ROLE OF TORSIN GENE FAMILY IN DYSTONIA AND GENETIC DETERMINANTS OF PENETRANCE

早发性扭转性肌张力障碍是一种运动障碍， 常染色体显性遗传方式，其特征是 通过扭曲肌肉挛缩症状被认为是由于 基底神经节异常这种疾病的基因DYT 1 最近被我们的小组克隆，并显示含有3-bp缺失 (GAG)去除保守区域中的谷氨酸， 与受影响的状态有关。此外，该基因还与 其他三个高度同源的人类基因（TORB，TRP 1，TRP 2）。这 该提案旨在表征DYT 1基因及其亲属， 确定遗传因素，可能会影响的发病率， 疾病，并产生该病症的真实鼠模型。的 Dytl和TORB基因的基因组结构将被充分表征 使有效的突变筛选、抗体生产成为可能， 生物化学分析与其他核心和项目， 这个戒酒会这将从cDNA中分离TRP 1和TRP 2基因 文库，其表达模式和染色体位置确定 并扫描参与其他形式的肌张力障碍， 非9 q34连锁家族如果有保证，单股 构象多态性分析（SSCP）和RNA/PCR直接测序 这些产品将用于检测这些基因的突变。影响和 来自一组20个DYT 1连锁家族的未受影响的基因携带者将被 用于连锁研究，以确定修饰表达的基因， GAG缺失导致高水平（60-70%）的减少 突变携带者之间的遗传变异。各种候选基因将被 如果有必要的话，我们将进行全基因组扫描。 我们还提出产生靶向转基因小鼠，其中小鼠DYT 1 将携带GAG缺失的基因导入内源性小鼠 在ES细胞中同源重组。这些动物将 分析神经形态学和行为表型。研究 这里提出的建议应该有助于阐明如何删除Glu残基 导致早发性肌张力障碍和遗传因素，可能会改变其 表情这些知识应该有助于更好地理解基础 神经节功能和可能的治疗干预， 在温和的表型。

Early onset torsin dystonia is a 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, DYTl 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 affected status. In addition, this gene is related to three other highly homologous human genes (TORB, TRP1, TRP2). This proposal is aimed at characterizing the DYTl 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 Dytl 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 and non-9q34 linked families. If warranted, singled-stranded conformation polymorphism analysis (SSCP) and direct sequencing of RNA/PCR products will be used to detect mutations in these genes. Affected and unaffected gene carriers from a set of 20 DYTl linked families will be used in linkage studies to identify genes which modify the expression of the GAG deletion resulting in the high level (60-70%) 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 DYTl 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 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.