Identification Of Gene Mutations Involved In Five Cases Of Inherited Coagulation Factor V Deficiency

Objective To characterize the gene mutation involved in five cases of inherited coagulation factorâ…¤(Fâ…¤)deficiency respectively. Methods Activity of Fâ…¤was determined by a one-stage clotting assay using Fâ…¤-deficiency plasma, and Fâ…¤antigen was measured by an ELISA assay. All the exons and exon-intron boundaries of the Fâ…¤gene were amplified by PCR and then DNA sequencing was performed. Restriction fragment length polymorphism (RFLP) was used to analyze the probands, their family members and healthy volunteers. Homology model of Fâ…¤a was used to analyze the influence of missense mutations. Results Both activity and antigen of Fâ…¤in the 5 patients was extremely lower compared with normal mixed plasma. And 6 mutations was identified in these 5 patients, a homozygous missense mutation G69969T resulting in G2079V was discovered in the patient 1; a compound heterozygous mutation of C45533T resulting in R712Ter and G45366A leading to C656Y in the patient 2, which was a novel missense mutation in exon 13; the patient 3 exist a homozygous C46253T mutation causing Arg952Cys, which was the first pathogenic missense mutation identified in the B domain of Fâ…¤gene; and a homozygous C46796T mutation corresponding with R1133Ter was found in the patient 4; patient 5 had a homozygous G16088C mutation in exon 3 with Asp68His. The result of DNA sequencing and RFLP showed that the three novel missense mutations were not SNP. Homology model of Fâ…¤a showed a reducing stability due to missense mutations. Conclusion G69969T, C45533T, G45366A, C46253T,C46796T and G16088C mutation of Fâ…¤gene are related to inherited Fâ…¤deficiency.