一个复合杂合突变导致的遗传性凝血因子V缺陷症家系  

Analysis of a pedigree with inherited factor V deficiency caused by compound heterozygous mutation

作　　者：郭跃丽[1] 孔万仲[1] 万箐 郑温洁莹 奚经巧[1] 刘斯奇 王明山[2] 金艳慧[2] Guo Yueli;Kong Wanzhong;Wan Jing;Zheng Wenjieying;Xi Jingqiao;Liu Siqi;Wang Mingshan;JinYanhui(Laboratory Department of Wenzhou Chinese Medicine Hospital,Wenzhou 325000,China;Department of Clinical Laboratory,The First Affiliated Hospital of Wenzhou Medical University,Wenzhou 325015,China)

机构地区：[1]温州市中医院检验科,325000 [2]温州医科大学附属第一医院医学检验中心,325015

出　　处：《中华血液学杂志》2021年第2期135-139,共5页Chinese Journal of Hematology

基　　金：温州市卫生健康委员会医药卫生科学研究项目计划(2015B06)。

摘　　要：目的探讨一个遗传性凝血因子Ⅴ(FⅤ)缺陷症家系的分子致病机制。方法DNA直接测序法分析先证者F5的全部外显子、侧翼序列、5′和3′端非翻译区及家系成员(共3代11人)相应的突变位点区域。通过CAT法检测凝血酶生成量;用ClustalX软件分析突变位点的保守性;用MutationTaster、PolyPhen-2、PROVEAN、LRT和SIFT等在线生物信息学软件预测突变位点对蛋白质功能的影响;用Swiss-PdbViewer软件分析氨基酸突变前后蛋白模型及分子间作用力的变化。结果先证者F5第8外显子存在c.1258G>T杂合错义突变(p.Gly392Cys)及第14外显子存在c.4797delG杂合缺失突变,导致框移并产生截断蛋白(p.Glu1572Lys fsX19);其祖父和父亲存在p.Gly392Cys杂合突变;其外祖母、母亲、小姨母和表妹均存在p.Glu1572Lys fsX19杂合突变。先证者凝血酶生成延迟和达峰时间比值明显增高。保守性分析结果表明,p.Gly392在10种同源物种中位于保守区域。五个在线生物信息学软件对p.Gly392Cys预测均显示为致病的突变,Mutation Taster对p.Glu1572Lys fsX19预测也显示为致病突变。蛋白模型分析显示,Gly392突变为Cys392后可导致原有氢键延长,并形成新的空间位阻,影响蛋白结构的稳定性。结论该家系F5第8外显子c.1258G>T杂合错义突变及第14外显子c.4797delG杂合缺失突变可能与该家系FⅤ水平降低有关。Objective To explore the molecular pathogenesis of a family with hereditary factorⅤ(FⅤ)deficiency.Methods All the exons,flanking sequences,5′and 3′untranslated regions of the F5 of the proband,and the corresponding mutation sites of the family members were analyzed via direct DNA sequencing.The CAT measurement was used to detect the amount of thrombin produced.The ClustalX software was used to analyze the conservation of mutation sites.The online bioinformatics software,Mutation Taster,PolyPhen-2,PROVEAN,LRT,and SIFT were applied to predict the effects of mutation sites on protein function.The Swiss-PdbViewer software was used to analyze the changes in the protein model and intermolecular force before and after amino acid variation.Results The proband had a heterozygous missense mutation c.1258G>T(p.Gly392Cys)in exon 8 of the F5,and a heterozygous deletion mutation c.4797delG(p.Glu1572Lys fsX19)in exon 14,which results in a frameshift and produces a truncated protein.Her grandfather and father had p.Gly392Cys heterozygous variation,whereas her maternal grandmother,mother,little aunt,and cousin all had p.Glu1572LysfsX19 heterozygous variation.The ratio of proband's thrombin generation delay to peak time was significantly increased.Conservation analysis results showed that p.Gly392 was located in a conserved region among the 10 homologous species.Five online bioinformatics software predicted that p.Gly392Cys was pathogenic,and Mutation Taster also predicted p.Glu1572Lys fsX19 as a pathogenic variant.Protein model analysis showed that the replacement of Gly392 by Cys392 can lead to the extension of the original hydrogen bond and the formation of a new steric hindrance,which affected the stability of the protein structure.Conclusion The c.1258G>T heterozygous missense mutation in exon 8 and the c.4797delG heterozygous deletion mutation in exon 14 of the F5 may be responsible for the decrease of FⅤlevels in this family.

关 键 词：凝血因子Ⅴ缺陷症 遗传性 生物信息学 

分 类 号：R554[医药卫生—血液循环系统疾病]