Screening for inherited thrombophilia might be warranted among Eastern Mediterranean sickle-ßeta-0 thalassemia patients

Abstract

The role of genetic thrombophilia in the development of both micro and macro vascular complications in patients with hemoglobinopathies (Sickle cell disease and thalassemia) have been investigated with some studies negating its role while others suggesting it. Lebanon is known to harbor sickle cell disease, thalassemia and sickle beta-thalassemia hemoglobinopathy patients along with a documented high prevalence of genetic thrombophilia mutations. Twelve sickle beta-0-thalassemia patients with no pervious history of thrombotic events were selected. These patients underwent a physical examination with history, echo Doppler, along with blood withdrawal for complete blood count and PCR analysis of a sample of DNA for Factor V Leiden G1691A, Factor II G20210A, and MTHFR C677T. Results were compared to a historical control of 50 Lebanese controls and 50 LebaneseThalassemia Intermedia (TI) patients. The results showed that 42%, 59%, and 8% of patients carried heterozygous Factor V Leiden, abnormal (homozygous & heterozygous) MTHFR, and heterozygous Factor II mutations respectively. The sickle-thalassemia patients were 5.24 and 4.39 times more likely to have Factor V Leiden as compared to the normal controls and TI patients respectively (p < 0.05). The increased prevalence of more than one prothrombotic genetic mutation among the group indicates a probable clustering phenomenon, unknown to us to which the high consanguinity rate (77%) may have contributed. The role of the specific MTHFR and Factor V Leiden double heterozygous combination in incidence, recurrence, and guidance of duration of therapy in VTE is not well defined in the literature despite the recognized higher risk of thrombosis among this patient population. Our findings suggest that genetic thrombophilia workup is necessary in patients with sickle-beta zero thalassemia presenting with thrombotic events and studies that include a larger number of patients are necessary in order to define specific guidelines.