Factor V R2 Mutation Test (H1299R)

The Factor V R2 Mutation Test (H1299R) is a genetic blood test that identifies whether you carry a specific inherited variant in the factor V gene, known as the R2 haplotype or H1299R. This variant is one of several genetic factors that can influence your tendency to form blood clots (thrombophilia). The test is particularly useful for individuals with a personal or family history of venous thromboembolism (VTE), unexplained or recurrent pregnancy loss, or for those undergoing thrombophilia screening alongside other genetic and acquired risk factors. It may also be requested when a clinician is investigating early-onset or unusual thrombosis, or when considering combined inherited risks such as factor V Leiden. A simple blood sample is all that is required, and results are interpreted in the context of your full clinical picture.

Genetic Variant Screened
- Factor V R2 (H1299R) variant: identifies the presence of the R2 haplotype in the factor V gene, which has been associated with a modestly increased risk of venous thrombosis, particularly when co-inherited with other thrombophilic variants.

Why it matters
Knowing your Factor V R2 status can help you and your clinician understand whether an inherited tendency to clot contributes to your personal or family history. This information supports informed decisions about risk management, including lifestyle measures, targeted thromboprophylaxis during high-risk periods (such as surgery, immobility, or pregnancy), and appropriate screening of at-risk relatives. It is not a diagnostic test for thrombosis on its own, but it adds valuable clarity when assessed alongside your medical history and other thrombophilia investigations.

Genetic Variant
- Factor V R2 (H1299R) variant

No special preparation required.

For blood tests, we recommend drinking plenty of water beforehand to ensure smooth sample collection. If you are taking any regular medication, continue to do so unless advised otherwise by your doctor.