Markers / Gene
SERPINA1
One position in this gene is readable from a home DNA test.
Alpha-1 antitrypsin, Z allele
rs28929474 · chr14:94,844,947 · C/T · evidence: established
Alpha-1 antitrypsin protects lung tissue from an enzyme released by white blood cells. The Z version folds badly, gets stuck in the liver, and leaves the lungs under-protected. It is the most common serious inherited cause of emphysema and it is very widely missed.
| If you carry | What it means |
|---|---|
| No copies | You do not carry the Z version |
| One copy | You carry one copy, which matters most if you smoke |
| Two copies | You carry two copies, and a simple blood test is the right next step |
| Ancestry group | T (the effect version) | |
|---|---|---|
| African | 0.0% | |
| American | 0.4% | |
| East Asian | 0.0% | |
| European | 1.7% | |
| South Asian | 0.0% |
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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