Genomics of mammalian posterior urethral valves

后尿路瓣膜(PUV)是男性儿童下尿路梗阻的主要原因。 占儿童终末期肾病的17%。尽管疾病的严重性及其对 死亡率和发病率，这种情况的分子基础在很大程度上是未知的，导致次优 诊断和治疗策略。该病的流行病学，以高选择性为特征 压力与适合度低的表型，表明显性从头突变或隐性突变 遗传在疾病决定中起着重要作用。 这项建议代表了我们奥布莱恩泌尿外科中心的一个试点项目的自然延续 目的确定后尿道瓣(PUV)的遗传易感因素。我们的中央 假说是罕见的变异对表型有很大的影响，是遗传结构的基础 PUV，并将高通量基因组研究与两种疾病小鼠模型的分析相结合 导致了新的疾病基因的识别。我们使用外显子组和基因组测序的初步数据， 在脊椎动物中的CNV分析和功能建模有力地表明我们可以成功地识别新的 影响规模大的基因组变异，即使在复杂的遗传结构和高遗传的情况下也是如此 异质性。特别是，通过研究大量PUV患者的CNV，我们发现了不同的新 PUV和下尿路畸形的候选基因。接下来，我们演示了小鼠的文字记录 其中一个候选基因Tbx6的剂量会导致高度渗透性发育不良和缺乏 类似于人类PUV的尿道化。同时，我们已经确定了一组基因，它们是 缺乏SALL1的小鼠突变中的失调，SALL1是一种转录因子，当在人类中突变时会引起 汤斯-布罗克斯综合征(TBS)，一种以各种畸形为特征的临床实体，包括肛门直肠 缺陷、PUV和尿道下裂。我们现在建议将我们的测序工作扩展到另外200个PUV三重奏， 并在一大群患者中复制研究结果，以确定新的基因。我们还将描述较低的 SALL1和Tbx6的尿路缺陷并生成完整的转录组数据集来识别下游 靶向并促进人类的基因识别。这项研究旨在解决慢性阻塞性肺疾病的分子病因 PUV，以改善对受这一严重疾病影响的儿童的诊断和个性化护理，并确定 可以接受治疗干预的途径。

Posterior urethral valves (PUV) are the major cause of lower urinary tract obstruction in male children and account for 17% of pediatric end-stage renal disease. Despite the severity of the disease and its impact on mortality and morbidity, the molecular basis of this condition is largely unknown, resulting in suboptimal diagnostic and therapeutic strategies. The epidemiology of the disease, characterized by high selective pressure versus a phenotype with low fitness, suggests that dominant de novo mutations or recessive inheritance play a major role in disease determination. This proposal represents the natural continuation of a Pilot project from our O'Brien Center of Urology and aims at the identification of the genetic susceptibility factors for posterior urethral valves (PUV). Our central hypothesis is that rare variants with large effect size on the phenotype underlie the genetic architecture of PUV, and that combining high-throughput genomic studies with analysis of two mouse models of disease will lead to the identification of novel disease genes. Our preliminary data using exome and geneome sequencing, CNV analysis, and functional modeling in vertebrate strongly indicate that we can successfully identify novel genomic variants with large effect size, even in scenario of complex genetic architecture and high genetic heterogeneity. In particular, by studying CNVs in a large cohort of PUV patient, we identified different novel candidate genes for PUV and lower urinary tract malformation. We next demonstrated that mouse transcript dosage of one of these gene candidates, Tbx6, results in highly penetrant maldevelopment and lack of canalization of urethra similar to human PUV. Simultaneously, we have identified a set of genes that are disregulated in mouse mutants lacking Sall1, a transcription factor that when mutated in humans causes Townes-Brocks Syndrome (TBS), a clinical entity characterized by different malformations, including anorectal defects, PUV, and hypospadias. We now propose to extend our sequencing effort to additional 200 PUV trios, and to replicate findings in a large cohort of patients to identify novel genes. We will also characterize the lower urinary tract defects of Sall1 and Tbx6 and generate whole transcriptome datasets to identify downstream targets and facilitate gene identification in humans. This study is designed to solve the molecular etiology of PUV, to improve diagnosis and individualized care for children affected by this severe condition, and to identify pathways that can be amenable to therapeutic interventions.