Genomic Analysis of Parkinson's Disease

 描述（由申请方提供）：帕金森病（PD）是一种成年发作的黑质神经退行性疾病，特征为静息性震颤、运动迟缓、肌肉强直和姿势不稳定。PD的全球患病率估计为100-200例/100，000，是神经退行性疾病的第二大常见原因。虽然大多数PD病例被认为是散发性的，但大约10-20%是家族性的。不幸的是，据估计，迄今为止，家族性PD的潜在遗传原因只有约30-40%得到了解释。孟德尔疾病致病突变的鉴定对于我们理解其发病机制至关重要。连锁分析与外显子组测序技术相结合已被证明是一种有效的策略，以快速确定新的致病基因在受影响的家庭。然而，这种方法可能难以应用于迟发性疾病，如PD和肌萎缩性侧索硬化症（ALS），由于寻找大的信息多代家系的内在困难。最近，我们开发了一种方法，通过使用索引家族病例（即每个家族一个受影响的成员）的外显子组测序结果，在无偏见的全基因组罕见变异分析中识别因果突变，并成功地确定了一个新的致病基因为家族性ALS。在这里，我们建议将这种方法应用于鉴定家族性PD的新致病基因。本提案的具体目标是：（1）新的候选致病家族性PD基因的发现将对研究者和Coriell研究所收集的约1，200份索引家族性PD样本进行外显子组测序。这些外显子组将在无偏见的全基因组罕见变异分析中与超过9，000个对照外显子组进行比较，以识别新的候选致病基因。（2.）致病性家族性PD基因的验证/复制。将通过检测受影响家族成员的分离和对二级对照组进行基因分型，进一步评价最佳候选基因/变体。将排除未正确分离或在对照中以显著百分比存在的变体，并重新评价相应基因的致病性质。将在405例家族性和302例散发性PD病例的复制组中对剩余基因进行测序，以评价这些基因突变的患病率。（3.）致病性家族性PD突变的功能分析将通过使用几种模型系统来评估鉴定的突变的功能后果。将使用已建立的测定法研究突变在诱导多能干细胞、果蝇和酵母模型中的致病作用。我们相信，该项目将导致发现一个或多个新的致病基因的PD。其他致病基因的鉴定将导致对导致这种毁灭性疾病的缺陷的更多了解，并为PD科学界开辟新的研究途径以及开发新的治疗靶点。

 DESCRIPTION (provided by applicant): Parkinson's disease (PD) is an adult-onset neurodegenerative disease of the substantia nigra characterized by resting tremor, bradykinesia, muscular rigidity and postural instability. The worldwide prevalence of PD is estimated at 100-200 cases per 100,000 and represents the second most common cause of neurodegenerative disease. Although most PD cases are considered sporadic, approximately 10-20% are familial in nature. Unfortunately, it is estimated that only ~30-40% of the underlying genetic causes of familial PD have been explained to date. The identification of causative mutations for Mendelian disorders is critical for our understanding of their pathogenesis. The combination of linkage analysis with exome sequencing techniques has proven to be an effective strategy to rapidly identify novel causative genes in affected families. However, this methodology can be difficult to apply to late-onset diseases such as PD and amyotrophic lateral sclerosis (ALS) due to the intrinsic difficulties of finding large informative multi-generational pedigrees. Recently, we have developed a methodology to identify causal mutations by using exome sequencing results of index familial cases (i.e. one affected member per family) in an unbiased genome-wide rare variant analysis and successfully identified a novel causative gene for familial ALS. Here we propose to apply this approach towards the identification of novel causal genes for familial PD. The Specific Aims of this proposal are: (1.) Discovery of Novel Candidate Causal Familial PD Genes. Approximately 1,200 index familial PD samples collected by the Investigators and Coriell Institute will be exome sequenced. The exomes will be compared to over 9,000 control exomes in an unbiased genome-wide rare variant analysis to identify novel candidate causal genes. (2.) Validation/Replication of Causal Familial PD Genes. Top candidate genes/variants will be further evaluated by testing for segregation in affected family members and genotyping a secondary panel of controls. Variants that do not segregate properly or are present at a signification percentage in controls will be excluded and the causative nature of the corresponding gene will be re-evaluated. Remaining genes will be sequenced in a replication panel of 405 familial and 302 sporadic PD cases to evaluate the prevalence of mutations in these genes. (3.) Functional Analysis of Causative Familial PD Mutations. The functional consequences of identified mutations will be evaluated though the use of several model systems. The pathogenic effect of the mutations in induced pluripotent stem cells, Drosophila and yeast models will be studied using established assays. We are confident that the proposed project will lead to the discovery of one or more novel causative genes for PD. The identification of additional causative genes will lead to an increased knowledge of the defects contributing to this devastating disease and open new avenues of research for the PD scientific community as well as the development of new therapeutic targets.