一个常染色体显性遗传先天性白内障家系致病基因筛查

目的: 对中国一个常染色体显性遗传先天性白内障家系(ADCC)的已知候选基因进行筛查以寻找致病位点。方法: 收集一个ADCC家系的临床资料并采集静脉血。在24个已知与ADCC相关基因附近选择微卫星标记,利用Linkage软件Mlink软件包进行连锁分析计算Lod值。结果: 此家系白内障类型为核性白内障,24个候选基因附近50个微卫星Lod值均小于0,微卫星所在区域与此家系致病基因无连锁关系。结论: 此ADCC家系致病基因不是已知的与ADCC相关基因,可能是一个新的致病基因突变导致此家系疾病发生。     

X连锁遗传高度近视家系分析

流行病学调查显示单纯性近视是多基因遗传病，6D以上的高度近视是单基因遗传病。目前已知的遗传方式包括常染色体显性、常染色体隐性及性连锁遗传等。本文描述了一个高度近视家系。经初步分析为X连锁隐性遗传，其中的一些情况与以往报道的X连锁不尽相同：女性携带者外显率较高；存在男性色素变性患者。现报告分析如下。     

一特殊表型的常染色体显性遗传先天性白内障家系致病基因的筛选与鉴定

背景遗传因素是先天性白内障的主要致病因素之一,致病基因的筛查是研究先天性白内障发病分子机制的重要步骤。目的明确一结晶样晶状体混浊的先天性常染色体显性遗传白内障（ADCC）家系的致病基因。方法收集山西省榆社县一个四代先天性结晶样混浊白内障家系22名成员,其中患者10例。在获得知情同意后,该家系成员进行家系调查以确定遗传方式。经裂隙灯显微镜检查和常规眼科临床检查确定表型。采集其中17例家系成员的外周静脉血5ml并提取DNA,ADCC的17个已知致病基因周围选取22个荧光标记的微卫星,通过对微卫星标志物的扩增和基因型分析对该家系进行基因两点连锁分析,并计算对数优势评分（LOD）值。对筛选的候选基因进行直接测序分析。结果该家系患者晶状体混浊表型非常类似,家系分析表明为四代垂直遗传,符合单基因ADCC的特点。基因连锁分析提示,该家系与微卫星D2S325位点和D2S2358位点连锁,最大LOD值分别为1．20（0=0）和0．22（0=0）,位于此区域内的CRYGD基因测序后发现一个已经报道的错义突变c．C70A（p．P23T）。结论CRYGD基因P23T突变是该家系结晶样晶状体混浊的致病原因。     

一个后极性白内障家系致病基因的筛查与鉴定

目的　对中国一个具有常染色体显性遗传特点的后极性白内障家系进行致病基因的筛查。方法　分别采集家系成员外周静脉血,提取基因组ＤＮＡ,根据临床表型选取６个候选基因（ＣＲＹＡＡ、ＣＲＹＡＢ、ＰＩＴＸ３、ＣＨＭＰ４Ｂ、ＭＩＰ、ＣＲＹＧＤ）设计引物,通过ＰＣＲ扩增ＤＮＡ片段,琼脂糖凝胶电泳分离ＤＮＡ片段,直接测序法寻找致病基因及突变位点。结果　该家系符合常染色体显性遗传家系特征,先证者表型为后极性白内障,通过候选基因外显子直接测序,发现家系内患者ＣＲＹＧＤ基因第２个外显子第１２７位碱基有１个Ｔ→Ｃ的点突变,此突变导致蛋白第４３位的色氨酸被精氨酸取代（Ｗ４３Ｒ）。结论　ＣＲＹＧＤ基因ｃ．Ｔ１２７Ｃ（ｐ．Ｗ４３Ｒ）突变是该后极性白内障家系的致病原因。     

常染色体显性遗传眼球震颤家系的临床表型及致病基因的研究

目的　研究１个中国人常染色体显性遗传性眼球震颤家系的临床特点,并通过候选基因直接测序的方法对该家系的致病基因及发病机制进行研究。方法　选择１个先天性眼球震颤家系,对家系所有成员进行全身检查及视力、眼位、眼球运动、眼球震颤中间带、验光等眼科的相关检查后,从家系中每一代各选１例患者（包括先证者）及正常人,进行候选基因ＦＲＭＤ７、ＧＰＲ１４３与ＰＡＸ６基因的外显子测序。结果　家系患者的眼球震颤为水平冲动型,并且具有中间带。除了先证者有部分眼组织缺损及小眼球等异常外,其余患者的眼前节均未见明显发育异常。家系患者ＰＡＸ６基因第７外显子的第３８２碱基发生了杂合突变（ｃ．Ｃ３８２Ｔ）,从而引起了氨基酸的改变（ｐ．Ｒ１２８Ｃ）,该突变可能影响了ＰＡＸ６蛋白与其调控的下游基因的调控序列的结合,进而导致ＰＡＸ６基因功能异常,影响眼部发育。结论　该常染色体显性遗传性眼球震颤家系的致病基因为ＰＡＸ６基因。     

一个X连锁遗传的先天性眼球震颤家系基因突变研究

目的 探讨一个X连锁遗传先天性特发性眼球震颤家系的致病基因.方法 为回顾性研究.通过询问病史、临床检查确定遗传表型;进行系谱分析确定遗传方式;通过连锁分析进行致病基因定位;通过基因序列分析发现致病基因突变.结果 经连锁分析,将致病基因定位于Xq25-Xq27 上微卫星位点DXS8044阳DXS1227之间;基因序列分析发现FRMD7基因第8外显子存在两个碱基的缺失.结论 FRMD7基因突变是导致该家系出现疾病的主要原因.     

国人常染色体显性先天性白内障家系致病基因的突变分析

目的 分析国人6个常染色体显性先天性白内障(ADCC)家系的基因突变,确定其致病基因及突变形式.设计实验性研究.研究对象6个ADCC家系.方法 应用聚合酶链反应(PCR)和DNA直接测序方法,对家系进行ADCC常见致病基因突变分析.主要指标基因序列.结果 对12个ADCC常见致病基因(CRYAA, CRYAB, CRYBB1, CRYBB2, CRYBA1, CRYGS ,CRYGC, CRYGD, GJA8, GJA3, MIP, BESP2)外显子及外显子内含子连接区进行DNA直接测序,发现7种碱基序列改变,并导致相应编码氨基酸变化,分别是位于CRYBB2基因cDNA序列445位C→T(R145W),452位A→G(0147R),461位C→T(T150M)和388位G→T碱基改变(D126Y);GJA8基因cDNA序列1055位A→G碱基替代(E352G);BFSP2基因cDNA序列1295位C→A(A407D)及MIP基因cDNA序列96位T→A碱基改变(Y23N).其中前3种序列改变已报道为单核苷酸多态性(SNP),经过对相应家系其他成员的分析发现后4种序列改变也为SNP.结论 先天性白内障的临床表型与基因型均有明显的遗传异质性,本试验在12个基因外显子及外显子内含子连接区内未发现导致这6个ADCC家系疾病表型的致病基因突变,但是发现了7种SNP改变,其中4种为本研究首次发现.     

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。     

一个中国原发性开角型青光眼家系致病基因研究

目的:鉴定一个江苏省南通市原发性开角型青光眼(POAG)家系的青光眼致病基因,分析该基因的临床表型和致病机制。方法:于2020-01/12回顾并招募了一个POAG家系,该家系跨越5代共33名,有13名家庭成员参与了研究,其中4名诊断为POAG,1名诊断为高眼压症,剩余8名未受影响。详细询问病史并进行全面的眼科检查,采用高通量测序筛选可能的致病基因,Sanger测序验证候选致病基因。结果:该家系患者均在青年时期发现眼压升高并诊断为青光眼,需手术治疗控制眼压,先证者最高眼压(IOP)达55mmHg。全外显子测序在先证者LTBP2基因上发现了一个杂合突变(c.1197C>A, p.Phe399Leu),Sanger测序验证该突变位点与家系疾病并不分离。结论:LTBP2 (c.1197C>A)突变不是该家系POAG的致病基因。但是LTBP2突变在POAG病例中的致病作用值得研究。     

一个X-连锁隐性遗传视网膜色素变性家系的RPGR基因新突变

目的 研究X-连锁隐性遗传视网膜色素变性(RP)家系RPGR基因突变男性患者和女性携带者的临床表型.方法 家系调查研究.收集RP先证者及其家系资料,完善眼科检查,抽取现存77名家系成员和80名正常对照者外周静脉血,提取DNA,进行聚合酶链反应(PCR),扩增RPGR基因外显子ORF15,扩增产物纯化后直接测序.结果 RP家系中,8例RP患者均为男性,呈隔代传递,不存在男性至男性的传递,患者的母亲及女儿都是致病基因携带者而不发病,符合X-连锁隐性遗传方式.在8例男性RP患者和14例女性致病基因携带者的RPGR基因外显子ORF15+577_578位点发现一个AG缺失突变,引起阅读框架的改变,该基因缺失突变在家系中共分离.AG缺失突变导致男性患者典型的RP改变,但发病时间和进展程度不一.携带有杂合型基因突变的14例女性携带者最具特征性的临床表型是中高度近视眼(-5.00～-22.00 D).结论 该RP家系患者由RPGR 基因外显子ORF15移码突变致g.ORF15+577_578delAG位点缺失.RPGR基因外显子ORF15的新突变可导致男性患者严重的RP表型,但女性致病基因携带者仅表现为中高度近视眼.(中华眼科杂志,2011,47:516-520)

Abstract：

Objective To screen the mutation in the RPGR gene in a large Chinese family with X-linked recessive retinitis pigmentosa (RP) and to describe the phenotype in affected males and female carriers. Methods Ophthalmic examinations were performed in 77 family members of a RP pedigree to identify affected individuals. Polymerase chain reaction (PCR) and direct sequencing were used for screening of mutations in RPGR gene exon ORF15. Results Mutation screening demonstrated a novel mutation, g.ORF15+577_ 578delAG, which caused an open reading frameshift and resulted in premature truncation of the RPGR protein. This mutation was detected in 8 affected male individuals and 14 obligate female carriers in this family and was found to segregate with the phenotype in this family. This mutation led to a severe RP phenotype in male affected individuals with some variability in the age of onset of night blindness and loss of visual acuity, but was recessive in female carriers without a RP phenotype. However the most striking phenotypic feature in female carriers in this pedigree was moderate to high myopia with refractive error ranging from -5.00 D to -22.00 D in 14 female carriers. Conclusions This novel mutation in RPGR ORF15 causes serious RP phenotype in males and no RP phenotype in female carriers. Moderate to high myopia was a particular feature for female carriers in this pedigree. Our finding expands the spectrum of RPGR mutations causing RP and phenotypic spectrum of the disease in Chinese family, which is useful for further genetic consultation and genetic diagnosis.     

A novel Nance-Horan syndrome mutation identified by next-generation sequencing in a Chinese family

AIM: To identify the disease-causing mutation in a four-generation Chinese family diagnosed with Nance-Horan syndrome (NHS). METHODS: A Chinese family, including four affected patients and four healthy siblings, was recruited. All family members received ophthalmic examinations with medical histories provided. Targeted next-generation sequencing approach was conducted on the two affected males to screen for their disease-causing mutations. RESULTS: Two male family members diagnosed with NHS manifested bilateral congenital cataracts microcornea, strabismus and subtle facial and dental abnormalities, while female carriers presented posterior Y-sutural cataracts. A novel frameshift mutation (c.3916_3919del) in the NHS gene was identified. This deletion was predicted to alter the reading frame and generate a premature termination codon after a new reading frame. CONCLUSION: The study discovers a new frameshift mutation in a Chinese family with NHS. The findings broaden the spectrum of NHS mutations that can cause NHS in Chinese patients.     

Great clinical variability of Nance Horan syndrome due to deleterious NHS mutations in two unrelated Spanish families

ABSTRACT

Background: Nance-Horan syndrome (NHS) is an X-linked rare congenital disorder caused by mutations in the NHS gene. Clinical manifestations include congenital cataracts, facial and dental dysmorphism and, in some cases, intellectual disability. The aim of the present work was to identify the genetic cause of this disease in two unrelated Spanish NHS families and to determine the relative involvement of this gene in the pathogenesis.

Materials and methods: Four members of a two-generation family, three males and one female (Family 1), and seven members of a three-generation family, two males and five females (Family 2) were recruited and their index cases were screened for mutations in the NHS gene and 26 genes related with ocular congenital anomalies by NGS (Next Generation Sequencing).

Results: Two pathogenic variants were found in the NHS gene: a nonsense mutation (p.Arg373X) and a frameshift mutation (p.His669ProfsX5). These mutations were found in the two unrelated NHS families with different clinical manifestations.

Conclusions: In the present study, we identified two truncation mutations (one of them novel) in the NHS gene, associated with NHS. Given the wide clinical variability of this syndrome, NHS may be difficult to detect in individuals with subtle clinical manifestations or when congenital cataracts are the primary clinical manifestation which makes us suspect that it can be underdiagnosed. Combination of genetic studies and clinical examinations are essential for the clinical diagnosis optimization.     

一个中国视网膜色素变性家系的RP3基因突变

目的 探讨一个中国视网膜色素变性(RP)家系的突变基因位点.方法 在获得知情同意后对该家系成员进行病史采集、眼部检查和病情追溯,绘制家系图,并对其中26例采血,进行DNA提取、聚合酶链反应、RP3基因外显子ORF15测序.结果 该家系共有成员57名,其中直系42名(含21例患者).患者表现为夜盲、近视、眼底色素沉着、血管细、视盘淡,视野向心性缩窄甚至呈管状,暗视视网膜电图(ERG)显示a波、b波振幅明显下降甚至记录不到.家系特点为男性患者的女儿全部患病、男性患者的母亲均是患者,符合X连锁显性遗传特征.经PCR反向测序,发现突变位点位于ORF15 1339delA.结论 该家系患者病变由RP3基因外显子ORF15 1339delA位点突变所致.     

The heterozygous EDNRB mutation in a Chinese family with Waardenburg syndrome type I

The genovariation of endothelin receptor type B (EDNRB) was identified in a Chinese family with Waardenburg syndrome type I (WS1) in the present study. WS1 was diagnosed in a 19-year-old young man, his older sister and aunt according to WS consortium criteria. After extracting genomic DNA from the peripheral blood samples, the coding exons and intronic regions of EDNRB were sequenced. A missense heterozygous mutation was found in the coding region of exon 2 in the EDNRB gene on chormosome 13q22.3 of the proband. The same mutation was detected in the proband’s afflicted paternal aunt and first older sister. Subsequent polyphen analysis and three-dimensional modeling confirmed that the c.469A>G heterozygous mutation in EDNRB was possibly pathogenic. This is the first report of EDNRB mutation as a potential disease-causing mutation in Chinese patients with WS1.     

眼白化病Ⅰ型家系致病基因GPR143新突变

目的：对收集的一例眼白化病1型家系的致病基因GPR143进行突变检测。方法抽取先证者两兄弟及其母亲的5ml外周血,酚-氯仿法抽提基因组DNA,通过聚合酶链反应（polymerase chain reaction,PCR）扩增眼白化病1型致病基因GPR143外显子及其相邻的内含子,并进行直接测序。结果 PCR结果显示两眼白化病1型的兄弟第五外显子均无产物,而其他8个外显子均有产物,相同反应条件下其母亲及正常对照组所有外显子都可扩增出产物,证明该眼白化病患者的致病基因GPR143的第五外显子缺如。结论本研究在眼白化病1型的患者的致病基因中发现了整个外显子的缺失突变,扩展了OA1致病基因的突变频谱。     

Homozygous and heterozygous Gly-188-Arg mutation of the rhodopsin gene in a family with autosomal dominant retinitis pigmentosa

Autosomal dominant retinitis pigmentosa (adRP) may be caused by point mutations in the rhodopsin gene in up to 20% of Spanish families. Most of the rhodopsin mutations causing adRP have been reported in the heterozygous state. We describe a patient with adRP who is homozygous for a missense mutation at codon 188 in the second intradiscal domain of rhodopsin. All her sons are heterozygous for the mutation and show an RP phenotype suggesting complete penetrance for this mutation. The homozygous carrier of the mutation Gly-188-Arg in the rhodopsin gene showed a later subjective onset of symptoms than the heterozygotes, suggesting that the photoreceptor degeneration induced by the mutation is not dramatically influenced by mutant allele dosage.     

晶状体蛋白基因在一先天性白内障家系中的突变筛查

目的研究晶状体蛋白基因与先天性白内障的关系。方法收集1个先天性白内障家系,制备外周血白细胞基因组DNA。除对CRYGD基因直接测序外,在距离已知晶状体蛋白基因5个厘摩范围内选取微卫星标记进行连锁分析,计算微卫星位点与致病基因之间的最大优势对数值(LOD SCORE),来确定晶状体蛋白基因与此家系致病基因的关系。结果当重组分数分别为0.1、0.2、0.3、0.4时,所选取的位于晶状体蛋白基因附近的14个微卫星位点与该家系致病基因之间连锁的LOD值均为负值,故排除连锁。CRYGD基因测序后在基因编码区及启动子、内含子与外显子连接处的剪切位点均未见任何碱基改变。结论晶状体蛋白基因非此家系的致病基因,为进一步定位与克隆该家系的致病基因,需进行全基因组扫描,以探求先天性白内障的分子发病机制。     

马凡综合征一家系的致病基因筛查

目的：对中国辽宁省一个具有常染色体显性遗传特点的马凡综合征( Marfan syndrole, MFS )家系进行突变基因的筛查。
　　方法：分别采集家系成员的外周静脉血,提取基因组DNA,通过对与马凡综合征相关的致病基因进行遗传学研究和分析,选取候选基因并设计引物,应用聚合酶链式反应( PCR)扩增DNA片段后进行琼脂糖凝胶电泳分离,利用直接测序法确定致病基因及其突变位点。
　　结果：该家系遗传方式符合常染色体显性遗传,先证者表型为双眼晶状体向鼻上方脱位,通过对候选基因外显子直接测序,发现该家系内患者原纤维蛋白基因-1(fibrillin-1 gene,FBN1)第7个外显子第640位碱基有1个A>G的点突变,此突变导致蛋白第214位的甘氨酸被丝氨酸取代(G214S)。
　　结论：FBN1基因 c. A640G(p. G214S)突变为该马凡综合征家系的致病因素。     

PAX6基因在一先天性无虹膜家系中的突变筛查

目的研究PAX6基因突变是否是导致一先天性无虹膜家系致病的原因。方法收集一先天性无虹膜家系,制备外周血基因组DNA,PCR扩增PAX6基因的外显子及其邻近的内含子,应用单链构象多态性（SSCP）法检测,如果发现变异条带,将相应的扩增产物回收并纯化后进行PAX6基因测序。测序结果与GenBank公布的PAX6基因正常序列比对,寻找有无突变。结果本家系43名成员中有8例患病,遗传方式符合常染色体显性遗传特点,40岁以上的4例患者眼压高于35mmHg。所有患者中未发现全身并发症。在家系所有患者中均未发现异常条带。结论 PAX6基因与该先天性无虹膜家系无关。该家系的致病基因有待进一步通过全基因组扫描的方法来确定。     

FGFR2 mutation in a Chinese family with unusual Crouzon syndrome

AIM: To describe the clinical characteristics with genetic lesions in a Chinese family with Crouzon syndrome. METHODS: All five patients from this family were included and received comprehensive ophthalmic and systemic examinations. Direct sequencing of the FGFR2 gene was employed for mutation identification. Crystal structure analysis was applied to analyze the structural changes associated with the substitution. RESULTS: All patients presented typical Crouzon features, including short stature, craniosynostosis, mandibular prognathism, shallow orbits with proptosis, and exotropia. Intrafamilial phenotypic diversities were observed. Atrophic optic nerves were exclusively detected in the proband and her son. Cranial magnetic resonance imaging (MRI) implied a cystic lesion in her sellar and third ventricular regions. A missense mutation, FGFR2 p.Cys342Trp, was found as disease causative. This substitution would generate conformational changes in the extracellular Ig-III domain of the FGFR-2 protein, thus altering its physical and biological properties. CONCLUSION: We describe the clinical presentations and genotypic lesions in a Chinese family with Crouzon syndrome. The intrafamilial phenotypic varieties in this family suggest that other genetic modifiers may also play a role in the pathogenesis of Crouzon syndrome.