Markers / Gene
ADH1B
One position in this gene is readable from a home DNA test.
How fast alcohol becomes acetaldehyde
rs1229984 · chr4:100,239,319 · T/C · evidence: established
This is the other half of the alcohol story. ALDH2 decides how fast acetaldehyde is cleared; ADH1B decides how fast it is made. The fast version produces acetaldehyde quickly, which makes drinking less pleasant and is strongly protective against alcohol dependence.
| If you carry | What it means |
|---|---|
| No copies | Standard version |
| One copy | One fast copy |
| Two copies | Two fast copies |
| Ancestry group | T (the effect version) | |
|---|---|---|
| African | 0.2% | |
| American | 5.8% | |
| East Asian | 69.7% | |
| European | 2.9% | |
| South Asian | 2.0% |
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