Factor V Leiden, prothrombin gene mutation, protein C and protein S deficiencies, antithrombin deficiency, and mutation of the methylene tetrahydrofolate reductase gene causing hyper-homocysteinemia are mentioned in literature as contributing factors leading to flap thrombosis; therefore, preoperative thrombophilia screening could be a cost-effective tool for the prevention of microvascular flap thrombotic complications [1,2,3]. The gene discussed is F5; the disease is Rare hereditary thrombophilia.