开角型青光眼有Rieger综合征患者中RIEG基因突变筛查

目的 分析国人开角型青光眼及Ｒｉｅｇｅｒ综合征中ＲＩＥＧ基因突变情况。方法 收集无血源关系的原发性开角型青光眼１５例、先天性青光眼８例、Ｒｉｅｇｅｒ综合征４例。制备全体患者的血白细胞基因组ＤＮＡ。应用ＰＣＲ法扩增所有样品中ＲＩＥＧ基因全部编码区（共６例引物），然后分别用异源双链－ＳＳＣＰ法筛查基因突变。结果 所分析的２７例患者基因组ＤＮＡ中均未检测到ＲＩＥＧ突变。结论 ＲＩＥＧ基因变异可能不是本组     

东北地区原发性闭角型青光眼家系PITX2基因和FOXC1基因突变筛查

目的通过分子遗传学研究筛查原发性闭角型青光眼家系PITX2基因和FOXC1基因突变情况。设计实验研究。研究对象东北地区原发性闭角型青光眼4个家系13例患者和24例健康成员。方法应用聚合酶链反应(PCR)扩增PITX2基因和FOXC1基因所有编码外显子,直接测序法筛查致病突变。主要指标PITX2基因、FOXC1基因序列。结果所分析的4个家系13例患者基因组DNA中均未检测到PITX2基因、FOXC1基因突变。结论 PITX2基因和FOXC1基因不是中国东北地区该原发性闭角型青光眼家系的致病病因。     

陕西省两个原发性开角型青光眼家系MYOC基因突变的研究

目的:研究陕西省两个原发性开角型青光眼家系MYOC基因突变情况。方法:分析陕西省两个原发性开角型青光眼家系。从先证者、家族成员及正常对照者外周静脉血中提取基因组DNA;根据MYOC基因编码序列合成7对特异性引物;应用PCR扩增MYOC基因3个外显子序列,DNA测序法双向测序筛选突变位点。结果:家系1中并未发现MYOC基因编码序列的突变位点;家系2中三个患者MYOC基因均存在异常(c.1021T>C杂合突变),导致myocilin蛋白第341位氨基酸由丝氨酸(S)转变为脯氨酸(P)即Ser341Pro错义突变,该家系正常成员及100例对照者中均未发现此突变。结论:MYOC基因Ser341Pro突变可能为家系2原发性开角型青光眼的致病原因。     

重庆地区开角型青光眼患者及其亲属和正常人群中小梁网糖皮质激素诱导反应蛋白基因突变的研究

目的 研究开角型青光眼患者及其亲属和正常人群中小梁网糖皮质激素诱导反应蛋白(TIGR)基因突变的情况。方法 (1)应用聚合酶链反应(PCR)方法,对15例开角型青光眼患者及其10例一级亲属和20例正常对照者的TIGR基因的3个外显子、部分内含子及部分启动子(7对引物)的各个片段进行扩增,应用单链空间构象多态(SSCP)分析法,筛选可能存在突变的PCR产物。(2)将筛选出的PCR产物交上海基康公司测序。(3)对突变片段行生物信息学分析。结果 (1)在重庆地区15例原发性开角型青光眼患者中,共发现TGR基因突变者5例,其中青少年型青光眼4例;在10例青光眼患者亲属中发现TIGR基因突变者2例;正常对照者20例中未发现TIGR基因突变。(2)PCR产物测序共发现4个序列改变,其中编码区2个,非编码区2个。编码区的2个突变位点(Ser55Thl、Asp247Stop)及第二内含子区bp35c→t的突变,均未见文献报道;而在启动子区域bp-83c→t的突变有文献报道为1个多态位点。(3)生物信息学分析结果显示编码区的突变可导致氨基酸序列、蛋白质的二级结构及等电点、抗原结合位点等发生改变。结论 TIGR基因突变与青少年开角型青光眼的发生密切相关,由此可推测青光眼患者的亲属发病率较正常人高。TIGR基因突变可引起TIGR蛋白结构及理化特性的变化,这些改变可能是引发开角型青光眼的危险因素之一。     

高度近视与原发性开角型青光眼

目的:从流行病学、临床特征及诊断、遗传学说及机制等方面对高度近视与原发性开角型青光眼的关系及研究进展进行综述。方法:仔细分析了28篇原文,总结出高度近视与原发性开角型青光眼的可能机理。结果:高度近视与原发性开角型青光眼密切相关,其可能的机制有:①升压基因学说。②胶原基因学说。结论:高度近视与原发性开角型青光眼密切相关,根据TIGR基因理论和胶原基因理论,高度近视与原发性开角型青光眼都与TIGR基因突变和胶原疾病有关。     

青光眼研究的分子遗传学方法和研究进展

原发性青光眼系具有遗传倾向的疾病。用分子遗传学方法寻找青光眼病人的致病基因、基因突变以及相应的编码蛋白缺陷是青光眼研究领域中的重要课题。目前定位致病基因的三个主要方法是 :候选基因途径、核型提示和连锁分析。常用研究途径是 :临床表现型———连锁研究———候选基因和突变分析。到目前为止已经鉴定出的基因有先天性青光眼的GLC3A ,GLC3B ;Rieger综合征的二个基因位点 4 q2 5,1 3 q1 4 ;无虹膜的PAX6;Lowe综合征OCRL 1 ;原发性开角型青光眼GLC1A ,GLA1B ,GLA1C ,GLA1D ,GLA1E ;小眼球、闭角型青光眼家系的染色体 1 1位点等。现在临床上定义为同一疾病的病症往往显现遗传异质性。在青光眼所涉及的蛋白中 ,比较明确的是先天性青光眼的细胞色素P4 50 1B1和开角型青光眼的小梁网诱导性糖皮质激素反应蛋白。这些已发现和逐渐将被定位的基因的重大意义在于给于青光眼基因型分类 ,建立表现型和基因型统一 ,同时改进常规治疗 ,开发新的药物 ,进而为基因治疗提供有力的依据。     

ATOH7和RFTN1与青少年型原发性开角型青光眼的关联研究

目的：前期研究显示ATOH7和RFTN1基因的SNPs之间的相互作用可增加成年型原发性开角型青光眼(primary open angle glaucoma, POAG)的患病风险,本实验研究ATOH7和RFTN1基因的序列变异在青少年型原发性开角型青光眼(juvenile-primary open angle glaucoma, JOAG)患者中的作用。

方法：研究对象包括青少年型原发性开角型青光眼患者共52例(确诊年龄<35岁)及298例对照者(年龄≥60岁)。收集研究对象的血样,提取DNA,然后对提取的DNA进行聚合酶链反应(PCR)后测定ATOH7单外显子的序列。另外对ATOH7上游单核苷酸多态性位点(SNP)(rs1900004和rs3858145)及RFTN1的SNP(rs690037)进行TaqMan分析检测其基因分型。

结果：在青少年型原发性开角型青光眼患者ATOH7单外显子测序结果中没有发现基因突变位点。ATOH7测序结果发现的两个SNPs：rs7916697、rs61854782和ATOH7上游SNPs(rs1900004、rs3858145)及RFTN1的SNP(rs690037)的单倍体型及等位基因频率在患者组与对照组无统计学意义(所有校正P > 0.05),ATOH7及RFTN1与青少年型原发性开角型青光眼没有相关性。

结论：本实验前期研究虽显示ATOH7和RFTN1基因的SNPs之间的相互作用可增加成年型原发性开角型青光眼的患病风险,但本研究未发现与青少年型原发性开角型青光眼有相关性,提示不同类型开角型青光眼可能在基因机制方面的差异,值得我们进一步研究     

睑裂狭小综合征Ⅱ型一家系未检测到FOXL2基因突变

目的 对一个常染色体显性遗传的睑裂狭小综合征Ⅱ型家系FOXL2基因突变进行研究.方法 采集一个中国人睑裂狭小综合征Ⅱ型家系的4例患者及家系中5例健康人和30例正常对照者外周静脉血样,提取基因组DNA,参考FOXL2基因序列,设计5对引物,应用PCR和DNA测序技术对FOXI2基因的编码区和启动子区进行扩增和突变检查.结果 成功提取了该家系中4例患者和5例健康人与30名正常对照者外周血基因组DNA,分段扩增出了FOXL2基因的编码区及启动子区,但5段测序结果显示该家系中4例患者和5例健康人与30名正常对照者的FOXL2基因测序结果相同.该家系患者FOXL2基因编码区及启动子区均未发现突变.结论 该家系睑裂狭小综合征的致病因素不是由FOXL2基因突变引起的.     

高度近视与原发性开角型青光眼关系的研究进展

临床和实验研究均发现,青光眼患者近视发生率高于非青光眼人群。反之,近视,尤其高度近视（high myopia,HM）人群较其它人群更常伴有青光眼。当HM与原发性开角型青光眼（primary open—angle glaucoma,POAG）并存时,病情变得尤其复杂。两者发病机制之间的关系,目前在分子和基因水平的研究重点是：胶原基因学说和升压基因学说。从病理学角度讲,高度近视与青光眼都是胶原病变;此外,二者的小梁网细胞在糖皮质激素诱导下易表达特异性蛋白,这可能与高度近视、原发性开角型青光眼的TIGR（trabecular meshwork induced glucocorticoid response protein）基因突变有关。本文从流行病学、发病机制、临床特征及诊断注意要点等方面对高度近视与原发性开角型青光眼的关系及研究进展进行综述。     

青光眼住院病人5年构成及视力损害分析

目的 对邯郸市眼科医院青光眼的住院病人5年构成和视力损害情况进行分析.方法 对2001～2005年邯郸市眼科医院住院患者中不同类型青光眼进行回顾性分析.结果 962例患者中,男性320例,女642例,平均年龄(61.2±13.6)岁.其中,原发性青光眼794例(82.5%),继发性青光眼127例(13.30%),先天性青光眼13例(1.4%).原发性青光眼中,急性闭角型青光眼424例(53.4%),慢性闭角型青光眼313例(37.4%),开角型青光眼57例(7.1%).原发性青光眼中双眼盲发生率7.9%(63/794),其中急性闭角型青光眼致盲、慢性闭角型青光眼、原发性开角型青光眼所致分别占36.5%(23/63)、52.3%(33/63)、11.1%(7/63);低视力发生率16.8%(134/794),其中急性闭角型青光眼、慢性闭角型青光眼致盲和原发性开角型青光眼所致分别占46.2%(62/134)、30.6%(41/134)和8.9%(12/134).结论 原发性闭角型青光眼是邯郸地区住院青光眼患者中的主要类型,而住院闭角型青光眼中,急性闭角型青光眼居多且视力损害重,如能加强和规范急性闭角型青光眼的早期防治和急诊处理,可大幅度降低青光眼的致盲率.     

Mendelian molecular genetics in glaucoma

Early-onset forms of glaucoma are inherited as Mendelian-dominant or Mendelian-recessive traits. They encompass primary congenital or infantile glaucoma; juvenile primary open-angle glaucoma; development glaucomas including Rieger syndrome, glaucoma associated with nail-patella syndrome, Peters' anomaly, and nanophthalmos; and glaucoma associated with pigment dispersion syndrome. Personalized gene therapy has been proposed as an alternative therapeutic strategy for ocular diseases. This approach might be applicable in families with primary congenital glaucoma and defined mutations in the CYP1B1 gene.     

Glaucoma genetics: where are we? Where will we go?

The understanding of the genetic basis of the glaucomas has advanced rapidly. Mutations in the myocilin gene (previously known as TIGR) at the GLC1A locus on chromosome 1q21-q31 occur in a subset of patients with juvenile- and adult-onset primary open-angle glaucoma. Five other genetic localizations for primary open-angle glaucoma have now been reported. In patients with primary congenital glaucoma, mutations have been found in the CYP1B1 gene on chromosome 2p21. At least one other locus for primary congenital glaucoma is mapped. In the developmental glaucomas, mutations in the PITX2 gene on chromosome 4q25 have been associated with Rieger syndrome, iris hypoplasia, and iridogoniodysgenesis. A second locus for Rieger syndrome resides on chromosome 13q14. Mutations in the FKHL7 gene on chromosome 6p25 have been described in patients with Axenfeld-Rieger anomaly. A new ocular finding of glaucoma in pedigrees with the nailpatella syndrome has been described, and mutations in the LMX1B gene on chromosome 9q34 are now known to underlie nail-patella syndrome. Two loci for the pigment dispersion syndrome have been mapped. This paper provides an overview of recent literature, summarizes developments in glaucoma genetics, and addresses their potential relevance to the clinical management of glaucoma.     

Genetic analysis of PITX2 and FOXC1 in Rieger Syndrome patients from Brazil

PURPOSE: Axenfeld-Rieger syndrome is a genetically heterogeneous, autosomal dominant disorder that is characterized by anterior segment defects, glaucoma, and extraocular anomalies. This study examined the two genes known to cause Rieger syndrome, PITX2 and FOXC1, for mutations in five Brazilian families with Axenfeld-Rieger syndrome. METHODS: Five families with a total of 23 persons affected by Axenfeld-Rieger syndrome were recruited for this study. A sequencing-based mutation screen was undertaken for the PITX2 and FOXC1 genes. Linkage analysis was used to study one large family for which no mutations were detected in the PITX2 or FOXC1 genes. RESULTS: Two of the five families harbored mutations in the PITX2 gene, but none of the families had a detectable FOXC1 mutation. Haplotypic analysis of three Rieger syndrome regions in a large family with Axenfeld-Rieger syndrome excluded linkage to the 4q25 (PITX2), 6p25 (FOXC1), and 13q14 (RIEG2) regions. CONCLUSIONS: It appears that the PITX2 gene is responsible for a significant portion of Axenfeld-Rieger syndrome in the Brazilian population. Furthermore, there is also evidence for the presence of genetic heterogeneity of the disorder within the Brazilian population. Finally, a large family with Axenfeld-Rieger syndrome has been identified that does not appear to harbor any of the three known loci. Axenfeld-Rieger syndrome gene segregation in this family likely represents a novel locus.     

Genetic studies on primary open angle glaucoma

Case work presents the newest studies on molecular genetics in primary open angle glaucoma. The molecular genetics in all types of glaucoma have been a subject of investigations for the last few years. As a result, two loci (GLC3A and GLC3B) have been identified for primary congenital glaucoma, one locus (GLC1A) for juvenile primary open angle glaucoma and further two loci (GLC1B and GLC1C) for adult-onset primary open angle glaucoma. The gene TIGR (trabecular meshwork inducible glucocorticoid response protein) localised in GLC1A was described last year for the first time, thereafter there were trials on mutations within this gene conducted successfully. In this review there are studies presenting the mapping of the first five GLC loci and identification of mutations.     

The attempt to identify mutations in TIGR gene in Polish patients with primary open angle glaucoma

PURPOSE: The case work presents studies on the identification of the most frequent TIGR mutations in Polish population with primary open angle glaucoma. The TIGR gene was identified in a GLC1A locus on chromosome 1 (1q) in a family with juvenile primary open angle glaucoma. The gene encodes TIGR protein (trabecular meshwork inducible gluco-corticoid response protein)--trabecular meshwork glucoprotein. MATERIAL AND METHODS: Ophthalmologic examination was performed in twenty subjects with juvenile primary open angle glaucoma. The blood samples were taken for DNA analyses. RESULTS: Neither any mutations nor polymorphic changes in TIGR gene were found. CONCLUSION: Our studies have not identified any mutations in exon 3 of TIGR gene. We cannot exclude, however, that mutations are localised in other exons or regulatory region of examined gene. The questions how many genes, how many mutations of these genes and how often they contribute to glaucoma in general population are still open? These are important questions to answer in order to get closer to understanding extremely complicated aetiology of glaucoma.     

Phenotypic variability and asymmetry of Rieger syndrome associated with PITX2 mutations

PURPOSE: Rieger syndrome is an autosomal dominant condition characterized by a variable combination of anterior segment dysgenesis, dental anomalies, and umbilical hernia. To date, reports have shown mutations within the PITX2 gene associated with Rieger syndrome, iridogoniodysgenesis, and iris hypoplasia. The purposes of this study were to determine the range of expression and intrafamilial variability of PITX2 mutations in patients with anterior segment dysgenesis. METHODS: Seventy-six patients with different forms of anterior segment dysgenesis were classified clinically. DNA was obtained and screened by means of polymerase chain reaction (PCR)-single-stranded conformation polymorphism (SSCP) and heteroduplex analysis followed by direct sequencing. RESULTS: Eight of 76 patients had mutations within the PITX2 gene. Anterior segment phenotypes show wide variability and include a phenocopy of aniridia and Peters', Rieger, and Axenfeld anomalies. Mutations include premature terminations and splice-site and homeobox mutations, confirming that haploinsufficiency the likely pathogenic mechanism in the majority of cases. CONCLUSIONS: There is significant phenotypic variability in patients with PITX2 mutations, both within and between families. Developmental glaucoma is common. The umbilical and dental abnormalities are highly penetrant, define those at risk of carrying mutations in this gene, and guide mutation analysis. In addition, there is a range of other extraocular manifestations.     

Four novel mutations in the PITX2 gene in patients with Axenfeld-Rieger syndrome

Mutational screening and sequence analysis of the PITX2 gene was performed in four families previously diagnosed with Rieger syndrome. The results of this analysis identified four novel mutations within the coding sequence of PITX2. These mutations were not identified in the sequence of 50 control individuals. Two mutations were found in the homeobox and would be expected to result in nonconservative amino acid changes within the second and third helixes. The remaining two mutations were found in the region downstream of the homeobox and are also predicted to result in missense mutations. In conclusion, mutations within the homeobox sequence and the adjacent coding sequence of PITX2 lead to various Rieger syndrome phenotypes characterized by a high incidence of glaucoma.     

Histopathology and molecular basis of iridogoniodysgenesis syndrome

Iridogoniodysgenesis is an autosomal dominant disorder in which there are abnormalities in the development of the iris stroma and trabecular meshwork tissues commonly resulting in glaucoma. The unoperated eye from an affected member of a family with iridogoniodysgenesis syndrome (IGDS) was removed shortly after death. Histopathological studies showed an incomplete, normally positioned line of Schwalbe and iris stromal hypoplasia. The molecular basis underlying the disorder is a missense mutation in the RIEG gene at 4q25, mutations of which have been previously shown to cause Axenfeld-Rieger syndrome (ARS). Coupled with another report of a missense mutation of the RIEG gene in a family with IGDS, we suggest that these mutations may interfere less with gene function and thereby may be responsible for a milder phenotype than occurs in the more characteristic ARS.     

原发性先天性青光眼CYP1B1基因变异初步研究

目的了解CYP1B1基因变异在中国原发性先天性青光眼(PCG)患者发病中的作用。方法收集来自不同地区的16例PCG患者,对其CYP1B1基因编码外显子进行直接测序,对照组进行单核苷酸多态性分析。结果在1例PCG患者中发现了一种变异,为8006G>A(R390H)。它是位于外显子III的错义突变。还发现了五种单核苷酸多态性,分别为3793T>G,R48G,A119S,A330S,V432L。结论CYP1B1基因是导致中国人PCG患者的致病基因,但也有其他变异可能和PCG变异有关。     

碳酸酐酶Ⅱ基因多态性与原发性开角型青光眼遗传易感性的关系

目的：分析碳酸酐酶Ⅱ基因多态性与原发性开角型青光眼遗传易感性的关系。方法：选取2012－01／2014－12在丽水市人民医院进行诊治的原发性开角型青光眼患者（观察组）50例与在丽水市人民医院门诊部体检的健康人（对照组）50例进行试验观察,常规肘静脉取血,使用聚合酶链反应和限制性片段长度多态性技术测试碳酸酐酶Ⅱ基因多态性的特点。结果：两组患者在和rs10504813位点rs3758078位点的分布符合哈迪－温伯格平衡定律（ Hardy －Weinberg equilibrium）,且试验结果显示在rs10504813位点中,两组的基因型频率的差异无统计学意义（P＞0．05）,但在等位基因频率分布之间的差异具有统计学意义（P＜0．05）;两组在rs3758078位点的基因型频率以及等位基因频率的差异无统计学意义（ P＞0．05）。两组患者在碳酸酐酶Ⅱ基因多态性进行单倍型分析发现, TAC单倍型携带者出现原发性开角型青光眼的风险较小。结论：碳酸酐酶Ⅱ基因多态性与原发性开角型青光眼的患病风险存在一定的关联,rs3758078位点基因平衡可能是患病风险低的主要原因;TAC单倍型携带者出现原发性开角型青光眼的风险较小。