复合杂合变异引起的凝血因子Ⅺ缺乏症两例  

Two cases of coagulation factorⅪdeficiency caused by compound heterozygous mutations

作　　者：李倩[1] 周敏[1] 徐勇[1] 曾慧[1] 徐岳一[1] 许佩佩[1] 陈兵[1] 周荣富[1] Li Qian;Zhou Min;Xu Yong;Zeng Hui;Xu Yueyi;Xu Peipei;Chen Bing;Zhou Rongfu(Department of Hematology,Nanjing Drum Tower Hospital,the Affiliated Hospital of Nanjing University Medical School,Nanjing,Jiangsu 210008)

机构地区：[1]南京大学医学院附属鼓楼医院,南京210008

出　　处：《中华医学遗传学杂志》2022年第6期597-601,共5页Chinese Journal of Medical Genetics

基　　金：十三五江苏省科教强卫医学领军人才与创新团队。

摘　　要：目的对两例凝血因子Ⅺ(coagulation factorⅪ,FⅪ)缺乏症患者进行基因检测及突变分析,探讨其分子发病机制。方法检测两例患者凝血功能及凝血因子水平明确临床表型,用PCR法扩增其F11片段并送检测序,筛选突变位点。应用生物信息学软件研究突变对FⅪ蛋白结构和功能的影响。结果例1活化部分凝血活酶时间(activated partial thromboplastin time,APTT)88.1 s、FⅪ活性(FⅪactivity,FⅪ:C)1.1%,例2 APTT 107.1s、FⅪ:C 3.8%,两例患者均确诊为FⅪ缺乏症。例1经TA质粒克隆测序发现F11基因存在复合杂合变异g.1305-1G>A和g.1325delT,且位于不同的DNA单链上。例2 PCR扩增产物直接测序发现存在复合杂合错义突变g.1124A>G和g.1550C>G。通过生物信息学软件分析发现突变基因对FⅪ蛋白质的结构和功能的异常产生较大影响。结论本研究中发现的F11基因g.1305-1G>A与g.1325delT复合杂合变异和g.1124A>G与g.1550C>G复合杂合错义突变,可能分别是两例FⅪ缺乏患者的分子发病机制。Objective To investigate the molecular pathogenesis of two coagulation factorⅪ(FⅪ)deficiency patients.Methods Coagulant assays:activated partial thromboplastin time(APTT),normal pooled-plasma corrected APTT test,PT,PT-INR and one-stage assay of coagulation factors activities were validated to diagnose coagulation factorⅪdeficiency.The patients’DNA samples were extracted and all exons and flanking sequences of F11 gene were amplified using PCR.After purified,the products of PCR were sequenced directly,the mutations were detected by comparing with wild sequences and analyzed using some bio-informatics softwares.Results The two patients were diagnosed with coagulation factorⅪdeficiency due to prolonged APTT,corrected APTT and low activities of coagulation factor FⅪ.The results of APTT,FⅪ∶C were 88.1s,1.1%and 107.1s,3.8%,and the prolonged APTT could be corrected to normal range 32.9s and 31.5s,respectively.Through genetic analysis,we discovered compound heterozygous mutations g.1305-1G>A and g.1325delT in patient 1 and the sequencing results of TA plasmid clones showed that the two mutations were located on different strands of chromosomes.Compound heterozygous mutations g.1124A>G and g.1550C>G were detected in patient 2 resulting in Lys357Arg and Cys482Trp.Software analysis indicated the mutations probably brought amino acid sequence changed,protein features affected and splice site changed.Conclusion Compound heterozygous mutations g.1305-1G>A,g.1325delT and g.1124A>G,g.1550C>G had been identified in two coagulation factorⅪdeficiency patients which might be responsible for their prolonged APTT and low FⅪ∶C.To the best of our knowledge,g.1325delT and g.1550C>G have been reported,while g.1124A>G and g.1305-1G>A are reported for the first time in the literature.

关 键 词：凝血因子Ⅺ缺乏症 基因突变 分子机制 

分 类 号：R554[医药卫生—血液循环系统疾病]