Identification of novel causative genes for neuro-cardio-facio-cutaneous syndromes by whole exome sequencing and functional analysis of pathogenic mutations

努南综合征、心-面-皮肤综合征（CFC）和Costello综合征属于一组遗传性疾病，其由编码RAS-MAPK（丝裂原活化蛋白激酶）信号传导途径的蛋白质的基因中的杂合种系突变引起。这些临床实体已被引入的名称为神经-心脏-面部-皮肤（NCFC）综合征或RASopathies。在大约30%的具有RAS病表型的患者中，在已知基因中未检测到致病性突变。我们将在具有明确表型的患者及其父母（三人组）中应用全外显子组测序，以鉴定NCFC综合征的新基因。通过对大量患者（280）中的这些候选基因进行测序，其中还包括表现出NCFC谱的可变表型的个体，我们将确认所分析的基因为疾病基因并确定相关的表型谱。我们项目的另一个重点将是与NCFC综合征相关的突变的功能分析。初步工作导致在与RAS信号相关的已知或新基因中鉴定出新的序列变异。我们将使用一系列成熟的生物化学和细胞生物学技术来研究先前确定的新疾病相关突变或本项目中通过全外显子组测序发现的突变的功能后果。我们期望获得宝贵的洞察力的遗传学的NCFC综合征和其潜在的病理生理基础，以及在复杂的调控网络的RAS-MAPK信号通路。

Noonan, cardio-facio-cutaneous (CFC), and Costello syndrome belong to a group of genetic disorders which are caused by heterozygous germline mutations in genes encoding proteins of the RAS-MAPK (mitogen-activated protein kinase) signalling pathway. These clinical entities have been introduced under the name neuro-cardio-facio-cutaneous (NCFC) syndromes or RASopathies. In about 30% of patients with a RASopathy phenotype no pathogenic mutation is detected in the known genes. We will apply whole exome sequencing in patients with a clear-cut phenotype and their parents (trios) to identify novel genes for the NCFC syndromes. By sequencing these candidate genes in a large cohort of patients (280), that also includes individuals exhibiting variable phenotypes of the NCFC spectrum, we will confirm the analyzed genes as disease genes and determine the associated phenotypic spectrum. Another focus of our project will be the functional analysis of mutations associated with NCFC syndromes. Preliminary work led to the identification of novel sequence variations in known or new genes associated with RAS signalling. We will use a battery of well established biochemical and cell biological techniques to study the functional consequences of previously identified novel disease-associated mutations or those found by whole exome sequencing in this project. We expect to gain valuable insight in the genetics of the NCFC syndromes and their underlying pathophysiological basis as well as in the complex regulatory network of the RAS-MAPK signalling pathway.