 However, the approach used so far to the measure of clotting in sickle cell disease was segmented in the sense that the various components of the hemostatic balance were studied separately.The thrombin generation test is a functional test which explores the coagulation globally, integrating both pro players that anticoagulants actors in the system. The investigators already used this test to demonstrate that the hemostatic potential was high in a cohort of affected children compared to control children of the same age. 