An overview of inherited factor VII deficiency

Factor VII (FVII) deficiency is the most common of the Rare Inherited Coagulation Disorders. The inheritance is autosomal recessive but there is variable penetrance. Overall there is poor correlation between the FVII level and the bleeding phenotype. Heterozygotes may have significant bleeding and severe homozygotes, or compound heterozygotes can be asymptomatic. Typically, homozygotes have FVII levels <10% and heterozygotes have levels above that. In most cases bleeding is uncommon with FVII levels>10–20%. A personal and family history is essential to determine the bleeding risk and to plan for surgical and obstetrical prophylaxis. Severe bleeding complications including central nervous system bleeding, gastrointestinal system bleeding and bleeding into the joints occurs in 10–15% of FVII deficient patients. Mucocutaneous bleeding is a common symptom but 30% of patients are asymptomatic. Fifty to 69% of women have heavy menstrual bleeding. Due to the limited number of publications regarding this rare disorder there are no consensus guidelines. There is registry data which has led to the best recommendations for treatment of bleeding episodes, initiation of long-term prophylaxis in addition to surgical plus ante and peripartum prophylaxis. Recombinant FVII concentrate is the best replacement therapy and a review of treatment and prophylaxis dosing is discussed.