Discover and functionally characterize full-penetrance causes of nephrosis/FSGS

描述(由申请人提供)：发现肾病/FSGS的完全外显性原因并从功能上描述其特征。慢性肾脏疾病(CKD)是危害人类健康的最高疾病之一，其患病率在近20年来一直在上升。肾病综合征(NS)的定义是明显的蛋白尿，导致低蛋白血症和水肿。它是儿童和年轻人CKD的第二大常见原因，根据对标准化类固醇治疗的反应被归类为“类固醇敏感”(SSNS)和“类固醇抵抗”(SRNS)。SRNS具有局灶节段性肾小球硬化(FSGS)的肾脏组织学特征，不可避免地导致CKD。FSGS在肾移植中有33%的复发风险，导致CKD复发。由于SRNS的发病机制尚不清楚，目前尚无根治性治疗方法。对于SRNS来说，主要原因(病因学)和疾病机制(发病机制)几十年来一直是一个难题。然而，对NS的全外显单基因致病因素(如足)的基因鉴定表明，肾小球足细胞是SRNS发病机制趋同的细胞类型。在之前的资助期间，我们定义了允许对SRNS变异进行预后分类的基因-表型相关性。更重要的是，通过发现PLCE1和COQ6基因的突变，我们通过基因图谱确定了可能适合特定治疗的NS的新的罕见单基因原因。我们现在建立了一种新的方法，即完整外显子组捕获(WEC)和下一代重测序，将其与先前的纯合性图谱(HM)相结合，以缓解其他强大的WEC方法的弱点。我们在全球67例SRNS/SSNS同胞病例队列中定位了隐性NS候选基因座。在这个队列中，我们最近发现CUBN和ARHGDIA的HM、WEC和MPS突变是SRNS的新的单基因原因，而EMP2突变是SSNS的第一个公认的原因。我们还在斑马鱼和小鼠身上建立了疾病模型(Coq6)，我们将利用这些模型对SRNS的单基因病因进行治疗性研究。因此，我们将追求以下具体目标(SA)：SA1。通过完整外显子捕获(WEC)和下一代重测序，利用现有的纯合性图谱(HM)数据，在&gt；67同胞对中发现新的单基因肾病病因。Sa 2.对新发现的SRNS/SSNS的单基因病因进行功能表征，以阐明其发病机制。对于新发现的SRNS/SSNS基因，研究斑马鱼和小鼠模型中的基因功能和治疗方法，包括Coq6-/-。

DESCRIPTION (provided by applicant): Discover and functionally characterize full-penetrance causes of nephrosis/FSGS. Chronic kidney diseases (CKD) take one of the highest tolls on human health, and their prevalence has been rising in the last 20 years. Nephrotic syndrome (NS) is defined by significant proteinuria, resulting in hypoalbuminemia and edema. It constitutes the second most frequent cause of CKD in children and young adults and is classified by response to a standardized steroid therapy as "steroid-sensitive" (SSNS) vs. "steroid-resistant" (SRNS). SRNS, with the renal histology of focal segmental glomerulosclerosis (FSGS), inevitably leads to CKD. FSGS carries a 33% risk of relapsing in a kidney transplant, causing recurrence of CKD. Since the pathogenesis of SRNS is unknown, no curative treatment is available. For SRNS, the primary causes (etiology) and disease mechanisms (pathogenesis) have been a conundrum for decades. However, gene identification of full-penetrance single-gene causes of NS (e.g. podocin) has identified the renal glomerular podocyte as the cell type at which disease mechanisms of SRNS converge. Within the previous funding period we defined genotype-phenotype correlations that allow for prognostic classification of SRNS variants. More importantly, by discovering mutations in the genes PLCE1 and COQ6, we identified by genetic mapping novel rare single-gene causes of NS that may be amenable to specific treatment. We now established a new approach of whole exome capture (WEC) and NextGen resequencing, combining it with prior homozygosity mapping (HM) to mitigate the weaknesses of the otherwise powerful WEC approach. We mapped recessive NS candidate loci in a worldwide cohort of 67 sibling cases with SRNS/SSNS. In this cohort, very recently, we identified by HM, WEC and MPS mutation of CUBN and ARHGDIA as novel single-gene causes of SRNS, and mutation of EMP2 as the first recognized cause of SSNS. We also established disease models in zebrafish and mice (for Coq6), which we will use for therapeutic studies on single-gene causes of SRNS. We, therefore will pursue the following specific aims (SAs): SA1. Discover novel single-gene causes of nephrosis by whole exome capture (WEC) and NextGen resequencing in >67 sib pairs with existing homozygosity mapping (HM) data. SA 2. Functionally characterize newly identified single-gene causes of SRNS/SSNS to delineate the pathogenesis. SA 3. For newly identified SRNS/SSNS genes study the gene function and therapeutic approaches in zebrafish and mouse models, including Coq6-/-.