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F2

Coagulation factor II (prothrombin)

Gene Number: 2147

Location: 11p11.2

Key Functions: Blood clotting, thrombin production, coagulation cascade regulation, hemostasis


F2 encodes coagulation factor II (prothrombin), a precursor to thrombin, the enzyme responsible for converting fibrinogen into fibrin during blood clot formation. Thrombin also activates platelets and additional coagulation factors, amplifying the clotting response.


Mutations in F2 can increase the risk of venous thromboembolism and other clotting disorders. Proper regulation of prothrombin levels is essential for balanced hemostasis and preventing excessive bleeding or pathological clotting.

SNP ID
Your Genotype
Alternative Alleles
Interpretation
rs1799963
No matching variant or no valid DNA data
A
No interpretation available
rs3136516
No matching variant or no valid DNA data
G
No interpretation available
rs5896
No matching variant or no valid DNA data
T
No interpretation available
rs1799963

  • GG – Normal prothrombin levels; typical venous thrombosis risk (R).

  • GA – One copy of the A allele (20210A) raises circulating prothrombin and VTE risk ~2.8× overall, and ~3.2× in individuals under 45 (R).

  • AA – Homozygous; rare—OR up to 6.74× for VTE in smaller studies (R).

Functional effect: The A allele increases prothrombin (Factor II) levels, promoting hypercoagulability and significantly raising risk for venous thromboembolism. Carriers on combined oral contraceptives or with Factor V Leiden have even higher risk (R).


rs3136516

  • AA – Baseline prothrombin regulation and average VTE risk (R).

  • AG – Slightly elevated VTE risk (OR ~1.45) compared to AA (R).

  • GG – Elevated VTE risk (OR ~1.48) compared to AA; moderate independent risk (R).

Functional effect: The G allele increases prothrombin splicing efficiency and levels, modestly elevating thrombosis risk—especially when combined with other procoagulant variants like Factor V Leiden (R).


rs5896

  • CC – Threonine/Threonine at position 165; standard prothrombin activity and baseline risk (R).

  • CT – Heterozygous Thr/Met; currently no definitive data on risk effects (R).

  • TT – Methionine/Methionine; limited data—potential association with modified bleeding or clotting risk in some populations (R).

Functional effect: The T allele (Met165) causes the T165M amino acid change in a conserved region. While biochemical plausibility exists, current evidence is limited and does not yet support strong clinical interpretation (R).


Learn more about what you can do to mitigate risks, and other factors involved by becoming a member of GenesUnveiled today!

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