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.     

视网膜色素变性中视紫红质与Peripherin／RDS基因的突变筛查

目的:迄今尚未见在国人中经序列分析确定该基因突变的报道。了解国人遗传性视网膜色素变性人群中视紫红质和peripherin/RDS基因的突变情况。方法:对83例遗传性视网膜色素变性先证者视紫红质基因全部编码区和peripherin/RDS部分编码区进行PCR扩增,用异源双链-SSCP法对扩增产物进行分析,寻找有差异电泳带纹的突变样本,序列分析确定突变。结果:83例中3例有视紫红质基因突变(Va1104Phe、Lys311Glu、Pro347Leu),其中两个新突变分别见于散发病例(Va1104Phe,杂合性)和常染色体隐性遗传视网膜色素变性家系(Lys311Glu,纯合性)。在peripherin/RDS基因中未发现突变。结论:在国人视网膜色素变性患者中视紫红质基因突变为常见致病原因。眼科学报1998;14:210～214     

常染色体隐性遗传视网膜色素变性CNGA1基因突变检测

目的检测常染色体隐性遗传视网膜色素变性患者杆体α—cGMP门离子通道基因（α—cGMP—gated cation channel，CNGA1）基因突变。设计对照性实验研究。研究对象35名常染色体隐性遗传视网膜色素变性（autosomal recessive retinitis pigmentosa，ARRP）家系的先证者和55名散发病例。随机收集100名正常人作为对照。方法采集患者外周血，应用DNA分离试剂盒提取DNA，应用11对CNGA1基因引物进行聚合酶链反应（polymerase chain reaction，PCR），扩增CNGA1基因的全部编码区及内含子外显子的拼接区。利用单链构象多态性（single strand conformation polymorphism，SSCP）技术，将PCR产物进行10％非变性聚丙烯酰胺凝胶电泳，用硝酸银染色，观察有无变异带。如果发现变异带，再将该PCR产物进行DNA测序。主要指标通过PCR，SSCP和DNA测序技术，发现CNGA1基因突变。结果未发现CNGA1基因突变。结论CNGA1基因突变在国人RP患者中的致病情况有待进一步研究。     

视紫红质基因突变相关的视网膜色素变性

视紫红质基因突变是导致视网膜色素变性最常见的原因,占常染色体显性遗传视网膜色素变性的25％～30％.在视网膜色素变性中已发现的视紫红质基因突变多达150余种.视紫红质基因突变可引起内质网应激、蛋白聚集、膜受体异常激活,从而导致视网膜色素变性.P23H和T17M等突变小鼠转基因模型的建立,为深入探讨视紫红质在视网膜色素变性中的作用,以及为干扰突变基因表达,替换突变基因等潜在治疗策略提供理论依据.     

视网膜色素变性一家系与IMPDH1基因突变相关

目的检测一个常染色体显性遗传性视网膜色素变性家系的IMPDHl基因的突变特征以及与临床表型的关系，探讨其病因和发病机制，利用分子遗传学的方法，确定家系内遗传连锁关系。方法严格按照有关伦理学要求进行家系收集，所有现存家系成员行详细的眼科检查（包括视力检查、裂隙灯和眼底镜检查、视野、暗适应阈值以及ERG检查）。提取该家系lO例患者、lO例未患病成员外周血基因组DNA：应用聚合酶链反应扩增IMPDHl第7外显子基因片段，利用扩增产物直接测序方法对样本进行IMPDHl基因突变检测。结果该家系中lO例患者的IMPDHl基因发生了Asp-226-Asn（GAC→AAC）的错义突变，lO例家系未患病成员则没有此突变。结论IMPDHl基因的一种已知突变Asp-226-Asn与该家系所发生的视网膜色素变性存在紧密连锁关系。     

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。     

常染色体显性遗传RP患者视紫红质基因突变的检测分析

目的研究常染色体显性遗传视网膜色素变性（ADRP）患者视紫红质（RHO）基因的突变特征及其在视网膜色素变性（RP）发病机制中的作用。方法应用变性高效液相色谱分析（DHPLC）技术和直接及克隆测序方法对RHO基因进行突变检测。结果一家系4例ADRP患者RHO基因的第297密码子存在杂合的两种类型密码子（AGC和AGT）。该家系的另3名患者未检测到该突变，对照组发现1例此类型沉默型突变。该家系在第3外显子3’端下游第4个碱基处发生C—T转换，其11个成员中该位点呈T纯合子1例，呈杂合子状态8例。对照组发现2例该位点的杂合子状态。结论视紫红质基因Ser-297-Ser突变与RP疾病未出现“共分离”现象，因此该沉默型突变不是该ADRP家系的致病原因，系RHO基因的多态现象。     

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的研究

目的探讨常染色体显性遗传型视网膜色素变性(autosomal dominant retinitis pigmentosa,ADRP)患者视紫红质(rhodopsin,RHO)基因是否存在突变。方法应用聚合酶链反应(polymerase chain reaction,PCR)扩增RHO第1、5外显子基因片段，以限制性核酸内切酶酶切消化技术检测38个ADRP家系的57名患者和60名正常对照者RHO第58、347密码子的突变。结果1个ADRP家系的4名患者第58密码子发生点突变，另2个ADRP家系的6名患者第347密码子也出现点突变，而对照者未发现上述两种突变。结论ADRP存在分子水平的遗传异质性，某些ADRP是由于RHO基因突变所致。(中华眼底病杂志,1998,14:108-110)     

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.     

常染色体显性视网膜色素变性家系视紫红质基因突变的检测分析

目的 观察一个常染色体显性视网膜色素变性(autosomal dominant retinitis pigmentosa,ADRP)家系的视紫红质(rhodopsin,RHO)基因突变特征。 方法 抽取20个ADRP家系成员外周血3～5 ml并提取DNA；聚合酶链反应(polymerase chain reaction,PCR)扩增RHO基因第1～5外显子基因片段, 用直接测序法对20个DNA样本进行RHO基因突变检测。 结果 该家系中10例ADRP患者的RHO基因的第182密码子发生G→A置换突变(Gly-182-Asp)，而在2例患者和8个未患病家系成员中均未发现此突变。 结论 Gly-182-Asp突变不一定是ADRP家系的致病原因;在RHO基因附近可能存在新的基因, 但还需要进一步研究证明。 (中华眼底病杂志, 2002, 18: 256-258)     

Expression of the TIGR gene in the iris,ciliary body,and trabecular meshwork of the human eye

Purpose: To identify mutations in the rhodopsin ( RHO ) gene in Chinese patients with autosomal dominant retinitis pigmentosa (ADRP) and to measure the prevalence rate of RHO mutations in Chinese ADRP cases. Methods: Thirteen Chinese families with ADRP were clinically characterized. The complete coding region and intron splice sites of RHO were analyzed for mutations with single-strand conformation polymorphism (SSCP) analysis and direct genomic sequencing. Results: One of the 13 Chinese families with ADRP was found to have a new, previously unidentified RHO mutation, a change from GAG to TAG at codon 341. The mutation (E341X) results in an in-frame stop codon, leading to the truncation of the rhodopsin protein. Mutation E341X was not detected in 100 normal control individuals. Patients carrying mutation E341X reported night blindness and showed optic atrophy, vessel attenuation, and a few bone spicule-like pigments in peripheral retina at the age of 23–25 years. At the age of 30 years, visual acuity was severely impaired, peripheral visual field was greatly constricted, rod and cone ERG was not detectable, and only a slight left cone response remained. Conclusion: We have identified a novel rhodopsin mutation (E341X) in a Chinese family with ADRP. The location and character of the mutation expand the spectrum of RHO mutations causing RP. Identification of a RHO mutation in one of the 13 ADRP families studied suggests that only 7.7% of the ADRP cases in a Chinese population were caused by RHO mutations, a ratio significantly lower than that from North America or Europe.     

汉族常染色体显性视网膜色素变性一家系的连锁分析及突变筛查

背景 原发性视网膜色素变性(RP)有明显的遗传异质性和表型异质性,目前已确定的致病基因较多,确定患病家系的致病基因是进行基因治疗的基础. 目的 对患常染色体显性遗传性RP(ADRP)的一个汉族家系进行致病基因的定位和基因突变分析.方法 此家系的5代21名成员纳入研究,包括12例ADRP患者和9名表型正常者.12例患者进一步接受中心视野、间接检眼镜、眼电图(EOG)、视网膜电图(ERG)检查.对22个已知的ADRP致病基因所在染色体位点进行连锁分析,以确定该家系与疾病连锁的染色体区域,随后对该区域附近的候选基因视紫红质(RHO)进行直接测序评估其突变情况. 结果 间接检眼镜检查该家系先证者眼底表现符合原发性RP表现,EOG和ERG表现为波形记录不到,视野呈向心性缩小.两点连锁分析结果显示,该家系致病基因位点与遗传标记D3S1292连锁,在θ=0.0时得到最大优势对数(LOD)值为3.6671.候选的RHO基因直接测序结果发现,该家系所有患者第53位密码子的第2个核苷酸均出现了C→G的突变,致其氨基酸由脯氨酸变为精氨酸(Pro53Arg),而该家系正常成员中未发现此突变. 结论 RHO基因的错义突变Pro53Arg与RP疾病出现共分离现象,可确定为该ADRP家系的致病基因.     

Retinal function and rhodopsin levels in autosomal dominant retinitis pigmentosa with rhodopsin mutations

We studied rod and cone function in 20 patients from six families with autosomal dominant retinitis pigmentosa, who represented five different point mutations in the gene encoding rhodopsin. In a family with a stop codon mutation at the carboxyl end of the molecule (glutamine-344), young members with the mutation were asymptomatic and clinically unaffected but showed about 1 log unit of rod sensitivity loss across the visual field and decreased rhodopsin levels; at this stage, cone function was essentially normal. In three families with mutations at the border of a transmembrane segment (arginine-135-leucine and arginine-135-tryptophan), there was neither detectable rod function nor measurable rhodopsin; cone function was variably impaired. Two families carrying different mutations (threonine-17-methionine and threonine-58-arginine) had altitudinal visual field defects with less impaired rod and cone function in the inferior than in the superior field. Rod adaptation was abnormal in both families, but the time course of adaptation differed between patients with the two mutations. Differences in the pattern of retinal dysfunction were therefore discernible in patients with different rhodopsin mutations.     

散发性视网膜色素变性视紫红质基因突变筛查

目的研究中国人散发性视网膜色素变性（sporadic retinitis pigmentosa，SRP）患者视紫红质（rhodopsin，RHO）基因突变频率及特征，揭示其在SRP发病机制中的潜在作用。方法运用聚合酶链反应一单链构象多态性（polymerase chain reaction—single—strand conformation polymorphism，PCR—SSCP）结合DNA测序技术，对80例SRP患者和80例健康对照者进行RHO基因5个外显子的突变筛查。结果SRP患者RHO基因5个外显子PCR扩增产物经SSCP分析后，发现其电泳带型与对照组一致，均包括2条单链带和1条双链带，且电泳迁移率相同，即在患者和对照组中均未检测到RHO基因突变。结论中国人SRP患者RHO基因外显子的突变率较低；PCR—SSCP分子遗传学方法快速、简单、灵敏，适用于大批量RP患者的基因变异筛查。（中国眼耳鼻喉科杂志，2008，8：351—353）     

Visual phenotype in patients with Arg41Gln and Ala196+1bp mutations in the CRX gene

Our aim was to describe the visual function characteristics of affected members from two unrelated families with different dominant mutations in the CRX gene. Standard full-field ERGs and high-intensity a-wave series were obtained. In addition, in most subjects, dark-adapted (DA) thresholds, color vision function (arrangement tests), and static perimetry were assessed. A point mutation in codon 41 of the CRX gene (Arg41Gln) was identified in family members from the RFS087 family who were tested on several occasions since 1983. Depending on age, affected members showed varying degrees of acuity loss, normal or slightly elevated DA thresholds, reduced cone a- and b-wave amplitudes, normal or minimally delayed cone b-wave implicit times, and normal rod and cone phototransduction gain parameters. An insertion mutation (Ala196+1bp) was found in two members of another family (RFS014). Affected members showed reduced visual acuity, normal or slightly elevated DA thresholds, relatively preserved rod ERG and substantially reduced or undetectable cone ERG, and normal rod phototransduction gain parameters. The Arg41Gln was associated with a late-onset, slowly progressing mild form of cone-rod dystrophy with cone loss but preserved rod and cone sensitivity until later in life. The Ala196+1bp mutation was associated with an early-onset, severe form of cone-rod dystrophy similar to that described in the original CORD2 family (Evans et al., Arch Ophthalmol 1995;113:195-201).     

Visual phenotype in patients with Arg41Gln and ala196+1bp mutations in the CRX gene

Our aim was to describe the visual function characteristics of affected members from two unrelated families with different dominant mutations in the CRX gene. Standard full-field ERGs and high-intensity a-wave series were obtained. In addition, in most subjects, dark-adapted (DA) thresholds, color vision function (arrangement tests), and static perimetry were assessed. A point mutation in codon 41 of the CRX gene (Arg41Gln) was identified in family members from the RFS087 family who were tested on several occasions since 1983. Depending on age, affected members showed varying degrees of acuity loss, normal or slightly elevated DA thresholds, reduced cone a- and b-wave amplitudes, normal or minimally delayed cone b-wave implicit times, and normal rod and cone phototransduction gain parameters. An insertion mutation (Ala196+1bp) was found in two members of another family (RFS014). Affected members showed reduced visual acuity, normal or slightly elevated DA thresholds, relatively preserved rod ERG and substantially reduced or undetectable cone ERG, and normal rod phototransduction gain parameters. The Arg41Gln was associated with a late-onset, slowly progressing mild form of cone-rod dystrophy with cone loss but preserved rod and cone sensitivity until later in life. The Ala196+1bp mutation was associated with an early-onset, severe form of cone-rod dystrophy similar to that described in the original CORD2 family (Evans et al., Arch Ophthalmol 1995;113:195-201).     

Molecular biological study of the rhodopsin gene in Japanese patients with autosomal dominant retinitis pigmentosa]

The author analyzed codon 347 of the rhodopsin gene using PCR (polymerase chain reaction) amplification and restriction enzymes in 19 unrelated Japanese families including 28 patients with autosomal dominant retinitis pigmentosa (ADRP). An allele of codon 347 mutation was found in a family (father and daughter). Sequence analysis shows that the mutation is from CCG to CTG. This mutation appears to be the cause of one form of ADRP, since it was also found in Japanese cases of ADRP which have a different racial background from families reported by Dryja et al.     

Ocular manifestations in autosomal dominant retinitis pigmentosa with a Lys-296-Glu rhodopsin mutation at the retinal binding site.

A lysine to glutamic acid substitution at codon 296 in the rhodopsin gene has been reported in a family with autosomal dominant retinitis pigmentosa. This mutation is of particular functional interest as this lysine molecule is the binding site of 11-cis-retinal. The clinical features of a family with this mutation have not been reported previously. We examined 14 patients with autosomal dominant retinitis pigmentosa and a lysine-296-glutamic acid rhodopsin mutation. Four had detailed psychophysical and electrophysiological testing. Most affected subjects had severe disease with poor night vision from early life, and marked reduction of visual acuity and visual field by their early forties. Psychophysical testing showed no demonstrable rod function and severely reduced cone function in all patients tested.     

Mutation of human retinal fascin gene (FSCN2) causes autosomal dominant retinitis pigmentosa

PURPOSE: To characterize the clinical features of 14 Japanese patients with autosomal dominant retinitis pigmentosa (ADRP) who were found to have a mutation in the FSCN2 gene. METHODS: Mutation screening by single-strand conformation polymorphism (SSCP) was performed in 120 unrelated patients with ADRP, 200 unrelated patients with autosomal recessive retinitis pigmentosa (ARRP), and 100 patients with simplex RP (SRP). The DNA fragment that showed abnormal mobility on SSCP was sequenced. The clinical features of these patients were determined by visual acuity, slit lamp biomicroscopy, electroretinography, fluorescein angiography, and kinetic visual field testing. RESULTS: A novel 208delG mutation in the FSCN2 gene was identified in 14 patients from four unrelated families with ADRP. The ophthalmic findings were typical of RP. CONCLUSIONS: The findings show that a 208delG mutation in the FSCN2 gene produces ADRP. This mutation was found in 3.3% of the patients with ADRP in Japan, which suggests that it may be relatively common in Japanese patients with ADRP.