MOLECULAR DISSECTION OF THE WILLIAMS SYNDROME DELETION

描述（改编自研究者摘要）：威廉姆斯综合征 (WS)是一种血管、结缔组织、内分泌 和中枢神经系统表现。 WS是由部分 染色体带7q11.23缺失，涉及弹性蛋白基因， 估计在1到3 Mb之间。 表型的复杂性和 缺失的大小表明， 基因有待鉴定。 删除区域将被物理定义 通过脉冲场凝胶电泳作图和YAC，P1， 使用STS内容映射的PAC、BAC和粘粒克隆。 亲和捕获， 外显子捕获、CpG岛克隆和cDNA文库筛选将用于 找出缺失的新基因。 将确定功能域 通过数据库，序列同源性和表达模式将通过 北方印迹和RT-PCR。 新的基因被怀疑在调节 在发育中的作用或具有中枢神经系统或内分泌系统 函数将作为详细研究的目标，包括获得 全长cDNA序列和基因组结构，鉴定和定位 小鼠同源物及胚胎组织和小鼠的原位杂交 胚胎 微缺失的大小与临床的关系 表型将通过微卫星标记检测患者进行检查， WS的可变表达。 基因组上的缺失将通过表达研究来研究， 未缺失的等位基因和邻近基因。 基因相互作用模型 包括多个基因缺失的累加效应， 对染色体结构的长期影响超出了删除， 印记 缺失形成的分子机制将是 研究了 低拷贝数重复序列侧翼的假设， 缺失区域和诱发减数分裂重组中的错误将是 通过克隆常见断点进行测试。 的标识 单倍不足导致WS表型的基因，它们的相互作用 和对非缺失基因的影响，并检测其机制 删除的形成将对新的发展产生影响， 治疗方式，以及提供洞察正常人 发展过程。

DESCRIPTION (Adapted from the Investigator's Abstract): Williams syndrome (WS) is a developmental disorder with vascular, connective tissue, endocrine and central nervous system manifestations. WS is caused by a partial deletion of chromosome band 7q11.23 that involves the elastin gene and is estimated to be between 1 and 3 Mb in size. Complexity of the phenotype and size of the deletions suggest the pathogenetic involvement of contiguous genes yet to be identified. The deletion region will be physically defined by pulsed-field gel electrophoresis mapping and contig building of YAC, P1, PAC, BAC and cosmid clones using STS content mapping. Affinity capture, exon trapping, CpG island cloning and cDNA library screening will be used to identify new genes in the deletion. Functional domains will be identified by database sequence homology and expression patterns will be determined by Northern blotting and RT-PCR. Novel genes suspected of playing a regulatory role in development or of having a central nervous system or endocrine function will be targeted for detailed study, to include obtaining full-length cDNA sequence and genomic structure, identifying and mapping the mouse homologue and in situ hybridization on fetal tissues and mouse embryos. The relationship between size of the microdeletion and clinical phenotype will be examined by microsatellite marker testing of patients with variable expression of WS. Cis- and trans-acting regulatory effects of the deletion on the genome will be investigated through expression studies of the non-deleted alleles and neighboring genes. Models of gene interaction to be evaluated include additive effects of the loss of multiple genes, long-range effects on chromatin structure beyond the deletion, and gametic imprinting. The molecular mechanisms underlying deletion formation will be investigated. The hypothesis of low-copy number repeats flanking the deletion region and predisposing to errors in meiotic recombination will be tested through cloning of the common breakpoints. The identification of the genes whose haploinsufficiency underlies the WS phenotype, their interaction and effects on non-deleted genes, and detection of the mechanism underlying deletion formation will have implications for the development of new therapeutic modalities as well as provide insight into normal human developmental processes.