Which statement regarding Factor XII deficiency is true?

Which statement regarding Factor XII deficiency is true?

• A. Causes Significant In Vivo Bleeding
• B. Cured By Vitamin K
• C. Does Not Require Treatment
• D. Leads To Reduced Fibrinogen Levels

Answer: (C)

Factor XII deficiency affects the laboratory finding (a prolonged aPTT) but does not cause a bleeding tendency in patients. In vivo, Factor XII is part of the contact activation pathway and is not essential for normal hemostasis, so individuals with this deficiency typically have no significant bleeding and do not require treatment. Vitamin K would not correct this deficiency because Factor XII is not vitamin K–dependent. There is also no association with reduced fibrinogen levels, since that protein’s levels are unrelated to Factor XII status. Therefore, no specific therapy is needed for asymptomatic Factor XII deficiency.

Factor XII deficiency affects the laboratory finding (a prolonged aPTT) but does not cause a bleeding tendency in patients. In vivo, Factor XII is part of the contact activation pathway and is not essential for normal hemostasis, so individuals with this deficiency typically have no significant bleeding and do not require treatment. Vitamin K would not correct this deficiency because Factor XII is not vitamin K–dependent. There is also no association with reduced fibrinogen levels, since that protein’s levels are unrelated to Factor XII status. Therefore, no specific therapy is needed for asymptomatic Factor XII deficiency.