视网膜色素变性一家系5′次黄嘌呤核苷磷酸脱氢酶基因突变检测

视网膜色素变性(RP)是一组视网膜感光细胞和视网膜色素上皮细胞变性导致的具有遗传和临床异质性的渐进性视网膜退化性疾病.RP是单基因遗传病,在遗传和表型上均具有较大的异质性.其遗传方式主要为:常染色体显性遗传(ADRP)、常染色体隐性遗传(ARRP)、X-染色体连锁遗传(XLRP)、双基因突变遗传(digenic RP)、线粒体遗传(mitochondrial RP)及不完全显性遗传.无家族史,则称为散发性[1].RP分子发病机制相当复杂.许多基因突变可导致RP,但没有任何一个单独突变可以解释超过10%的散发病例[2].随着分子生物学技术的发展及其在眼科遗传领域的应用,人们已能在DNA分子水平认识RP基因及其分子缺陷.随着克隆技术及人类基因组全序列测定的重大突破,人们对于其分子病理有了一定的了解和认识,极大地加快了人类疾病相关基因的定位克隆.我们对一个苏格兰RP家系进行5'次黄嘌呤核苷一磷酸脱氢酶(IMPDHI)基因突变的检测,并探讨其临床应用价值.现将结果报道如下.志谢本文为第一作者在英国攻读博士学位课题的一部分,导师授权本部分内容在国内报道;本工作得到哈尔滨医科大学傅松滨教授的大力支持,特致谢意     

眼病候选基因芯片在一汉族视网膜色素变性家系分子遗传学中的应用

背景 视网膜色素变性(RP)是一种累及视网膜光感受器细胞及色素上皮细胞的遗传性致盲眼病.RP的发病机制及临床特征较复杂,具有遗传异质性和临床异质性.随着基因组学的迅猛发展,越来越多的研究手段应用于RP致病基因筛查.目的 通过眼科基因芯片测序方法探讨一常染色体遗传RP家系临床表型及其基因突变情况.方法 于2013年6月在重庆市荣昌县收集一汉族RP家系,对该家系所有患者进行眼科检查确诊后,抽取12名家系成员外周静脉血各1 ml,应用华大基因眼科芯片目标区域捕获技术进行基因突变检测.该基因芯片覆盖了眼病相关的基因编码区(包括59个RP候选基因),选择家系内2例RP患者(Ⅱ5、Ⅱ7)的DNA样本进行目标区域捕获测序.通过生物信息学技术对测序结果进行分析,对共有的变异位点进行Sanger测序验证.结果 该家系为常染色体遗传的RP家系.通过基因芯片分析发现该家系Ⅱ5和Ⅱ7患者存在2个共有基因突变:USH2A (c.3065T＞C,p.Phe1022Ser)突变和PDE6A(c.1699G＞A,p.Ala1319Gly)突变,家系其他成员检测结果表明2个基因突变未与疾病共分离.该眼科基因芯片高通量测序技术虽然未定位该家系致病基因,但快速排除了RP常见候选基因,为进一步分析奠定了研究基础.结论 采用基于目标区域捕获测序的眼科基因芯片技术可以快速、准确地筛查RP常见候选基因,是眼科疾病遗传研究的一项适用且高效的新方法.     

常染色体显性遗传视网膜色素变性致病基因的研究进展

视网膜色素变性（retinitis pigmentosa,RP)是常见的遗传性视网膜变性疾病，它具有高度的遗传异质性，有不同的遗传方式和临床表型，目前已发现常染色体显性遗传型视网膜色素变性（autosomal dominant retinitis pigmentosa,ADRP)的12种基因，其中已被克隆的有RHO，RDS，ROM1，RP1，NRL及CRX，未被克隆的有RP9，RP10，RP11，RP13，RP17及RP18，本文主要介绍与ADRP相关的几个基因的最新研究进展。     

常染色体显性遗传性视网膜色素变性基因型-表型研究进展

视网膜色素变性(RP)是视网膜感光细胞和色素上皮细胞变性导致的最常见的遗传性致盲眼底病，具有高度的遗传异质性及临床异质性。常染色体显性遗传性视网膜色素变性(ADRP)是较为常见的遗传方式。介绍4种主要的ADRP致病基因及其产物的结构和功能，分析遗传缺陷导致视网膜色素变性的饥制，并对相关基因的临床表型研究进行了归纳总结。     

一视紫红质基因突变常染色体显性遗传视网膜色素变性家系的临床特征及其与基因型的关系

视网膜色素变性(RP)是以夜盲、进行性视野损害、视网膜色素沉着、视盘呈蜡黄色萎缩和视网膜电图(ERG)呈熄灭型为主要临床特征的遗传性致盲眼病[1,2].RP遗传方式复杂,以常染色体显性遗传RP(ADRP)为多见[3].在已成功克隆出15个ADRP致病基因中,视紫红质(RHO)基因是引起ADRP的主要致病基因,大约20%的ADRP患者存在RHO基因突变[4-6].RHO突变位点很多,表型各异.为探讨RHO基因型与RP的关系,我们观察了1个RHO基因突变的ADRP家系中RP患者的临床特征.现将结果报道如下.     

常染色体显性遗传视网膜色素变性基因检测研究进展

视网膜色素变性(RP)是一组进行性的可致肓的遗传性视网膜疾病,以视网膜光感受器和色素上皮细胞变性为主要特征,发病率约为1/4000,全世界受累人数约为1百万人.RP具有明显的临床和遗传异质性.常染色体显性遗传视网膜色素变性(ADRP)占RP的20％～25％,目前共定位了21个位点,其中克隆了19个基因.由于ADRP危害较为严重、发病率较高,近年来已成为眼科遗传学研究的热点.此文对近年来研究进展做一综述.     

常染色体显性遗传视网膜色素变性患者视紫红质基因和视网膜变性慢基因突变检测分析

视网膜色素变性(RP)是一组常见的视网膜感光细胞和色素上皮细胞变性导致夜盲和进行性视野缺损的遗传性眼底病,其发病机制尚未完全明确.RP具有高度的遗传异质性,其遗传方式非常复杂,分为常染色体显性遗传(ADRP)、常染色体隐性遗传(ARRP)、X-连锁遗传(XLRP)和双基因型遗传(Digenic RP),最近报道还有线粒体遗传方式(mitochondrial RP)[1].视紫红质基因(RHO)是最早被识别的RP基因,在ADRP中发病率占30%～40%[2],而盘膜周边蛋白/视网膜变性慢基因(peripherin/RDS)在ADRP中占5%[3].我们对13个ADRP家系进行了RHO和视网膜变性慢基因(RDS)检测分析,观察其突变特征,现将其结果报道如下.     

常染色体遗传型视网膜色素变性相关基因的研究进展

视网膜色素变性（RP）是常见的致盲性眼病,具有高度的遗传性和表型异质性。RP致病基因的确立对探讨该病的发病机制、预防和治疗具有重要的意义。近年来,RP的研究有了新的进展,就常染色体显性遗传RP（adRP）与常染色体隐性遗传RP（arRP）相关基因的研究进行综述,归纳其中常见致病基因的作用及其突变发病的可能机制,为RP的研究提供一定参考。     

视网膜色素变性基因治疗的相关研究进展

视网膜色素变性(RP)是以视杆和视锥感光细胞退化及视网膜色素上皮细胞变性为特征的遗传性视网膜疾病。RP发病年龄和病情进展与基因和遗传方式有关，受环境影响。基因治疗通过载体转移治疗性基因，对靶细胞进行遗传修饰，纠正或替代致病RP基因。本文介绍RP基因治疗相关基因载体研究进展，并就5个常见基因型(RHO、PDE6B、MERTK、RLBP1、RPGR)对RP基因治疗疗效及安全性研究进展予以综述。     

目标区域捕获技术鉴定一RP家系USH2A基因的新复合杂合突变

背景 RP为遗传性致盲眼病,其遗传方式和临床表型呈高度异质性,对患者的突变基因进行筛查和诊断对于进一步的基因治疗研究有重要意义. 目的 利用目标区域捕获技术确定中国一常染色体隐性遗传RP家系成员的临床表型及基因突变方式.方法 收集2013年暨南大学附属深圳眼科医院1个汉族RP家系,对该RP家系的4个成员进行眼科检查,抽取家系成员的外周血后,利用华大基因眼科芯片目标区域捕获技术对先证者进行基因突变检测,利用PCR以及Sanger测序法对RP家系中正常表型的成员进行基因突变点验证. 结果 该家系共3代5名成员,Ⅰ1、Ⅰ2、Ⅱ2和Ⅲ1均为表型正常者,Ⅱ1为先证者,自18岁出现夜盲及视力下降,呈管状视野缺损.先证者眼底检查发现视盘呈蜡黄色和视网膜骨细胞样色素沉积,荧光素血管造影可见片状遮蔽荧光和周边视网膜透见荧光.该家系遗传方式符合常染色体隐性遗传.芯片分析发现先证者USH2A基因存在由c.9958 G＞T(p.Gly3320Cys)错义突变和c.11156 G＞A(p.Arg3719His)错义突变组成的复合杂合突变,而其表型正常的父亲(Ⅰ 1)为c.9958 G＞T(p.Gly3320Cys)杂合突变,表型正常的母亲(Ⅰ 2)为c.11156 G＞A(p.Arg3719His)杂合突变,表型正常的女儿(Ⅲ1)为c.9958 G＞T(p.Gly3320Cys)杂合突变. 结论 该RP家系可能由USH2A基因的c.9958 G＞T和c.11156G＞A复合杂合突变导致.眼科芯片技术可以快速准确地筛查RP常见候选基因.     

视网膜色素变性治疗最新进展

视网膜色素变性(retinitis pigmentosa,RP)是视网膜感光细胞和色素上皮细胞变性导致的最常见遗传性致盲眼病,预后不佳,目前尚无有效的预防和治愈方法。近年来,随着基因治疗、视网膜移植等技术在动物实验中的广泛开展,给人类RP的治疗带来了新的希望。本文对RP的各种最新治疗进展进行综述。     

Applications of CRISPR/Cas9 in retinal degenerative diseases

Gene therapy is a potentially effective treatment for retinal degenerative diseases. Clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 (Cas9) system has been developed as a new genome-editing tool in ophthalmic studies. Recent advances in researches showed that CRISPR/Cas9 has been applied in generating animal models as well as gene therapy in vivo of retinitis pigmentosa (RP) and leber congenital amaurosis (LCA). It has also been shown as a potential attempt for clinic by combining with other technologies such as adeno-associated virus (AAV) and induced pluripotent stem cells (iPSCs). In this review, we highlight the main points of further prospect of using CRISPR/Cas9 in targeting retinal degeneration. We also emphasize the potential applications of this technique in treating retinal degenerative diseases.     

视网膜色素变性研究新进展

视网膜色素变性(retinitis pigmentosa,RP)也称为色素性视网膜炎。RP是由于视网膜色素上皮细胞功能逐渐丧失及光感受器进行性凋亡从而导致不可逆的视力损伤的一组遗传性眼病。因其表型和遗传均具有异质性,发病机制复杂,目前尚无单一有效的治疗方法。本文报告近年来RP在诊疗方面的进展。     

常染色体隐性遗传视网膜色素变性的相关基因研究进展

视网膜色素变性(rentinitis pigmentosa，RP)是一种发病机制尚未完全明确的遗传性致盲性视网膜疾病，特征性表现为夜盲、进行性视野缩窄和视力下降，眼底可见骨细胞样色素沉着、视网膜血管变细和视盘蜡黄三联症。RP具有较大的遗传异质性和临床异质性，其中常染色体隐性遗传视网膜色素变性(autosomal recessive RP，ARRP)占RP的5%～20%，目前已定位43个致病基因，克隆了其中40个，并且不断有新的相关致病基因被报道。本文就近3a发现与ARRP相关的AGBL5、ARHGEF18、HGSNAT和ZNF408四个基因研究进展作一综述。     

Management of hereditary retinal degenerations: present status and future directions.

Research on hereditary retinal degenerations has considerably improved our understanding of these disorders, although much remains to be learned about the exact mechanism involved in the pathogenesis. The advent of recombinant DNA technology will refine diagnostic capabilities, which have so far been based on the manifestations of the disease to localization of the molecular defects. The correlation of the molecular defects with the phenotype of the disease will result in better prognostic counseling for patients. In certain forms of retinitis pigmentosa, such as Refsum disease, gyrate atrophy of the choroid and retina, and abetalipoproteinemia, exact biochemical defects have been identified and specific treatments have been applied with some success. In other forms of retinitis pigmentosa, various investigations have suggested the possibilities of arresting the progress of degeneration by means such as the use of growth factors and controlling apoptosis. Efforts to alter the expression of the mutated gene or to introduce a normal gene into the genome are in their infancy, but results are encouraging. Vitamin A has been tried in patients with retinitis pigmentosa, and the results demonstrate statistically significant beneficial effects of this vitamin, suggesting that the course of the disease can be decelerated to some extent. Another interesting research area with potential for therapeutic application is the replacement of the retinal pigment epithelium or the degenerated neural retina by transplantation of the respective cell types. Clinical trials are being conducted both with retinal pigment epithelium and neuroretinal transplants.     

An atypical phenotype of macular and peripapillary retinal atrophy caused by a mutation in the RP2 gene

AIMS: To determine the molecular basis and describe the phenotype of an atypical retinal dystrophy in a family presenting with bilateral, progressive central visual loss. METHODS: Family members were examined. Investigations included Goldman perimetry, electrophysiology, and autofluorescence imaging. Candidate gene screening was performed using SSCP and sequence analysis. The proband's lymphoblastoid cells were examined for protein expression. RESULTS: Fundal examination of the proband, his mother, and brother revealed peripapillary and macular atrophy. Autosomal dominant retinal dystrophy was suspected, but less severe disease in the mother led to screening for mutations in X linked genes. A 4 bp microdeletion in exon 3 of the RP2 gene, segregating with disease, was identified. No RP2 protein expression was detected. CONCLUSION: The distinct phenotype in this family, caused by this frameshifting mutation in RP2, broadens the phenotypic spectrum of X linked retinitis pigmentosa. The absence of RP2 protein suggests that loss of protein function and not novel gain of function could account for the atypical phenotype. A definitive diagnosis of X linked retinitis pigmentosa permits appropriate genetic counselling with important implications for other family members. Clinicians should have a low threshold for screening RP2 in families with retinal dystrophy, including posterior retinal disease, not immediately suggestive of X linked inheritance.     

碘酸钠诱发的视网膜色素变性动物模型研究进展

视网膜色素变性(RP)是一组以视网膜色素上皮(RPE)和感光细胞的功能障碍或丧失为主要特征的致盲眼病,有很大的临床和遗传异质性.碘酸钠是抗代谢药物,可以选择性破坏RPE,它引起的视网膜病变与人类RP疾病的片状RPE缺损极为相似,因此常被用来制作RP疾病的模型.碘酸钠能诱发多种实验动物的RP模型,人们多使用单次碘酸钠注射的方法建立RP动物模型.由于碘酸钠诱发的RP动物模型的发病年龄和疾病进展均可人为操控,制备简单,病变稳定,周期短,且某些动物的RPE细胞在特殊条件下有再生的潜能,极有利于RP发病机制、药物或干/前体细胞治疗及再生医学方面的研究.目前有关碘酸钠诱发动物RP模型的研究和应用已有不少报道.本文根据国内外文献将碘酸钠诱发的RP动物模型的研究进展作一综述.     

Polypoidal choroidal vasculopathy in a case with retinitis pigmentosa

There have been no reports describing polypoidal choroidal vasculopathy (PCV) in eyes with retinitis pigmentosa (RP). A 63-year-old woman who had been diagnosed as having RP was referred to us because of sudden onset of blurred vision in her right eye. Funduscopic examination revealed retinal findings typical of RP in both eyes. The macular area of the right fundus showed polypoidal lesions with massive hemorrhages. Fluorescein angiography and indocyanine green angiography showed multiple polypoidal lesions. Optical coherence tomography showed a large hemorrhagic retinal pigment epithelial (RPE) detachment and polypoidal lesions. The PCV subsided after three applications of anti-vascular endothelial growth factor (VEGF) therapy and a single application of photodynamic therapy, but “mottled lesions” with hyper- and hypofluorescence appeared temporal to the macula after disappearance of hemorrhage. We present a case of PCV in an eye with RP. Further studies are necessary to clarify whether anti-VEGF therapies could affect RPE status in eyes with RP.     

Mutation screening of Pakistani families with congenital eye disorders

To map the disease loci several Pakistani families suffering from autosomal recessive retinitis pigmentosa with preserved para-arteriolar retinal pigment epithelium and Leber congenital amaurosis (LCA) were analyzed. Analysis revealed close genetic linkage between the disease phenotype of some of the families (3330RP, 111RP and 010LCA) and the microsatellite markers on chromosome 1q31. Mutation screening of the candidate gene CRB1 revealed a G to A transversion in exon 7 in arRP family 330RP and a T to C substitution in another arRP family, 111RP. In exon 9 of the CRB1 gene a T to C transversion was found in the family suffering from LCA (010LCA).The LCA phenotype of another family (011LCA) in which the CRB1 locus was excluded, showed linkage with microsatellite markers D17S1294 and D17S796 on chromosome 17p13.1. The association of the candidate gene GUCY2D (17p13.1) with the disease phenotype was excluded as no disease-associated mutation was found in any of its exons. Mutation screening of another candidate gene, AIPL1 located in the same region, showed a novel homozygous C to A substitution in exon 2. These sequence changes are unique for the Pakistani families and some of these have not been reported previously.     

脑源性神经营养因子治疗视网膜色素变性的研究进展

脑源性神经营养因子(BDNF)是一种由脑组织合成并广泛分布于中枢神经系统的小分子碱性蛋白.研究发现,BDNF对视网膜神经节细胞(RGCs)、视网膜感光细胞(RPCs)和视网膜色素上皮(RPE)细胞均有保护、营养及抗凋亡作用.视网膜色素变性(RP)是由于RPCs及RPE细胞凋亡引起的视网膜退行性疾病.RP动物模型证实了BDNF的长期给药对于RP的治疗价值.然而BDNF在体内的半衰期较短,且无法跨越血-视网膜屏障由循环系统输送到视网膜,这给BDNF用于RP的治疗带来了挑战.为了使BDNF在眼内可以稳定持续地释放,多种新型给药方式已被尝试,包括基因工程技术、细胞移植技术、高分子材料缓释系统及滴眼液等.本文就BDNF对RP治疗的研究现状及BDNF的新型给药方式做一综述.