rs16969968
How hard nicotine grips, if you smoke
What this position does
This change alters a nicotine receptor subunit in the brain. It does not make anyone start smoking, but among people who do smoke it is one of the strongest known predictors of how many cigarettes a day they end up on and how hard quitting is.
What each result means
| If you carry | What it means |
|---|---|
| No copies of the effect version GG | You do not carry it, so nicotine has no extra grip from this gene Neither copy carries the higher-dependence version. |
| One copy AG | One copy, a somewhat harder time quitting if you smoke Among smokers, associated with roughly one extra cigarette a day and a harder time quitting. |
| Two copies AA | Two copies, a markedly harder time quitting if you smoke Among smokers, associated with about two extra cigarettes a day, greater difficulty quitting, and a measurably higher lung cancer risk that runs through the extra smoking. The actionable part is simple: if you smoke, this is a reason to get real help rather than relying on willpower. |
Worth knowing. Only relevant if you smoke or have smoked. It says nothing about whether you would start.
How common each version is
| Ancestry group | A (the effect version) | |
|---|---|---|
| African | 2.3% | |
| American | 20.9% | |
| East Asian | 2.7% | |
| European | 36.6% | |
| South Asian | 18.2% |
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.
How many people carry each result
| Ancestry group | GG | AG | AA |
|---|---|---|---|
| African | 633 / 661 | 25 / 661 | 3 / 661 |
| European | 205 / 503 | 228 / 503 | 70 / 503 |
| East Asian | 477 / 504 | 27 / 504 | 0 / 504 |
| South Asian | 332 / 489 | 136 / 489 | 21 / 489 |
| American | 224 / 347 | 101 / 347 | 22 / 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: Trait.
Where this fits
Common questions
What is rs16969968?
rs16969968 is a position in the CHRNA5 gene on chromosome 15. This change alters a nicotine receptor subunit in the brain. It does not make anyone start smoking, but among people who do smoke it is one of the strongest known predictors of how many cigarettes a day they end up on and how hard quitting is.
What does it mean if I have AA at rs16969968?
Two copies, a markedly harder time quitting if you smoke. Among smokers, associated with about two extra cigarettes a day, greater difficulty quitting, and a measurably higher lung cancer risk that runs through the extra smoking. The actionable part is simple: if you smoke, this is a reason to get real help rather than relying on willpower.
What does it mean if I have GG at rs16969968?
You do not carry it, so nicotine has no extra grip from this gene. Neither copy carries the higher-dependence version.
How do I find out my rs16969968 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: Trait.