What does factor XI do?
Factor XI is one of the essential blood proteins and plays a role in aiding the blood to clot. Mutations of the F11 gene result in deficient levels of functional factor XI. The symptoms of factor XI deficiency occur, in part, due to this deficiency.
What is a factor 11 deficiency called?
Factor XI (FXI) deficiency, also called hemophilia C, plasma thromboplastin antecedent deficiency and Rosenthal syndrome, was first recognized in 1953 in patients who experienced severe bleeding after dental extractions. Its incidence is estimated at 1 in 100,000 in the general population.
How is factor XI deficiency treated?
Individuals with factor XI deficiency may need specific therapy for surgery, accidents, and dental extractions. Several therapies are available which include fresh frozen plasma, factor XI concentrates, fibrin glue, antifibrinolytic drugs, and desmopressin. Each has advantages and risks to be considered.
What happens if there is a factor deficiency?
Factor X deficiency is a rare genetic blood disorder that causes the normal clotting process (coagulation) to take longer than normal. This causes people to bleed for a longer of amount of time. Factor X is a clotting protein (also called a clotting factor).
What is the most common cause of factor XI deficiency?
Most cases of factor XI deficiency are caused by mutations in the F11 gene, which provides instructions for making the factor XI protein. This protein plays a role in the coagulation cascade, which is a series of chemical reactions that forms blood clots in response to injury.
Why is factor IX called Christmas disease?
Hemophilia B occurs when clotting factor IX is either absent or not present in sufficient amounts. Hemophilia B is also known as Christmas disease. It is named after the first person to be diagnosed with the disorder in 1952, Stephen Christmas.
What is normal factor XI levels?
The normal range for factor XI activity levels is 65 to 130 U/dL, or 65% to 130%. If your results are lower than normal, it means you may have factor XI deficiency. This condition is quite rare and happens most often among people with Ashkenazi Jewish background.
Does factor XI increase in pregnancy?
Laboratory studies of factor XI during pregnancy. Unlike plasma levels of factor VIII and von Willebrand factor [22,23], FXI levels do not rise significantly during pregnancy. Indeed, FXI activity has been reported to remain stable  or decrease  during pregnancy in healthy women without FXI deficiency.
What is the result of a deficiency of factor IX?
Without enough factor IX, the blood cannot clot properly to control bleeding. There are several types of hemophilias, including hemophilia A and B. Hemophilia A is 7 times more common than hemophilia B. Hemophilia B is the result of a deficiency of clotting factor IX.
What activates factor XI?
Factor XI (FXI) is also a zymogen of the serine protease that is activated by FXII or thrombin, or autocatalytically. It is composed of four so-called apple domains in the heavy chain and a protease domain, and circulates as a homodimer.