四个遗传性凝血因子V缺陷症家系临床表型和基因型变化的研究

目的 研究4个遗传性凝血因子V(FV)缺陷症家系的临床表型和基因突变.方法 测定家系成员活化部分凝血活酶时间(APTT)、凝血酶原时间(PT)及FV促凝活性(FV:C)和FV抗原(FV:Ag)含量进行表型诊断;用PCR法扩增先证者F5基因的25个外显子及其侧翼序列,PCR产物纯化后直接测序,检测其基因突变.结果 4例先证者APTT、PT明显延长,血浆FV:C和FV:Ag含量均显著降低.基因分析发现,先证者1的F5基因存在G16088C(Asp68His)杂合错义突变及4种位于同一条染色体上的杂合多态性T35788C(Met385Thr)、A47295G(Hisl299Arg)、A58668G(Metl736Val)和A74083G(Asp2194Gly);先证者2的F5基因存在CA6253T(Arg952Cys)和CA6724T (Glnl 109stop)两种纯合突变;先证者3的F5基因存在C67793G(Pr02006Ala)纯合错义突变;先证者4的F5基因存在C74022T(Arg2174Cys)纯合错义突变.结论 Asp68His、Arg952Cys、Glnl109stop、Pro2006Ala和Arg2174Cys这5种突变,及Met385Thr、Hisl299Arg、Metl736Val和Asp2194Gly这4种多态性是导致相应先证者I型遗传性FV缺陷症的原因.其中,Glnl109stop、Pro2006Ala和Arg2174Cys是国际七首次报道的新突变.

Analysis of phenotype and genotype in four Chinese pedigrees with inherited coagulation factor V deficiency

Objective To identify the phenotype and genotype in four Chinese pedigrees with inherited coagulation factor V(F V)deficiency.Methods The tests of activated partial thromboplastin time (APTT),prothrombin time(PT),FV activity(FV:C)and FV antigen(FV:Ag)were used for phenotype diagnosis.All the exons and exon-intron boundaries of F5 gene were amplified by PCR and analyzed by direct sequencing.Results The APTT and PT in each of the four probands were obviously prolonged.and both activity and antigen of F V in the four probands were extremely lower compared with that of normal mixed plasma.Sequencing of F5 gene in proband 1 identified a heterozygous mutation,G16088C(Asp68His),and four polymorphisms,T35788C(Met385Thr),A47295G(Hisl299Arg),A58668G(Metl736Val)and A74083G(Asp2194Gly),which were located in the same chromosome;proband 2 was homozygous for two mutations,CA6253T(Arg952Cys)and C46724T(Glnl 109stop);the F5 gene of proband 3 showed a homozygous missense mutation,C67793G(Pm2006Ala);and pmband 4 was homozygous for one missense mutation,C74022T(Arg2174Cys).Conclusion Five mutations(Asp68His,Arg952Cys,Glnl 109stop,Pro2006Ala and Arg2174Cys)and four polymorphisms(Met385Thr,Hisi299Arg,Metl736Val and Asp2194Gly)may lcad to type I inhefited FV deficiency for these four pmbands,respectively.GInl109stop,Pm2006Ala and Arg2174Cys haven't been identified before.