血友病A的基因治疗研究进展

经过多年的研究和探索,血友病A的基因治疗取得了很大进展。尽管存在许多困难和障碍,但基因治疗仍是彻底治愈血友病A的最理想的方法。在不久的将来,基因治疗将成为除蛋白替代疗法外血友病A患者的另一种选择。     

2A型血管性血友病vWF的基因突变

目的 研究中国人２Ａ型血管性血友病（ｖｏｎ Ｗｉｌｌｅｂｒａｎｄ ｄｉｓｅａｓｅ,ｖＷＤ）的分子病理机理,了解 ｖＷＤ的临床表现型和基因型的相关性。方法 对１２６例先天性出血性疾病患者进行了出血时间、ｖＷＦ：Ａｇ、ＦⅧ：ＣＡｇ、瑞斯脱素诱导的血小板聚集率的检测和ｖＷＦ的血浆多聚物分析。对２Ａ型血管性血友病的患者用多聚酶链反应、变性梯度凝胶电泳,结合测序的方法进行了基因突变的研究。结果 确诊２Ａ型血     

中国人家族性结直肠癌错配修复基因大片段变异分析

目的分析中国人家庭性结直肠癌错配修复基因大片段变异的特点。方法 采用多重连接探针扩增技术，分析32例具有家庭史结直肠癌、20例散发性结直肠癌患者错配修复基因MSH2的16个外显子、MLH1的19个外显子及7个其它基因外显子的拷贝数。研究工作包括：（1）双盲法分析阴性和阳性对照样本，完成方法学可靠性检验；（2）分析结直肠癌患者外周血细胞DNA，筛查MSH2和MLH1基因大片段变异。结果 多重连接探针扩增技术分析系统稳定检出阳性对照样本的DNA大片段缺失；在3/32（9.4%）具有家庭聚集性结直肠癌患者中检出遗传性MSH2基因DNA大片段缺失。而在20例散发性结直肠癌患者未检出这类突变。结论 中国人家族性结直肠癌患者中错配修复基因的大片段变异是频发事件，对此类患者的遗传检测应包含错配修复基因大片段变异的筛查。     

重型血友病A凝血因子Ⅷ第1内含子倒位的基因检测

目的 在中国重型血友病A(haemophilia A,HA)患者中筛查凝血因子Ⅶ(factor Ⅷ,FⅧ)基因第1内含子倒位,并对受累患者家系成员行携带者检查和产前基因诊断.方法 对重型HA患者(F Ⅷ:C<1%)采用长距离PCR法首先筛查第22内含子倒位,对第22内含子倒位阴性的应用双管多重PCR法进行第1内含子倒位检测,对第1内含子倒位阳性患者的女性家属进行携带者检测,对女性携带者所孕胎儿进行产前检测.用基因连锁分析和DNA测序法加以验证.结果 从247例重型HA患者中共检测出118例第22内含子倒位和7例第1内含子倒位,第1内含子倒位突变在中国重型HA人群中的发病率约为2.8%;随访到的两个受累患者家系A和B中各检出6名和2名女性携带者,家系A中产前检出1名第1内含子倒位受累胎儿.结论 采用双管多重PCR法可以直接检测凝血因子Ⅷ第1内含子倒位突变,完善了重型血友病A家系携带者检测和产前诊断.     

布氏菌544A基因片段的PCR扩增及其序列分析

利用ＰＣＲ和ＤＮＡ重组技术，成功的扩增了牛布氏菌５４４Ａ基因。回收含Ｂｒ．ａｂｏｒｔｕｓ５４４ＡＤＮＡ片段，插入ＳｍａＩ单酶切的ｐＵＣ９载体中，进行核苷酸序列分析，证实克隆的ＤＮＡ片段长度为２２４ｂｐ，在该序列中含有单个开放新闻记者框架。将重组用Ｋｐｎ１和ＢａｍＨ１双酶切下Ｂｒ．ａｂｏｒｔｕｓ５４４ａＤＮＡ片段标记探针，均与６种布氏菌杂交出现阳性结果。说明Ｂｒ．ａｂｏｒｔｕｓ５４４Ａ２２４ｂｐＤＮ     

PCR-构象敏感凝胶电泳技术在血友病A基因分型诊断及携带者检测中的应用

所有的HA家系(含散发)进行直接基因诊断,理论上可筛查新突变并明确其突变类型.该法简便、快速、成本低,在HA直接基因诊断及携带者筛查中优势独特,应具重要应用价值.     

一个复合杂合变异导致的遗传性凝血因子Ⅻ缺陷症家系分析

目的检测1个遗传性凝血因子Ⅻ(coagulation factorⅫ,FⅫ)缺陷症家系的基因变异,探讨其分子致病机制。方法用DNA直接测序法对F12基因进行变异分析;在野生型pIRES2-EGFP/FⅫ表达质粒基础上,构建变异型FⅫ表达质粒,Polyfect转染试剂瞬时转染293T细胞,分别测定上清液中FⅫ活性(FⅫactivity,FⅫ∶C)和FⅫ抗原(FⅫantigen,FⅫ∶Ag),测定细胞裂解液中FⅫ∶Ag,并用Western印迹进行验证。结果先证者F12基因第1外显子启动子区为46TT基因型,在第13和14外显子存在g.8489G>A(p.Glu502Lys)和g.8699G>C(p.Gly542Ser)复合杂合变异。瞬时转染结果显示,FⅫp.Glu502Lys变异体蛋白上清液中FⅫ∶C和FⅫ∶Ag分别为野生型的28%和24%,细胞裂解液中FⅫ∶Ag为野生型的39%;FⅫp.Gly542Ser变异体蛋白上清液中的FⅫ∶C和FⅫ∶Ag分别为野生型的32%和17%,细胞裂解液中FⅫ∶Ag为野生型的59%。结论先证者F12基因型46TT,p.Glu502Lys和p.Gly542Ser复合杂合变异导致其FⅫ水平极度降低;体外表达实验证实变异蛋白p.Glu502Lys和p.Gly542Ser存在合成和分泌障碍。     

10例血友病A患者的FⅧ因子基因内含子22倒位分析

１０例血友病Ａ患者的ＦⅧ因子基因内含子２２倒位分析吴竞生，陈云弟，王寅文，陈美珏，王祖贻，潘理明，汪健，丁浩血友病Ａ（ＨＡ）是凝血因于Ⅷ（ＦⅧ）基因缺陷所致的Ｘ－连锁隐性出血性遗传病。ＦⅧ因子基因突变类型众多，１９９３年发现约一半重型ＨＡ是由ＦⅧ基因...     

KMT2A基因新发无义变异导致Wiedemann-Steiner综合征一例

目的:对1例原因不明发育迟缓伴面部畸形患儿进行分子遗传学分析,明确其致病原因。方法:二代全外显子组测序(whole exome sequencing,WES)筛选符合表型并可能致病的基因变异,应用Sanger测序在患者及其父母中进行变异验证。结果:WES结果显示患儿 KMT2A基因(NM_001197104...     

Identification of 217 unreported mutations in the F8 gene in a group of 1,410 unselected Italian patients with hemophilia A

To provide a National database, 1,410 unrelated hemophilia A (HA) patients were investigated using screening methods denaturing high-performance liquid chromatography (DHPLC), conformational-sensitive gel electrophoresis (CSGE)] and/or direct sequencing. F8 gene mutations were identified in 877 (81%), 146 (82%), and 133 (89%) families with severe, moderate, or mild HA, respectively. Among the 382 different mutations detected, 217 (57%) have not previously been reported in the F8 Haemophilia A Mutation, Structure, Test and Resource Site (HAMSTeRS) database. Mutations leading to a null allele accounted for 82, 15%, and less than 1% of severe, moderate, or mild HA, respectively. A missense mutation was identified in 16%, 68%, and 81% of severe, moderate, or mild HA, respectively. They included 105 missense mutations (48%), 41 small deletions (19%), 25 splice site mutations (12%), 24 nonsense mutations (11%), 18 insertions (8%), three large deletions (1%), and one deletion plus insertion. Unreported mutations were distributed throughout the F8 gene, as they affected all F8 exons but exon 20. We report a wide spectrum of mutations collected in a large National database. The type of mutation was a strong predictor of the clinical phenotype. This database is expected to considerably improve the genetic counseling and medical care of HA families in Italy.     

F8基因倒位检测及其在甲型血友病基因诊断中的应用

目的建立F8基因第22内含子倒位突变检测新方法,应用于甲型血友病(hemophilia A)基因诊断。方法应用长距离PCR(long distance-polymerase chain reaction,LD-PCR)、倒位PCR(inversion-PCR,IPCR)技术检测31例甲型血友病患者F8基因22内含子倒位;对于倒位突变阳性患者的母亲应用上述两种方法进行携带者诊断;而对倒位携带者孕妇于孕中期抽取羊水,进行产前基因诊断。结果31例甲型血友病患者中查出7例存在倒位突变;4例倒位突变阳性患者的母亲有3例为倒位携带者;对1例倒位携带者孕妇进行了产前诊断,确定其胎儿无倒位突变。结论LD-PCR、I-PCR技术可快速检测F8基因22内含子倒位突变,可应用于患者及携带者基因诊断;I-PCR可用于F8基因22内含子倒位的产前基因诊断。     

Prevalence of small rearrangements in the factor VIII gene F8C among patients with severe hemophilia A

Hemophilia A is a common X-linked bleeding disorder caused by various types of mutations in the factor VIII gene F8C. The most common intron 22-inversion is responsible for about 40% of the severe hemophilia A cases while large deletions, point mutations and small (less than 100 bp) deletions or insertions are responsible for the disease in the rest of patients. We report on nine novel (6 deletions, two indels and one partial duplication) and five recurrent small rearrangements identified in 15 German patients with severe hemophilia A, negative for the intron 22-inversion. c.2208-2214delTTATTAC/c.2207-2215insCTCTT and c.4665-4678del/c.4664-4678insAAGGAA identified in the present study are the first small indels described in the factor VIII gene. Our analyses suggest that the prevalence of this type of mutations (predominantly located in exon 14) among patients with severe phenotype and negative for the common intron 22-inversion, is about 30%. The correlation between these molecular defects and formation of factor VIII inhibitors as well as the parental origin of the de novo mutations are evaluated. Finally we show that denaturing HPLC (DHPLC) and classic heteroduplex analysis (HA) are able to detect these sequence alterations on 100% and could be preferred as a screening approach when analysing for mutations in factor VIII in severely affected patients.     

Identification of seven novel mutations of F8C by DHPLC

Hemophilia A is an X-linked recessive disorder resulting from deficiency of Factor VIII (F8C), an important protein in blood coagulation. A large number of disease producing mutations have been reported in the F8C gene. However, a comprehensive analysis of mutations is difficult to conduct due to the large gene size, its many scattered exons, and the high frequency of de novo mutations. In this study, we performed analysis using PCR, Conformation Sensitive Gel Electrophoresis (CSGE), Denaturing High Performance Liquid Chromatography (DHPLC) and direct sequencing. We found seven novel mutations causing severe, moderate and mild Hemophilia A: IVS14-1G>A, G458V, T1695S, L1758P, Q2311P, 1441delT, 1269-1271insA. At least four variants detected by DHPLC (IVS14-1G>A, Q2311P,_R698W and D1241Q) were not detectable by CSGE.     

一个遗传性癫痫伴热性惊厥附加症家系的临床表型及 SCN1A基因变异分析

目的:分析1个遗传性癫痫伴热性惊厥附加症(genetic epilepsy with febrile seizures plus,GEFS+)家系的临床表型及遗传特征进行分析。方法:收集先证者及其家系成员的临床资料并提取外周血DNA,对先证者采用高通量测序以确定潜在的变异位点,对其家系成员采用Sanger测序进行验证。...     

Detection of 95 novel mutations in coagulation factor VIII gene F8 responsible for hemophilia A: results from a single institution

Hemophilia A (HA) is an X‐linked hereditary bleeding disorder defined by a qualitative and/or quantitative factor VIII (FVIII) deficiency. The molecular diagnosis of HA is challenging because of the high number of different causative mutations that are distributed throughout the large F8 gene. The putative role of the novel mutations, especially missense mutations, may be difficult to interpret as causing HA. We identified 95 novel mutations out of 180 different mutations responsible for HA in 515 patients from 406 unrelated families followed up at a single hemophilia treatment center of the Bicêtre university hospital (Assistance Publique‐Hôpitaux de Paris [AP‐HP], Le Kremlin‐Bicêtre). These 95 novel mutations comprised 55 missense mutations, 12 nonsense mutations, 11 splice site mutations, and 17 small insertions/deletions. We therefore developed a mutation analysis based on a body of proof that combines the familial segregation of the mutation, the resulting biological and clinical HA phenotype, and the molecular consequences of the amino acid (AA) substitution. For the latter, we studied the putative biochemical modifications: its conservation status with cross‐species FVIII and homologous proteins, its putative location in known FVIII functional regions, and its spatial position in the available FVIII 3D structures. The usefulness of such a strategy in interpreting the causality of novel F8 mutations is emphasized. Hum Mutat 27(7), 676–685, 2006. © 2006 Wiley‐Liss, Inc.     

Direct transmission of a tandem duplication in the short arm of chromosome 8

A family is described in which a mother and her two children carry a tandem duplication of the short arm of chromosome 8. Their phenotypes are similar and characterised by distinct facial dysmorphism, small stature and mild mental retardation. This is one of the first cases of direct familial transmission of a partial duplication of an autosomal chromosome segment.     

A patient with treatment-resistant schizophrenia and cytochrome P4502D6 gene duplication

We describe a patient with treatment-resistant schizophrenia who had a duplication in the cytochrome P450IID6 (CYP2D6) gene. This severely ill 71-year-old-woman had responded poorly to several neuroleptics. Molecular genetic study revealed CYP2D6 gene duplication, which results in excessive activity of CYP2D6 that metabolizes various commonly used neuroleptics. The mutation may have contributed to treatment resistance in this case.     

一例视网膜色素变性患者 C2ORF71基因的变异分析

目的:分析1例视网膜色素变性(retinitis pigmentosa, RP)患者的基因变异,明确其可能的遗传学病因。方法:应用全外显子测序技术对先证者进行致病基因筛查,结合临床表型确定可疑变异,应用Sanger测序法验证检出的变异,分析双亲携带变异位点的情况。采用多种软件对所检出的变异进行致病性分析。结果:全外显子...     

MCCC2基因变异致3-甲基巴豆酰辅酶A羧化酶缺乏症患儿的家系分析

目的对1例临床疑诊3-甲基巴豆酰辅酶A羧化酶缺乏症(3-methylcrotonyl-coenzyme A carboxylase deficiency,MCCD)患儿及其父母进行基因变异分析,寻找该家系的致病变异,为临床诊断提供分子遗传学依据。方法抽提先证者及其父母的外周血基因组DNA,应用全外显子组基因测序技术对疑似为MCCD疾病的先证者进行致病基因筛查。根据高通量测序结果,对先证者及其父母进行变异位点的Sanger测序验证分析。应用计算机软件预测变异位点氨基酸进化保守性和变异可能导致的蛋白质结构和功能变化,分析变异位点的性质。结果Sanger测序结果显示先证者为MCCC2基因c.1342G>A(p.Gly448Ala)纯合错义变异,为未报道过的新变异。先证者母亲为c.1342G>A(p.Gly448Ala)杂合变异携带者,父亲未检测到该变异。用PolyPhen-2和Mutation Taster软件预测该变异为致病性,变异区域序列在不同物种间高度保守。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,MCCC2基因c.1342G>A(p.Gly448Ala)变异判定为可能致病性变异(PM2+PP2~PP5)。结论先证者MCCC2基因c.1342G>A(p.Gly448Ala)纯合错义变异是其分子发病机制,基因变异分析有助于明确临床诊断。