c.332C＞T，一个新的X染色体连锁视网膜劈裂突变位点及其致病机制

发布时间：2018-03-11 14:31

本文选题：XLRS　切入点：视网膜劈裂　出处：《南京医科大学》2012年硕士论文　论文类型：学位论文

【摘要】：背景和目的：X染色体连锁视网膜劈裂（X-Linked Retinoschisis，XLRS），又称先天性视网膜劈裂，主要发生于男性青少年，是男性青少年黄斑变性的一个主要病因，以视网膜神经纤维层撕裂为特征，严重影响视力。该病主要是X染色体连锁遗传，基因XLRS1(X-Linked Retinoschisin1,X染色体连锁视网膜劈裂蛋白1，NCBI Gene ID:6247)的突变经由从携带者女性经由X染色体传给男性后代而致病，也有少部分病例是常染色体显性遗传。本文通过对于一个XLRS病例的研究，发现了一个新的XLRS1突变位点，，并对该突变位点的致病机制做了进一步的研究，试图阐明该突变位点的分子致病机制。方法：通过视力、眼底镜检查、OCT检查和ERG检查临床诊断一例XLRS受累的7周岁男孩。通过抽提该男孩及其父母血液DNA，分别测序XLRS16个外显子序列，以确定突变位点和致病基因的遗传模式。后续研究，通过慢病毒稳定转染、融合蛋白技术和定点突变技术，建立了能够稳定表达带有标签融合蛋白3×FLAG的RS1（Retinoschisin1,视网膜劈裂蛋白）的293T细胞株。对该细胞株的RS1蛋白表达模式以及蛋白的多聚体形成模式进行分析。结果：确定该XLRS受累男孩病例的XLRS1基因发生了点突变，突变位点位于CDS区第332，碱基从野生型的C突变为T（c.332CT）。患者母亲测序显示在同样位点同时存在野生型C和突变型T两个等位基因。患者父亲XLRS1为野生型。都过嘌呤霉素筛选，获得了成功表达RS1野生型和RS1突变型蛋白的两株293T。蛋白质表达模式分析发现c.332CT的RS1突变无法分泌至细胞外。结论：发现了XLRS1基因一个新的突变位点c.332CT，该突变型基因符合X染色体连锁隐性遗传模式，可能是突变RS1蛋白的分泌障碍导致了XLRS。
[Abstract]:Background and objective: X chromosome linked retinal cleavage X-Linked Retinoschiosis (XLRSs), also known as congenital retinoschisis, mainly occurs in male adolescents and is a major cause of male adolescent macular degeneration, characterized by retinal nerve fiber layer tear. The disease is mainly X-linked, and the mutation in the gene XLRS1(X-Linked Retinoschisin 1 X linked retinal cleavage protein (1 NCBI Gene ID: 6247) is caused by transmission from the female carrier to the male offspring via the X chromosome. A few cases are autosomal dominant inheritance. In this paper, a new XLRS1 mutation site was found in a XLRS case, and the pathogenicity of the mutation site was further studied. This paper attempts to elucidate the molecular pathogenesis of the mutation site. Methods: a 7 year old boy with XLRS involvement was clinically diagnosed by Oct and ERG. The XLRS16 exons were sequenced by extracting the DNA from the blood of the boy and his parents. In order to determine the genetic pattern of mutation sites and pathogenicity genes, the following studies were carried out, including stable transfection of lentivirus, fusion protein technique and site-directed mutagenesis, A 293T cell line was established which could stably express RS1 Retinoschisin 1 (retinal splitting protein) with labeled fusion protein 3 脳 FLAG. The expression pattern of RS1 protein and the pattern of protein polymorphic formation were analyzed. Results: a point mutation in the XLRS1 gene was identified in the boy case of XLRS involvement. The mutation locus was located in region 332of CDS, and the base mutation was transformed from wild type C to TX c.332CT.Among the same locus, two alleles of wild type C and mutant T were found in the mother of the patient. The father of the patient, XLRS1, was a wild type. All of them were screened by purine mycin. Two strains of RS1 wild-type and RS1 mutant proteins were obtained. The protein expression pattern analysis showed that the RS1 mutation of c.332CT could not be secreted out of the cell. Conclusion: a new mutation locus c.332CTin XLRS1 gene was found. The mutant gene is in line with the X chromosome linkage recessive genetic pattern, which may be caused by the secretion of mutant RS1 protein.
【学位授予单位】：南京医科大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：R774.1

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