDR1基因进行精细定位和克隆。除了实际鉴定MCDR1基因和鉴定突变外，所有这些先前的目标都已经实现(S)。目前的提议将通过继续正在进行的位置克隆战略努力来实现这一点。具体目标1是继续确定北卡罗来纳州黄斑营养不良(MCDR1)家系，以试图进一步缩小遗传间隔。目前的间隔已被调查者的实验室缩小到600kb。具体目标2是继续鉴定和鉴定MCDR1候选基因。该小组最近从基因组区域内的PAC(P1人工染色体)中确定了27个新的候选基因。具体目的3是对MCDR1家族中的这些基因进行突变筛查。这将主要通过蛋白质截断测试(PTT)(如果片段大小为300-1000个核苷酸)或单链构象多态(SSCP)如果片段小于300个核苷酸来实现。如果在这些候选基因中没有发现突变，将识别更多的基因并确定其优先顺序。具体目的4：一旦鉴定出MCDR1基因，将对AMD患者进行MCDR1基因突变筛查，以评估其在AMD中的作用以及该突变在普通人群中的流行情况。预计三年内实现上述具体目标。然而，由于MCDR1基因的鉴定时间很难预测，因此讨论了这一提议的未来目标，以防该基因更早被发现。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包括AMD在内的黄斑疾病。最后，将创建转基因、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.