Genetics of Congenital Obstructive Uropathy

描述（由申请人提供）：先天性肾脏和尿路异常（CAKUT）占全球儿童终末期肾衰竭的40-50%。在CAKUT分类中，先天性梗阻性尿路病是一种常见且严重的畸形形式。先天性肾积水是产前超声检查发现的最常见的泌尿道异常，发生率高达2%。先天性梗阻性尿路病可以是家族性或散发性疾病，具有高度可变的表型表达。由于缺乏对原发性发病机制的基本认识，诊断和治疗选择受到严重限制。我们最近在斑马鱼中实施了与功能建模相结合的全外显子组测序，以在高达2.3%的患有先天性阻塞性尿路病和相关尿路畸形的患者中鉴定DSTYK中的显性突变（Sanna-Cherchi等人，New Engl J Med 2013）。由DSTYK编码的蛋白质在肾发生期间充当成纤维细胞生长因子（FGF）信号传导的正调节剂。这项研究说明了在动物模型中将全外显子组测序与功能建模相结合的能力，以鉴定以高遗传异质性、不完全突变、可变表型表达和小/中等谱系大小为特征的性状中的新型致病突变。在这里，我们建议在胚胎发育和肾发生在细胞培养和小鼠模型窝藏Dstyk突变的功能的特点，我们的基因鉴定工作扩展到50个额外的家庭与常染色体显性遗传先天性梗阻性尿路病和斑马鱼进行功能建模，以确定新的易感基因。这项研究将提供深入了解人类和动物模型先天性梗阻性尿路病的发病机制，并将有助于开发新的诊断和治疗策略。

DESCRIPTION (provided by applicant): Congenital Anomalies of the Kidney and the Urinary Tract (CAKUT) account for 40-50% of pediatric end-stage kidney failure worldwide. Among CAKUT categories, congenital obstructive uropathy represents a common and severe form of malformation. Congenital hydronephrosis is the most frequent anomaly of the urinary tract detected by prenatal ultrasound, occurring in up to 2% of normal pregnancies. Congenital obstructive uropathy can occur as familial or sporadic disease with highly variable phenotypic expression. Due to paucity of fundamental insight about primary pathogenesis, diagnostic and therapeutic options are severely limited. We recently implemented whole exome sequencing combined to functional modeling in zebrafish to identify dominant mutations in DSTYK in up to 2.3% of patients with congenital obstructive uropathy and associated urinary tract malformations (Sanna-Cherchi et al, New Engl J Med 2013). The protein encoded by DSTYK acts as a positive regulator of fibroblast growth factor (FGF) signaling during nephrogenesis. This study illustrates the power of combining whole exome sequencing with functional modeling in animal models to identify novel disease causing mutations in traits characterized by high genetic heterogeneity, incomplete penetrance, variable phenotypic expression, and small/medium pedigree size. Here we propose to characterize the function of DSTYK during embryonic development and nephrogenesis in cell cultures and in mouse models harboring Dstyk mutations, to extend our gene identification effort to 50 additional families with autosomal dominant congenital obstructive uropathy and to perform functional modeling in zebrafish to identify novel susceptibility genes. This study will provide insight into the pathogenesis of congenital obstructive uropathy in humans and animal models and will help develop new diagnostic and therapeutic strategies.