Synthesis of a mouse model of the dysfibrinogen Vlissingen/Frankfurt IV

The dysfibrinogen Vlissingen/Frankfurt IV is characterized as a deletion of Asn319 and Asp320 from the C-terminus of the gamma-chain of fibrinogen. This dysfibrinogen, which was identified in several family members that are all heterozygous for the in-frame 6-bp deletion, is associated with both venous and arterial thrombosis. Here, we describe the generation of a murine model of the V/F IV dysfibrinogen using gene targeting of mouse gamma-chain DNA. Preliminary analysis shows that the human and mouse variant fibrinogens are similar: analogous to the human V/F IV protein, the D1 fragment of the variant mouse fibrinogen is partially protected from digestion in the presence of calcium or Gly-Pro-Arg-Pro. These heterozygous mice provide the first opportunity to examine the association of thrombophilia and dysfibrinogenemia in a controlled genetic background.