Markers / Gene
IL23R
One position in this gene is readable from a home DNA test.
A protective variant for Crohn's disease
rs11209026 · chr1:67,705,958 · G/A · evidence: established
Most variants raise risk. This one lowers it, substantially, for Crohn's disease and for psoriasis and ankylosing spondylitis. It is carried by about one European in sixteen and is essentially absent elsewhere. It also pointed drug developers straight at the IL-23 pathway, which is now the target of several real medicines.
| If you carry | What it means |
|---|---|
| No copies | You do not carry the protective version |
| One copy | You carry one protective copy |
| Two copies | You carry two protective copies |
| Ancestry group | A (the effect version) | |
|---|---|---|
| African | 0.3% | |
| American | 5.2% | |
| East Asian | 0.0% | |
| European | 6.2% | |
| South Asian | 1.2% |
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