原发性先天性青光眼GLC3C位点关键基因筛查及功能鉴定

Primary Congenital Glaucoma (PCG) is a rare eye disease that is different from the adult-onset glaucoma. It’s highly related to the genetics and irreversible leading blindness. In my previous fund of Youth from the National Natural Science Foundation, we have sequenced the only two known genes----CYP1B1 and LTBP2. This project is based on our previous study. Due to the lowest mutation rate in Chinese Han patients around the world, we consider there is another deleterious gene in Chinese Hans. We confirmed the locus GLC3C was associated with the PCG and further narrowed the positive area through the transmission disequilibrium test by 152 trios (probands and their healthy parents). A haplotype (including five htSNPs and 22 kilo-basepair long) was related on the occurrence of this disease. We hypothesize that there is a new gene located in the locus GLC3C. In this project, we will use the collected sporadic cases of Primary Congenital Glaucoma (cases: controls = 200:200), and design the target genes panel to perform Next-generation Sequencing. There are 23 key genes in the locus GLC3C to be sequenced among 22Kb +/- 1Mb area. By studying the promoters and exons of these genes, we hope to characterize and clone the pathogenic or susceptible gene in this locus. Then we’ll use Sanger sequencing to double check the results. We expect to verify the gene’s function both in vitro and in vivo, and explain the pathogenesis of PCG in Chinese Hans. It supposed to be the third deleterious gene of PCG and more popular in Chinese Han patients. The two known genes just induced a little part of PCG in Chinese Hans. It’s very necessary to identify the representative gene in Chinese Han patients, and explain more nosogenesis in PCG. It will be helpful for the precise diagnosis, proper treatment, and genetic counseling to the patients, and expand way of understanding the mechanism of glaucoma to the ophthalmologists.

原发性先天性青光眼（PCG）是不同于成人型青光眼的一类与遗传高度相关的罕见不可逆性致盲眼病。本课题组前期在对PCG目前仅有的两个致病基因----CYP1B1和LTBP2研究基础上，针对我国汉族患者人群已知基因突变率极低的现状，又在散发病例的核心家系中证实了遗传位点----GLC3C的存在，并将高风险单倍型的阳性关联区域缩小锁定在22Kb范围。本项目拟在已有的工作基础上，提出在GLC3C区域存在着新的致病基因假说，拟在该区域（22Kb ±1Mb）设计目标基因的外显子及调控区域序列捕获，对散发PCG病例（病例：对照=200：200）进行高通量测序，而后通过基因功能学实验，鉴定出新的致病/易感基因，这将有望成为第三个PCG基因，更加代表着中国汉族遗传背景，阐释更大部分PCG的发病机制，为有相关病史患者提供遗传咨询、精确诊断、预测疗效奠定基础，并为了解青光眼的发病机制开拓思路。

原发性先天性青光眼（PCG）是一类严重危害婴幼儿视觉健康的致盲性眼病，其特征性地表现为房角结构的发育不良，造成房水流出受阻，进而引起眼压升高、视神经损害。PCG的发生与遗传因素高度相关，已有多个致病基因被报道。本课题组前期已对两个PCG的重要致病基因——CYP1B1和LTBP2进行了详尽的基因型、表型研究，又在散发病例的核心家系中证实了遗传位点——GLC3C的存在。针对已知致病基因在我国汉族患者人群中突变率极低的现状，我们对一个新近报道的PCG致病基因——TEK，以及另外两个暂未发现致病基因的PCG关联位点——GLC3B和GLC3C展开了靶向二代测序及后续的功能学验证，以期能够阐释更大部分PCG的遗传学机制。我们的研究首次报道了我国PCG患者TEK基因的突变谱及突变率，并成功验证了部分功能缺失型TEK突变，此项成果进一步确立了TEK基因突变与PCG的关联，并为这部分患者提供遗传咨询、精确诊断奠定了基础。此外，在GLC3B和GLC3C位点，我们分别鉴定到了PCG的两个新候选致病/风险基因PHACTR4与PGF，为日后进一步深化对PCG发病机制的探究提供了科学依据。