TORSIN GENE FAMILY AND DYSTONIA AND MODIFYING GENES

早发性扭转性肌张力障碍是一种遗传性运动障碍， 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， 与情感状态有关。 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 DYT 1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， 与其他核心和项目一起进行生化分析 在这个项目中。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连锁家系的连锁分析。 如果有正当理由，单身- 单链构象多态性分析（SSCP）和直接测序 将使用RNA/PCR产物检测这些基因中的突变。 改变GAG缺失表达的受影响基因， 在高水平（60- 70%）的减少携带者中， 变异的原因然后将首先筛选各种候选基因， 如果有必要，我们将进行全基因组扫描。 我们亦建议 以产生靶向转基因小鼠，其中携带小鼠DYT 1基因的小鼠 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 用于神经形态和行为表型。 建议的研究 这将有助于阐明Glu残基的缺失如何导致 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 基底神经节功能和可能的治疗干预， 导致更温和的表型。

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.