| Prothrombotic Condition (%) |
Investigations |
| Myeloproliferative disease (49%) |
Peripheral blood JAK2(V617F) mutation |
| Bone marrow biopsy (aspirate cytology, cytogenetic studies, trephine histology) |
| Paroxysmal nocturnal haemoglobinuria (19%) |
Flow cytometry of peripheral blood cells showing CD55 and CD59 deficient clones |
| Factor V Leiden (12%) |
Leiden mutation (R506Q) by Peripheral blood molecular analysis (Functional Clotting assays during acute thrombosis not reliable) |
| Prothrombin gene mutation (3%) |
Molecular analysis for G20210A mutation |
| Inherited protein C deficiency (4%) |
Qualitative or quantitative defect in Protein C. The assay is a generally a functional one and identifies both qualitative and quantitative deficiency (after acute thrombosis and off warfarin) |
| Inherited protein S deficiency (3%) |
Qualitative or quantitative defect in Protein S. ELISA for free Protein S antigen. Functional Protein S test also available. (after acute thrombosis and off warfarin) |
| check for AT3 levels- again functional and needs to be off heparin (part of thrombophilia screening) |
| Behcet’s disease (4%) |
Oral ulcers at least 3 times within one year period along with 2 out of the following 4 "hallmark" symptoms: |
| 1) Genital ulcers |
| 2) Skin lesions |
| 3) Ocular inflammation |
| 4) Pathergy reaction (papule >2 mm, 24-48 hours or more after needle-prick). |
| Antiphospholipid syndrome (25%) |
Diagnosis of APS requires one clinical manifestation |
| 1)Arterial, venous, or small vessel thrombosis |
| 2) One or more unexplained deaths of a morphologically normal fetus at or beyond the 10th week of gestation and/or 3 or more unexplained consecutive spontaneous abortions before the 10th week of gestation. |
| and one laboratory manifestation on 2 or more occasions |
| 1)Anti-cardiolipin Immunoglobulin (Ig) G and/or IgM |
| 2)Anti-β2 glycoprotein I Ig G and/or Ig M |
| 3) Lupus anticoagulant assay |
| Oral contraceptives or pregnancy (33%) |
The oral contraceptive pill (OCP) is associated with an additional risk factor in the majority, and the direct relationship with BCS is unclear. |
| Ulcerative Colitis (8%) |
Colonoscopy if symptoms suggestive |
| Coeliac disease |
Anti-TTG and Anti-EMA antibodies, Endoscopic D2 biopsy |