Therefore, the differential diagnosis of underlying etiologies of Budd-Chiari syndrome (BCS) includes the following: myeloproliferative neoplasm (MPN), malignancy, paroxysmal nocturnal hemoglobinuria, anti-phospholipid syndrome, sickle cell anemia, and inherited hypercoaguable states, including factor V Leiden, prothrombin 20210 mutation, and protein C and S and anti-thrombin deficiencies [1]. The gene discussed is F2; the disease is myeloproliferative neoplasm.