Clotting factors are proteins in the blood that help control bleeding. When a clotting factor is missing or does not work properly, the coagulation process malfunctions and bleeding continues for longer than it should. Many people are familiar with factor VIII deficiency (hemophilia A) and factor IX deficiency (hemophilia B). But there are a number of other rare bleeding disorders. As with factor VIII and factor IX deficiencies, people with these rare disorders can find treatment at a hemophilia treatment center (HTC) under the care of a hematologist, and can find support at their local bleeding disorders chapter. Below is a brief overview of rare clotting factor deficiencies:
Clotting Factor
I
Other Names
Fibrinogen deficiency
Three variations:
Afibrinogenemia: Fibrinogen is absent.
Hypofibrinogenemia: Some protein with normal structure is present, but it’s below levels needed for effective clotting.
Dysfibrinogenemia: A normal amount of fibrinogen is manufactured by the liver, but it doesn’t clot properly.
Incidence
Afibrinogenemia: 1 in 1 million
Hypofibrinogenemia: not available
Dysfibrinogenemia: 1 in 1 million
• Affects men and women equally
Bleeding Severity
Usually mild, except in afibrinogenemia
Treatment
• RiaSTAP™ fibrinogen concentrate
• Cryoprecipitate
• Fresh frozen plasma
Clotting Factor
II
Other Names
Prothrombin deficiency
Incidence
1 in 2 million
• Affects men and women equally
Bleeding Severity
Usually mild
Treatment
• Prothrombin complex concentrate
• Fresh frozen plasma
Clotting Factor
V
Other Names
Labile factor deficiency, proaccelerin deficiency, Owren’s disease, parahemophilia
Incidence
Fewer than 200 cases have been documented worldwide
• Affects men and women equally
Bleeding Severity
Usually mild
Treatment
Fresh frozen plasma
Clotting Factor
VII
Other Names
Labile factor deficiency, proconvertin deficiency, Alexander’s disease
Incidence
1 in 500,000
• Affects men and women equally
Bleeding Severity
Severe when factor levels are low
Treatment
• Recombinant factor VIIa (rFVIIa)
• Prothrombin complex concentrate
• Fresh frozen plasma
Clotting Factor
X
Other Names
Stuart-Prower factor deficiency
Incidence
1 in 1 million
• Affects men and women equally
Bleeding Severity
Moderate to severe when factor levels are low
Treatment
• Coagadex®
• Prothrombin complex concentrate
• Fresh frozen plasma
Clotting Factor
XI
Other Names
Hemophilia C, plasma thromboplastin antecedent (PTA) deficiency, Rosenthal syndrome
Incidence
1 in 100,000
• Affects men and women equally
Bleeding Severity
Mild to moderate when factor levels are low
Treatment
• Antifibrinolytic drugs
• Fibrin glue
• Fresh frozen plasma
Clotting Factor
XII
Other Names
Hageman factor deficiency
Incidence
1 in 1 million
• Affects men and women equally
• More common in Asians than other ethnic groups
Bleeding Severity
Mild
Treatment
No treatment required
Clotting Factor
XIII
Other Names
Fibrin stabilizing factor deficiency
Incidence
1 in 5 million
• Affects men and women equally
Bleeding Severity
Severe
Treatment
• Corifact®
• Tretten®