What is the difference between haemophilia A and haemophilia B?

There are two main types of haemophilia: haemophilia A and haemophilia B. In haemophilia A there is a lack of clotting factor VIII (eight) and in haemophilia B there is a lack of clotting factor IX (nine).1

The clinical features of haemophilia A and haemophilia B are identical.