Factor XII deficiency is an inherited disorder that affects a
protein (factor XII) involved in blood clotting. When you bleed,
the body launches a series of reactions that help the blood
clot. This is called the coagulation cascade. The process
involves special proteins called coagulation factors. (Factor
XII is a coagulation factor in this series of reactions.) Each
factor has a reaction that triggers the next reaction. The final
product of the coagulation cascade is the blood clot. When one
or more of these clotting factors are missing, there is usually
a higher chance of bleeding. A lack of factor XII does not cause
the affected person to bleed abnormally, but the blood takes
longer than normal to clot in a test tube. Factor XII deficiency
is a rare inherited disorder. There are usually no symptoms.
Factor XII deficiency is usually found when clotting tests are
done for routine screening. Tests may include: Treatment is
usually not needed. The outcome is expected to be good without
treatment. There are usu