视网膜色素变性遗传致病基因peripherin/RDS的突变筛选

目的 了解中国视网膜色素变性患者（RP）中peripherin/RDS基因的突变谱及突变率。方法 应用聚合酶链-异源双链-单链构象多态性（PCR-SSCP）及DNA序列分析技术对收集的15个常染色体显性遗传视网膜色谱变性家系和55例散发视网膜色素变性患者peripherin/RDS基因的第一，第二外显子进行检测。结果 15个家系及55例散发患者未检测到peripherin/RDS基因突变。结论 本研究所检测的视网膜色素变性患者与RDS基因无关，显示视网膜色素变性的遗传异质性。     

视紫红质基因型与视网膜色素变性临床表型相关性的初步研究

目的:对国人视网膜色素变性(retinitis pigmentosa RP)患者中视紫红质基因不同突变与临床表型相关性进行初步研究。方法:对经异源双链-SSCP和序列分析确定为视紫红质基因不同位点突变的3例RP患者,收集其详细临床资料,比较其异同。结果:详细描述了3例已知突变患者的临床表现。视紫红质基因不同位点突变,临床表现不尽相同,发生在杆细胞外节胞液侧的突变,常导致严重类型的Ⅰ型视网膜色素变性;而发生在杆细胞外节盘膜内的突变,常引起相对较轻的Ⅱ型视网膜色素变性。结论:本文3例视紫红质基因不同位点突变与临床表型有一定关系,但要建立基因突变与表型间确切的对应关系和规律,尚需积累更多病例资料进一步分析研究。眼科学报1999;15:204-206。     

视网膜色素变性视紫红质基因突变检测分析

目的 研究视网膜色素变性患者视紫红质基因突变及其与临床表现的关系.方法 应用聚合酶链反应和直接测序技术,对33例视网膜色素变性先证者进行了视紫红质基因整个编码区及内含子外显子拼接区的突变筛选,其中常染色体显性遗传5例、常染色体隐性遗传8例,散发患者20例;同时应用裂隙灯、眼底镜、动静态视野计和视网膜电流图对患者进行临床检测.随机收集50例正常人进行对照检测.结果 发现1例散发患者有视紫红质基因P347L突变,呈杂合子,密码子347由CCG变成CTG.该患者13岁出现夜盲,46岁时视力和视野损害较重,视网膜电图检查杆体和锥体无反应.眼底显示视盘萎缩,血管变性,视网膜可见大量骨细胞样色素沉着.结论 视紫红质基因P347L基因突变患者有较为严重的临床改变;而且P347L突变被认为是该患者的病因.     

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.     

X-连锁和双基因型视网膜色素变性的相关基因研究进展

视网膜色素变性（retinitis pigmentosa,RP)是一组进行性、可致盲的单基因遗传性视网膜疾病，以视网膜光感受器和色素上皮功能进行性受损为主要特征。X－连锁RP和双基因型RP是视网膜色素变性的不同类型，在遗传和临床上各具特点。目前，X－连锁RP已定位6个致病基因，并克隆了2个基因（RP2和RP3）；双基因型RP是由2种不同基因（peripherin/RDS和ROM1基因）的杂合子突变导致的。     

激素性高眼压与TIGR/MYOC基因突变的关系

目的研究准分子激光术后使用激素类滴液引起眼压升高的患者和小梁网糖皮质激素诱导反应蛋白(trabecularmeshwork induced glucocorticoid response protein,TIGR/MYOC)基因编码区的突变情况并初步探讨这类疾病在基因水平的发病机制。方法选取在我院进行准分子激光术后常规使用激素类滴眼液导致眼压升高患者30例,抽取外周静脉血2mL。用酚-氯仿法提取全基因组DNA,然后应用聚合酶链式反应(polymerase chain reaction,PCR)扩增TIGR/MYOC基因3个外显子(7对引物)的各个片段;采用ABI-3730自动测序仪对扩增的PCR产物进行双向测序;对PCR产物测序结果及突变片段进行初步分析。结果 30例患者中有1例发现MYOC基因致病突变Arg342Lys,即2271G→A;6例发现有2271杂合突变;5例发现有同一种同义突变Glu352Glu即2302G→A。PCR产物测序共发现2个序列突变即编码区突变点Arg342Lys和同义突变点Glu352Glu。结论初步实验结果显示,MYOC基因编码区突变点Arg342Lys和此处杂合突变可能与激素性高眼压的发生有一定的联系。     

视网膜色素变性患者视紫红质E341ter基因突变及临床表型分析

目的 探讨常染色体显性遗传视网膜色素变性患者视紫红质基因突变及其与临床表型的关系。方法 应用聚合酶链反应（polymerase chain reaction,PCR)和单链构象多态性（single strand conformation polymorphism,SSCP)技术,对13个常染色体显性遗传视网膜色素变性家系的27例成员,进行视紫红质基因整个编码区的突变筛选,对SSCP检测有变异带的外显子PCR产物进行测序;同时应用裂隙灯、眼底镜、动静态视地和视网膜电流图（ERG）对患者进行临床检测。随机收集30例正常人进行对照检测。结果 发现1个家系患者有视紫红质E341ter突变,呈杂合子,密码子341第一个碱基由G变成T。该家系临床表现为青年期出现夜盲,视力和视野损害较重,ERG检查杆体和锥体无反应或仅有较小的锥体反应。结论 视紫红质基因突变家系的视网膜色素变性病史开始于杆体功能的丢失,进而累及锥体系统,并最终导致视功能严重丧失。视紫红质E341ter突变被认为是该家系的病因。     

MerTK基因突变致视网膜色素变性的研究进展

视网膜色素变性是一种遗传性视网膜变性性疾病,目前已发现的致病基因众多.近年来发现受体酪氨酸激酶在视网膜色素上皮代谢中起到重要作用,其受体酪氨酸激酶基因(MerTK基因)突变致视网膜色素变性成为致病基因研究的新热点.本文就MerTK基因突变所致视网膜色素变性的研究现状作一综述.     

我国东北地区两家系原发性开角型青光眼的OPTN基因新突变研究

目的 研究我国东北地区两家系原发性开角型青光眼(POAG)的致病基因并确定其基因突变位点.方法 病例对照实验.对两家系POAG患者进行临床研究和系谱分析.采集L家系6例患者和6例健康成员与C家系4例患者和4例健康成员的静脉血,提取基因组DNA.通过连锁分析,确定致病基因的染色体位点后,应用聚合酶链反应(PCR)扩增OPTN基因外显子,直接测序确定致病的基因突变位点.结果 L家系POAG患者的OPTN基因第10外显子发生错义突变,1274 位点AAA变为GAA,对应的赖氨酸替换为谷氨酸(Lys322Glu).L家系中健康成员、C家系全部成员及87名正常人均未发现该位点突变.结论 OPTN基因新突变(Lys322Glu)是L家系POAG的致病基因.     

视网膜色素变性与基因突变

视网膜色素变性 (RP)是常见的致盲性遗传疾病 ,目前已发现有数十个基因的 15 0多个突变位点与其有关。与常染色体显性遗传、常染色体隐性遗传和性连锁遗传相对应的最常见的突变基因分别是视红紫质基因、杆体环鸟苷酸磷酸二脂酶基因和三磷酸鸟苷酸酶调节因子基因 ,其他的突变基因还有盘膜边缘蛋白基因 (常染色体显性遗传 )、杆体环鸟苷酸离子通道基因、RPE6 5基因、视黄醛结合蛋白基因和酪氨酸激酶受体基因 (常染色体隐性遗传 ) ,RP2基因(性连锁遗传 ) ,线粒体DNA细胞色素b基因等 ,每个突变基因对应于人群中不同的RP患者。基因治疗将成为治疗RP的根本方法 ,而对RP突变基因的定位、基因的生物学功能、突变所造成的分子病理机制的深入认识 ,是进行基因治疗的关键。     

Peripherin/RDS gene mutation (Pro210Leu) and polymorphisms in Japanese patients with retinal dystrophies

PURPOSE: To determine the frequency of peripherin/RDS (retinal degeneration slow) gene mutations in Japanese patients with retinal dystrophies. METHODS: We analyzed the peripherin/RDS gene in 54 unrelated Japanese patients with retinal dystrophies. Genomic DNA was amplified by polymerase chain reaction (PCR) and the PCR products were sequenced. We also examined 100 healthy subjects, seeking mutations or variations of the peripherin/RDS gene. RESULTS: Of the 54 Japanese patients, one with retinitis pigmentosa had a heterozygous C to T change at the second nucleotide at codon 210 of exon 2 (CCT to CTT/Pro210Leu) of the peripherin/RDS gene. None of the 100 individuals with normal fundi had the Pro210Leu mutation of the peripherin/RDS gene. Three variants of the peripherin/RDS gene (GTC to GTT/Val106Val, Glu304Gln, and Gly338Asp) were also found. The first variation (GTC to GTT/Val106Val) was silent. Two concurrent missense variations (Glu304Gln and Gly338Asp) were seen in 25.9% of the affected patients and in 29% of the healthy individuals. CONCLUSION: A novel mutation (Pro210Leu) of the peripherin/RDS gene has been found in one Japanese patient with retinitis pigmentosa. The alterations of Val106Val, Glu304Gln, and Gly338Asp may be polymorphic variants in the Japanese population.     

Phenotypic expression of autosomal dominant retinitis pigmentosa in a Swedish family expressing a Phe-211-Leu variant of peripherin/RDS

PURPOSE : To characterize the clinical phenotype, with emphasis on electrophysiology, of members of a Swedish family with autosomal dominant retinitis pigmentosa due to a novel mutation, F211L, in the peripherin/RDS gene. METHODS : Nine patients with autosomal dominant retinitis pigmentosa and two healthy family members underwent a full clinical evaluation including kinetic visual field testing, measurement of dark adaptation threshold, and full-field electroretinography. Blood samples were collected and DNA analysis was performed using denaturing gradient gel electrophoresis (DGGE). RESULTS : The grandfather, six of seven siblings from the middle generation, and two young boys carried the mutation F211L in the peripherin/RDS gene. The mutation segregated with the clinical presentation of disease. Fundus examination revealed mainly macular atrophy. All assessed parameters of retinal function (visual acuity, dark adaptation threshold, visual fields, and full-field electroretinograms) demonstrated a successive reduction with increasing age. Full-field electroretinograms showed a diminished rod response in all affected individuals and a reduction of the cone b-wave amplitudes with increasing age, indicating retinitis pigmentosa. In the affected family members, the disease seems to progress at a similar rate with increasing age. CONCLUSIONS : The peripherin/RDS gene mutation F211L is associated with a clinical phenotype and includes early loss of rod function and successive reduction of cone function with increasing age, but impressively well-preserved visual acuity and visual fields in young and middle-aged patients and moderately reduced vision in the old patient. Compared to previously described phenotypes segregating with mutations in the peripherin/RDS gene, the present family demonstrates a more benign clinical phenotype, which is concordant within the family.     

Mutations in the peripherin/RDS gene are an important cause of multifocal pattern dystrophy simulating STGD1/fundus flavimaculatus

AIM: To describe the phenotype and to analyse the peripherin/RDS gene in 10 unrelated families with multifocal pattern dystrophy simulating Stargardt disease (STGD1). METHODS: The probands of 10 families and 20 affected family members underwent an ophthalmic examination including dilated fundus examination, fundus autofluorescence imaging and optical coherence tomography (OCT). In all probands and in selected family members, fluorescein angiography, electrophysiological testing and visual field analysis were performed. Blood samples were obtained from affected and unaffected family members for analysis of the peripherin/RDS gene. RESULTS: All 10 probands carried mutations in the peripherin/RDS gene. Nine different mutations were identified, including six mutations that were not described previously. All probands showed a pattern dystrophy with yellow-white flecks in the posterior pole that strongly resembled the flecks seen in STGD1, on ophthalmoscopy as well as on autofluorescence and OCT. Clinical findings in the family members carrying the same mutation as the proband were highly variable, ranging from no visible abnormalities to retinitis pigmentosa. CONCLUSIONS: Mutations in the peripherin/RDS gene are the major cause of multifocal pattern dystrophy simulating STGD1/fundus flavimaculatus. This autosomal dominant disorder should be distinguished from autosomal recessive STGD1, in view of the different inheritance pattern and the overall better visual prognosis.     

Late-Onset Central Areolar Choroidal Dystrophy Caused by a Heterozygous Frame-Shift Mutation Affecting Codon 307 of the Peripherin/RDS Gene

Mutations in the peripherin/RDS gene have been identified in families with various retinopathies including those affecting primarily the macula and those restricted to the retinal periphery. Here, we describe the clinical findings of two sisters with late-onset central areolar choroidal dystrophy (CACD). The two siblings underwent genetic testing and were found to be carriers of a heterozygous frame-shift mutation 920delT affecting codon 307 of the peripherin/RDS gene and resulting in a truncated, likely functionless, protein with an altered C-terminus (Leu307fsX83). The identical mutation has previously been reported to cause slowly progressive autosomal dominant retinitis pigmentosa. In our two patients, the Leu307fsX83 mutation accounts for an unusually mild form of retinal degeneration.     

Late-onset central areolar choroidal dystrophy caused by a heterozygous frame-shift mutation affecting codon 307 of the peripherin/RDS gene

Mutations in the peripherin/RDS gene have been identified in families with various retinopathies including those affecting primarily the macula and those restricted to the retinal periphery. Here, we describe the clinical findings of two sisters with late-onset central areolar choroidal dystrophy (CACD). The two siblings underwent genetic testing and were found to be carriers of a heterozygous frame-shift mutation 920delT affecting codon 307 of the peripherin/RDS gene and resulting in a truncated, likely functionless, protein with an altered C-terminus (Leu307fsX83). The identical mutation has previously been reported to cause slowly progressive autosomal dominant retinitis pigmentosa. In our two patients, the Leu307fsX83 mutation accounts for an unusually mild form of retinal degeneration.     

Extensive intrafamilial and interfamilial phenotypic variation among patients with autosomal dominant retinal dystrophy and mutations in the human RDS/peripherin gene.

Clinical phenotypes of patients with mutations in the human RDS/peripherin gene are described. A 67-year-old woman, who carried a 1 base pair deletion in codon 307, presented with typical late onset autosomal dominant retinitis pigmentosa (RP). In another autosomal dominant pedigree, a nonsense mutation at codon 46 caused 'inverse' retinitis pigmentosa-like fundus changes associated with progressive cone-rod degeneration in a 58-year-old man, whereas his 40-year-old son presented with yellow deposits in the retinal pigment epithelial layer resembling a pattern dystrophy, and with moderately reduced rod and cone function, as determined by two colour dark adapted threshold perimetry and electroretinography. It is suggested that both clinical pictures within this latter family may represent manifestations of fundus flavimaculatus. The clinical data of the three patients provide further evidence for the remarkable variety of disease expression within and between families with mutations in the RDS/peripherin gene. Currently, the most comprehensive statement could be that RDS/peripherin mutations are associated either with typical RP or with various forms of flecked retinal disease.     

Retinal histopathology of an autopsy eye with advanced retinitis pigmentosa in a family with rhodopsin Glu181Lys

PURPOSE: To compare histologic findings in an autopsy eye of an 84-year-old man with advanced retinitis pigmentosa and rhodopsin, Glu181Lys, with two cases of autosomal dominant retinitis pigmentosa (one with rhodopsin, Pro23His, and one with rhodopsin, Cys110Arg) and with a normal control, all of comparable age. METHODS: All eyes were prepared for light and electron microscopy within 6 hours after death. RESULTS: Extensive photoreceptor degeneration was revealed in the eyes with retinitis pigmentosa. Some macular cones showed membranous swirls only in the eye with rhodopsin, Glu181Lys. CONCLUSION: The retinal degeneration caused by rhodopsin, Glu181Lys, can feature membranous swirls in the inner segments of cones in the macula. These swirls have not been reported in other cases of dominant retinitis pigmentosa studied so far, and their pathogenesis remains to be defined.