Haemophilia A (Q39574)

Haemophilia A is the most common form of haemophilia characterised by spontaneous or prolonged haemorrhages due to factor VIII deficiency. Depending on the extent of the factor VIII deficiency, it can be severe (biological activity of factor VIII below 1%), moderately severe (activity of factor VIII between 1% and 5%), or mild (activity of factor VIII between 5 and 40%).