CHRNA5Your two copies: rs16969968A/rs16969968A
AAIncreased risk
A nicotine receptor in the brain linked to heavy smoking.
This result changes the label.
Example report. Made from Leslie Knope's DNA data so you can see what yours will look like. Get your own report
Other substancesExample report
Nicotine
Cigarettes, Zyn
Use with caution
This variant is linked to heavier smoking and finding it harder to quit. Stop-smoking medicines appear to help people with this result as much as or more than others.
The genes behind this label
The guidelines read 3 genes for nicotine. Each card shows the two copies this person inherited and what they mean.
COMTYour two copies: rs4680A/rs4680G
Intermediate function
One copy works and one works less well.
Breaks down dopamine and other brain chemicals.
This result changes the label.
CYP2A6Your two copies: *1/*1
Normal metabolizer
Both copies work normally.
Breaks down nicotine.
This result doesn't change the label.
What the guidelines say
What each guideline says about your result.
CHRNA5Increased risk
Gene2Rx research summary
Use with caution Evidence: strongSee the drug page (Gene2Rx research summaries, opens in a new tab)
- In plain words
- This variant is linked to heavier smoking and finding it harder to quit. Stop-smoking medicines appear to help people with this result as much as or more than others.
- What it means
- One or two rs16969968 A alleles (Asn398). The Asn398 receptor shows reduced response to nicotinic agonists in vitro. Associated with more cigarettes per day, higher risk of nicotine dependence, later smoking cessation and earlier lung cancer diagnosis in smokers. In a cessation trial, carriers of the high-risk haplotype benefited more from cessation pharmacotherapy than non-carriers.
- What the research suggests
- Higher risk of heavy, persistent use. For patients who want to quit, offer cessation pharmacotherapy with counseling rather than an unassisted attempt.
COMTIntermediate function
Gene2Rx research summary
Use with caution Evidence: weakSee the drug page (Gene2Rx research summaries, opens in a new tab)
- In plain words
- This result has been studied in relation to smoking, but the findings are mixed, so it tells you little about how you respond to nicotine.
- What it means
- rs4680 Val/Met. Moderately lower COMT activity. Associations with nicotine reward, withdrawal and smoking behavior are inconsistent across studies.
- What the research suggests
- No genotype-based change to cessation treatment; monitor craving as usual.
CYP2A6Normal metabolizer
Gene2Rx research summary
Use as directed Evidence: strongSee the drug page (Gene2Rx research summaries, opens in a new tab)
- In plain words
- Your body is expected to clear nicotine at a typical rate.
- What it means
- No reduced-function allele detected among those assessed. Typical nicotine clearance. The CYP2A6*4 deletion, *12 hybrid and duplications are not assessed, so reduced activity cannot be ruled out.
- What the research suggests
- Typical response to nicotine. In smokers with normal nicotine metabolism, varenicline was more effective than the nicotine patch in a randomized trial.
About nicotine
Nicotine is the addictive substance in tobacco and the active ingredient in nicotine replacement products used to quit smoking.
Others in other substances
Compare all 7 other substancesDon't change a dose on your own. Bring this report to your prescriber or pharmacist. They can weigh it with everything else they know about you.