Markers / Gene
F5
One position in this gene is readable from a home DNA test.
Factor V Leiden
rs6025 · chr1:169,519,049 · C/T · evidence: established
A change in clotting factor V that makes it resist being switched off, so clots form a little too readily. It is carried by roughly one in twenty people of European descent.
| If you carry | What it means |
|---|---|
| No copies | You do not carry Factor V Leiden |
| One copy | You carry one copy, so clotting risk is raised in specific situations |
| Two copies | You carry two copies, a higher clotting risk worth raising with a doctor |
| Ancestry group | T (the effect version) | |
|---|---|---|
| African | 0.0% | |
| American | 1.0% | |
| East Asian | 0.0% | |
| European | 1.2% | |
| South Asian | 1.1% |
1000 Genomes Project phase 3, via Ensembl, retrieved 2026-09-23. These groupings are coarse and flatten a great deal of internal diversity, particularly within Africa. A variant being common somewhere tells you where a piece of your ancestry probably comes from, and nothing else.
Where this gene fits
If you have taken a home DNA test, these positions are already in your file.
Read my file