Thrombophilia is a group of hereditary and acquired risk factors which induce a hypercoagulable state of the blood and cause a higher tendency to develop venous thromboembolic events. Hereditary thrombophilia can, on the one hand, be caused by deficiencies or dysfunctions of the natural anticoagulants (antithrombin, protein C and protein S) as a result of mutations; on the other hand, mutations in genes coding for clotting factors can result in a hyperfunction of these factors which leads to a higher tendency to thrombosis. One of these mutations is the Factor V Leiden mutation which makes clotting factor V resistant to inhibition by activated protein C (APC). The risk of venous thrombosis is highly dependent of the type of hereditary thrombophilia: deficiencies of the physiological anticoagulants are very rare (prevalence <1%) but are associated with a high thrombotic risk. Aberrant proteins with a gain of function, like Factor V Leiden and prothrombin G20210A, are more prevalent (prevalence ~5%) but the thrombotic risk in carriers of these mutations is lower.
The main research topic of the hemostasis unit (located in the UZ Brussel laboratory for Clinical biology) is inherited antithrombin deficiency. Over the past 20 years, our center has become a reference center for this disorder. Besides phenotypical characterization, we are the only Belgian center performing molecular analysis to unravel the genetic background of inherited AT deficiency. We collaborate with different national and international laboratories and hospitals for the diagnostic work-up of their AT deficient patients.
During the past 10 years, the study of inherited protein C deficiency was added to our research topics. Since molecular analyses of the protein C gene was not offered by any Belgian center, we decided to implement this in the UZ Brussel. Like in inherited antithrombin deficiency, we aim to better understand phenotype-genotype correlation and to identify new pathologic mutations.
Our aim is to provide a more patient-specific counseling (including treatment and prognosis) according to the (sub)classification of the deficiency.