Nonrecurrent rearrangements, genome architecture and neurodegenerative disease.

在过去的15年中，许多神经系统疾病的特征不是基因内编码区突变的结果，而是由于基因组的改变而表现出来。由于基因组重排引起的疾病被称为基因组疾病。在后基因组时代，随着通过比较基因组杂交（aCGH）和其他阵列技术的高分辨率基因组分析的广泛临床应用，亚显微重排越来越被认为是神经系统疾病的原因。基因组重排可以是复发性的，具有固定的基因组断裂点位置，或者是非复发性的，大小不同，具有不同的断裂点，但在不相关的患者中共享特定基因组间隔的最小重叠区域（SRO）。我们假设非复发性 重排可能通过不同于已确立的重组机制的机制发生，我们的初步研究强烈支持这一假设。此外，我们认为，一些非经常性的重排可能会导致由于特定的基因组结构特征，造成这种重排的易感性。我们将通过以下实验来研究这些假设：1）绘制重复重排的断点，2）进行重排的基因组区域的生物信息学分析，3）通过直接DNA测序确定重组产物。与Potocki-Lupski综合征（PTLS）相关的非复发性17 p重复。与CMT 1A或HNPP神经病变相关的非复发性PMP 22重排将被详细研究。我们将以这种方式 确定重组的底物，深入了解基因组结构和相关区域，并可能推断机制。提出了三个具体的目标：（1）确定与Potocki-Lupski综合征相关的17号染色体近端短臂重复的大小和断点连接：（2）仔细检查Potocki-Lupski综合征患者的三个非复发性重复，以确定起源的父母，以及发生从头重复的父母染色体的结构;和（3）从通过多重连接依赖性探针扩增（MLPA）筛选复发性CMT 1A重复和HNPP缺失的神经病患者的大队列中，鉴定不具有通常复发性CMT 1A重复或HNPP缺失的那些患者，并通过aCGH检查这种非复发性重排的结构，并确定断点处的序列 交叉点我们的发现将对这些和其他可能由基因拷贝数变异（CNV）引起的神经退行性疾病具有广泛的诊断和治疗意义。

It has become apparent during the last 15 years that many neurological disease traits are not the result of coding region mutations within genes, but instead manifest because of alterations of the genome. Diseases due to genomic rearrangements have been referred to as genomic disorders. In the post-genomic era, with widespread clinical application of high-resolution genome analyses by comparative genome hybridization (aCGH) and other array technologies, submicroscopic rearrangements are increasingly being recognized as a cause of neurologic disease. Genomic rearrangements can be recurrent with fixed positions for genomic breakpoints or nonrecurrent varying in size and with different breakpoints, but sharing a Smallest Region of Overlap (SRO) of a specific genomic interval among unrelated patients. We hypothesize that nonrecurrent rearrangements may occur by mechanisms that are distinct from well-established recombination mechanisms and our PRELIMINARY STUDIES strongly support this hypothesis. Furthermore, we suggest that some nonrecurrent rearrangements may result because of specific genomic architectural features causing susceptibility to such rearrangements. We will investigate these hypotheses experimentally by: 1) mapping breakpoints of duplication rearrangements, 2) bioinformatic analyses of the genomic region undergoing rearrangement, and 3) determining the products of recombination through direct DNA sequencing. Non recurrent duplication of 17p associated with Potocki-Lupski Syndrome (PTLS). and non recurrent PMP22 rearrangements associated with CMT1A or HNPP neuropathy will be studied in detail. In this manner we will identify the substrates for recombination, gain insights into genome architecture and regions involved, and potentially infer mechanism. Three specific aims are proposed: (1) Determine the sizes and breakpoint junctions of duplications of the proximal short arm of chromosome 17 associated with the Potocki-Lupski syndrome; (2) Carefully examine trios of patients with Potocki-Lupski syndrome who have nonrecurrent duplications to determine parent of origin, and structure of the parental chromosome on which the de novo duplication occurred; and (3) From a large cohort of patients with neuropathy who are screened for the recurrent CMT1A duplication and HNPP deletion by multiplex ligation- dependent probe amplification (MLPA) identify those that DO NOT have the usual recurrent CMT1A duplication or HNPP deletion and examine the structure of such nonrecurrent rearrangements by aCGH and determine the sequence at the breakpoint junctions. Our findings will have widespread diagnostic and therapeutic implications for these and other neurodegenerative diseases that can result from gene copy number variation (CNV).