利用新一代测序技术对2个非综合征高度近视家系行致病基因的克隆研究

The inherited high myopia is a common eye disorder, the high prevalence and blindness of which predispose individuals to a great deal of pain through their whole life. Recently,5 genes were identifed associated with familial high myopia. However, all five genes identified in a monogenic high myopia family, can only explain a really small proportion of high myopia subjects because of its heritability and the pathogenesis of high myopia is still unclear. Progress of the new sequencing technology promoted the rapid development of the whole-genome sequencing and whole genome exon sequencing faster, and provided an opportunity to more accurate localization, cloning of new genes. We collected 2 pedigrees with non-syndromic autosomal dominant high myopia (1 of which had been located). Then we would like to clone new causative genes of the pedigrees by exome sequencing analysis. Finally, we study the new causative gene function.The completion of this project can provide guidance for the genetic diagnosis, prevention and treatment of high myopia, and then has great social significance.

高度近视是一种常见的眼科遗传性疾病，其高患病率及高致盲率给广大患者的生活、工作、学习造成极大的痛苦。目前虽已发现5个家族性高度近视的致病基因，但由于高度近视存在明显的遗传异质性，这些基因能够解释的高度近视病人还非常少，绝大部分高度近视的遗传病因仍然未知。新一代测序技术的进步使全基因组测序在实验室广泛开展成为可能，并成功应用于遗传学和分子生物学等多个领域，为更快、更准确地定位、克隆新基因提供了契机。本研究旨在利用新一代测序技术中的外显子组测序等方法对申请人在既往研究中收集到的2个非综合征型常染色体显性遗传高度近视大家系HM-FR1和HM-FR2（其中HM-FR1家系已确定致病基因连锁区间）进行高度近视致病基因的克隆研究，并初步探索其与高度近视相关的分子遗传机制。本项目的开展将为遗传性高度近视的基因诊断、预防和治疗提供理论指导。

高度近视是一种常见的眼科遗传性疾病，其高患病率及高致盲率给广大患者的生活、工作、学习造成极大的痛苦。目前虽已发现5个家族性高度近视的致病基因，但由于高度近视存在明显的遗传异质性，这些基因能够解释的高度近视病人还非常少，绝大部分高度近视的遗传病因仍然未知。本项目对一个非综合征型常染色体显性遗传高度近视家系HM-SR3-2进行连锁与外显子组测序研究，发现P4HA2基因c.871 G>A杂合突变在家系中与疾病共分离，且此突变位点未在209例正常人中发现，P4HA2基因是这个家系的致病基因。在本项目新招募的285例散发患者中，发现P4HA2基因c.448 A>G，c.419 A>G，c.1349-1350delGT, c. 1327A>T杂合突变，且在300例正常人中未发现。QPCR结果提示，患者淋巴细胞中P4HA2 mRNA表达量低于正常人，且在加入吐根碱之后达到正常人表达水平。Western blot的结果显示，患者P4HA2蛋白表达量降低。P4HA2错义突变体亚细胞定位没有改变。本项目的开展丰富了高度近视的突变谱，为遗传性高度近视的基因诊断、预防和治疗提供理论指导。