Inherited aortic disease: identification of novel disease genes and functional analysis of the molecular pathogenesis

在西方国家，胸主动脉瘤和夹层(TAAD)约占死亡率的1%。TAAD可作为孤立的非综合征形式发生，或与其他临床特征一起发生，例如在Marfan或Loeys-Dietz综合征患者中。TAAD有很强的遗传易感性。个性化的风险评估、预防措施的应用以及适当的治疗和善后概念在很大程度上取决于对潜在疾病的正确诊断。结合临床和分子遗传学信息对正确诊断至关重要。只有大约一半的患者在已知疾病基因中显示出致病突变，因此进一步的异质性是明显的。该项目的中心目标是确定TAAD的其他疾病基因。我们将在10名TAAD患者中进行完整的外显子组测序(WES)，并随后进行多个外显子组比较，从而通过遗传(但不是功能)方法产生新的候选基因。我们将在我们的180例突变阴性的TAAD谱系障碍患者中，通过基因小组测序来验证新的候选基因和已经发现的候选基因(初步工作)。这一概念使人们能够更深入地了解许多候选基因的表观特性(许多患者)。通过使用各种分子生物学、生化和细胞生物学方法，我们将分析新的TAAD相关突变的病理生理后果。这对于确认稀有序列变异体的致病性是至关重要的。此外，更好地了解TAAD的分子发病机制可能有助于开发基于科学的治疗方案。在我们的初步工作中，一个患病家庭的亲属的WES鉴定CDKL1是一个新的TAAD候选基因。我们通过在第二个家族的两个患病同胞中发现另一个CDKL1序列改变，证实了CDKL1是一个疾病基因。因此，我们将立即开始对可能致病的CDKL1蛋白变体进行功能分析。逐渐地，我们将在我们的功能分析中包括尚未发现和有待验证的致病序列变化。这些研究将适用于不同类别的蛋白质。我们的最终目标是为TAAD谱系障碍患者提供充分的基于病因学的护理，我们拟议的项目涵盖了现代人类遗传学研究的整个范围，包括临床上详细描述的患者的整个外显子组和基因小组测序，以及致病突变的功能表征。

Thoracic aortic aneurysms and dissections (TAAD) account for about 1% of mortality in western countries. TAAD may occur as isolated nonsyndromic form or in conjunction with other clinical features such as in patients with Marfan or Loeys-Dietz syndrome. There is a strong genetic predisposition to TAAD. Individualized risk assessment, application of preventive measures and adequate therapy and aftercare concepts strongly depend on proper diagnosis of the underlying disease. Combined clinical and molecular genetic information is crucial for correct diagnosis. Only about half of the patients show pathogenic mutations in known disease genes, thus further heterogeneity is evident. The central goal of the project is to identify additional disease genes for TAAD. We will perform whole exome sequencing (WES) in 10 patients with TAAD and subsequent multiple exome comparison, thereby generating novel candidate genes by a genetic (but not functional) approach. We will verify novel candidate genes and already uncovered candidate genes (preliminary work) by gene panel sequencing in our cohort of 180 mutation negative patients with TAAD spectrum disorders. This concept enables a deeper view (many patients) in the phenocritical properties of a number of candidate genes. By using various molecular biological, biochemical and cell biological methods, we will analyze the pathophysiological consequences of the novel TAAD-associated mutations. This is essential in order to confirm the pathogenicity of rare sequence variants. Moreover, a better understanding of the molecular pathogenesis of TAAD may enable developing scientifically based treatment options. In our preliminary work, WES of relatives in an affected family identified CDKL1 as a novel TAAD candidate gene. We verified CDKL1 as a disease gene by uncovering another CDKL1 sequence alteration in two affected sibs in a second family. Therefore, we will start immediately with functional assays for the putative pathogenic CDKL1 protein variants. Gradually, we will include yet to be discovered and to be verified pathogenic sequence changes in our functional analyses. These studies will be adapted to the respective classes of proteins. With the ultimate goal to provide an adequate etiology-based care for patients with TAAD spectrum disorders, our proposed project covers the entire spectrum of modern human genetic research including whole exome and gene panel sequencing in clinically detailed characterized patients as well as functional characterization of pathogenic mutations.