Abstract:

Objective To investigate the gene mutations of coagulation factor Ⅶ（FⅦ） and the clinical characteristics in 9 patients with hereditary FⅦ deficiency. Methods FⅦ activity（FⅦ：C） and FⅦ antigen （FⅦ：Ag） were determined by one-stage clotting test and double-antibody sandwich enzyme-linked immunosorbent assay （ELISA）,respectively. Genomic DNA was extracted from peripheral blood. All the exons and flank sequences of FⅦ gene were amplified by polymerase chain reaction （PCR）,and gene analysis was performed by direct sequencing. Results A total of 10 different mutations were identified in 9 patients with hereditary FⅦ deficiency,including 3 splice site mutations and 7 miss sense mutations. One patient had p.Tyr128（68）Cys homozygous mutation,FⅦ：C was 0.8%,FⅦ：Ag was 2.5%,and the clinical characteristic was severe bleeding. Five patients had double heterozygous mutations,p.Thr241（181）Asn with p.Gly406（346）Asn,IVS1a+5G>A with p.His408（348）Gln,IVS5-1G>A with p.His408（348）Gln,c.*64G>A with p.Ile213（153）Asn and p.Cys389（329）Gly with p.His408（348）Gln,and FⅦ：C were 1.2%,4.4%,1.0%,0.5% and 1.2%,respectively. The clinical bleeding symptoms had various severities. Three patients had mono-heterozygous mutations,p.Cys389（329）Gly,p.His408（348）Gln and p.Thr419（359）Met,and FⅦ：C were 0.5%,8.3% and 9.4%,respectively. The first patient had a history of bleeding,and the other 2 patients had no significant bleeding. Conclusions A total of 10 types of gene mutations are identified in 9 patients with hereditary FⅦ deficiency. p.Gly406（346）Asn,c.*64G>A and p.Ile213（153）Asn are found newly,and p.His408（348）Gln is a common mutation,and FⅦ：C has no correlation with clinical phenotypes.

Key words: Hereditary coagulation factor Ⅶ deficiency, Gene mutation, Phenotype