视网膜色素变性患者特异性光感受器细胞核受体基因突变检测分析

发布时间：2018-06-29 06:16

本文选题：视网膜色素变性 + NR2E3基因　；参考：《宁夏医科大学》2012年硕士论文

【摘要】：目的视网膜色素变性(RP)是一种常见的致盲性遗传眼病，目前已发现至少62个基因与其有关，并且每个突变基因对应不同的遗传类型的RP患者。本研究目的观察特异性光感受器细胞核受体（NR2E3）基因在宁夏地区RP患者中的突变频率及特征，并探讨其在RP发病机制中的作用。方法经全面眼科检查确诊的120例RP患者纳入研究。研究对象均来自宁夏回族自治区，其中，常染色体显性遗传RP（adRP）患者33例，来自18个家系；常染色体隐性遗传RP（arRP）患者20例，来自15个家系；散发型RP（sRP）患者67例。同时选取100名健康成年人作为对照组。抽取受检者外周静脉血3～5ml，乙二胺四乙酸（EDTA）抗凝，采用北京天根公司的DNA抽提试剂盒提取全基因组DNA，按已发表的NR2E3基因序列资料（GeneBank accession No.：NG_009113），参照Yang等报道设计引物，运用聚合酶链反应（PCR）和直接测序方法，进行NR2E3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，再运用多因素logistic分析研究NR2E3基因突变位点对RP的作用。结果120例RP患者NR2E3基因检测出变异位点12个；其中，，5个位于非编码区，7个位于第4、6、7外显子上。12个变异位点中，新发现变异位点6个。外显子上7个变异位点中，同义突变3个；错义突变4个。统计学分析结果显示，所有变异位点均为NR2E3基因多态性。多因素Logistic回归分析显示，变异位点均与RP的发生无相关性。18例adRP先证者、67例sRP患者和正常对照组中，分别有1、3、2例先证者的NR2E3基因第4外显子上发现p.Glu121Lys变异。发生该位点变异的adRP患者家系（NXRP-1）另外8例患者中，出现p.Glu121Lys位点变异5例，未出现变异3例。出现变异的6例患者发病年龄较未出现p.Glu121Lys位点变异的3例患者早，且较早出现明显的中心视力损害。结论宁夏地区RP患者NR2E3基因致病突变率小于1%，明显低于中国其他地区的报道。一个adRP家系（NXRP-1）NR2E3基因中p.Glu121Lys变异与RP未出现“共分离”现象，因此p.Glu121Lys不是导致该家系发生RP的致病原因，但此位点多态性在该家系9例患者中发现6例，其临床表型较未出现p.Glu121Lys位点多态性的RP患者严重，可能系修饰基因。
[Abstract]:Objective retinitis pigmentosa (RP) is a common blindness hereditary ophthalmopathy. At least 62 genes have been found to be associated with RP, and each mutant gene corresponds to a different genetic type of RP patients. Objective to observe the mutation frequency and characteristics of specific photoreceptor nuclear receptor (NR2E3) gene in RP patients in Ningxia and to explore its role in the pathogenesis of RP. Methods 120 RP patients confirmed by ophthalmology were included in the study. The subjects were 33 autosomal dominant RP (ADRP) patients from 18 families, 20 autosomal recessive RP (ARRP) patients from 15 families, and 67 sporadic RP (SRP) patients. At the same time, 100 healthy adults were selected as control group. The peripheral venous blood (3ml) and ethylenediamine tetraacetic acid (EDTA) were extracted from the peripheral venous blood of the subjects. The whole genome DNA was extracted by using the DNA extraction kit of Beijing Tiangen Company. According to the published data of NR2E3 gene sequence (GeneBank accession No.: NG009113), the primers were designed with reference to Yang et al. Polymerase chain reaction (PCR) and direct sequencing were used to detect the mutations in the intron region of NR2E3 gene, and the effect of NR2E3 mutation site on RP was studied by multivariate logistic analysis. Results there were 12 NR2E3 mutation loci in 120 patients with RP, of which 5 were located in non-coding region and 7 in exon 4, 6 of which were newly discovered. Of the 7 mutation sites in exon, 3 were synonymous mutations and 4 were missense mutations. Statistical analysis showed that all mutation sites were NR2E3 gene polymorphisms. Multivariate logistic regression analysis showed that there was no correlation between the mutation sites and the occurrence of RP. In the 18 cases of adRP probands, 67 cases of SRP patients and 2 cases of normal controls, the mutation of P. Glu121Lys was found in exon 4 of NR2E3 gene in 2 cases of proband. Among the other 8 patients with NXRP-1, 5 had the mutation of p.Glu121Lys, and 3 had no variation. The onset age of 6 patients with mutation was earlier than that of 3 patients without the mutation of p.Glu121Lys, and the central visual impairment was earlier than that of the patients without the mutation of p.Glu121Lys. Conclusion the mutation rate of NR2E3 gene in RP patients in Ningxia is less than 1, which is significantly lower than that reported in other regions of China. In an adRP pedigree (NXRP-1) NR2E3 gene, p Glu121Lys mutation was not cosegregated with RP, so P. Glu121Lys was not the cause of RP in this pedigree, but this locus polymorphism was found in 6 out of 9 patients in this pedigree. Its clinical phenotype is more serious than that of RP patients without P. Glu121 Lys polymorphism, and it may be a modified gene.
【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

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