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

摘要早发性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 与受影响状态相关联。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 Dytl和TORB基因的基因组结构将得到充分描述 使高效的突变筛查、抗体生产和 与其他岩心和项目一起进行生化分析 这个节目。TRP1和Trp2基因将从cDNA中分离出来 文库，它们的表达模式和染色体位置确定 并使用LINK扫描是否涉及其他形式的肌张力障碍 分析和非9q34链接族。如果有必要，单人搁浅 构象多态分析(SSCP)和RNA/PCR直接测序 这些产品将被用于检测这些基因的突变。受影响和 来自20个DYT1连锁家系的未受影响的基因携带者将是 在连锁研究中用来识别改变其表达的基因 GAG缺失导致高水平(60%-70%)的还原 突变携带者之间的外显性。各种候选基因将会是 首先进行筛查，然后，如果有必要，我们将继续进行全基因组扫描。 我们还建议产生靶向转基因小鼠，其中小鼠DYT1 含有Gag缺失的基因被导入内源性小鼠 在ES细胞中通过同源重组定位。这些动物将成为 分析神经形态和行为表型。这些研究 在这里提出的建议应该有助于阐明Glu残基的删除如何 引起早发性肌张力障碍和可能改变其的遗传因素 表情。这些知识应该有助于更好地理解基本的 神经节功能和可能导致的治疗干预 在较温和的表型。

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.