Prothrombin Mutation

• Biochemical aspects:
  • 5-18% of hypercoagulation cases.
  • Autosomal dominant; 1-3% of Caucasion population; risk increased 3 fold (heterozygote)
• Pathological Basis:
  • Single base pair substitution at nucleotide position 20210 in chromosome 11, guanine-> adenine (G20210A). This results in relatively high prothrombin level with increased risk for venous thrombosis (132% vs 105% of normal).
  • Some patients do not have thrombosis unless exposed to hemostatic challenge.
  • Increased risk for hypercoagulation in combination with Protein C or S deficiency.
  • Laboratory: Factor II assay, PCR testing for G20210A
• Treatment:
  • Treatment for acute episode: heparin.
  • Long term treatment: coumadin.