Markers / Condition
Which genes affect smoking and lung disease?
Nothing here says anything about whether somebody starts smoking. What these variants change is how hard it is to stop once started, and how much damage is done along the way. One of them is the single most actionable result on this site for anyone who smokes.
The markers
| Marker | Gene | What it does | Evidence |
|---|---|---|---|
| rs16969968 | CHRNA5 | How hard nicotine grips, if you smoke | established |
| rs1051730 | CHRNA3 | How many cigarettes a day, if you smoke | established |
| rs28929474 | SERPINA1 | Alpha-1 antitrypsin, Z allele | established |
| rs1042713 | ADRB2 | The airway receptor that asthma inhalers act on | strong |
How hard nicotine grips, if you smoke
rs16969968 · CHRNA5
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.
Two copies: Two copies, a markedly harder time quitting if you smoke
How many cigarettes a day, if you smoke
rs1051730 · CHRNA3
Sitting in the same nicotine receptor cluster as the dependence variant, and inherited with it. Its effect is measured directly in cigarettes per day, and through that in lung cancer and emphysema risk. Nothing about this was shaped by evolution: tobacco arrived a few hundred years ago and found a receptor system built for something else.
Two copies: You carry two copies
Alpha-1 antitrypsin, Z allele
rs28929474 · SERPINA1
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.
Two copies: You carry two copies, and a simple blood test is the right next step
The airway receptor that asthma inhalers act on
rs1042713 · ADRB2
Beta-2 receptors relax the smooth muscle around your airways. They are what a blue reliever inhaler targets. This variant changes how the receptor behaves after repeated stimulation, which is why it has been studied for asthma treatment response.
Two copies: You have the glycine version on both copies
Which versions do you carry?
All of these are readable from an ordinary home DNA test file, in your browser, without uploading it anywhere.
Read my fileCommon questions
Which genes affect smoking and lung disease?
Nothing here says anything about whether somebody starts smoking. What these variants change is how hard it is to stop once started, and how much damage is done along the way. One of them is the single most actionable result on this site for anyone who smokes. The markers most often cited are rs16969968 in CHRNA5, rs1051730 in CHRNA3, rs28929474 in SERPINA1, rs1042713 in ADRB2.
What does rs16969968 do?
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. Carrying two copies: two copies, a markedly harder time quitting if you smoke.
What does rs1051730 do?
Sitting in the same nicotine receptor cluster as the dependence variant, and inherited with it. Its effect is measured directly in cigarettes per day, and through that in lung cancer and emphysema risk. Nothing about this was shaped by evolution: tobacco arrived a few hundred years ago and found a receptor system built for something else. Carrying two copies: you carry two copies.
What does rs28929474 do?
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. Carrying two copies: you carry two copies, and a simple blood test is the right next step.
What does rs1042713 do?
Beta-2 receptors relax the smooth muscle around your airways. They are what a blue reliever inhaler targets. This variant changes how the receptor behaves after repeated stimulation, which is why it has been studied for asthma treatment response. Carrying two copies: you have the glycine version on both copies.
Reference information, not medical advice and not a diagnosis. See the medical disclaimer.