非典型Stickler综合征I型三个家系的遗传分析及产前诊断

目的：:分析非典型Stickler综合征I型患者的临床表现和遗传学病因,为患者基因诊断、遗传咨询、产前诊断提供理论依据。方法：:实验研究。收集3个典型Stickler综合征I型家系患者的临床表型资料,采集患者及家系其他成员的外周血提取基因组DNA。应用全外显子组测序筛查可疑基因变异,对候选变异进行Sanger测序验证并...     

Peters综合征临床特征和基因突变的研究

目的：分析国人Peters综合征的临床特征,并确定致病基因突变,为该病的临床诊断和治疗及发病原因提供依据。方法：选取2012/2015年在常州市第二人民医院眼科就诊的10例先天性角膜混浊的患者,并收集详细的相关临床资料。征得患者及其家系成员的同意后抽血制备基因组DNA,用聚合酶链反应( PCR)对致病基因PITX2的编码区及其临接内含子进行扩增后,直接测序分析该基因。同时检测100位无亲缘关系的正常人外周血标本进行对照验证。结果：患者1例的临床特点包括先天性角膜中央部混浊白斑,伴有相应区域的角膜后部基质变薄和后弹力层缺损,且患者伴有全身系统如心脏和听力损害等改变,符合Peters综合征的临床诊断;该患者PITX2基因突变筛查结果发现了1种新突变,c.788G>A,导致该基因的功能异常,而家属中表型正常者及无亲缘关系的正常对照者均未发现该基因突变。结论：先天性角膜混浊患者10例中检测到1个新PITX2基因突变,符合Peters综合征的临床诊断,这是中国首次报道Peters综合征的PITX2基因突变,结果丰富了PITX2基因突变频谱,并进一步明确了Peters综合征的临床特点,为该病的临床诊断和治疗及发病原因提供了依据。     

原纤维蛋白1基因新突变导致单纯性晶状体异位

目的 研究我国单纯性晶状体异位家系的致病基因,并确定基因突变。方法 对单纯性晶状体异位一家系进行临床研究和系谱分析。采集家系中7例患者和3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)扩增原纤维蛋白(FBN)1基因外显子,直接测序确定致病的基因突变。采用PCR和限制性内切酶法进行群体分析。结果单纯性晶状体异位患者的FBN1基因外显子6发生了错义突变,cDNA 640位的鸟嘌呤被腺嘌呤取代(13640A);对应的甘氨酸改变为丝氨酸(G214S)。突变后Eag I内切酶位点消失。家系中健康成员和50名正常人均未发现该突变。结论 FBN1基因新突变G640A(G214S)是该家系单纯性晶状体异位的致病基因突变。（中华眼科杂志,2004,40：828-831)     

第二代测序技术在一中国先天性白内障家系致病基因检测中的应用

背景 某些遗传性疾病具有高度遗传异质性,因此传统的Sanger测序技术已经不能满足医学研究及临床工作的需求.第二代测序(NGS)技术由于具有费用低及检测速度快的优点而得到广泛应用,但在先天性眼病突变基因的检测中的应用效果有待验证.目的 探讨NGS技术对先天性白内障患者进行致病基因诊断和产前诊断的可行性.方法 于2013年1月收集来自河南省洛阳市的一汉族先天性白内障家系,抽取家系中3例患者(Ⅱ2、Ⅲ3、Ⅲ4)和3名表型正常者(Ⅱ3、Ⅲ1、Ⅲ2)的外周血各2 ml,EDTA抗凝,在河南省医学遗传研究所应用NGS技术对先证者进行基因突变位点检测,并采用Sanger测序技术对NGS结果进行验证,然后用Sanger测序技术对该家系其他成员的外周血样本进行突变位点的序列分析,根据确定的致病突变位点对先证者的胎儿进行产前诊断.本研究遵循赫尔辛基宣言,检测方案经河南省人民医院医学伦理委员会批准,所有研究对象均签署知情同意书.结果 该家系4代14位成员中共5例患者,其中男2例,女3例,分布于Ⅰ、Ⅱ、Ⅲ代中,其他家系成员表型正常,符合常染色体显性遗传方式.NGS检测发现先证者Ⅲ3CRYBB1基因第6外显子上存在c.682T＞C(p.S228P)杂合突变,Sanger法验证了该点突变.Sanger法检测发现家系中患者均存在CRYBB1基因c.682 T＞C突变,而家系中表型正常者CRYBB1基因的c.682位点基因型为T/T野生型.产前诊断结果显示胎儿(Ⅳ1)CRYBB1基因c.682位点基因型为T/T野生型.结论 NGS可用于先天性白内障基因突变的快速检测,该家系致病性基因为CRYBB1基因c.682T＞C突变,应用NGS技术结合一代测序技术成功对先证者进行了产前诊断.     

遗传性Leber视神经病变家系致病基因突变分析

目的 探讨遗传性Leber视神经病变(LHON)家系的致病基因突变位点.方法 家系调查研究.对LHON家系成员进行临床检查,抽取部分家系成员外周血提取基因组DNA,应用聚合酶链反应(PCR)和DNA序列测定法,检测家系成员线粒体DNA上的突变位点.结果 该家系3代14例成员中共有7例患者,其中男性2例,女性5例,家系图分析符合母系遗传特征.对其中4例患者及3例未发病家系成员进行线粒体DNA突变检测,显示4例患者及2例未发病家系成员携带G11778A位点突变.结论 线粒体DNA的G11778A突变位点是导致该家系患者发病的致病基因.对尚未发病的基因突变携带者进行早期干预治疗,有可能延缓或阻止疾病的发生与发展.     

中国一先天性无虹膜家系的遗传分析及PAX6基因突变位点的检测

背景 先天性无虹膜是双眼发病的遗传性疾病,目前的研究表明先天性无虹膜患者配对盒转录因子6(PAX6)基因突变位点具有多样性. 目的 通过目标序列捕获测序结合一代测序验证技术对1个中国先天性无虹膜家系进行基因突变位点的筛查和遗传分析.方法 采用横断面研究方法,本研究组于2016年3月纳入在郑州大学第一附属医院确诊的1个中国汉族先天性无虹膜家系,并对该家系成员进行致病突变基因检测.该家系全体成员均接受神经系统、口服葡萄糖耐量试验等全身体格检查以及眼科相关检查.采集现存家系所有成员前臂静脉血10 ml以提取基因组DNA,以先证者基因组DNA为模板行前房角发育异常致病基因的目标基因定点捕获测序分析,经与各基因库比对筛选出候选致病基因位点,采用PCR法对该家系成员行致病基因位点DNA片段扩增,采用Sanger测序技术在该家系除先证者以外的2例患病者和表型正常成员中进行候选致病基因验证. 结果 该家系共3代9名成员,Ⅰ1去世,现存8位成员,包括患病者3例(Ⅱ2及其子代Ⅲ1、Ⅲ2)和表型正常者5人,符合常染色体显性遗传模式.所有家系成员未发现神经系统异常,口服葡萄糖耐量试验结果均呈阴性.3例患病者视力均明显下降且不能矫正,眼压平均值为21 mmHg(1 mmHg=0.133 kPa),患者均存在虹膜完全缺如、角膜基质层混浊、眼球水平震颤、黄斑中心凹发育不良症状.此外,Ⅱ2患者存在左眼上睑下垂、右眼先天性白内障表现,Ⅲ2同时存在双眼先天性白内障、双侧晶状体不全脱位.先证者目标序列捕获测序分析及数据库比对显示,所有患病者PAX6基因第6号外显子上碱基替换c.183C＞A,经Sanger测序验证后证实突变基因与表型共分离. 结论 PAX6基因c.183C＞A突变是该先天性无虹膜家系的致病突变位点.     

一Stickler综合征家系的临床特征及分子遗传学分析

目的：:研究一Stickler综合征家系的临床表型及分子遗传学特点,并确定致病基因及其突变。方法：:实验研究。对一Stickler综合征家系4代11例患者进行临床特征及系谱分析。采集该家系先证者及其他成员（患者及正常人）的外周静脉血标本,并利用高通量二代测序技术对先证者及正常对照样本行全外显子组测序（WES）分析。针对...     

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.     

格子状角膜营养不良一家系的TGFBI基因突变研究

目的对我国鄂西北地区一格子状角膜营养不良家系进行研究,探讨这一格子状角膜营养不良类型与TGFBI基因突变的关系。方法选取该家系共18例,包括第三代患者及配偶13例,第四代患者2例及无临床症状者3例。收集该家系所有研究对象外周血,提取基因组DNA,PCR扩增TGFBI基因4、11、12、14号外显子片段并进行直接测序,证实其突变位点。以家系内无近亲关系配偶5人和1名健康者为阴性对照。结果该家系基本符合常染色体显性遗传模式的特征,为LCD I/IIIA型。TGFBI基因编码区进行基因直接测序,发现10例患者和2例无症状者携带者共同突变点为H626R。结论该家系为格子状角膜营养不良LCD I/IIIA型家系,该家系角膜混浊的直接原因是TGFBI基因H626R突变。     

两个Waardenburg综合征家系致病基因突变和临床特征分析

目的 分析两个Waardenburg综合征家系中先证者和2例患病家系成员的临床表现和致病基因突变特征。设计 回顾性病例系列。研究对象 2018年北京同仁医院两个Waardenburg综合征家系4例患者。方法 记录两个家系中先证者和患病成员以及可疑患病成员的病史以及毛发和皮肤色素异常的情况，并对先证者和2例患病成员进行详细眼科检查和耳科听力检测。采集先证者、其父母及患病成员的外周血样。对先证者进行Waardenburg综合征的6个已知的致病基因Sanger测序检测，应用多种在线生物信息学分析软件对检出的突变进行致病性预测，并对致病性突变进行家系共分离验证，最后根据美国医学遗传学与基因组学学会致病性分级指南对突变进行分级。主要指标 致病基因突变、眼部及全身色素异常情况、眼底情况、听力。结果 在两个Waardenburg综合征家系中分别检出EDNRB 基因p.G186E和PAX基因p.C70R 两个杂合错义突变，分别导致Waardenburg综合征IV型和Waardenburg综合征I型。两个家系的先证者均有虹膜色素异常、听力差、头发变白和鼻根部宽的表现，但程度和部位有所不同。两个家系内所有确诊或可疑患病的成员均有头发变白或额前白发，而无皮肤色素异常表现。结论 本研究确定了两个Waardenburg综合征家系的致病基因，扩大了PAX3和EDNRB基因突变谱，基因检测是可疑Waardenburg综合征患者鉴别诊断及分型的重要手段。     

Radial perivascular retinal degeneration: a key to the clinical diagnosis of an ocular variant of Stickler syndrome with minimal or no systemic manifestations

PURPOSE: To identify the genetic defect and present the ocular and extraocular findings in a large pedigree of predominantly ocular Stickler syndrome. DESIGN: Observational case series. METHODS: An eight-generation pedigree with hereditary retinal detachments was retrospectively and prospectively studied. Clinical information was obtained by medical records, telephone interviews, medical questionnaires, detailed ophthalmologic examinations, physical examinations, and personal observations. Linkage analysis of the COL2A1 gene was performed on 21 family members, and mutation analysis was performed on three family members. RESULTS: The pedigree consisted of 100 affected individuals. The ocular findings, frequently bilateral, consisted of radial perivascular retinal degeneration (RPRD) (100%), vitreous syneresis (100%), high myopia (76%), retinal detachment (65%), presenile cataract development (occurring before 50 years of age; 78%), and glaucoma (18%). Most (70%) of the retinal detachments occurred between 4 and 18 years of age. Extraocular manifestations, characteristic for Stickler syndrome, were detected in only four of 100 (4%) affected individuals. Linkage analysis with COL2A1 flanking markers showed evidence for linkage to the COL2A1 locus. The COL2A1 gene analysis identified a mutation converting a codon TGC for cysteine(86) to a premature termination codon in the alternatively spliced exon 2. CONCLUSIONS: A variant of Stickler syndrome, caused by mutations in exon 2 of COL2A1, may present in families with all of the ocular findings and no clinically identifiable extraocular findings associated with Stickler syndrome. The predominant ocular findings are a congenitally abnormal vitreous and an acquired radial perivascular retinal degeneration that may lead to complicated childhood and adult retinal detachment.     

Familial retinal detachment associated with COL2A1 exon 2 and FZD4 mutations

Background: To characterize the clinical and genetic abnormalities within two Australian pedigrees with high incidences of retinal detachment and visual disability. Design: Prospective review of two extended Australian pedigrees with high rates of retinal detachment. Participants: Twenty‐two family members from two extended Australian pedigrees with high rates of retinal detachment were examined. Methods: A full ophthalmic history and examination were performed, and DNA was analysed by linkage analysis and mutation screening. Main Outcome Measures: Characterization of a causative hereditary gene mutation in each family. Results: All affected family members of one pedigree carried a C192A COL2A1 exon 2 mutation. None of the affected family members had early‐onset arthritis, hearing abnormalities, abnormal clefting or facial features characteristic of classical Stickler syndrome. All affected members of the familial exudative vitreoretinopathy pedigree carried a 957delG FZD4 mutation. Conclusions: Patients with retinal detachment and a positive family history should be investigated for heritable conditions associated with retinal detachment such as Stickler syndrome and familial exudative vitreoretinopathy. The absence of non‐ocular features of Stickler syndrome should raise the possibility of mutations in exon 2 of COL2A1. Similarly, late‐onset familial exudative vitreoretinopathy may appear more like a rhegmatogenous detachment and not be correctly diagnosed. When a causative gene mutation is identified, cascade genetic screening of the family will facilitate genetic counselling and screening of high‐risk relatives, allowing targeted management of the pre‐detachment changes in affected patients.     

Autosomal dominant rhegmatogenous retinal detachment associated with an Arg453Ter mutation in the COL2A1 gene

PURPOSE: To investigate the clinical features and molecular causes of autosomal dominant rhegmatogenous retinal detachment (RRD) in two large families. METHODS: Clinical examination and linkage analysis of both families using markers flanking the COL2A1 gene associated with Stickler syndrome type 1, the loci for Wagner disease/erosive vitreoretinopathy (5q14.3), high myopia (18p11.31 and 12q21-q23), and nonsyndromic congenital retinal nonattachment (10q21). RESULTS: Fifteen individuals from family A and 12 individuals from family B showed RRD or retinal tears with minimal (family A) or no (family B) systemic characteristics of Stickler syndrome and no ocular features of Wagner disease or erosive vitreoretinopathy. The RRD cosegregated fully with a chromosomal region harboring the COL2A1 gene with maximum lod scores of 6.09 (family A) and 4.97 (family B). In family B, an Arg453Ter mutation was identified in exon 30 of the COL2A1 gene, that was previously described in a patient with classic Stickler syndrome. In family A, DNA sequence analysis revealed no mutation in the coding region and at the splice sites of the COL2A1 gene. CONCLUSIONS: In two large families with RRD, linkage was found at the COL2A1 locus. In one of these families an Arg453Ter mutation was identified, which is surprising, because all predominantly ocular Stickler syndrome cases until now have been associated with protein-truncating mutations in exon 2, an exon subject to alternative splicing. In contrast, the Arg453Ter mutation and other protein-truncating mutations in the helical domain of COL2A1 have been associated until now with classic Stickler syndrome.     

Stickler syndrome and vitreoretinal degeneration: correlation between locus mutation and vitreous phenotype. Apropos of a case

BACKGROUND: Autosomal dominant vitreoretinopathies are characterized by genetic heterogeneity. Structural mutations in COL2A1 are the most frequent cause of Stickler syndrome with ocular involvement. The affected patients have a characteristic vitreous alteration, so-called membranous vitreous, or type 1 vitreous phenotype. Recently a novel mutation in the gene encoding the alpha 1 chain of type XI collagen (COL11A1) was reported in rare Stickler pedigrees, with a different, so-called beaded or type 2 vitreous phenotype. METHODS: Five patients of an Italian family affected by high myopia, high frequency of retinal detachment, and other systemic stigmata evocative of Stickler syndrome (flat midface, depressed nasal bridge, short nose, spondyloepiphyseal dysplasia and osteoarthritis) were studied. Genetic investigations were also performed, considering three candidate loci for Stickler syndrome and Wagner syndrome (COL2A1, COL11A1, WGN1). RESULTS: Segregation analysis was performed utilizing polymorphic markers. COL2A1 and WGN1 segregations were excluded; COL11A1 showed concordance with the disease. The vitreous phenotype of the family was a typical type 1 or "membranous" vitreous, although all the previously reported COL11A1-related Stickler syndromes had always shown the type 2 or "beaded" vitreous phenotype. CONCLUSIONS: The clear presence of the type 1 or "membranous" vitreous phenotype in our family, despite the probable mutation in the COL11A1 gene, suggests greater phenotypical heterogeneity and a more extensive mutation spectrum, even of the COL11A1 gene, than previously thought, explaining the basis for the different vitreous phenotypes seen in Stickler syndrome.     

Type 1 Stickler syndrome: a histological and ultrastructural study of an untreated globe

AIMS: To present a histological and ultrastructural study of an untreated globe in a patient with genetically confirmed type 1 Stickler syndrome. METHODS: Histological and electron microscopic examinations were performed on the enucleated globe from the proband of a pedigree with type 1 Stickler syndrome. Linkage analysis was carried out using polymorphic markers flanking the COL2A1 gene and the mutation was identified by direct sequencing. RESULTS: The significant retinal abnormality was incarceration of vitreous collagen within glial strands on the inner surface of an atrophic and gliotic detached retina. The incarcerated collagenous layers contained glial cells and extended from the retina to form strands, some of which contributed to a retrolental membrane. Mutation screening detected a C to T mutation in exon 47 that inserted a premature termination codon into the reading frame of the mRNA. Sequence analysis of three of the four affected children confirmed that they were also heterozygous for the base change. The youngest child's DNA was not analysed. CONCLUSIONS: The study represents the first evidence of abnormal interactions between pathological vitreous collagen and the inner retina in a patient with type 1 Stickler syndrome with a confirmed mutation in the COL2A1 gene.     

Identification of a stop codon mutation in exon 2 of the collagen 2A1 gene in a large stickler syndrome family

PURPOSE: To describe the clinical features and identify the mutation responsible for an autosomal dominant vitreoretinal degeneration occurring in a previously unreported large family. DESIGN: Cohort study. METHODS: Family members were evaluated clinically over a 30-year period. Genealogical investigation, genetic linkage to known vitreoretinal degenerations, and mutation screening of the COL2A1 gene were performed. RESULTS: We identified a single large family (2,384 total family members) with vitreoretinal degeneration spanning 12 generations. We reviewed the clinical records of 165 family members (95 affected and 70 unaffected). The common clinical findings in affected individuals included early-onset posterior perivascular retinal degeneration, vitreous degeneration, and retinal detachment. The incidence of retinal detachment was 57% (95/165) and the mean age of onset was 15.2 years. Orofacial, skeletal, and auditory abnormalities were seen in 0%, 5%, and 7.5%, respectively, in a subset of 28 affected subjects. Linkage to the collagen COL2A1 locus was demonstrated and a cytosine to adenosine transition identified within exon 2, leading to the creation of a stop codon at position 86 (Cys86Stop). CONCLUSIONS: Identification of the mutation in this family enables diagnosis of individuals at risk for potentially blinding complications in this condition at an early age. Given the variability of the Stickler phenotype, mutation detection allows for more comprehensive genetic counseling and directs clinical monitoring to family members inheriting the disease gene.     

睑裂狭小综合征一家系的FOXL2基因突变研究

目的确定一个常染色体显性遗传的睑裂狭小综合征（BPES）家系的致病基因及其突变位点和类型。方法应用聚合酶链反应和直接测序技术,对来自同一家系的4例BPES患者及家系中6例正常人和50例正常对照者的外周血DNA进行分子遗传学分析,筛查FOXL2基因的外显子序列。结果来自同一家系的4例BPES患者均发现有FOXL2基因892C〉T的改变,为无义突变,而家系中6例正常人及50例正常对照者的FOXL2基因中均未发现突变。结论FOXL2基因的一种已知突变可能是该BPES家系的重要致病因素。     

Genetic testing in four Indian families with suspected Stickler syndrome

Purpose:Stickler syndrome is associated with the development of rhegmatogenous retinal detachment (RRD), and often presents with ocular, auditory, skeletal, and orofacial abnormalities. Molecular analysis has proven effective in diagnosis, confirmation and classification of the disease. We aimed to describe the utility of next-generation sequencing (NGS) in genetic analysis of four Indian families with suspected Stickler syndrome.Methods: The index cases presented with retinal detachment with family history. Genetic analysis in the index case was performed by next-generation sequencing of inherited retinal degeneration genes, and validated by Sanger sequencing followed by co-segregation analysis in the other family members.Results: Twenty patients were included for the genetic analysis (15 males and 5 females from four families). Clinical details were available for 15 patients (30 eyes). Fourteen eyes (11 patients) developed RRD. In the 16 eyes without RRD, 8 underwent barrage laser to lattice degeneration and 8 were under observation. Disease segregating heterozygous mutations with pathogenic/likely pathogenic effect was identified in COL2A1 (c.4318-1G>A, c.141G>A, c.1221+1G>A for 3 families) and COL11A1 (c.1737+1 G>A for 1 family) gene. In addition to the mutation in the COL2A1 gene, a pathogenic heterozygous variant associated with risk for arrhythmogenic right ventricular cardiomyopathy (ARVC) was identified in one member.Conclusion: NGS testing confirmed the presence of the causative gene for Stickler syndrome in the index case followed by evaluation of family members and confirmation of genetic and ocular findings. We believe that this may be the first such report of families with RRD from India.