Identification of new mechanisms for human congenital disorders

描述（由申请人提供）：在确定先天性人类综合征的遗传原因方面取得了重大进展。与此同时，已知基因的突变仍然只能解释人类颅面表型广谱的一小部分。这在一定程度上可能是由于筛选的局限性，因为目前大多数遗传筛选都集中在基因编码区域的序列分析上，因此无法检测到基因缺失/重复或基因功能中重要调控元件的变化。此外，许多先天性人类疾病的遗传原因仍然未知，因此无法在人类患者中进行评估。在本提案中，我们计划通过全基因组拷贝数变异分析来扩大颅面表型的遗传研究。这一努力将导致识别与已知基因相关的其他突变（缺失/重复），并将指导新因素的发现，从而使人类研究人员能够对疾病机制有新的认识。候选基因将根据其在感兴趣的基因组区域中的位置和动物模型的功能研究来确定。在受影响个体中进行突变筛查将为该基因在人类疾病中的致病作用提供额外的支持。在本提案中，我们计划利用我们从患有颅面异常的人类先天性疾病患者收集的DNA样本，这些患者已经检查了已知在相应表型中起作用的基因突变。我们对样本的一部分拷贝数变异进行了初步分析，发现了许多涉及已知基因的改变，以及以前未报道的新区域的变化。因此，我们相信我们的研究将产生关键数据，这将导致识别人类颅面综合征的新遗传原因，从而将在人类颅面生物学领域产生重大影响。具体来说，我们计划通过拷贝数变异分析来确定在人类颅面综合征中受影响的基因组区域（目标1）；使用斑马鱼模型评估与这些基因组区域相关的候选基因在综合征中的潜在作用（目标2）；并检查人类患者DNA中点突变的最佳候选基因，以进一步确认/表征它们在相应综合征中的作用（目标3）。

DESCRIPTION (provided by applicant): Significant progress has been achieved in the identification of genetic causes for congenital human syndromes. At the same time, mutations in known genes still explain only a small portion of the broad spectrum of human craniofacial phenotypes. This may be due, in part, to screening limitations, since the majority of current genetic screens focus on sequence analysis of the coding region(s) of a gene(s) and, therefore, fail to detect gene deletion(s)/duplication(s) or changes in regulatory elements important in gene function. In addition, the genetic causes for many congenital human conditions are still unknown and thus cannot be evaluated in human patients. In this proposal, we plan to expand genetic studies of craniofacial phenotypes through genome-wide copy number variation analysis. This effort will result in identification of additional mutations (deletions/duplications) associated with known genes and will direct discovery of novel factors, therefore empowering human researchers with new insight into disease mechanisms. Candidate genes will be identified based on their location within a genomic region of interest and functional studies in animal models. Mutation screening in affected individuals will provide additional support for a causative role for the gene in human disease. In this proposal, we plan to utilize our collection of DNA samples from patients with human congenital conditions involving craniofacial anomalies which was already examined for mutations in genes known to play a role in the corresponding phenotypes. Our preliminary analysis of a subset of our sample for copy number variants resulted in identification of numerous alterations involving known genes as well as changes in novel, previously unreported, regions. Therefore, we believe that our study will generate critical data that will lead to the identification of new genetic causes for human craniofacial syndromes and thus will have a high impact in the field of human craniofacial biology. Specifically, we plan to identify genomic regions that are affected in human craniofacial syndromes by copy number variation analysis (Aim 1); evaluate candidate genes associated with these genomic region(s) for their potential role in the syndrome(s) using the zebrafish model (Aim 2); and examine best candidate genes for point mutations in human patient DNA to further confirm/ characterize their role in the corresponding syndromes (Aim 3). PUBLIC HEALTH RELEVANCE: Our project is aimed at identification of the novel genetic causes of human craniofacial syndromes using new genomic screening technology and studies in animal models. The knowledge obtained from this project will provide insight into disease mechanisms(s) and eventually lead to improved diagnosis, genetic counseling and treatment of affected patients and their families.