A factor IX-deficient mouse model for hemophilia B gene therapy

Abstract
We have generated a mouse where the clotting factor IX (FIX) gene has been disrupted by homologous recombination. The FIX nullizygous (−/−) mouse was devoid of factor IX antigen in plasma. Consistent with the bleeding disorder, the factor IX coagulant activities for wild-type (+/+), heterozygous (+/−), and homozygous (−/−) mice were 92%, 53%, and FIX gene via adenoviral vectors. Thus, these factor IX-deficient mice provide a useful animal model for gene therapy studies of hemophilia B.