ISOLATION OF THE HUNTINGTON'S DISEASE GENE

这项建议的长期目标是了解 遗传性神经病学的分子和生化基础 亨廷顿病(HD)。就像大多数人一样 遗传性神经疾病，对 HD的生化基础或受影响基因的性质。这个 只有真正了解疾病并发展的希望 有效的治疗方法，是分离和表征正常和 有缺陷的等位基因。这个项目的主要目标是分离出 HD基因，采用反向遗传策略。 远端有大量的单拷贝DNA片段 4号染色体短臂的一部分，也就是 HD基因已定位，已分离，将进行区域定位 使用体细胞杂交，并用来汇编长距离 人类基因组DNA的几百万个碱基对的限制图 HD基因。距离较近且位于相反两边的DNA片段 将使用几种方法来鉴定HD基因。单人 复制跨越包含HD基因的区域的DNA片段 将被分析以确定哪些代表部分 表达的基因以及是否有检测到的DNA序列 先天性巨结肠症患者的重组。基因组和cdna克隆 代表HD基因附近的表达基因将 检查以确定它们的表达和/或结构是否 在患有这种疾病的患者身上发生了变化。如果发现了这样的变化， 候选基因将从基因组DNA文库中分离出来 与HD患者的结构和序列进行比较 来自未受影响个体的相应基因。 HD基因的分离及其功能的研究 将提供100%准确的临床前诊断能力 这种起病年龄较晚的疾病，很可能导致 开发有效的治疗方法来预防或延迟发病 症状。

The long term objective of this proposal is to understand the molecular and biochemical basis for the inherited neurological disorder, Huntingtons Disease (HD). As in the case with most inherited neurologic disorders, nothing is known about the biochemical basis of HD or the nature of the affected gene. The only real hope of understanding the disease and developing effective therapies, is to isolate and characterize the normal and defective alleles. The major aim of this project is to isolate the HD gene, using the strategy of reverse genetics. A large number of single copy DNA fragments from the distal portion of the short arm of chromosome 4, the region where the HD gene is located, have been isolated, will be regionally mapped using somatic cell hybrids, and used to compile a long range restriction map of several million base pairs of DNA around the HD gene. DNA fragments that are close to, and on opposite sides of the HD gene will be identified using several approaches. Single copy DNA fragments spanning the region containing the HD gene will be analyzed to determine which represent portions of expressed genes and whether any detect DNA sequence rearrangements in patients with HD. Genomic and cDNA clones representing expressed genes in the vicinity of the HD gene will be examined to determine if their expression and/or structure is altered in patients with the disease. If such alterations are found, the candidate gene will be isolated from genomic DNA libraries from and HD patient and the structure and sequence compared to the corresponding gene from unaffected individuals. The isolation of the HD gene and an understanding of its function will provide the capability for 100% accurate preclinical diagnosis of this late age of onset disorder and may well lead to the development of effective therapies to prevent or delay onset of symptoms.