2型Usher综合征和视网膜色素变性家系USH2A基因突变及临床表型分析

目的观察2型Usher综合征(USH2)和视网膜色素变性(RP)患者的基因突变型及其临床表型。方法2018年8月至2019年1月于河南省立眼科医院就诊的USH2和RP 3个家系的4例患者和11名正常家系成员纳入研究。详细询问病史并行视力、眼底彩色照相、OCT、视野、全视野ERG检查。3个家系中,家系1为USH2;家系2、3为RP。采集患者及其家系成员外周静脉血,提取全基因组DNA,应用基于靶向捕获的二代测序技术进行基因测序,对可疑致病突变位点通过Sanger进行验证,并在家系成员中进行共分离。结果家系1先证者除眼底有RP表现外,同时合并神经性耳聋。基因检测结果显示,先证者USH2A基因第64、5号外显子分别存在c.13877-13880 del AGAC(p.Q4626P)(M1)、c.798 del T(p.F266L)(M2)2个杂合性移码突变。家系2、3先证者仅有眼底典型RP表现。基因检测结果显示,家系2先证者USH2A基因第70、37、29号外显子分别存在c.15178T>c(p.S5060P)(M3)、c.6986C>A(p.P2329H)(M4)2个杂合性错义突变和c.5836C>T(p.R1946X)(M5)终止突变。家系3先证者USH2A基因第67、57号外显子分别存在c.14951C>T(p.P4984L)(M6)、c.11156G>A(p.R3719H)(M7)2个杂合性错义突变。保守性分析结果显示,USH2A p.Q4626P、p.F266L、p.S5060P、p.P2329H、p.P4984L所对应的氨基酸位点在多个物种中均高度保守。检测出的7个致病突变中,M1~M4、M6为新发现突变位点。结论USH2A基因突变是导致USH2和非综合征性RP的主要原因;不同突变位点影响蛋白质翻译和合成,导致不同临床表型。     

应用新一代目标区域捕获测序揭示视网膜色素变性患者的EYS基因突变

目的应用新一代测序技术研究一例散发视网膜色素变性（RP）患者的致病基因突变位点及其临床表型。方法实验研究。 收集一散发的RP家系,共3名家庭成员参与研究。其中1名患者,2名正常家属。采集3 ml外周静脉血,提取基因组DNA,运用目标区域捕获测序技术来筛查目前已报道的201个遗传性视网膜疾病的致病基因,测序结果运用生物信息学分析得到候选基因,最后用Sanger测序验证。结果临床检查结果显示患者呈现典型的RP临床症状。遗传学筛查结果证实患者在EYS基因上存在2个复合杂合突变：1个杂合的错义突变（c.6416G>A,p.C2139Y）,1个杂合的无义突变（c.8012T>A,p.L2671X）。Sanger测序结果证实为阳性并且分别遗传自父亲母亲,为常染色体隐性遗传。EYS基因被报道为RP的主要致病基因之一。结论本例患者的EYS基因存在2个杂合突变,是导致RP的致病原因。     

结晶样视网膜色素变性中与CYP4V2基因相关的致病突变

目的：使用Sanger测序法鉴定2个中国结晶样视网膜色素变性(BCD)家系中CYP4V2基因的突变位点。

方法：收集2019-01/09临床诊断为BCD患者的临床相关资料。采集患者、患者家系成员的外周血,提取DNA,利用Sanger测序法鉴定突变位点。

结果：共收集2个BCD先证者,先证者均表现为渐进性视力下降,眼底均可见典型的结晶样物质沉积。测序发现先证者1及其患病的哥哥,妹妹均在CYP4V2基因上存在c.802-8_810del17insGC的纯合突变。而先证者2则在CYP4V2基因上存在c.219T>A(p.F73L)、c.802-8_810del17insGC杂合突变。

结论： 中国BCD患者中最常见的c.802-8_810del17insGC突变在先证者1家系中为纯合突变,是其家系的致病突变。而先证者2则携带了中国BCD患者最常见的c.802-8_810del17insGC杂合突变,同时先证者2还携带c.219T>A(p.F73L)错义突变,突变均影响了CYP4V2基因的正常编码,进而导致疾病。     

Ⅱ型Usher综合征或39型视网膜色素变性患者的临床表型、致病基因与新突变位点分析

目的　观察Ⅱ型Usher综合征（USH2）或39型视网膜色素变性患者的临床表型,分析患者的致病基因与新突变位点。方法　收集临床诊断为USH2或39型视网膜色素变性患者的相关资料和样本,进行全外显子测序,对测序结果进行分析后锁定致病基因与突变位点,并用Sanger测序验证其突变位点。结果　本研究共收集5例患者,来自于3个不同家系,测序数据解读结果显示USH2A基因为5例患者的致病基因,在USH2A基因上共检出3个纯合突变。先证者1（F1-Ⅱ1）及其患病的弟弟（F1-Ⅱ2）在USH2A基因上均存在c.8232G>C (p.W2744C)(M1)纯合突变。先证者2（F2-Ⅱ1）和其患病的妹妹（F2-Ⅱ2）则在USH2A基因上均存在c.8559-2A>G(M2)纯合突变。先证者3（F3-Ⅱ1）在USH2A基因上发现c.12778C>T（p.Q4260X）(M3)纯合突变。其中所发现的M3突变为首次报道。结论　USH2A基因突变是导致USH2和39型视网膜色素变性的主要致病原因,USH2A基因突变所致疾病具有典型的遗传异质性和临床异质性,不同的突变所致疾病表型存在差异。     

家族性渗出性玻璃体视网膜病变致病基因 FZD4变异位点的遗传学研究

目的筛查一个家族性渗出性玻璃体视网膜病变(FEVR)致病基因变异的突变位点。 方法2019年7月收集常染色体显性遗传FEVR家系三代6例的临床资料。采集家系中2例FEVR患者和2位眼正常者的外周血样本。利用二代高通量基因测序技术及Sanger测序对4位受检者的20 000个基因进行测序分析，比较分析眼科疾病相关基因，明确该家系致病基因的突变位点。 结果本家系的先证者，女性，15岁，右眼最佳矫正视力为0.6，左眼最佳矫正视力为0.5。眼底检查结果显示视网膜周边部血管分支多，呈"柳枝"样形态，荧光素眼底造影可见无血管区。患儿四肢修长，身材高大，全身患有二尖瓣和三尖瓣关闭不全，疑似Loeys-Dietz综合征。先证者父亲右眼最佳矫正视力为0.2，左眼最佳矫正视力为0.5，曾行双眼激光治疗，眼底显示有FEVR改变。其余家族成员中，先证者祖父母可见晶状体混浊，眼底检查未见异常；先证者母亲和姑母，视力良好，眼前节及眼底检查均未见异常。家系中4位受检者周围血的遗传基因检测结果显示，先证者及其父亲2例FEVR患者携带基因/转录本FZD4/NM_012193.3核苷酸杂合变异c.1498delA，氨基酸变异p.Thr500fs，该变异导致第500位氨基酸由苏氨酸突变为亮氨酸，可致后续蛋白翻译发生提前终止，产生截断蛋白。根据美国医学遗传学与基因组学学会遗传变异分类标准与指南，该变异被评定为疑似致病性变异，2位眼正常人未检测出该基因变异。4位受检者中发现先证者及其母亲携带基因/转录本转化生长因子β2(TGFβ2)/NM_001135599.3核苷酸杂合变异c.673G>A，氨基酸变异p.Glu225Lys，该变异点为临床意义不明变异，可能与Loeys-Dietz综合征相关。 结论FZD4基因核苷酸变异c.1498delA(p.Thr500fs)属于基因位点变异，该变异可以解释此FEVR家系的致病原因。FZD4和TGFβ2基因突变可以共存于一个个体。     

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。     

目标区域捕获测序检测到一视网膜色素变性家系ABCA4基因新突变

目的研究我国一个常染色体隐性遗传的视网膜色素变性（RP）家系患者的临床表型及致病基因突变,并分析表型与基因型间的关系。方法实验研究。收集了宁夏人民医院眼科诊治的一个RP家系的临床资料,共有7名家庭成员参与研究,其中包括2名患者和5名正常成员。完善家系内所有参与成员的眼科检查,包括最佳矫正视力（BCVA）、视野、眼底照相、光学相干断层扫描（OCT）及全视野视网膜电流图（ERG）等。针对180个已知的遗传性视网膜疾病致病基因及9个高度可疑的候选基因设计目标区域捕获芯片,利用该捕获芯片对先证者（Ⅳ-4）进行目标区域内的高通量二代测序,借助优化的生物信息学分析对捕获的遗传变异进行筛查过滤,最终通过家系内共分离验证确认致病突变,进一步分析该突变与患者表型间的关系。结果临床检查结果表明该家系内的2名患者的临床表现均符合典型的RP改变,遗传学分析结果证实了ABCA4基因c.419G>A突变是该家系的致病突变。该突变导致了ABCA4基因所编码的蛋白第140号氨基酸由精氨酸变为谷氨酰胺（p.Arg140Gln）,保守性分析显示该突变位点在各物种中高度保守,PloyPhen-2软件预测结果表明该突变具有较高的致病性。结论本研究借助基于高通量二代测序平台的目标区域捕获测序,首次发现了ABCA4基因新突变p.Arg140Gln是一个常染色体隐性遗传RP家系的致病突变,进一步扩充了ABCA4基因的遗传突变谱及表型谱。     

RPGRIP1基因新突变致Leber先天性黑矇一家系

目的确定1个汉族Leber先天性黑矇(LCA)家系的致病基因突变。方法回顾性研究。2018年10月在河南省立眼科医院就诊的LCA一家系1例患者和3名家系成员纳入研究。详细询问患者病史并行物体注视性质、追随试验、裂隙灯显微镜、散瞳验光、眼底照相及全视野ERG检查;家系成员行BCVA、裂隙灯显微镜联合前置镜、验光、眼底照相及全视野ERG检查。采集先证者及其兄长、父母的外周静脉血5 ml,提取全基因组DNA。应用包含441个致病基因的遗传眼病捕获芯片进行靶向捕获富集高通量测序以获得致病基因及突变。对可疑致病突变位点通过Sanger进行验证,并行生物信息学分析确定基因突变位点的致病性。结果患者表现为自幼不追物但有明显畏光和眼球震颤;双眼眼前节及眼底无异常;全视野ERG检查可见双眼视锥、视杆系统功能严重下降。基因检测结果显示,患者RPGRIP1基因存在c.1635dupA和c.3565C>T两个突变。其中,RPGRIP1 c.1635dupA为新发突变。RPGRIP1基因c.1635dupA和c.3565C>T构成复合杂合突变。生物信息学分析结果显示,c.3565C>T为致病突变,c.1635dupA为可能致病突变。结论RPGRIP1基因新发突变c.1635dupA与c.3565C>T构成复合杂合突变可能是本家系的致病原因。     

一个中国全色盲家系CNGB3基因新突变

目的探讨全色盲一家系的致病基因突变。方法采用家系调查研究方法,于2018年11月对河南省立眼科医院收集的来自河南省洛阳市的汉族全色盲一家系进行基因测序。详细采集患者的病史资料,对患者及其家系成员进行最佳矫正视力(BCVA)测定,采用裂隙灯显微镜和前置镜检查眼前节和眼底,采用客观和主觉验光法对受检者进行屈光度检查,采用孟塞尔色觉测试工具Munsell FM 100进行色觉检查,采用国际标准化5项全视野闪光视网膜电图(FERG)评估视网膜功能,采用眼底照相仪进行眼底照相,采用频域光相干断层扫描成像(SD-OCT)观察受检者视网膜结构。采集先证者(Ⅲ1)及其胞弟(Ⅲ2)、父母的外周静脉血各4 ml提取全基因组DNA,采用包含441个致病基因的遗传眼病捕获芯片进行靶向捕获富集高通量测序。由于未检测到有意义的致病基因及突变,因此将Ⅲ1、Ⅲ2及其父母的DNA进行人全基因组测序。测序数据通过与疾病相关的数据库进行比对,对受检者的DNA进行Sanger测序并对其结果进行生物信息学分析。结合家系图与先证者进行共分离分析。结果该全色盲家系包括三代10名成员,患病者2例,遗传方式符合常染色体隐性遗传模式。Ⅲ1及Ⅲ2均表现为自幼发生的、与年龄增长无关的视力低下和畏光;眼底检查可发现视网膜色素沉积;SD-OCT检查示双眼黄斑区外界膜及椭圆体带反射信号欠规则;色觉检查示双眼全色盲。FERG示患者双眼暗视0.01、3.0和10.0 ERG a、b波振幅及振荡电位轻度下降,明视ERG a、b波振幅及30 Hz ERG各波振幅严重下降。Ⅲ1和Ⅲ2存在CNGB3基因1个新的突变位点c.129+1G>A和1个已知的突变位点c.1285dupT组成的复合杂合突变。结论CNGB3基因c.129+1G>A和c.1285dupT的复合杂合突变可能是本家系的致病原因,该家系成员在CNGB3基因2个位点同时出现变异时才表现出临床症状。     

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.     

LRP5基因一个新的突变位点相关的家族性渗出性玻璃体视网膜病变

目的分析家族性渗出性玻璃体视网膜病变(FEVR)一家系的临床表型和基因突变特点。方法采用家系调查研究方法,收集2019年10月于西安交通大学第一附属医院诊断为FEVR的1个汉族家系2代3名成员。对患者及其父母进行视力、眼压、裂隙灯显微镜和广角荧光素眼底血管造影(FFA)检查,采集3名成员外周血送检,应用高通量测序法筛选致病基因,针对检测出的变异位点进行Sanger测序验证,根据美国医学遗传学协会(ACMG)指南和Mutation Taster、Polyphen-2、PROVEN及REVEL软件对新发现的变异位点进行致病性分析。结果先证者,男,27岁,裸眼视力(UCVA)右眼1.0,左眼1.2,眼压正常,眼底检查可见双眼颞侧周边部视网膜血管迂曲扩张,FFA示双眼周边视网膜血管扩张成毛刷样改变并有无灌注区形成。先证者母亲51岁,最佳矫正视力(BCVA)双眼均为1.0,眼底检查可见左眼颞侧周边视网膜血管迂曲,FFA示左眼颞侧周边视网膜末梢血管荧光素渗漏。先证者父亲56岁,BCVA双眼均为1.0,眼底可见视盘周围萎缩环及豹纹状眼底,FFA未见眼底血管有明显荧光素渗漏。基因检测结果显示LRP5基因c.4110T>G(p.Cys1370Trp)和FSCN2基因c.1495G>A(p.Gly499Ser)2个新的突变位点。根据ACMG指南,c.4110T>G为临床意义未明的变异,Mutation Taster、Polyphen-2、PROVEN及REVEL软件预测该变异会对基因或基因产物造成有害影响,REVEL评分为0.93,可能为致病变异。结论LRP5基因c.4110T>G(p.Cys1370Trp)可能是引起FEVR的1个新的突变位点,丰富了LRP5基因的突变谱。     

Novel mutations in CRYBB1/CRYBB2 identified by targeted exome sequencing in Chinese families with congenital cataract

AIM: To summarize the phenotypes and identify the underlying genetic cause of the CRYBB1 and CRYBB2 gene responsible for congenital cataract in two Chinese families. METHODS: Detailed family histories and clinical data were collected from patients during an ophthalmologic examination. Of 523 inheritable genetic vision system-related genes were captured and sequenced by targeted next-generation sequencing, and the results were confirmed by Sanger sequencing. The possible functional impacts of an amino acid substitution were performed with PolyPhen-2 and SIFT predictions. RESULTS: The patients in the two families were affected with congenital cataract. Sixty-five (FAMILY-1) and sixty-two (FAMILY-2) single-nucleotide polymorphisms and indels were selected by recommended filtering criteria. Segregation was then analyzed by applying Sanger sequencing with the family members. A heterozygous CRYBB1 mutation in exon 4 (c.347T>C, p.L116P) was identified in sixteen patients in FAMILY-1. A heterozygous CRYBB2 mutation in exon 5 (c.355G>A, p.G119R) was identified in three patients in FAMILY-2. Each mutation co-segregated with the affected individuals and did not exist in unaffected family members and 200 unrelated normal controls. The mutation was predicted to be highly conservative and to be deleterious by both PolyPhen-2 and SIFT. CONCLUSION: The CRYBB1 mutation (c.347T>C) and CRYBB2 mutation (c.355G>A) are novel in patients with congenital cataract. We summarize the variable phenotypes among the patients, which expanded the phenotypic spectrum of congenital cataract in a different ethnic background.     

Mutation screening of the GUCA1B gene in patients with autosomal dominant cone and cone rod dystrophy

Background: Heterozygous mutations in GUCA1A (MIM # 600364) have been identified to cause autosomal dominantly inherited cone dystrophy, cone rod dystrophy and macular dystrophy. However, the role of GUCA1B gene mutations in inherited retinal disease has been controversial. We therefore performed a mutation analysis of the GUCA1B gene in a clinically well characterized group of patients of European and North-American geographical origin with autosomal dominantly inherited cone dystrophy and cone rod dystrophy. Material and Methods: Twenty-four unrelated patients diagnosed with cone dystrophy or cone rod dystrophy according to standard diagnostic criteria and a family history consistent with an autosomal dominant mode of inheritance were included in the study. Mutation analysis of all coding exons of the GUCA1B gene was performed by polymerase chain reaction amplification of genomic DNA and subsequent DNA sequencing. Results: Three different sequence variants, c.-17T>C, c.171T>C, c.465G>T were identified. The sequence variant c.465G>T encodes a conservative amino acid substitution, p.Glu155Asp, located in EF-hand 4, the calcium binding site of GCAP2 protein. All sequence variants were previously reported in healthy subjects. Conclusion: The absence of clearly pathogenic mutations in the selected patient group suggests that the GUCA1B gene is a minor cause for retinal degenerations in Europeans or North-Americans.     

Preliminary report on screening IGSF3 gene mutation in families with congenital absence of lacrimal puncta and canaliculi

AIM: To investigate the efficacy and safety of phacoemulsification combined with goniosynechialysis and/or endoscopic cyclophotocoagulation (PGE group and PG group) for the treatment of patients with coexisting primary angle-closure glaucoma (PACG) and cataracts. Methods: The clinical data of patients with PACG and cataract were retrospectively reviewed. There was a total of 88 eyes in the study and were divided into two groups, 42 eyes in PGE group and 46 eyes in PG group. Surgery success cumulative survival, preoperative and postoperative intraocular pressure (IOP), number of IOP-lowering medications, best corrected visual acuity (BCVA) in the two groups were observed for more than 12mo and compared within each group and between two groups. Results: The mean IOP in Phaco-GSL-ECP group declined from 24.9 mm Hg preoperatively to 14.1 mm Hg at the first month after operation (P＜0.001) and 16.2 mm Hg at the last visit (P＜0.001). The mean IOP in Phaco-GSL group declined from 24.1 mm Hg preoperatively to 13.0 mm Hg at the first month (P＜0.001) and 15.3 mm Hg at the last visit (P＜0.005). The mean medications reliance in Phaco-GSL-ECP group was reduced from 1.62 preoperatively to 0.13 at the last visit (P＜0.001), meanwhile in Phaco-GSL group the mean medications reliance was reduced from 0.87 to 0.10 (P＜0.001). There was significant difference at baseline, then disappeared at the last visit (P=0.01 vs P=0.867). At the last visit, BCVA increased from 0.21 to 0.60 in Phaco-GSL-ECP group (P＜0.001) and from 0.25 to 0.67 in Phaco-GSL group (P＜0.001). The success rate of Phaco-GSL-ECP group at 1mo visit was 95.2%, at the last visit was 70.7%. The success rate of Phaco-GSL at 1mo was 100%, was 73.4% at the last visit. Conclusion: Phaco-GSL-ECP shows promise for PACG patients with cataracts to reduce IOP, lighten the medication burden and improve visual acuity, and Phaco-GSL still has its value in specific patients.     

Characterization of the geometric properties of the sclero-conjunctival structure: a review

AIM: To investigate the variation of IGSF3 gene in three families with congenital absence of lacrimal puncta and canaliculi, and to lay a foundation for further research on the pathogenic gene of congenital lacrimal duct agenesis. METHOD: The members of the three families were recruited. The ophthalmologic examinations in details, including slit-lamp biomicroscope, intraocular pressure and fundus examination, etc were carried out. All patients were checked with paracentesis of puncta membrane and lacrimal duct probing, as well as the CT-DCG (computed tomography-dacryocystography). Peripheral blood of 13 participants (3 normal) from three families were collected, 4 mL each, for genomic DNA extraction, and 11 exon fragments of IGSF3 gene were amplified and sequenced by polymerase chain reaction (PCR) to determine whether there were IGSF3 genetic variation. RESULTS: A total of 13 members from three families were screened for 4 synonymous variants: c.930C>T (p.Pro366=), c.1359T>C (p.Ser709=), c.1797G>A (p.Ser855=), c.1539G>A (p.Ser769=), and 6 missense variants: c.1507G>A (p.Gly759Ser), c.1783T>C (p.Trp851Arg), c.1952G>T (p.Ser 907Ile), c.3120C>G (p.Asp1040Glu), c.3123C>G (p.Asp1041Glu), c.3139_3140insGAC (p.Asp1046_Pro1047insAsp), and the latter three were only found in two patients with absence of lacrimal puncta and canaliculi combined with congenital osseous nasolacrimal canal obstruction from the first family. CONCLUSION: The same IGSF3 gene mutation c.3139_3140insGAC is found in the patients with congenital absence of lacrimal puncta and canaliculi combine with osseous nasolacrimal canal obstruction.     

Novel TRPM1 mutations in two Chinese families with early-onset high myopia, with or without complete congenital stationary night blindness

AIM: To investigate the relationship between high myopia [with or without complete congenital stationary night blindness (CSNB1)] and TRPM1 and NYX. METHODS: Two unrelated families with early-onset high myopia (eoHM) and 96 normal controls were recruited. Sanger sequencing or clone sequencing were used for mutation screening. Further analyses of the available family members and the 96 normal controls were subsequently conducted to obtain additional evidence of the pathogenicity of these variants. The initial diagnosis of the probands was eoHM. We performed a further comprehensive examination of the available family members after mutations were detected in TRPM1 or NYX. RESULTS: Two novel compound heterozygous mutations in TRPM1 were detected in the recruited families. The proband in family A with eoHM carried a c.2594C>T missense mutation in exon 19 and a c.669+3_669+6delAAGT splicing mutation, which was co-segregated with CSNB1 in this family. A patient in family B with a compound heterozygous missense mutation (c.3262G>A and c.3250T>C) was detected. No mutations were found in NYX. These two identified compound heterozygous mutations were not found in the 96 normal controls. After further examination of the family members, the patients in family A could be diagnosed as eoHM with CSNB1. However due to the limited clinic data, the patient in family B cloud not clearly diagnosed as CSNB1. CONCLUSION: This study has expanded the mutation spectrum of TRPM1 for CSNB1 and additional studies are needed to elucidate the association between isolated high myopia and TRPM1 and NYX.     

A common founder mutation of CERKL underlies autosomal recessive retinal degeneration with early macular involvement among Yemenite Jews

PURPOSE: To investigate the genetic basis and clinical manifestations of a characteristic form of retinal degeneration in the Yemenite Jewish population. METHODS: Haplotype analysis for all known genes and loci underlying autosomal recessive nonsyndromic retinal degeneration was performed in a Yemenite Jewish family segregating autosomal recessive severe retinal degeneration. The causative mutation was detected by direct sequencing of the underlying gene, and its prevalence in additional affected and unaffected Yemenite Jews was determined. Patients who were homozygous for this mutation underwent ophthalmic evaluation, including funduscopy, electroretinography, electro-oculography, perimetry, and color vision testing. RESULTS: In the studied Yemenite Jewish family, we found evidence for linkage to the CERKL gene. Direct sequencing revealed a novel homozygous splice-site mutation, c.238+1G>A. An in vitro splicing assay demonstrated that this mutation leads to incorrect splicing. c.238+1G>A was found to cause retinal degeneration in six additional Yemenite Jewish families. The carrier frequency of this mutation in the Yemenite Jewish population is 4.4%. All c.238+1G>A homozygotes manifest widespread progressive impairment of rod and cone function with early macular involvement. CONCLUSIONS: c.238+1G>A is the second reported mutation of CERKL and is a prevalent founder mutation that underlies approximately 33% of autosomal recessive retinal degeneration cases in the Yemenite Jewish population. It is associated with a characteristic retinal degeneration phenotype with early macular involvement, concomitant progression of rod and cone impairment, and characteristic fundus findings. The identification of this mutation and phenotype will facilitate molecular diagnosis, carrier screening, and genetic counseling in the Yemenite Jewish population.     

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WES筛选得到的突变位点,通过Sanger测序对家系成员的其他患者及正常人进行扩大验证。结果：该家系Stickler患者临床特点主要包括先天性高度近视、白内障、玻璃体变性、视网膜脱离以及Marfan样体型,面中部扁平、低鼻梁、短鼻、听力障碍及关节活动度大等。在该家系10例现存Stickler患者中发现COL2A1（NM_033150）基因c.710delG:p.G237fs杂合变异,导致开放阅读框第710位碱基G缺失,其后部序列发生移码,从而导致其蛋白翻译在第237位氨基酸残基提前终止,蛋白整体结构产生变化从而丧失其正常功能。而无Stickler病史家系成员中未发现此突变位点。结论：本研究确定了1个Stickler综合征家系,并在该家系中确定了COL2A1（NM_033150）基因c.710delG:p.G237fs杂合变异。