Hematology: Prothrombin G20210A

Definition

• Cause: G20210A Point Mutation in Prothrombin (Factor II)
  • Results in Increased Prothrombin Biosynthesis & Increased Concentration of Prothrombin in Circulation
• The Second Most Common Congenital Hypercoagulability Disorder
• Prevalence: 2.0%

VTE Risk

• Increased Risk for VTE (Odds Ratio 2.8-3.8)
• Risk Further Increased if Mutation is Homozygous
• Can Have Concurrent Factor V Leiden Mutation
  • Referred to as a Double/Combined Heterozygote
  • Further Increases Risk for VTE (Odds Ratio 20.0)

Diagnosis

• Diagnosis: DNA/Genetic Testing
• Indication for Testing:
  • Thrombophilic Family (Strong Family History of VTE)
  • VTE at a Young Age (< 50 Years)
  • VTE in an Unusually Location (Portal/Hepatic/Mesenteric/Cerebral)
  • Recurrent VTE
• In General, If Testing Should Also Test for Other Inherited Thrombophilias
  • *See Hematology & Oncology: Factor V Leiden
  • *See Hematology & Oncology: Antithrombin-III Deficiency
  • *See Hematology & Oncology: Protein C Deficiency
  • *See Hematology & Oncology: Protein S Deficiency

Management

• VTE Treatment: Anticoagulation – Similar to the General Population
• VTE Prevention: Generally Can Avoid Routine Chronic Anticoagulation Unless Otherwise Indicated or High-Risk