摘要目的 对1个近亲婚配的遗传性凝血因子Ⅶ(coagulation factor Ⅶ,FⅦ)与因子Ⅹ(factor Ⅹ,FⅩ)联合缺陷症家系进行基因突变检测,探讨其分子发病机制.方法 检测先证者及其家系共6名成员的凝血酶原时间(prothrombin time,PT)、活化部分凝血活酶时间(activated partial thromboplastin time,APTT)、纤维蛋白原(fibrinogen,FIB)、血浆FⅦ活性(FⅦactivity,FⅦ∶C)、FⅩ活性(FⅩ activity,FⅩ∶C)及FⅦ抗原(FⅦantigen,FⅦ∶Ag)、FⅩ抗原(FⅩ antigen,FⅩ∶Ag)；用DNA直接测序法分析先证者F7、F10基因的全部外显子、侧翼、5’和3’非翻译区及家系成员相应的突变位点区域,用反向测序证实所发生的突变.结果 先证者PT(76.4s)和APTT(60.2s)明显延长,FⅦ∶C(4％)、FⅦ∶Ag(6％)和FⅩ∶C(6％)、FⅩ∶Ag(33％)明显降低；先证者外祖母、父亲、母亲和女儿的PT(分别为16.4s、15.8s、16.9s、16.5s)和APTT(分别为44.0s、42.1s、41.1s、43.5s)稍延长,FⅦ∶C(分别为34％、39％、31％、40％)、FⅩ∶C(分别为50％、58％、47％、42％)和FⅩ∶Ag(分别为51％、54％、58％、47％)稍降低,其FⅦ∶Ag及弟弟的凝血表型指标均在正常参考范围.测序结果显示先证者F7基因第8外显子发生了g.11267C＞T纯合突变,导致Arg277Cys,F10基因第8外显子存在g.28139G＞T纯合突变,导致Val384Phe；先证者外祖母、父亲、母亲和女儿均存在F7基因第8外显子g.11267C＞T和F10基因第8外显子g.28139G＞T杂合突变；先证者弟弟F7与F10基因为正常野生型.结论 该遗传性凝血因子Ⅶ与Ⅹ联合缺陷症家系先证者的F7和F10基因分别存在g.11267C＞T(Arg277Cys)、g.28139G＞T(Va1384Phe)纯合突变,且遗传自近亲结婚的父母.F7基因g.11267C＞T(Arg277Cys)和F10基因g.28139G＞T(Val384Phe)与该遗传性凝血因子Ⅶ与Ⅹ联合缺陷症家系的FⅦ和FⅩ水平降低有关.

abstractsObjective To identify potential mutations and explore the molecular mechanism underlying combined inherited coagulation factors Ⅶ (FⅦ) and Ⅹ (F Ⅹ) deficiency for a family featuring consanguineous marriage between maternal cousins.Methods Prothrombin time (PT),activated partial thromboplastin time (APTT),fibrinogen,FⅦ activity (FⅦ ∶ C),FⅩ activity (FⅩ ∶ C),FⅦ antigen (F Ⅶ ∶ Ag),FⅩ antigen (FⅩ ∶ Ag) and other coagulant parameters of the proband and 5 family members were measured.Potential mutations in exons,exon-intron boundaries and 5',3' untranslated sequences of F7 and F10 genes were screened by polymerase chain reaction and direct sequencing.Suspected mutations were confirmed by sequencing the opposite strand.Results PT and APTT of the proband were obviously prolonged to become 76.4 s and 60.2 s,respectively.FⅦ ∶ C,FⅦ ∶ Ag,FⅩ ∶ C and FⅩ ∶ Ag of the proband were obviously reduced to become 4％,6％,6％ and 33 ％,respectively.Both PT and APTT of her grandmother,father,mother and daughter were slightly prolonged,which have measured 16.4 s,15.8s,16.9 s,16.5 s,and 44.0 s,42.1 s,41.1 s,43.5 s,respectively.And their FⅦ ∶ C (34％,39％,31％,40％,respectively),F Ⅹ ∶ C(50％,58％,47％,42％,respectively) andFⅩ ∶ Ag (51％,54％,58％,47％,respectively) were slightly reduced,while FⅦ ∶ Ag was in the normal range.The coagulant parameters of her younger brother were within normal range.Two homozygous mutations,g.11267C＞T in exon 8 of F7 gene,which resulted in an Arg277Cys substitution,and g.28139G＞T in exon 8 of F10 gene which led to a Val384Phe substitution,were identified in the proband.The proband's grandmother,parents and daughter were heterozygous for both Arg277Cys and Val384Phe mutationss.Wild-type alleles of both F7 and F10 genes were also found in the younger brother.Conelusion A homozygous Arg277Cys mutation and a Val384Phe mutation have been respectively identified in the F7 and F10 genes,which can explain the low levels of FⅦ and FⅩ in this family.The former has been inherited from the consanguineous parents.