Markers / Gene
CLOCK
One position in this gene is readable from a home DNA test.
Morning or evening person
rs1801260 · chr4:56,301,369 · A/G · evidence: moderate
CLOCK is a core gene of the circadian machinery that keeps your body on a roughly 24-hour cycle. The variant version is associated with going to bed later and preferring evenings. In an environment of electric light and indoor work, a late clock stops being a preference and becomes a mismatch.
| If you carry | What it means |
|---|---|
| No copies | You have the earlier-clock version on both copies |
| One copy | You carry one later-clock copy |
| Two copies | You have the later-clock version on both copies |
| Ancestry group | G (the effect version) | |
|---|---|---|
| African | 15.2% | |
| American | 23.8% | |
| East Asian | 10.1% | |
| European | 30.5% | |
| South Asian | 38.3% |
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