rs1799930
Fast or slow acetylator
What this position does
NAT2 clears a specific class of chemicals: several drugs, and the compounds formed when meat is charred. Roughly half of Europeans are slow acetylators and clear them sluggishly. The frequency shifted as populations took up farming, and it is one of the best documented cases of diet reshaping a detoxification gene.
Liver. Shaped by a changing chemical diet, from foraging to farming to industry. This is one of the variants that differs sharply between human populations, because something in the environment made one version worth having.
A chemical environment that keeps changing
The liver evolved to clear what plants and smoke put into people. It now also handles drugs, solvents and the products of charred meat, which arrived far too recently to have shaped anything.
What changed: Farming, the last 12,000 years. Grain, milk, settlement, crowds and the diseases crowds carry. Most of the adaptations a consumer chip can read are younger than this, which is why they still differ so sharply between populations.
Why it spread: well established. The environmental pressure behind this variant is documented and not in serious dispute.
Spiral Staircase, chapter 14: The Liver and the Chemical Century Spiral Staircase is written by the same author as this site.
What each result means
| If you carry | What it means |
|---|---|
| No copies of the effect version GG | Fast acetylator at this position The rapid version on both copies. |
| One copy AG | Intermediate One slow copy. |
| Two copies AA | Slow acetylator at this position Slow clearance. This matters in two real places: isoniazid, the main tuberculosis drug, builds up in slow acetylators and needs monitoring, and slow acetylators who are also heavily exposed to aromatic amines, historically in dye and rubber work and in heavy smoking, carry a higher bladder cancer risk. |
Worth knowing. Acetylator status is set by a combination across several NAT2 positions. This reads the most common one and is an indication rather than a full result.
How common each version is
| Ancestry group | A (the effect version) | |
|---|---|---|
| African | 23.8% | |
| American | 17.1% | |
| East Asian | 25.6% | |
| European | 28.2% | |
| South Asian | 36.0% |
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.
How many people carry each result
| Ancestry group | GG | AG | AA |
|---|---|---|---|
| African | 385 / 661 | 238 / 661 | 38 / 661 |
| European | 267 / 503 | 188 / 503 | 48 / 503 |
| East Asian | 286 / 504 | 178 / 504 | 40 / 504 |
| South Asian | 202 / 489 | 222 / 489 | 65 / 489 |
| American | 241 / 347 | 93 / 347 | 13 / 347 |
Counts of people, not modelled frequencies: every one of the 2,504 individuals sequenced by the 1000 Genomes Project phase 3, tallied by the genotype they carry. Deriving these from allele frequencies instead would assume random mating inside each group and undercount the homozygotes.
How to find out which you have
If you have taken a test with 23andMe, AncestryDNA, MyHeritage, Family Tree DNA, TellMeGen or Living DNA, this position is very likely already in the raw data file they gave you. You do not need another test.
One thing to watch if you look it up by hand: testing companies report some positions from one DNA strand and some from the other, and the file does not say which. Read the letters as they appear and you will get the opposite of the truth for some positions. Sequencings resolves that automatically.
Source
Coordinates and allele pair verified against Ensembl GRCh37. Direction of effect verified against VEP protein consequences or 1000 Genomes population frequency. Category: Population adaptation.
Where this fits
Common questions
What is rs1799930?
rs1799930 is a position in the NAT2 gene on chromosome 8. NAT2 clears a specific class of chemicals: several drugs, and the compounds formed when meat is charred. Roughly half of Europeans are slow acetylators and clear them sluggishly. The frequency shifted as populations took up farming, and it is one of the best documented cases of diet reshaping a detoxification gene.
What does it mean if I have AA at rs1799930?
Slow acetylator at this position. Slow clearance. This matters in two real places: isoniazid, the main tuberculosis drug, builds up in slow acetylators and needs monitoring, and slow acetylators who are also heavily exposed to aromatic amines, historically in dye and rubber work and in heavy smoking, carry a higher bladder cancer risk.
What does it mean if I have GG at rs1799930?
Fast acetylator at this position. The rapid version on both copies.
How do I find out my rs1799930 genotype?
If you have taken a home DNA test, this position is very likely in the raw data file you were given. Sequencings reads that file in your browser without uploading it, and resolves which DNA strand each position was reported from, which is the step most manual lookups get wrong.
This is reference information, not medical advice, and not a diagnosis. See the medical disclaimer. Category: Population adaptation.