Haemophilia B
Haemophilia B is due to a deficiency of Factor IX. It is also known as Christmas Disease (after the person in whom the disease was first identified). The genetic defect is sex-linked and approximately 1 in 50,000 are affected. If untreated, patients with severe deficiencies may have frequent spontaneous bleeding into joints and muscles; they bleed excessively during minor surgery (e.g. tooth extraction) and may suffer life-threatening bleeding from trauma or even relatively mild injury. Replacement of the missing Factor IX corrects the bleeding problem.
Correlation of Coagulation Factor activity
and disease severity
in Haemophilia A and B
| Coagulation Factor Activity (% normal) | Clinical Manifestation |
|---|---|
| <2 | Severe – frequent spontaneous bleeds from early life, joint deformity and crippling if not adequately treated |
| 2-10 | Moderate – post-traumatic bleeding, occasional spontaneous bleeds |
| >10 | Mild – post-traumatic bleeding |
Patient Information Leaflets (PIL)

