1例复合杂合突变导致遗传性凝血因子Ⅺ缺陷症的家系分析  

Analysis of a pedigree causing by compound heterozygous mutation with hereditary coagulation factor Ⅺ deficiency

作　　者：罗婷婷 胡波[1] 迟佳妮 孙维杰 LUO Tingting;HU Bo;CHI Jiani;SUN Weijie(Department of Clinical Laboratory,the First Affiliated Hospital of Ningbo University,Ningbo,Zhejiang 315010,China)

机构地区：[1]宁波大学附属第一医院检验科,浙江宁波315010

出　　处：《中国优生与遗传杂志》2024年第9期1901-1904,共4页Chinese Journal of Birth Health & Heredity

基　　金：宁波市重点研发计划暨“揭榜挂帅”项目(2023Z166)。

摘　　要：目的对1例遗传性凝血因子Ⅺ缺陷症家族进行表型和基因型分析,并探讨其分子发病机制。方法用凝固法对先证者及其家系成员进行凝血酶原时间(PT)、活化部分凝血活酶时间(APTT)、凝血因子Ⅷ、Ⅸ、Ⅺ、Ⅻ活性检测,用酶联免疫吸附法检测凝血因子Ⅺ抗原。我们使用Sanger测序技术对F11基因的外显子和侧翼序列进行了分析,使用Clustalx-2.1-win软件进行同源保守性分析,运用Mutation Taster在线工具预测突变位点的危害性,并通过PyMOLWin对突变蛋白结构进行模拟构建。结果先证者APTT延长至76.8 s,同时,凝血因子Ⅺ活性和抗原分别下降为2%和4%。基因型分析显示先证者携带F11基因第7号外显子c.738G>A(p.Trp228stop)和第13号外显子c.1556G>A(p.Trp501stop)两个杂合无义突变。保守性分析显示Trp228和Trp501在7种同源物种中高度保守。在线生物信息学分析提示两种突变均被认为是有害的。蛋白模型分析显示,这两种突变导致了截短蛋白的产生,进而使蛋白质丧失结构完整性。结论p.Trp228stop和p.Trp501stop无义突变可能是凝血因子Ⅺ缺乏症在先证者和家族成员中的分子发病机制。Objective To examine the physical characteristics and genetic composition of a family affected by hereditary coagulation factorⅪdeficiency,and to explore the underlying molecular mechanisms causing this condition.Methods Prothrombin time(PT),activated partial thromboplastin time(APTT),and the activity of coagulation factorsⅧ,Ⅷ,Ⅺ,andⅪwere assessed using coagulation methods.The enzyme-linked immunosorbent assay was employed to detect the coagulation factorⅪantigen.Sanger sequencing was employed to analyze exons and their flanking sequences of the F11 gene.Homolog conservation analysis of the mutation sites was conducted using Clustalx-2.1-win.The Mutation Taster online bioinformatics software was used to forecast the mutations harmfulness.Simulation and construction of the mutated protein structure were carried out using PyMOLWin.Results The proband exhibited a significantly prolonged APTT of 76.8 s,with a notable decrease in both coagulation factorⅪactivity(2%)and antigen(4%).Genotypic analysis identified two heterozygous nonsense mutations in exon 7 c.738G>A(p.Trp228stop)and exon 13 c.1556G>A(p.Trp501stop)of the F11 gene in proband.Conservation analysis showed that Trp228 and Trp501 were highly conserved among seven homologous specie.Online bioinformatics analysis showed that both mutations were harmful.Protein model revealed that both mutations produced truncated proteins,leading to a loss of structural integrity.Conclusion The p.Trp228stop and p.Trp501stop nonsense mutations could be the molecular pathogenesis of coagulation factorⅪdeficiency in the proband and his family members.

关 键 词：凝血因子Ⅺ 复合杂合突变 截短蛋白 F11基因 

分 类 号：R596[医药卫生—内科学]