prothrombin (F2) gene p.G20210A

Epidemiology

• 1-2% of non-hispanic whites & Mexican-Americans
• 0.3% of blacks

Genetics

• involves a single nucleotide polymorphism (SNP) resulting in a guanine substitution for an adenine at position 20210 within the 3' untranslated region of the prothrombin gene
• prothrombin G20210A mutation stabilizes prothrombin mRNA increasing prothrombin levels by 30% in heterozygotes & 70% in homozygotes
• heterozygosity for G20210A increases risk of venous thromboembolism 2.5 fold
  • most patients are asymptomatic
• heterozygosity for G20210A & factor V Leiden increases risk of venous thromboembolism 5-7 fold

Clinical significance

• G20210A mutation associated with hypercoagulability
  • 3-fold risk for initial venous thromboembolism (VTE)
  • not associated with increased risk of recurrent VTE
• along with factor V Leiden mutation, responsible for 2 of the most common inherited types of hypercoagulability

Specimen

• whole blood

More general terms

• prothrombin genotyping

Additional terms

• prothrombin; coagulation factor II; contains: activation peptide fragment 1; activation peptide fragment 2; thrombin light chain; thrombin heavy chain (F2)