中国人与欧美人USH2A基因突变谱不同

Usher综合征是一种常见的综合征性视网膜色素变性（RP）,为常染色体隐性遗传性疾病,具有临床和遗传高度异质性。迄今已将Usher综合征的致病基因定位了12个染色体位点,确定了其中的9个致病基因。很多研究证实USH2A基因是Usher综合征的主要致病基因,USH2A基因突变还可引起单纯性RP,但国内的一些研究结果发现,中国人USH2A基因突变谱与欧美人不同。中国人RP致病的热点基因谱尚有待进一步研究。     

常染色体显性遗传视网膜色素变性的相关基因研究概况

视网膜色素变性(retinitispigmentosa,RP)是一种发病机制尚未完全明确的遗传性疾病,其在遗传和表型上具有较大的异质性。其中常染色体显性遗传视网膜色素变性(autosomadominantretinitpigmentosa,ADRP)占RP的20%～25%,目前发现至少有19个致病基因,其中11个已被克隆。本文将就ADRP的相关致病基因的研究进展作一综述。     

先天性特发性眼球震颤的致病基因和基因位点

先天性特发性眼球震颤（CIN）是指出生后早期出现的、无明显诱因的双眼非自主性、有节律的往返运动。CIN发病率为0.015%～0.14%。CIN患者可表现为不同程度的视力下降以及代偿头位等临床特征。CIN的病因和发病机制不明,但存在家族遗传倾向,可表现为常染色体显性、常染色体隐性以及X连锁遗传。目前报道的与常染色体显性遗传模式相关的致病基因位点有4个,与X连锁遗传模式相关的致病基因位点有3个,而只有位于X染色体上的酵母功能域包含蛋白7（FRMD7）基因被确定与CIN发病相关。笔者现就CIN的遗传特征、临床表型以及相关的致病基因位点、致病基因的发现进行综述,并阐述FRMD7基因突变引起的眼球震颤的发病机制。     

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。     

视网膜色素变性分子遗传学研究现状

视网膜色素变性是由于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最常见的遗传性眼底病 ,具有大的临床和遗传异质性。其遗传方式可为常染色体显性、常染色体隐性、X染色体连锁遗传和散发型。目前已发现RP相关基因 1 4种 ,其中常染色体显性遗传 4种 ,常染色体隐性遗传 8种 (包括视紫质 ) ,X染色体连锁遗传 2种。本文着重阐述了已知RP相关基因的研究现状。     

核前体mRNA的剪接与视网膜色素变性

视网膜色素变性（RP）是一组常见的遗传性视网膜变性疾病,具有高度的遗传异质性。在超过40个不同种类的RP致病基因中包括一部分全身广泛表达的基因,最具代表性的为5个核前体mRNA（pre—mRNA）的剪接相关基因。在RP基因的最新研究中,人们认识到核前体mRNA剪切缺陷在常染色体显性遗传RP（adRP）病因学中占有非常重要地位,同时也使人们对核前体mRNA剪切这一基本的生物学过程有了更清楚的认识。目前,人们在此领域的研究主要集中在两个方面：（1）adRP相关的核前体mRNA剪切基因（adRP-剪接因子）突变如何影响核前体mRNA剪切功能。（2）这些全身表达的基因变异为何特异性地引起视网膜病变。这两个研究主题也恰恰吻合了此类疾病发病机制中的前后两个重要环节。近年来,人们已经在第一个研究主题中取得了显著的进步,第5个adRP-剪接因子SNRNP200基因的克隆及其相关功能研究是此研究方向的重要进步之一。在第二个研究主题中人们也进行了大量的工作,各种生物模型的建立使得人们对疾病的病理过程有了更清晰的描述,然而在关键的发病机制问题上依然面临着许多令人迷惑的问题。总结adRP-剪接因子的最新研究成果,重点阐述核前体mRNA的剪接缺陷引发RP的分子机制研究中亟待解决的问题。     

视网膜色素变性发病机制及治疗进展

视网膜色素变性（retintis pigmentosa,RP）是指以进行性感光细胞及色素上皮功能丧失为共同表现的遗传性、退行性的疾病,RP是主要的致盲性眼病。其遗传方式包括X连锁遗传、常染色体隐性或者显性遗传,也有散发。临床表现为典型的三联征:骨细胞样色素沉着、视网膜血管缩窄和视盘蜡样苍白。RP具有高度的基因异质性(多个突变位点引起同一疾病）及表型异质性。本文对RP的发病机制和治疗方法进行简要综述。     

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。     

视网膜色素变性的相关基因研究进展

视网膜色素变性(RP)是由于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一种常见的、遗传性、致盲性眼底病,具有较大的临床和遗传异质性。迄今通过连锁分析和侯选基因筛查,已有14个常染色体显性遗传ADRP;20个常染色体隐性遗传ARRP和5个X-染色体连锁遗传型XLRP位点被定位,其中32个基因已被克隆,每种遗传方式都有多个基因被克隆。对于这些致病基因的结构、突变及其功能目前已经有了新的研究进展。     

De novo mutation in the RP1 gene (Arg677ter) associated with retinitis pigmentosa

PURPOSE: The Arg677ter mutation in the RP1 gene is one of the most common causes of autosomal dominant retinitis pigmentosa (RP). In the current study, a de novo Arg677ter RP1 gene mutation was identified in a patient with RP. METHODS: RP1 gene mutation screening was performed in probands with simplex RP. In one proband with the RP1 mutation, paternity was established by analyzing 24 short tandem repeat polymorphisms. Additional candidate RP genes, including rhodopsin, RDS/peripherin, RP2, and RPGR, were also examined in this proband. Phenotype was characterized with psychophysics, electroretinography, and optical coherence tomography. RESULTS: An RP1 (Arg677ter) mutation was identified in one of the patients with simplex RP, but the sequence change was not detected in his parents. Parentage was confirmed, and other candidate genes were negative for mutations. Retinal function and cross-sectional imaging studies in the patient indicated greater rod than cone dysfunction with a photoreceptor basis for the abnormalities. CONCLUSIONS: The de novo origin of an RP1 (Arg677ter) mutation in a patient with simplex RP suggests that this common autosomal dominant RP mutation can arise independently in the population and supports the hypothesis of a mutational hotspot in the RP1 gene.     

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。     

CERKL mutations and associated phenotypes in seven Spanish families with autosomal recessive retinitis pigmentosa

PURPOSE: Retinitis pigmentosa (RP) is a genetically heterogeneous group of inherited retinopathies. Up to now, 39 genes and loci have been implicated in nonsyndromic RP, yet the genetic bases of >50% of the cases, particularly of the recessive forms, remain unknown. A novel gene (CERKL) has been described as associated with RP26. It encodes a ceramide kinase that is assumed to be involved in sphingolipid-mediated apoptosis in the retina. This is a report of the phenotypes and genotypes of persons carrying disease-causing mutations in CERKL. METHODS: Two hundred ten unrelated Spanish families with nonsyndromic autosomal recessive RP were analyzed for sequence variations. Seven of these families presented a mutation in CERKL. Nine affected persons of these families were clinically investigated, including visual field, electrophysiology, and fundus examination. RESULTS: The mutation p.Arg257ter was identified in the homozygous state in all seven affected families. The patients with this variation in CERKL presented a common phenotype with characteristic macular and peripheral lesions. CONCLUSIONS: This study presents the first genotype-phenotype correlation for persons carrying p.Arg257ter mutation and provides clues for a characteristic phenotype of these mutations among persons with autosomal recessive cases.     

Multicenter genetic study of retinitis pigmentosa in Japan: II. Prevalence of autosomal recessive retinitis pigmentosa

Retinitis pigmentosa (RP) is a group of genetically heterogeneous diseases with autosomal recessive (AR), autosomal dominant, and X-linked modes of inheritance. Autosomal recessive retinitis pigmentosa (ARRP) is the most common form in Japan. A genetic analysis was done to determine the prevalence of ARRP indirectly, to provide an estimation of changing trends in the overall prevalence of RP. Data on the frequency of consanguinity and marriage year of normal parents of 59 ARRP patients were obtained from a nationwide multicenter survey of typical retinitis pigmentosa conducted in 1990. The gene frequency of ARRP was 0.01145 (Dahlberg's formula). In 1990, the number of young symptomatic ARRP patients decreased, while the number of patients aged 40 years and older increased. The total number of symptomatic ARRP patients in 1990 was nearly 21% higher than in 1970. Despite a dramatic decline in consanguinity in recent decades in Japan, the number of ARRP patients has increased. This increase is attributed to greater longevity and overall population growth. Our results suggest that the total number of RP patients has not decreased, and may even have increased.     

常染色体显性视网膜色素变性家系的基因连锁定位和候选基因的序列分析

目的对一常染色体显性视网膜色素变性（RP）家系进行致病基因的连锁定位，并对候选基因进行序列分析。方法在家系中进行全基因组扫描以确定与疾病连锁的染色体区域，对该区域附近的候选基因进行直接序列分析。结果此家系致病基因的最小可能区域（MCR）被定位于19号染色体微卫星标记D19S246和D19S601之间不到5厘摩（cM）的区域。对该区域附近的候选基因进行直接序列分析的结果并未发现致病性基因突变。结论CRX（锥杆细胞同源基因）和PRPF3l基因是该家系的非致病性基因，在19号染色体上可能存在导致常染色体显性视网膜色素变性（adRP）的新的致病基因。     

Update on the molecular genetics of retinitis pigmentosa

Retinitis pigmentosa (RP) is a heterogeneous group of retinal dystrophies characterized by photoreceptor cell degeneration. RP causes night blindness, a gradual loss of peripheral visual fields, and eventual loss of central vision. Advances in molecular genetics have provided new insights into the genes responsible and the pathogenic mechanisms of RP. The genetics of RP is complex, and the disease can be inherited in autosomal dominant, recessive, X-linked, or digenic modes. Twenty-six causative genes have been identified or cloned for RP, and an additional fourteen genes have been mapped, but not yet identified. Eight autosomal dominant forms are due to mutations in RHO on chromosome 3q21-24, RDS on 6p21.1-cen, RP1 on 8p11-21, RGR on 10q23, ROM1 on 11q13, NRL on 14q11.1-11.2, CRX on 19q13.3, and PRKCG on 19q13.4. Autosomal recessive genes include RPE65 on chromosome 1p31, ABCA4 on 1p21-13, CRB1 on 1q31-32.1, USH2A on 1q41, MERTK on 2q14.1, SAG on 2q37.1, RHO on 3q21-24, PDE6B on 4p16.3, CNGA1 on 4p14-q13, PDE6A on 5q31.2-34, TULP1 on 6p21.3, RGR on 10q, NR2E3 on 15q23, and RLBP1 on 15q26. For X-linked RP, two genes, RP2 and RP3 (RPGR), have been cloned. Moreover, heterozygous mutations in ROM1 on 11q13, in combination with heterozygous mutations in RDS on 6p21.1-cen, cause digenic RP (the two-locus mechanism). These exciting molecular discoveries have defined the genetic pathways underlying the pathogenesis of retinitis pigmentosa, and have raised the hope of genetic testing for RP and the development of new avenues for therapy.