Markers / Gene
NUDT15
One position in this gene is readable from a home DNA test.
Thiopurine sensitivity, NUDT15
rs116855232 · chr13:48,619,855 · C/T · evidence: established
Azathioprine and mercaptopurine are used in inflammatory bowel disease, transplant medicine and leukaemia. NUDT15 variants cause severe bone-marrow suppression at normal doses, and they are the main cause of this in East Asian populations, where TPMT testing alone misses it.
| If you carry | What it means |
|---|---|
| No copies | Normal function |
| One copy | Intermediate metaboliser |
| Two copies | Poor metaboliser |
| Ancestry group | T (the effect version) | |
|---|---|---|
| African | 0.1% | |
| American | 4.5% | |
| East Asian | 9.5% | |
| European | 0.2% | |
| South Asian | 7.0% |
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.
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