Factor VIII and haemophilia

Haemophilia A (classical haemophilia, often simply termed haemophilia) is an X-linked recessive disorder caused by a deficiency of factor VIII. Von Willebrand disease is a related disorder, also caused by a defect in the factor VIII complex, as discussed below. 

Persons suffering from haemophilia A exhibit markedly reduced levels (or the complete absence) of factor VIII complex in their blood. This is due to the lack of production of factor VIII C. 

CH12 RECOMBINANT BLOOD PRODUCTS AND THERAPEUTIC ENZYMES 

Persons expressing 5 per cent or above of the normal complex levels experience less severe clinical symptoms. Treatment normally entails administration of factor VIII complex purified from donated blood. More recently, recombinant forms of the product have also become available. Therapeutic regimens can require product administration on a weekly basis, for life. About 1 in 10 000 males are born with a defect in the factor VIII complex and there are approximately 25 000 haemophiliacs currently resident in the USA. 

---

There are two types haemophilia A, or classical haemophilia, is due to lack of Factor VIII and haemophilia B, or Christmas disease, is due to lack of Factor IX. 

---