新致病基因DIEXF在唇裂发生中的遗传效应及作用机制研究

Non-syndromic cleft lip only (NSCLO) is the most common maxillofacial birth defects. Because of long treatment period, it gives family and society a heavy burden, and seriously affects the quality of births. NSCLO has complex pathogenesis, the current achievements could not be used as theoretical basis for prenatal diagnosis and prevention. So, it is need to find a gene target with more pathogenic role in NSCLO and grasp the specific pathogenic mechanisms to lay foundation for the targeted prevention measures. Applicant preliminary found that DIEXF gene was significantly associated with NSCLO from Western Chinese Han population, but its genetic effects and mechanism in NSCLO remains unclear. Therefore, the project intends to taking advantage of NSCLO trios performing the DIEXF gene sequencing to screen for genetic variations, calculating the genetic effects on NSCLO from Western Chinese Han population; And use DIEXF knockout model and related molecular biology techniques from cells, organs at different levels and angles, to study the mechanism of DIEXF gene during the lip and craniofacial development. Eventually, it will clarify the pathogenic pathways and key targets of DIEXF gene in the etiology of cleft lip, and provide new research means for the goals of individualized treatment for cleft lip and palate, Finally, it will lay foundation for the eventual precise prevention of cleft lip and palate among Chinese population.

非综合征型唇裂（NSCLO）是颌面部最常见的出生缺陷。由于其治疗周期长，给家庭和社会带来沉重负担，严重影响出生人口素质。NSCLO致病机理复杂，当前的研究结果尚不能作为产前诊断和预防的理论依据。需要寻找更具致病作用的基因靶点,并掌握其具体致病机制，为釆取有针对性的防治措施奠定基础。申请者前期研究发现DIEXF基因与中国汉族人群NSCLO的发生密切相关，但其在NSCLO发生中的遗传效应和作用机制未知。为此，本项目拟在利用NSCLO家系对DIEXF基因进行测序来筛查遗传变异，计算其对中国汉族人群NSCLO发生的遗传效应的基础上，采用DIEXF基因敲除模型及相关分子生物学技术从细胞、器官不同层面和角度，研究DIEXF基因在唇部及颅面部发育中的作用机制。最终阐明DIEXF基因在唇裂发生中的致病途径和关键靶点，为唇腭裂实现个体化治疗的目标提供新的研究手段，为最终实现中国人群唇腭裂精准防治奠定基础。

非综合征型唇裂（NSCLO）是颌面部最常见的出生缺陷，其致病机理复杂。本项目前期从5个唇腭裂全基因组关联研究、全基因组关联研究Meta分析及候选基因关联研究选择了50个常见SNP位点（分布在14条染色体22个基因上），在440个中国西部汉族人群非综合征型唇腭裂患者-父母核心家系（138个单纯唇裂家系，144个单纯腭裂家系，158个非综合征型唇裂伴腭裂家系）中研究这些位点与中国汉族人群唇腭裂发生的关联性，研究结果发现了DIEXF（rs12063989）、VAX1、MAFB、FOXE1等基因与中国西部人群NSCLO、NSCL/P的发生密切相关。为了全面、深入地筛查易感位点，本项目进一步采用目标区域测序对DIEXF所在单倍型区域（包含DIEXF基因和IRF6基因）和GWAS报道关联位点所定位的单倍型区域进行遗传变异位点筛查，并进行关联分析和大样本人群队列验证研究，最后结合连锁分析和logistic回归分析在IRF6基因内含子区域筛选到了真正的易感位点rs12043599，该位点对中国西部汉族人群NSCLO发生的人群归因风险百分比是26.43%。这一发现将为中国人群唇腭裂致病机理的研究开辟新的视野。