Haemophilia C (also known as plasma thromboplastin antecedent (PTA) deficiency or Rosenthal syndrome) is a mild form of haemophilia affecting both sexes, due to factor XI deficiency. In the United States, it is thought to affect 1 in 100,000 of the adult population, making it 10% as common as haemophilia A.Click to see full answer. Also question is, how is hemophilia C caused?Hemophilia C is a mild form of the disease that’s caused by a deficiency of factor XI. People with this rare type of hemophilia often don’t experience spontaneous bleeding. Hemorrhaging typically occurs after trauma or surgery. Hemophilia is an inherited genetic condition.Also Know, what are the 3 types of hemophilia? Hemophilia A, B & C: The Three Different Clotting Factor Deficiencies. The two most common types of hemophilia are factor VIII deficiency (hemophilia A) and factor IX deficiency (hemophilia B, or Christmas disease). Keeping this in consideration, how common is hemophilia C? Hemophilia C (major form) occurs with an estimated prevalence of 1 case per 100,000 population in the United States, a rate that makes hemophilia A 10 times more common than hemophilia C.What is the difference between hemophilia AB and C?People born with hemophilia have little or no clotting factor. A third, rarer form of the disease is called hemophilia C. Each type is directly related to a specific factor, namely, hemophilia A is a Factor VIII deficiency, hemophilia B is a Factor IX deficiency and hemophilia C is a Factor XI deficiency.