TORSIN GENE FAMILY AND DYSTONIA AND MODIFYING GENES

早发性扭转肌张力障碍是一种遗传性运动障碍 常染色体显性方式，外显性降低，其特征是 通过扭转肌肉痉挛。症状被认为是由 基底节异常。这种疾病的基因DYT1具有 最近被我们的团队克隆，并被证明含有3-bp的缺失 (GAG)，去除保守区域中的谷氨酸，该区域唯一 与影响状态相关联。此外，该基因与 另外三个高度同源的人类基因(TORB、TRP1、Trp2)。这 该提案旨在描述DYT1基因及其近亲的特征， 确定可能影响外显性的遗传因素 疾病，并为这种疾病产生一个真正的小鼠模型。这个 将全面描述DYT1和TORB基因的基因组结构 使高效的突变筛查、抗体生产和 与其他岩芯和项目一起进行生化分析 在这个节目中。TRP1和Trp2基因将从cDNA中分离出来 文库及其表达模式和染色体定位 确定并扫描是否涉及其他形式的肌张力障碍 非9q34连锁家系的连锁分析。如有根据，单项- 链构象多态性分析(SSCP)和直接测序 的RNA/PCR产物将被用来检测这些基因的突变。 受影响的基因改变了导致GAG缺失的表达 在运营商之间外显率降低的高水平(60%-70%) 突变的可能性。各种候选基因将首先被筛选出来， 如有必要，我们将进行全基因组扫描。我们还提议 产生携带DYT1基因的靶向转基因小鼠 通过以下方式将Gag缺失引入内源性小鼠基因座 ES细胞中的同源重组。这些动物将被分析 神经形态和行为表型。这项研究建议 这应该有助于阐明谷氨酸残基的缺失是如何导致 早发性肌张力障碍及其可能改变的遗传因素 表情。这些知识应该会使我们更好地理解 基底节功能和可能的治疗干预措施 导致较温和的表型。

Early onset torsion dystonia is movement disorder inherited in an autosomal dominant manner with reduced penetrance, that is characterized by twisting muscle contractures. Symptoms are believed to result from abnormality in the basal ganglia. The gene for this disorder, DYT1 has recently been cloned by our group and shown to contain a 3-bp deletion (GAG), removing a glutamic acid in a conserved region that is uniquely associated with affect status. In addition, this gene is related to three other highly homologous human genes (TORB, TRP1, TRP2). This proposal is aimed at characterizing the DYT1 gene and its relatives, determining genetic factors that may influence the penetrance of the disease, and generating an authentic murine model for the disorder. The genomic structure of the DYT1 and TORB genes will be fully characterized making possible efficient mutation screening, antibody production, and biochemical analyses in conjunction with the other cores and projects in this program. The TRP1 and TRP2 genes will be isolated from cDNA libraries, their expression patterns and chromosomal locations determined and scanned for involvement in other forms of dystonia using linkage analysis in non-9q34 linked families. If warranted, single- stranded conformation polymorphism analysis (SSCP) and direct sequencing of RNA/PCR products will be used to detect mutations in these genes. Affected genes which modify the expression of the GAG deletion resulting in the high level (60-70 percent) of reduced penetrance among carriers of the mutation. Various candidate genes will be screened first then, if necessary, we will proceed to a full genome scan. We also propose to generate targeted transgenic mice where the mouse DYT1 gene harboring the GAG deletion is introduced into the endogenous mouse locus by homologous recombination in ES cells. These animals will be analyzed for neuromorphological and behavioral phenotypes. The studies proposed here should help to elucidate how the deletion of a Glu residue causes early onset dystonia and the genetic factors that may modify its expression. This knowledge should lead to a better understanding of basal ganglia function and possible therapeutic interventions that could result in milder phenotypes.