一个遗传性玻璃体淀粉样变性家系TTR基因的突变检测

目的 对1个遗传性玻璃体淀粉样变性家系进行致病基因分析.方法 采集该家系4个成员(包括临床确诊患者3例,无症状者1例)的外周静脉血,提取基因组DNA.PCR方法扩增TTR基因的4个外显子,产物直接测序进行基因突变检测,同时选择150名无亲缘关系的正常对照.结果 该家系的4例受检者中均检测到TTR基因第3外显子第103位密码子发生了G＞C(Gly103Arg)杂合突变,而150名正常对照中未发现相同的突变.结论 TTR基因Gly103Arg杂合突变可能与该家系遗传性玻璃体淀粉样变性的发病有关.     

早发性帕金森病parkin基因的一个新的点突变

目的：观察不同亚型帕金森病（Parkinson's disease,PD）患者中是否存在parkin基因新的突变以及突变的分布，探讨parkin基因在PD发病机理中的可能作用。方法：70例患者被分为早发性PD和晚发性PD，70名正常体检者为对照组。以基因组DNA为模板，扩增parkin基因的全部12个外显子，然后行单链构象多态性（single-strand conformation polymorphism,SSCP）电泳观察，对泳动异常者进行DNA序列测定，以确定外显子中存在的突变及其分布。结果：70例患者中有4例SSCP泳动异常，测序证实1例早发性PD患者的外显子7存在1个未曾报道过的新的点突变位点Gly284Arg。结论：parkin基因点突变也是我国早发性PD患者的致病原因之一。     

一个白化病家系的TYR基因突变分析北大核心CSCD

目的对1个白化病家系的TYR基因进行突变检测,为遗传咨询和产前诊断提供参考。方法应用PCR技术扩增TYR基因的全部外显子区和外显子-内含子交界区序列,进行DNA测序。结果测序结果显示家系2例患者的TYR基因第2外显子存在c．896G〉A（p．Arg299His）纯合突变,7名表型正常的家系成员的TYR基因第2外显子存在c．896G〉A（Arg299His）杂合突变,7名家系成员和4名正常对照者则均未检测到该突变。结论TYR基因第2外显子c．896G〉A（p．R299H）突变应为该白化病家系的致病原因。     

九例遗传性凝血因子Ⅶ缺陷症患者的分子发病机制与临床特性

目的 探讨9个遗传性凝血因子Ⅶ( coagulation factorⅦ,FⅦ)缺陷症家系的基因突变类型与临床特征.方法 检测凝血酶原时间、活化部分凝血活酶时间及FⅦ活性和抗原等指标以明确诊断;用PCR法扩增先证者F7基因的全部外显子及侧翼序列、5′和3′非翻译区.PCR产物纯化后直接测序,寻找基因突变,用反向测序证实所发生的突变.结果 9个家系中的先证者凝血酶原时间均延长,FⅦ活性在2.0％～6.0％之间,7例先证者的FⅦ抗原显著减低.共发现8种F7基因突变,其中g.8355 A＞T(Gln100Leu)、g.11243T＞C(Ser269Pro)和g.11520_11521insT 3种突变为首次发现;6种突变发生在催化区;缺失突变和插入突变各1种,其余均为错义突变;所有的基因突变均来自先证者的父亲和(或)母亲,发现5个家系存在近亲婚配.g.27_28delCT、Cys329Gly、Arg304Trp和His348Gln突变在无亲缘关系的家系中重复出现.不同基因突变类型的临床表型有较大差异:2例His348Gln及1例Arg304Trp纯合突变可表现为轻型和无症状,2例g.27_28delCT纯合、杂合突变分别表现为中型、无症状,4例双杂合突变分别表现为1例(Ser269Pro和Cys329Gly)无症状、2例(Arg304Trp和Cys329Gly与Arg277Cys和g.11520_11521insT)轻型、1例(Gln100Leu和His348Gln)中型.结论 中国汉族人群中存在导致F7基因缺陷的突变热点.遗传性凝血因子Ⅶ缺陷症患者的临床表型与FⅦ活性、F7基因突变类型无明显的相关性.     

Arg304Trp导致的遗传性凝血因子Ⅶ缺陷症家系分析

目的对1例姨表近亲结婚的遗传性凝血因子Ⅶ（coagulation factorⅦ,FⅦ）缺陷症家系进行表型与基因型分析。方法检测血浆中凝血酶原时间（prothrombin time,PT）、FⅦ促凝活性（FⅦprocoagulant activity,FⅦ：C）及其它凝血指标以明确诊断;用DNA直接测序法对先证者及家庭成员FⅦ基因的全部外显子及其侧翼、启动子区进行分析,寻找基因突变,用反向测序证实所发现的突变。结果先证者的PT和FⅦ：C明显异常,分别为35.1s和3%;其父亲、母亲、大儿子和小儿子的PT稍延长,FⅦ：C明显降低。先证者FⅦ基因外显子8存在11348C→T纯合突变导致Arg304Trp;其父亲为该突变位点的杂合子,其母亲、大儿子和小儿子均为Arg304Trp杂合突变和Arg353Gln杂合多态性。结论先证者纯合突变Arg304Trp遗传自近亲结婚且具有相同杂合突变位点的父母。Arg353Gln多态性可能不是影响该家系成员血浆FⅦ：C水平的主要因素。     

角膜营养不良家系的TGFBI基因突变研究

目的确定中国角膜营养不良患者所存在的TGFBI基因突变类型。方法对3个角膜基质营养不良家系和1个Thiel—Behnke角膜营养不良家系进行分析，其中1个家系成员是蒙古族人，另3个家系则是汉族人。利用合成的TGFBI基因13个外显子的特异性引物，应用聚合酶链反应进行扩增，并直接测序分析。结果1个颗粒状角膜营养不良家系患者中检测到R555W突变；1个Thid-Behnke角膜营养不良家系患者为R555Q突变；另外2个Avellino角膜营养不良家系患者中发现R124H突变，这3种突变均为杂合子。结论研究表明R555和R124密码子在中国人常染色体显性遗传性角膜营养不良的发病机理中起重要作用。Thiel-Behnke角膜营养不良患者为R555Q突变，在我国属首次报告。     

黄体生成素β Gly102Ser基因多态性与多囊卵巢综合征的相关性研究

目的探讨黄体生成素β(Luteinizing hormoneβ-subunit,LHβ)Gly102Ser及黄体生成素受体(Luteinizing hormone receptor,LHR)基因多态性与PCOS的相关性。方法应用聚合酶链反应-限制性片段长度多态性(Polymerase chain reaction-restriction fragment length polymorphism,PCR-RFLP)检测LHβGly102Ser多态性,分析LHβ基因多态性与多囊卵巢综合征(polycystic ovary syndrome,PCOS)的相关性。结果 PCOS组中LHβGly102Ser基因有14例突变型,占3.3%。对照组中3例突变,占1.1%;PCOS组LHβGly102Ser基因突变率显著高于对照组(P=0.006);LHβGly102Ser基因突变型的血清基础LH水平低于对照组(P0.05),但突变组有降低趋势;PCOS组内血清LH2mmol/L的患者,LHβ基因Gly102Ser发生突变的比例显著增加(P=0.003)。结论 PCOS人群中存在LHGly102Ser基因多态性,此多态性与PCOS有明显的相关性。LHβGly102Ser基因多态性可能是PCOS发病的危险因素之一。     

家族性常染色体隐性遗传早发性帕金森综合征ATP13A2基因突变研究

目的 探讨常染色体隐性遗传早发性帕金森综合征(autosomal recessive early-onset parkinsonism,AREP)家系患者中ATP13A2基因的突变特点.方法 应用聚合酶链反应结合DNA直接序列分析方法对25个已排除Parkin,DJ-1和PINK1基因纯合突变及复合杂合突变的AREP家系共46例患者进行ATP13A2基因突变分析.结果 AREP患者中未发现ATP13A2基因的致病突变,发现了6个已知多态,为IVS6+70A>G、IVS12+66A>G、m1849C>T、IVS20-56 G>A、m2671C>T和m2824G>A.结论 家族性AREP患者中ATP13A2基因的突变可能罕见.     

一个遗传性多发性骨软骨瘤家系EXT1基因的突变分析CSCD

目的对1个遗传性多发性骨软骨瘤（hereditary multiple exostosis, HME）家系的先证者进行候选致病基因EXTI和EXT2的所有外显子检测,以寻找该HEM家系的致病性突变。方法应用PCR技术扩增EXT1、EXT2的全部外显子并进行直接Sanger测序分析。结果测序结果显示先证者EXT1基因第4外显子存在e．1202de1T（P．1401Tfs＊2）杂合缺失突变,该突变导致401位后的编码氨基酸发生移码,并在第402位引入终止密码,使EXTl编码的全长746氨基酸组成的蛋白质缩减至由402个氨基酸组成的截短型蛋白。该家系的其他6例患者均存在EXTle．1202delT的杂合移码突变,而表型正常家系成员未检测到该突变,符合基因型一表型共分离。未检测到EXT2基因的可疑突变。结论EXT1c．1202delT杂合移码突变是导致这个HME家系患者发病的分子机制。     

一例巨轴索神经病患者中发现GAN基因两种新型致病突变北大核心CSCD

目的寻找1例疑似巨轴索神经病患者的致病突变位点,为疾病诊断提供科学资料。方法应用目标序列捕获测序技术对患者进行遗传筛查,找到巨轴突蛋白基因（Gigaxonin,GAIN）的可疑致病突变位点,并提取患者父母的外周血DNA,进行Sanger测序验证。同时对200名正常人的400个GAN基因进行Sanger测序。此外,应用生物信息学软件Polyphen对突变巨轴突蛋白进行了功能预测。结果在患者GAN基因中鉴定出2种新型突变：c．778G〉T（p．Glu260Ter）和c．277G〉A（p．Gly93Arg）,为复合杂合突变;Sanger测序证实c．778G〉T（p．Glu260Ter）突变源于父方,c．277G〉A（P．Gly93Arg）突变则与母亲相同。在200名正常人GAN基因中未检测到同样的突变,排除其为多态性。生物信息学分析预测这两种新型GAN突变均可引发巨轴突蛋白功能异常。结论研究鉴定出了患者GAN的两种新型突变,它们均可能引起巨轴突蛋白结构和功能的异常,从而导致疾病的发生,为日后类似疾病的诊断提供了依据。     

中国人WD基因第14和18号外显子的错义突变

目的了解中国人肝豆状核变性（Ｗｉｌｓｏｎ＇ｓｄｉｓｅａｓｅ,ＷＤ）基因第１４和１８号外显子的突变情况,与国外报道的这两个外显子的高突变频率进行比较。方法应用聚合酶链反应－单链构像多态（ＰＣＲ－ＳＳＣＰ）结合ＤＮＡ测序技术,对４４例无亲缘关系的ＷＤ患者及６０例正常对照进行突变检测。结果一例患者在１４号外显子发生了Ａｒｇ１０４１Ｐｒｏ（３１２１Ｇ→Ｃ）纯合错义突变,另一例患者在１８号外显子发生了Ａｓｎ１２７０Ｓｅｒ（３８０９Ａ→Ｇ）杂合错义突变。结论Ａｒｇ１０４１Ｐｒｏ为未报道过的新型错义突变,Ａｓｎ１２７０Ｓｅｒ突变与国外报道一致。但均未呈热区分布。     

PARKIN-coding polymorphisms are not associated with Parkinson's disease in a population from northeastern Mexico

Early- and late-onset Parkinson's disease (EOPD and LOPD) have been associated with mutations in the PARKIN gene. Several studies have reported association of Parkinson's disease (PD) with different polymorphisms in different ethnic populations. To study the role of PARKIN polymorphisms as risk factors for PD in a genetically homogeneous northeastern Mexican population, four previously described coding polymorphisms (Ser167Asn, Val380Leu, Arg366Trp, and Asp394Asn) were analyzed by using the PCR-RFLP technique. This case–control study comprised 117 unrelated patients (mean age 59 ± 12 years, range 25–83 years) and 122 healthy unrelated control subjects (mean age 50 ± 15 years, range 25–85 years). The homozygous Trp366 and Asn394 genotypes were not present in our study. The Ser167Asn and Val380Leu polymorphisms were not associated with this disease. For the control group, Ser167Asn and Val380Leu were in Hardy–Weinberg disequilibrium. Given that the main causes of Hardy–Weinberg disequilibrium in controls are selection bias or genotyping error, a competing risk of death associated with the mutant gene could be an explanation of this disequilibrium and lack of association.     

一个纤维蛋白原γ链g．7590G〉T杂合突变导致遗传性低纤维蛋白原血症家系的分析CSCD

目的对一个遗传性低纤维蛋白原血症家系进行基因突变分析,并探讨其发病的分子机制。方法采集先证者及其家系成员（3代共9人）的外周血样,用自动化血凝仪分析凝血酶原时间（prothrombin time,PT）、活化部分凝血活酶时间（activated partial thromboplastin time,APTT）和凝血酶时间（thrombin time,TT）;用凝血酶凝固法（Clauss法）与免疫比浊法分别测定血浆纤维蛋白原的活性（fibrinogen activity,Fg∶C）和抗原水平（fibrinogen antigen,Fg∶Ag）;用PCR扩增纤维蛋白原FGA、FGB和FGG基因的所有外显子及其侧翼序列,对PCR产物进行纯化后直接测序;用Swiss软件对突变蛋白进行预测。结果先证者APTT、PT和TT均延长,Fg∶C（0.69 g/L）和Fg∶Ag（0.72 g/L）明显降低;其母亲、外祖母Fg∶C分别为0.99 g/L和0.83g/L,Fg∶Ag为1.02 g/L和0.87 g/L,均有不同程度的降低。其他家系成员的凝血指标均在正常范围。先证者FGG基因第8外显子存在7590位置的G〉T杂合突变,导致纤维蛋白原D结构域的313位丝氨酸突变为异亮氨酸（Ser313Ile）;其母亲和外祖母亦为Ser313Ile杂合子,其他家系成员则为野生型。模型分析显示Ser313突变为Ile后,同Asn319、Asp320之间的氢键消失,可能影响钙离子的正常结合。此外,该突变导致中性非极性的Ser变成了非极性、疏水性的Ile,使侧链变长,可能影响纤维蛋白原的折叠、构象及稳定性,导致血浆纤维蛋白原水平降低。结论纤维蛋白原γ链Ser313Ile的杂合突变是引起该家系遗传性低纤维蛋白原血症的原因。     

Ten novel mutations in VMD2 associated with Best macular dystrophy (BMD)

Mutations in the vitelliform macular dystrophy 2 (VMD2) gene encoding besrtophin are responsible for Best macular dystrophy (BMD), a juvenile-onset autosomal dominant disorder of the central retina. Here, we report ten novel VMD2 mutations identified in clinically diagnosed BMD patients. The heterozygous alterations include nine missense mutations (c.32A>T, c.76G>C, c.85T>C, c.122T>C, c.122T>C, c.310G>C, c.722C>A, c.880C>G, c.893T>C) resulting in amino acid changes (respectively: Asn11Ile, Gly26Arg, Tyr29His, Leu41Pro, Trp102Arg, Asp104His, Thr241Asn, Leu294Val and Phe298Ser) located within four previously defined hotspot regions of the gene. In addition, a silent exonic mutation (c.624G>A) was identified in a two generation BMD pedigree. To determine a possible pathogenic effect of this variant, the consequences on splicing behaviour and potential exonic splice enhancer (ESE) motifs were analyzed. Finally, a 1-bp deletion (c.779delC) resulting in a frameshift mutation (Pro260fsX288) was found in exon 7, representing the first case of a potential frameshift mutation that affects the N-terminal half of the VMD2 protein. Besides a dominant negative effect which is likely attributable to the identified missense mutations, the deletion mutation suggests haploinsufficiency as an infrequent disease-causing mechanism in BMD.     

Biochemical characterization of a neuroserpin variant associated with hereditary dementia

Neuroserpin isolated from inclusion bodies in the brain of a patient with a neurodegenerative disease was characterized biochemically. The protein consisted of residues 20 to 410 of the neuroserpin precursor deduced from its cDNA sequence indicating the entire molecule was deposited. A minor amount started with residue 19 of the precursor, and the carboxyl terminus was heterogeneous ending at residues 405, 407, 409, and 410. Arg was present at position 52. No normal Ser52 was found indicating that only mutant neuroserpin was present in the inclusion bodies. The three potential Asn glycosylation sites all contained carbohydrate. DNA sequence analysis of exons 2 to 9 of the neuroserpin gene in the proband showed the published normal neuroserpin sequence except for the presence of both adenine and cytosine at the first position of codon 52, that indicates heterozygosity for both the normal Ser(AGT) and variant Arg(CGT) at this position in the expressed protein. Restriction fragment length polymorphism analysis of a polymerase chain reaction product from exon 2 revealed the propositus and his affected sibling both were heterozygous for the mutation whereas 100 unaffected controls were negative. Chemical characterization of the variant neuroserpin will significantly enhance the understanding of this protein in both normal physiology and neurodegenerative diseases.     

Genotypic and phenotypic analysis of a case with inherited coagulation factor X deficiencyCSCD

Objective: To explore the correlation between F10 gene mutation and its phenotype in a Chinese pedigree affected with FX deficiency. Methods: Prothrombin time(PT), activated partial thromboplastin time(APTT), fibrinogen, F II activity(FII: C), FVII activity (FVII: C), FIX activity (FIX: C), FX activity(FX: C) were determined with a one-stage clotting assay. The FX antigen(FX: Ag) was detected with an enzyme linked immunosorbent assay(ELISA). The 8 exons, introns and 5' and 3' untranslated regions(UTR) of the F10 gene of the proband and her family members were subjected to PCR amplification and Sanger sequencing. Suspected mutation was confirmed by reverse sequencing. Polymorphisms were excluded by direct sequencing of 100 healthy individuals. Results The PT and APTT of the proband have prolonged to 16. 1 s and 49. 0 s, respectively. Her FX: C and FX: Ag were reduced by 27% and 56%, and her mother's PT, APTT, FX: C and FX :Ag were 14.8 s, 37.4 s, 44%, 34%, respectively. Her grandmother's PT, APTT, FX: C and FX: Ag were 15. 8 s, 42. 2 s, 31%, 45%, respectively. The results of her father and other family members were all within the normal range. Genetic analysis has revealed a heterozygous G>A mutation in the proband at position 28076 in exon 8 of the F10 gene, which resulted in a p. Gly363Ser substitution. The same mutation was also found in her mother and grandmother. No mutation of the F10 gene was found in her father. Gly363Ser may result in changes in the secondary structure of the F X protein and reduction of its activity. Conclusion The g. 28076G > A (p. Gly363Ser) mutation of the F10 gene probably underlies the F X deficiency in this pedigree. The mutation was discovered for the first time in Chinese patients. © 2018 MeDitorial Ltd. All rights reserved.     

PINK1基因外显子拷贝数分析方法的建立及应用

目的 建立PINK1(PTEN-induced kinase 1)基因外显子拷贝数分析方法 ,并应用该方法 分析常染色体隐性遗传性早发型帕金森综合征(autosomal recessive early onset Parkinsonism,AREP)PINK1基因拷贝数变异(copy-number variation,CNV)的特点.方法 应用实时荧光定量聚合酶链反应(polymerase chain reaction,PCR)技术分析方法 ,对30个正常对照和22个中国AREP汉族家系先证者的PINK1基因进行外显子拷贝数分析.结果 应用实时荧光定量PCR技术完成了PINK1基因第1～8外显子拷贝数分析,获得了扩增效率和特异性均满意的反应条件及各外显子引物.所检测的AREP先证者未发现PINK1基因的外显子拷贝数变异.结论 建立了PINK1基因外显子拷贝数分析方法 .中国人AREP患者PINK1基因外显子拷贝数变异可能罕见.     

PINK1基因外显子拷贝数分析方法的建立及应用

目的 建立PINK1(PTEN-induced kinase 1)基因外显子拷贝数分析方法 ,并应用该方法 分析常染色体隐性遗传性早发型帕金森综合征(autosomal recessive early onset Parkinsonism,AREP)PINK1基因拷贝数变异(copy-number variation,CNV)的特点.方法 应用实时荧光定量聚合酶链反应(polymerase chain reaction,PCR)技术分析方法 ,对30个正常对照和22个中国AREP汉族家系先证者的PINK1基因进行外显子拷贝数分析.结果 应用实时荧光定量PCR技术完成了PINK1基因第1～8外显子拷贝数分析,获得了扩增效率和特异性均满意的反应条件及各外显子引物.所检测的AREP先证者未发现PINK1基因的外显子拷贝数变异.结论 建立了PINK1基因外显子拷贝数分析方法 .中国人AREP患者PINK1基因外显子拷贝数变异可能罕见.