Hemophilia
The two most common types of hemophilia are Factor VIII and Factor IX Deficiency. Because
hemophilia is carried on the X chromosome (one in the pair that determine sex), most patients
with hemophilia are males.
- Factor VIII Deficiency, also called classic hemophilia or hemophilia A, occurs in about 1 in
every 10,000 live male births in the United States. - Factor IX Deficiency or hemophilia B, also called Christmas Disease or hemophilia B, is
rarer.
Von Willebrand Disease
The most common of all inherited bleeding disorders by both men and women, affecting up to
one in every 100 individuals. It is caused by two missing or poorly functioning clotting factors:
von Willebrand Factor and Factor VIII. Von Willebrand Factor is a "glue-like" adhesive protein
that carries and protects Factor VIII in the blood and sticks to blood vessel walls when they are
injured.
About von Willebrand Disease – Fact Sheet
Other Bleeding Disorders