视网膜色素变性患者视网膜色素变性1基因突变的检测分析

发布时间：2018-02-24 16:37

本文关键词： 视网膜色素变性 RP1基因突变　出处：《宁夏医科大学》2012年硕士论文　论文类型：学位论文

【摘要】：目的视网膜色素变性（retinitis pigmentosa,RP）是一组常见的单基因遗传性、致盲性眼病，目前尚无有效的治疗方法。目前，通过连锁分析和候选基因筛查，已发现63个基因与RP有关。RP1基因突变占ADRP致病突变的2%～7%，仅次于RHO和RDS。本研究的目的是研究RP1基因在宁夏地区RP患者中的突变频率及特征，进一步探讨其在RP发病机制中的潜在作用。方法按国际通用的RP诊断标准收集宁夏回族自治区110例RP患者，其中包含35例常染色体显性遗传性RP（ADRP）患者和75例散发患者（SRP）为RP患者组，同时收集100例正常对照者为正常对照组，抽取外周静脉血3～5ml，EDTA抗凝，采用DNA提取试剂盒（北京天根生化科技有限公司）提取全基因组DNA。按基因库的RP1基因序列资料（GeneBank登录号：NG_009840），参照Payne等报道的方法对RP1基因进行PCR引物设计，在设计引物时使其扩增区域覆盖RP1基因的4个外显子及其附近拼接位点中的内含子，共设计、合成21对引物。应用聚合酶链反应（polymerase chainreaction, PCR）和直接测序法进行RP1基因全编码区和邻近剪切位点的内含子区域序列突变的检测。运用多因素分析和基于网络的评分软件PolyPhen、Sorting Intolerant FromTolerant（SIFT）对研究结果进行分析。结果RP患者组和正常对照组RP1基因共检测出11个变异位点，其中错义突变6个：p.Gly706Arg、p.Arg872His、p.Asn985Tyr、p.Ala1670Thr、p.Ser1691Pro、p.Cys2033Tyr，同义突变3个：p.Gln1008Gln、p.Lys1152Lys、p.Gln1725Gln，非编码区域突变2个：c.788-92TC、c.*247AC。p.Lys1152Lys和c.*247AC为新发现的突变位点。RP患者组第3内含子c.788-92TC的突变频率与正常对照组相比差异有统计学意义（χ~2=9.12,P0.01）；3’-侧翼序列区c.*247AC的突变频率高于正常对照组，差异有统计学意义（χ~2=12.77, P0.01），且与RP发生呈显著正相关（r=1.11, P0.05）。在110例RP患者中，发现83例患者均同时携带p.Arg872His、p.Ala1670Thr和p.Ser1691Pro三个错义突变。在正常对照组中有22例出现p.Arg872His的突变，另有36例同时出现p.Ala1670Thr和p.Ser1691Pro突变。三个错义突变在RP患者中的发生率均显著高于正常对照组（χ~2=59.87, χ~2=33.21; P0.01）。PolyPhen分析显示，p.Arg872His、p.Ala1670Thr、p.Ser1691Pro均为保护性突变。SIFT分析显示，这3个突变对RP均表现为保护作用。对患者的临床表现进行分析，发现携带上述3个突变的PR患者平均年龄为43.54±12.32岁，夜盲出现的平均年龄为30.54±13.68岁，，最佳矫正视力平均为0.50±0.38；未携带上述3个突变的PR患者平均年龄为34.87±17.60岁，夜盲出现的平均年龄为21.06±16.24岁，最佳矫正视力平均为0.40±0.33；2组患者夜盲出现的平均年龄、最佳矫正视力比较差异有统计学意义（t=2.01, t=2.11; P0.05）。结论在宁夏回族自治区RP患者中，RP1基因的致病突变率低于中国其他地区的人群。研究发现非编码区域碱基改变c.*247AC的突变与RP发生呈显著正相关。p.Arg872His、p.Ala1670Thr和p.Ser1691Pro突变均系单核苷酸多态现象，三者的协同出现可能对RP起到一定的保护作用，同时也可能降低了RP1基因致病突变的发生率。
[Abstract]:Objective To study the mutation frequency and characteristics in RP patients in Ningxia region by linkage analysis and candidate gene screening . The aim of this study is to study the mutation frequency and characteristics of the RHO and RDS in RP patients in Ningxia region . Methods A total of 110 RP patients were collected from Ningxia Hui Autonomous Region by RP - PCR , including 35 patients with autosomal dominant hereditary RP ( ADRP ) and 75 sporadic patients ( SRP ) as RP patients . Results The mutation frequency of the 3rd intron c . 788 - 92TC in RP patient group was higher than that of the normal control group ( 蠂 ~ 2 = 9.12 , P0.01 ) . The mutation frequency of the third intron c . 788 - 92TC in RP patients was higher than that of the normal control group ( 蠂 ~ 2 = 12.77 , P0.01 ) . Among 110 RP patients , 83 patients were found to carry three missense mutations of p . Arg872His , p . Ala1670Thr and p . Ser1691Pro . In the normal control group , there were 22 cases with p . Arg872His mutation and 36 cases with p . Ala1670Thr and p . Ser1691Pro mutation . The incidence of three missense mutations in RP patients was significantly higher than that in the normal control group ( 蠂 ~ 2 = 59.87 , 蠂 ~ 2 = 33.21 ; P0.01 ) . The average age of patients with PR was 43.54 卤 12.32 years old , the average age of night blindness was 30.54 卤 12.32 years old , the average age of night blindness was 30.54 卤 13.68 years old , the average age of night blindness was 34.87 卤 17.60 years old , the average age of night blindness was 34.87 卤 17.60 years old , the average age of night blindness was 21.06 卤 16.24 years old , the average age of night blindness was 34.87 卤 17.60 years old . Conclusion : In the RP patients of Ningxia Hui Autonomous Region , the mutation rate is lower than that in other regions of China . It is found that the mutation of the non - coding region is positively correlated with the occurrence of RP . p . Arg872His , p . Ala1670Thr and p . Ser1691Pro mutation are single nucleotide polymorphism .

【学位授予单位】：宁夏医科大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：R774.1

【参考文献】