DXS52(St14)在血友病甲基因诊断中的方法改进及应用

目的 改进DXS52(St14)在血友病甲(hemophilia A,HA)基因连锁分析中的实验方法并应用于基因诊断,报道DXS52位点与FⅧ基因发生重组的2个家系.方法 采用PCR和琼脂糖凝胶电泳对61个非倒位HA家系的DXS52位点进行基因检测,并用FⅧ基因内的Bcl Ⅰ、HindⅢ、Xba Ⅰ、STRl、STRl3、STR22和STR24这7个位点以及DXS52位点对这61个家系进行基因连锁分析.结果 DXS52位点在43个HA家系中可提供信息,可诊断率为70.5%(43/61).其中8个家系仅DXS52单个位点能提供信息,占13.1%;两个家系的DXS52与FⅧ基因发生基因重组.结论 采用新的实验条件可使DXS52位点基因检测得到准确清晰的实验结果.该位点可诊断率高,目前是HA连锁基因分析中不可缺少的诊断位点,但该位点位于FⅧ基因外,与FⅧ基因间存在重组可能,单独应用于诊断时应谨慎.

Abstract：

Objective To improve the experimental method of DXS52 (St14) and apply it to genetic testing for hemophilia A (HA). Methods PCR of DXS52 and agarose gel electrophoresis were performed for genetic testing in 61 non-inversion HA families. Linkage analysis of 7 loci within the FⅧ gene including Bcl Ⅰ , Hind Ⅲ, Xba Ⅰ , STR1, STR13, STR22 and STR24 were also carried out for the 61 families.Results DXS52 can provide information in 43 out of 61 families and the diagnostic rate was 70. 5%. Eight families can be diagnosed only by DXS52 locus, accounting for 13. 1%. Two families were found to have recombination between DXS52 and FⅧ. Conclusion The new experimental conditions can reach accurate and clear results in DXS52 genetic testing. This gene maker has high diagnostic rate, so it is an indispensable linkage analysis method in HA gene diagnosis. More caution should be paid when using the extragenic locus DXS52 to perform gene diagnosis because of its high recombinant rate with FⅧ.     

现行唐氏综合征筛查方法之我见

唐氏综合征筛查的血清学方法的不足唐氏综合征(又称21三体综合征或先天愚型)等染色体三体综合征是具有痴呆、器官畸形等一系列症状的最常见的严重先天性出生缺陷,发生率为1/800新生儿,35岁以上高龄孕妇娩出的患儿发生率更高。北京市每年在约16.1万个新生儿中都会发现20多例先天愚型患儿,给家庭和社会造成极大负担。此类病至今尚无有效治疗方法,产前筛     

多重连接探针扩增技术的研究进展及其应用

多重连接探针扩增技术(multiplex ligation-dependentprobe amplification,MLPA)是一种高通量、针对待测核酸中靶序列进行定性和定量分析的新技术。该技术仅需20ng/μlDNA,即可通过简单的杂合、连接、PCR扩增及电泳步骤,在同一反应管中对四十多个不同的靶基因进行检测和定量分析。这一技术最先于2002年由荷兰的Schouten等[1]报道。如今短短几年中,该技术已被欧洲、亚洲等几十个实验室采用。迄今为止,已有150多篇不同领域采用该技术方法的报道在重要刊物上发表。     

巨细胞病毒与动脉粥样硬化的临床研究

目的 研究巨细胞病毒和动脉粥样硬化的关系。方法 用ＰＣＲ的方法检查巨细胞病毒在颈内动脉、冠状动脉和血中的分布情况，并与健康人对照。结果 ８３．３％～８６．７％的动脉粥样硬化患者的动脉壁中存在巨细胞病毒，而非动脉粥样硬化患者的动脉壁中只有６．７％的标本中见巨细胞病毒，两者相差有高度显著性（Ｐ〈０．０１）；在４２．４％的动脉粥样硬化患者的血中查见世细胞病毒，而对照组中只有３％查到巨细胞病毒，两者相差有     

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.     

Detection of factor Ⅷ intron 1 inversion in severe haemophilia A

Objective Screening the intron 1 inversion of factor Ⅷ (FⅧ) in the population of severe haemophilia A(HA) in China and performing carrier detection and prenatal diagnosis. Methods Using LD-PCR to detect intron 22 inversions and multiple-PCR within two tubes to intron 1 inversions in sereve HA patients. Carrier detection and prenatal diagnosis were performed in affected families. Linkage analysis and DNA sequencing were used to verify these tests. Results One hundred and eighteen patients were seven diagnosed as intron 22 inversions and 7 were intron 1 inversions out of 247 severe HA patients. The prevalence of the intron 1 inversion in Chinese severe haemophilia A patients was 2. 8% (7/247). Six women from family A and 2 from family B were diagnosed as carriers. One fetus from family A was affected fetus. Conclusion Intron 1 inversion could be detected directly by multiple-PCR within two tubes. This method made the strategy more perfective in carrier and prenatal diagnosis of haemophilia A.     

两种常见缺失型α-地中海贫血快速检测技术的研究

目的：建立简便快速准确可推广使用的检测α－地中海贫血（α-Thal)右侧失型（－α^3.7)和左侧缺失型（－α^4.2)的聚合酶链反应（PCR）方法。方法：自行研究设计两组引物。优化PCR反应条件。PCR反应产物用1％琼脂糖凝胶电泳分离,溴化乙啶染色,UVP凝胶成像仪下观察记录电泳图谱。结果：运用引物A′、B′、C3进行PCR,出现1700bp扩增带表示－α^3.7,出现1900bp扩增带表示α－珠蛋白基因正常或为野生型。二条扩增带同时出现表示是－α^3.7缺失杂合子。无任何扩增带表示是是东南亚型缺失纯合子。运用引物G′、E、F′进行PCR,根据出现1580bp扩增带和1180bp扩增带可诊断为－α^4.2,还可区分杂合子与纯合子。结论：本研究设计的两组引物及优化的PCR条件,可以简便准确地检测出α－Thal标本中有无－α^4.2和－α^3.7。     

聚合酶链反应检测同源性变形链球菌

目的：建立一种简便,快速,具有特异性检测和识别变形链球菌的方法。方法：根据葡聚糖基因设计的具有特异性针对变形链球菌的寡核苷酸引物,通过聚合酶链反应扩增一个１８８ｂｐ的ＤＮＡ片段以检测变链菌株和从人的口腔提取的菌斑和唾液标本。结果：这种聚合酶链反应的方法检测变链菌具有特异性和敏感性。结论：葡聚糖酶聚合酶链反应适合于特异性的检测和识别变形链球菌。     

实时荧光聚合酶链反应结合融解曲线分析在α-地中海贫血基因诊断中的价值

目的建立自动化、高通量、准确快速检测缺失型α地中海贫血基因型的技术。方法运用SYBRGreen1和ABI7000热循环仪分别进行3个实时荧光定量聚合酶链反应(SYBRQPCR),同时进行融解曲线(D.C)和Tm值分析,根据特定Tm值对应的D.C峰值判定基因型,即以该峰值≥Cutoff值定为PCR结果阳性。将PCR产物重组到T载体,筛选到含正确扩增片段的克隆,以梯度稀释重组质粒DNA为模板,进行SYBRQPCR得出标准曲线。从而定量未知标本。结果优化了3个SYBRQPCR反应的引物及其浓度,热循环条件等。检测SEA等位基因的PCR产物长800bp,Tm=82.5℃±1℃。αα等位基因的PCR产物长206bp,Tm=83.0℃±1℃。非SEA等位基因的PCR产物长436bp,Tm=84.0℃±1℃。重组质粒拷贝数在1至105范围内,其对数值与CT值均呈良好线性关系。该检测技术的灵敏度较常规PCR结合琼脂糖凝胶电泳法高出16倍以上。联合运用3个SYBRQPCR反应可以为SEA缺失携带者、缺失型HbH病、非缺失型HbH病、α地贫2纯合子、Bart′s水肿胎儿综合征做出基因诊断,并可用于产前诊断。结论该技术具有自动化程度高、不需荧光标记探针、成本低、易质控、防污染、高通量等优点,适于临床推广应用。     

中国广西,广东,四川区β—地中海贫血基因突变类型及产前基...

beta-Thalassemia is one of the most common single gene disorders in South China, and ten different point mutations and frameshifts have been observed among Chinese. We studied 150 chromosomes of 95 beta-thalassemia patients from Guangxi, Guangdong and Sichuan Provinces using the polymerase chain reaction followed by dot hybridization with specific oligonucleotide probes. The most common mutations were the frameshift at codon 41-42 and the nonsense mutation at codon 17 in Guangxi and Sichuan, and the codon 41-42 frameshift and IVS-II-654 mutation in Guangdong. The A-G mutation at -28 of the promoter was common in Sichuan but not in the other two provinces. Three mutations, -30, IVS-I-1 and IVS-I-5, were not observed. A prenatal diagnosis program using these techniques has been initiated based on these data. Fourteen pregnancies at risk for beta-thalassemia have been diagnosed successfully.