Markers / Gene
CYP1A2
One position in this gene is readable from a home DNA test.
How fast you clear caffeine
rs762551 · chr15:75,041,917 · A/C · evidence: moderate
CYP1A2 does about ninety-five per cent of the work of breaking caffeine down. This position marks the faster and slower versions of the enzyme.
| If you carry | What it means |
|---|---|
| No copies | Fast metaboliser |
| One copy | Slower metaboliser |
| Two copies | Slow metaboliser |
| Ancestry group | C (the effect version) | |
|---|---|---|
| African | 43.8% | |
| American | 24.2% | |
| East Asian | 32.7% | |
| European | 32.0% | |
| South Asian | 46.5% |
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