CHRNA5
AAIncreased risk
You carry a variant linked to heavier smoking and a harder time quitting. CHRNA5 is a nicotine receptor in the brain linked to heavy smoking.
Changes the guidance for 1 of your substancesExample report. Made from Leslie Knope's DNA data so you can see what yours will look like. Get your own report
Starter Report
Prepared for Leslie Knope
Version 4.6
Example made Nov 8, 2026
How these genes may affect your response to substances.
- Data source
- 23andMe
- Genome build
- GRCh37
- Genes analyzed
- 7
- Substances
- 4
How to read this report
- Step 1
Two copies of each gene
You inherit one copy from each parent. The report names the pair, such as *1/*2.
- Step 2
The pair gives a gene result
Such as Poor metabolizer. The color shows it: typical, reduced, poor.
- Step 3
The result sets each substance's label
Consider alternative Use with caution Use as directed Unable to determine
- Step 4
Then talk to your prescriber
Don't change or stop a substance on your own. Unable to determine doesn't mean normal.
How to read this report
- Step 1
Two copies of each gene
You inherit one copy from each parent. The report names the pair, such as *1/*2.
- Step 2
The pair gives a gene result
Such as Poor metabolizer. The color shows it: typical, reduced, poor.
- Step 3
The result sets each substance's label
Consider alternative Use with caution Use as directed Unable to determine
- Step 4
Then talk to your prescriber
Don't change or stop a substance on your own. Unable to determine doesn't mean normal.
What stands out in your genes
rs16969968A/rs16969968A
COMT
Intermediate function
One copy works and one works less well. COMT breaks down dopamine and other brain chemicals.
Changes the guidance for 1 of your substancesCYP1A2
Rapid metabolizer
One copy works normally and one works faster than usual. CYP1A2 breaks down caffeine and some medicines, such as clozapine.
Changes the guidance for 1 of your substancesYour genes at a glance
All 7 results. Find more details in the Genes section, or select a gene below for its full explanation.
- Each dot is a copy
- works normally
- works less well
- works faster than usual
- Letters: your DNA letters, where copy function isn’t defined
- Color is the result
-
- Normal / typical / favorable
- Intermediate / decreased
- Poor / increased risk
- Rapid / increased
- Not determined
| Gene | Result |
|---|---|
| CHRNA5 | AA Increased riskrs16969968A/rs16969968A |
| COMT | Intermediate functionrs4680A/rs4680G |
| CYP1A2 | Rapid metabolizer*1/*30 |
| ADH1B | Normal functionrs1229984C/rs1229984C |
| Gene | Result |
|---|---|
| ALDH2 | Normal functionrs671G/rs671G |
| CYP2A6 | Normal metabolizer*1/*1 |
| CYP2B6 | Normal metabolizer*1/*1 |
Don'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.
Your substances
4 substances. Open one to see the research behind its label.
Browse drug classes
- Use with caution
- Use as directed
Other substances4 substances
Compare other substances All drug classes
Alcohol Use as directed Your genes have little effect on how your body handles alcohol.ADH1BNormal functionALDH2Normal function
ADH1BNormal function
Gene2Rx research summary
Use as directed See the drug page (Gene2Rx research summaries, opens in a new tab)
- In plain words
- Your genes have little effect on how your body handles alcohol.
- What it means
- Two Arg48 alleles (rs1229984). Usual rate of ethanol oxidation. Compared with His48 carriers, associated with higher risk of alcohol dependence and, among heavy drinkers in East Asian studies, higher risk of esophageal and head and neck cancer. Only rs1229984 is assessed: ADH1B*3 (rs2066702), common in people of African ancestry, is not read, so its carriers are reported here.
- What the research suggests
- Follow standard guidelines for alcohol consumption.
ALDH2Normal function
Gene2Rx research summary
Use as directed See the drug page (Gene2Rx research summaries, opens in a new tab)
- In plain words
- Your genes have little effect on how you clear the toxic by-product of alcohol.
- What it means
- Two Glu504 alleles (rs671 G/G, ALDH2*1/*1). Normal acetaldehyde clearance; typical risk of flushing, hangover and alcohol dependence for this gene.
- What the research suggests
- Standard advice on drinking limits.
CaffeineCoffee, Tea Use with caution Caffeine may wear off slightly sooner for you than average. The usual advice on caffeine limits applies.CYP1A2Rapid metabolizer
CYP1A2Rapid metabolizer
Gene2Rx research summary
Evidence: moderateSee the drug page (Gene2Rx research summaries, opens in a new tab)
- In plain words
- Caffeine may wear off slightly sooner for you than average. The usual advice on caffeine limits applies.
- What it means
- One rs762551 A allele (*1/*30). Modestly higher CYP1A2 activity, mainly in smokers. Note: in the coffee and cardiovascular literature, A/C carriers are classed as 'slow' metabolizers.
- What the research suggests
- Caffeine may be cleared somewhat faster than average. Standard advice on moderate intake applies.
KetamineKetalar Use as directed Your body processes ketamine at the usual rate.CYP2B6Normal metabolizer
CYP2B6Normal metabolizer
Gene2Rx research summary
Evidence: strongSee the drug page (Gene2Rx research summaries, opens in a new tab)
- In plain words
- Your body processes ketamine at the usual rate.
- What it means
- Usual CYP2B6 activity and expected N-demethylation of ketamine to norketamine. CYP3A4 contributes to the same step, and the relative roles of the two enzymes are still debated.
- What the research suggests
- Initiate with standard ketamine doses per clinical practice and titrate to effect.
NicotineCigarettes, 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.CHRNA5Increased riskCOMTIntermediate functionCYP2A6Normal metabolizer
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.
Use with caution 2 substances
Use as directed 2 substances
No substances match
Check the spelling, try the brand or generic name, or clear the search and filters.
Your genes
7 genes from the 23andMe file. Results that differ from the most common one come first, then typical results.
Two dots per gene, one for each copy you inherited:
- works normally
- works less well
- works faster than usual
Color shows the overall gene result. Dot fill shows each copy’s function; lettered dots show your DNA letters where copy function isn’t defined.
- Normal / typical / favorable
- Intermediate / decreased
- Poor / increased risk
- Rapid / increased
- Not determined
Not typical
3 genesYour result differs from the most common one. Not every difference changes the guidance for your substances.- CHRNA5
A nicotine receptor in the brain linked to heavy smoking.
AAIncreased riskrs16969968A/rs16969968A1 substanceChanges the guidance for 1CHRNA5 rs16969968 A allele: 3.2% to 40.7% of DNA copies across ancestry groups
Your result has 2 copies of this allele. These gnomAD frequencies count DNA copies, not people who share your genotype or phenotype, and do not measure your chance of side effects. No ancestry is assumed for you.
Counts below show copies of the A allele / total DNA copies measured.
- African / African American
- 5.9%2,458 / 41,526
- Admixed American
- 22.6%3,458 / 15,290
- Amish
- 40.7%368 / 904
- Ashkenazi Jewish
- 37.5%1,302 / 3,470
- East Asian
- 3.2%166 / 5,186
- Finnish
- 32.7%3,455 / 10,568
- Middle Eastern
- 40.1%118 / 294
- European (non-Finnish)
- 34.7%23,587 / 67,982
- South Asian
- 22.2%1,069 / 4,826
- Remaining ancestry group
- 27.5%581 / 2,112
Reference: gnomAD v4.1 genomes, GRCh38 15-78590583-G-A. Frequencies are allele count divided by allele number within each ancestry group. Study groups are not representative of the worldwide population. Data retrieved 2026-10-17.
- COMT
Breaks down dopamine and other brain chemicals.
Intermediate functionrs4680A/rs4680G · One copy works and one works less well.1 substanceChanges the guidance for 1COMT rs4680 A allele: 27.4% to 66.4% of DNA copies across ancestry groups
Your result has 1 copy of this allele. These gnomAD frequencies count DNA copies, not people who share your genotype or phenotype, and do not measure your chance of side effects. No ancestry is assumed for you.
Counts below show copies of the A allele / total DNA copies measured.
- African / African American
- 31.0%12,853 / 41,484
- Admixed American
- 40.4%6,184 / 15,292
- Amish
- 66.4%604 / 910
- Ashkenazi Jewish
- 45.3%1,571 / 3,466
- East Asian
- 27.4%1,414 / 5,152
- Finnish
- 55.3%5,854 / 10,592
- Middle Eastern
- 46.9%138 / 294
- European (non-Finnish)
- 51.8%35,191 / 67,942
- South Asian
- 44.5%2,147 / 4,822
- Remaining ancestry group
- 41.8%883 / 2,110
Reference: gnomAD v4.1 genomes, GRCh38 22-19963748-G-A. Frequencies are allele count divided by allele number within each ancestry group. Study groups are not representative of the worldwide population. Data retrieved 2026-10-17.
- CYP1A2
Breaks down caffeine and some medicines, such as clozapine.
Rapid metabolizer*1/*30 · One copy works normally and one works faster than usual.1 substanceChanges the guidance for 1
Typical
4 genesThe most common result. The substances that depend only on these genes should work as expected.- ADH1B
Turns alcohol into acetaldehyde, a toxic by-product.
Normal functionrs1229984C/rs1229984C · Both copies work normally.1 substanceGuidance unchangedADH1B rs1229984 C allele: 29.6% to 99.7% of DNA copies across ancestry groups
Your result has 2 copies of this allele. These gnomAD frequencies count DNA copies, not people who share your genotype or phenotype, and do not measure your chance of side effects. No ancestry is assumed for you.
Counts below show copies of the C allele / total DNA copies measured.
- African / African American
- 98.8%41,031 / 41,534
- Admixed American
- 93.2%14,240 / 15,282
- Amish
- 89.9%820 / 912
- Ashkenazi Jewish
- 73.1%2,539 / 3,472
- East Asian
- 29.6%1,530 / 5,168
- Finnish
- 99.7%10,586 / 10,618
- Middle Eastern
- 78.6%231 / 294
- European (non-Finnish)
- 96.4%65,617 / 68,036
- South Asian
- 95.9%4,626 / 4,822
- Remaining ancestry group
- 88.4%1,861 / 2,106
Reference: gnomAD v4.1 genomes, GRCh38 4-99318162-T-C. Frequencies are allele count divided by allele number within each ancestry group. Study groups are not representative of the worldwide population. Data retrieved 2026-10-17.
- ALDH2
Clears acetaldehyde, the toxic by-product of alcohol.
Normal functionrs671G/rs671G · Both copies work normally.1 substanceGuidance unchangedALDH2 rs671 A allele: 0% to 22.5% of DNA copies across ancestry groups
Your result has 0 copies of this allele. These gnomAD frequencies count DNA copies, not people who share your genotype or phenotype, and do not measure your chance of side effects. No ancestry is assumed for you.
Counts below show copies of the A allele / total DNA copies measured.
- African / African American
- <0.1%8 / 41,546
- Admixed American
- <0.1%14 / 15,274
- Amish
- 0%0 / 912
- Ashkenazi Jewish
- 0%0 / 3,470
- East Asian
- 22.5%1,154 / 5,132
- Finnish
- <0.1%1 / 10,598
- Middle Eastern
- 0%0 / 294
- European (non-Finnish)
- <0.1%2 / 68,020
- South Asian
- <0.1%4 / 4,820
- Remaining ancestry group
- 0.5%10 / 2,108
Reference: gnomAD v4.1 genomes, GRCh38 12-111803962-G-A. Frequencies are allele count divided by allele number within each ancestry group. Study groups are not representative of the worldwide population. Data retrieved 2026-10-17.
- CYP2A6
Breaks down nicotine.
Normal metabolizer*1/*1 · Both copies work normally.1 substanceGuidance unchanged - CYP2B6
Breaks down efavirenz, ketamine, methadone and some drugs for depression.
Normal metabolizer*1/*1 · Both copies work normally.1 substanceGuidance unchangedCYP2B6 normal metabolizer: estimated in 13.0% to 48.6% of people across population groups
These CPIC estimates describe this phenotype, not your exact DNA combination or your chance of side effects. Frequencies vary by population; no ancestry is assumed for you.
- African American/Afro-Caribbean
- 33.4%
- Central/South Asian
- 42.2%
- East Asian
- 48.6%
- European
- 43.0%
- Latino
- 33.6%
- Near Eastern
- 29.1%
- Oceanian
- 13.0%
- Sub-Saharan African
- 14.3%
Estimated from published allele frequencies, rather than a direct count of people with this result. Study coverage and methods vary. Reference: CPIC CYP2B6 frequency table and methods. Data retrieved 2026-10-17.
Not in your Starter Report
116 more medications in the Full Report
The Full Report reads 23 more genes from the same 23andMe file and checks prescription medications in 25 groups, including antidepressants, pain relievers and cancer drugs.
About this report
What it covers, where the guidance comes from, and what the data can and can't show.
What's in it
4 substances, 1 group, 7 genes
Starter Report, version 4.6. Made Nov 8, 2026 from a 23andMe file.
This report includes information about how your genetics may influence your response to common substances like caffeine, alcohol, nicotine, and ketamine. For information on 100+ prescription medications, upgrade to the full report.
What's new in version 4.6Download the PDFOpen the original layout
What the data can show
- All 7 genes have a clear result from the 23andMe data, with missing positions filled in from a reference panel.
- 4 substances have a result.
- Rare variants can be missed. Arrays test selected positions; imputation helps fill the gaps but can still miss rare variants.
Where the guidance comes from
Every substance names its source, and some have more than one. Gene2Rx is not affiliated with or endorsed by CPIC, the FDA or DPWG.
- Gene2RxGene2Rx research summaries. Published studies we summarize where no guideline exists yet.4 substances
How we read your DNA
- Step 1
We fill in positions your array didn't test by comparing your data with a large reference panel.
- Step 2
We name the two copies of each gene you inherited, such as *1/*2.
- Step 3
We look up what that pair means in published tables, then match it to each substance's guidance.
Questions
What do I do now?
If you may have an unusual response to a medication you take or are thinking about taking, talk with your healthcare provider or a genetic counselor before making any changes. The sources linked beside each finding explain its evidence and limits. Not every finding supports a treatment change.
Should I change medications or my dose based on this report?
No. Don't change a dose or stop a medication without talking to your healthcare provider first. Consumer DNA data is not clinical grade, so use this report to start a conversation with your provider, who may order a clinical lab test. Read more about consumer tests and the research behind this advice.
Are these expert annotations?
Each finding names its source. This report includes CPIC, FDA, DPWG and Gene2Rx interpretations, with different levels of evidence. Those organizations don't endorse Gene2Rx's own interpretations, which explain the research behind a finding and its limits.
Why would my results change?
Your genes don't change, but research does. Guidelines and drug labels are updated when new research meets strict standards and experts agree. Your report keeps the guidance used when it was made; an updated report can use newer guidance.
I don't see my medication. Why not?
Not every medication is affected by genetics, and some need more research before guidance exists. A medication can also be missing because of your report tier, your data or what this report covers. A missing medication may still have guidance from a clinical guideline or a drug label.
More questions? Email contact@gene2rx.com.
This is not a clinical test. Results are predictions from consumer DNA data and published research. They may be wrong. Don't change or stop a medication without talking to your prescriber, and confirm any result that matters with a clinical-grade test.
gene2rx.com · PharmacogeneticsExample report · Complete report for your doctor or pharmacist
Starter Report
Prepared for Leslie Knope
4 substances · 7 genes · 1 drug class
This complete edition includes every gene result and every medication in this report tier, including results labeled “Use as directed,” all source guidance, evidence levels and limitations.
This is not a clinical test. Results are predictions from consumer DNA data and published research. The quality of submitted data is not independently verified and errors can affect the report. Do not change a dose or stop a medication without talking to your prescriber. Confirm any result that matters with a clinical-grade test.
Coverage depends on your data and report tier. A medication missing from this report may still have guidance from a clinical guideline or product label.
Reading the guidance
Consider alternative
0
Use with caution
2
Use as directed
2
Unable to determine
0
Use as directed: no change suggested by the assessed genetic findings. Use with caution: a dose change, slower titration or monitoring may be suggested. Consider alternative: discuss another medication or the source’s dose advice. Unable to determine: the available data could not establish a result. These labels do not guarantee effectiveness or freedom from side effects.
Report contents
Gene results at a glance · Complete medication guidance · Gene details and frequencies · About this report
Other substances4 substances
Your genes at a glance
All 7 results. Evidence and actionability differ by gene and medication. An activity score adds the activity values of your gene copies; higher scores indicate more enzyme activity. The detailed gene section explains each result.
| Gene | Your two copies | Genotype | Phenotype | Activity score |
|---|---|---|---|---|
| ADH1B | rs1229984C/rs1229984C | Normal Function | - | |
| ALDH2 | rs671G/rs671G | Normal Function | - | |
| CHRNA5 | AA | rs16969968A/rs16969968A | Increased Risk | - |
| COMT | rs4680A/rs4680G | Intermediate Function | - | |
| CYP1A2 | *1/*30 | Rapid Metabolizer | - | |
| CYP2A6 | *1/*1 | Normal Metabolizer | - | |
| CYP2B6 | *1/*1 | Normal Metabolizer | - |
Color shows the overall gene result. Dot fill shows each copy’s function; lettered dots show your DNA letters where copy function isn’t defined.
- Normal / typical / favorable
- Intermediate / decreased
- Poor / increased risk
- Rapid / increased
- Not determined
Filled dots: works normally. Half-filled: works less well. Empty: does not work. Ringed: more active than usual. Dotted gray: not determined. Letters show DNA bases without assigning copy function. A non-normal allele does not necessarily change medication guidance.
Complete medication guidance
All 4 substances, grouped by drug class. Each source’s wording and evidence level are retained; sources may offer different recommendations.
Other substances 4 substances
2 Use with caution2 Use as directed
AlcoholUse as directedYour genes have little effect on how your body handles alcohol. ADH1B Normal functionALDH2 Normal function |
|---|
ADH1B: Normal function Gene2Rx research summary, ADH1B Use as directed See the drug page (Gene2Rx research summaries, opens in a new tab)
|
ALDH2: Normal function Gene2Rx research summary, ALDH2 Use as directed See the drug page (Gene2Rx research summaries, opens in a new tab)
|
CaffeineUse with cautionCoffee, Tea Caffeine may wear off slightly sooner for you than average. The usual advice on caffeine limits applies. CYP1A2 Rapid metabolizer |
|---|
CYP1A2: Rapid metabolizer Gene2Rx research summary, CYP1A2 Use with caution Evidence: moderateSee the drug page (Gene2Rx research summaries, opens in a new tab)
|
KetamineUse as directedKetalar Your body processes ketamine at the usual rate. CYP2B6 Normal metabolizer |
|---|
CYP2B6: Normal metabolizer Gene2Rx research summary, CYP2B6 Use as directed Evidence: strongSee the drug page (Gene2Rx research summaries, opens in a new tab)
|
NicotineUse with cautionCigarettes, Zyn 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. CHRNA5 Increased riskCOMT Intermediate functionCYP2A6 Normal metabolizer |
|---|
CHRNA5: Increased risk Gene2Rx research summary, CHRNA5 Use with caution Evidence: strongSee the drug page (Gene2Rx research summaries, opens in a new tab)
|
COMT: Intermediate function Gene2Rx research summary, COMT Use with caution Evidence: weakSee the drug page (Gene2Rx research summaries, opens in a new tab)
|
CYP2A6: Normal metabolizer Gene2Rx research summary, CYP2A6 Use as directed Evidence: strongSee the drug page (Gene2Rx research summaries, opens in a new tab)
|
Gene details and frequencies
All 7 genes. Frequency context describes populations, not your chance of a side effect. A missing frequency estimate means no supported reference is available for that result.
ADH1B Normal function
rs1229984C/rs1229984C · Both copies work normally.
Turns alcohol into acetaldehyde, a toxic by-product.
1 substance lists this gene. Guidance unchanged
ADH1B rs1229984 C allele: 29.6% to 99.7% of DNA copies across ancestry groups
Your result has 2 copies of this allele. These gnomAD frequencies count DNA copies, not people who share your genotype or phenotype, and do not measure your chance of side effects. No ancestry is assumed for you.
Counts below show copies of the C allele / total DNA copies measured.
- African / African American
- 98.8%41,031 / 41,534
- Admixed American
- 93.2%14,240 / 15,282
- Amish
- 89.9%820 / 912
- Ashkenazi Jewish
- 73.1%2,539 / 3,472
- East Asian
- 29.6%1,530 / 5,168
- Finnish
- 99.7%10,586 / 10,618
- Middle Eastern
- 78.6%231 / 294
- European (non-Finnish)
- 96.4%65,617 / 68,036
- South Asian
- 95.9%4,626 / 4,822
- Remaining ancestry group
- 88.4%1,861 / 2,106
Reference: gnomAD v4.1 genomes, GRCh38 4-99318162-T-C. Frequencies are allele count divided by allele number within each ancestry group. Study groups are not representative of the worldwide population. Data retrieved 2026-10-17.
ALDH2 Normal function
rs671G/rs671G · Both copies work normally.
Clears acetaldehyde, the toxic by-product of alcohol.
1 substance lists this gene. Guidance unchanged
ALDH2 rs671 A allele: 0% to 22.5% of DNA copies across ancestry groups
Your result has 0 copies of this allele. These gnomAD frequencies count DNA copies, not people who share your genotype or phenotype, and do not measure your chance of side effects. No ancestry is assumed for you.
Counts below show copies of the A allele / total DNA copies measured.
- African / African American
- <0.1%8 / 41,546
- Admixed American
- <0.1%14 / 15,274
- Amish
- 0%0 / 912
- Ashkenazi Jewish
- 0%0 / 3,470
- East Asian
- 22.5%1,154 / 5,132
- Finnish
- <0.1%1 / 10,598
- Middle Eastern
- 0%0 / 294
- European (non-Finnish)
- <0.1%2 / 68,020
- South Asian
- <0.1%4 / 4,820
- Remaining ancestry group
- 0.5%10 / 2,108
Reference: gnomAD v4.1 genomes, GRCh38 12-111803962-G-A. Frequencies are allele count divided by allele number within each ancestry group. Study groups are not representative of the worldwide population. Data retrieved 2026-10-17.
CHRNA5 Increased risk
AArs16969968A/rs16969968A
A nicotine receptor in the brain linked to heavy smoking.
You carry a variant linked to heavier smoking and a harder time quitting.
1 substance lists this gene. Changes the guidance for 1
CHRNA5 rs16969968 A allele: 3.2% to 40.7% of DNA copies across ancestry groups
Your result has 2 copies of this allele. These gnomAD frequencies count DNA copies, not people who share your genotype or phenotype, and do not measure your chance of side effects. No ancestry is assumed for you.
Counts below show copies of the A allele / total DNA copies measured.
- African / African American
- 5.9%2,458 / 41,526
- Admixed American
- 22.6%3,458 / 15,290
- Amish
- 40.7%368 / 904
- Ashkenazi Jewish
- 37.5%1,302 / 3,470
- East Asian
- 3.2%166 / 5,186
- Finnish
- 32.7%3,455 / 10,568
- Middle Eastern
- 40.1%118 / 294
- European (non-Finnish)
- 34.7%23,587 / 67,982
- South Asian
- 22.2%1,069 / 4,826
- Remaining ancestry group
- 27.5%581 / 2,112
Reference: gnomAD v4.1 genomes, GRCh38 15-78590583-G-A. Frequencies are allele count divided by allele number within each ancestry group. Study groups are not representative of the worldwide population. Data retrieved 2026-10-17.
COMT Intermediate function
rs4680A/rs4680G · One copy works and one works less well.
Breaks down dopamine and other brain chemicals.
1 substance lists this gene. Changes the guidance for 1
COMT rs4680 A allele: 27.4% to 66.4% of DNA copies across ancestry groups
Your result has 1 copy of this allele. These gnomAD frequencies count DNA copies, not people who share your genotype or phenotype, and do not measure your chance of side effects. No ancestry is assumed for you.
Counts below show copies of the A allele / total DNA copies measured.
- African / African American
- 31.0%12,853 / 41,484
- Admixed American
- 40.4%6,184 / 15,292
- Amish
- 66.4%604 / 910
- Ashkenazi Jewish
- 45.3%1,571 / 3,466
- East Asian
- 27.4%1,414 / 5,152
- Finnish
- 55.3%5,854 / 10,592
- Middle Eastern
- 46.9%138 / 294
- European (non-Finnish)
- 51.8%35,191 / 67,942
- South Asian
- 44.5%2,147 / 4,822
- Remaining ancestry group
- 41.8%883 / 2,110
Reference: gnomAD v4.1 genomes, GRCh38 22-19963748-G-A. Frequencies are allele count divided by allele number within each ancestry group. Study groups are not representative of the worldwide population. Data retrieved 2026-10-17.
CYP1A2 Rapid metabolizer
*1/*30 · One copy works normally and one works faster than usual.
Breaks down caffeine and some medicines, such as clozapine.
1 substance lists this gene. Changes the guidance for 1
CYP2A6 Normal metabolizer
*1/*1 · Both copies work normally.
Breaks down nicotine.
1 substance lists this gene. Guidance unchanged
CYP2B6 Normal metabolizer
*1/*1 · Both copies work normally.
Breaks down efavirenz, ketamine, methadone and some drugs for depression.
1 substance lists this gene. Guidance unchanged
CYP2B6 normal metabolizer: estimated in 13.0% to 48.6% of people across population groups
These CPIC estimates describe this phenotype, not your exact DNA combination or your chance of side effects. Frequencies vary by population; no ancestry is assumed for you.
- African American/Afro-Caribbean
- 33.4%
- Central/South Asian
- 42.2%
- East Asian
- 48.6%
- European
- 43.0%
- Latino
- 33.6%
- Near Eastern
- 29.1%
- Oceanian
- 13.0%
- Sub-Saharan African
- 14.3%
Estimated from published allele frequencies, rather than a direct count of people with this result. Study coverage and methods vary. Reference: CPIC CYP2B6 frequency table and methods. Data retrieved 2026-10-17.
About this report
7 of 7 genes have results; 4 substances have a determined guidance label.
Rare variants can be missed. Arrays test selected positions; imputation helps fill the gaps but can still miss rare variants.
How the results were read
Untested array positions are estimated using a reference panel (imputation). The two gene copies are named and matched to published phenotype tables and medication guidance.
Sources
Gene2Rx - Gene2Rx research summaries: 4 substances. Published studies we summarize where no guideline exists yet.
Source links in the medication guidance remain clickable in the PDF. Gene2Rx is not affiliated with or endorsed by CPIC, the FDA or DPWG. Research summaries can have different evidence and actionability from clinical guidelines.
Questions
What do I do now?
If you may have an unusual response to a medication you take or are considering, talk with your healthcare provider or a genetic counselor before making changes. The sources beside each finding explain its evidence and limits. Not every finding supports a treatment change.
Should I change medications or my dose based on this report?
No. Do not change a dose or stop a medication without talking to your healthcare provider first. Consumer DNA data is not clinical grade. Use this report to start a conversation with your provider, who may order a clinical lab test. Research on consumer genetic testing.
Are these expert annotations?
Each finding names its source. CPIC, FDA, DPWG and Gene2Rx interpretations have different levels of evidence. These organizations do not endorse Gene2Rx interpretations, which explain the research and its limitations alongside each finding.
Why would my results change?
Your genes do not change, but research does. Guidelines and drug labels are updated when new research meets strict standards and experts agree. Your report preserves the guidance used when it was made; an updated report may use newer guidance.
I do not see my medication. Why not?
Not every medication is affected by genetics, and some need more research before guidance exists. A medication may also be missing because of your report tier, your data or what this report covers. A missing medication may still have guidance from a clinical guideline or drug label.
Why should I confirm results before changing treatment? Consumer data is not clinical grade and the findings are predictions. Additional genetic variation, health conditions and other medicines can affect response. Discuss any treatment decision with your healthcare provider or pharmacist.
More questions: contact@gene2rx.com. Full interactive report: gene2rx.com.
Compact report · ExampleStarter Report
Prepared for Leslie Knope · Nov 8, 2026 · Version 4.6
23andMe · GRCh37 · 7 genes · 4 substances
All results, summarized. Use the detailed report for full source recommendations, evidence, dose calculations and frequencies. Sources may offer different advice.
Not a clinical test. Do not change or stop a medication without your prescriber. Confirm important findings with a clinical-grade test. Missing or undetermined results do not mean normal results.
Gene results
| Gene | Copies | Genotype | Phenotype | Score |
|---|---|---|---|---|
| ADH1B | rs1229984C/rs1229984C | Normal Function | - | |
| ALDH2 | rs671G/rs671G | Normal Function | - | |
| CHRNA5 | AA | rs16969968A/rs16969968A | Increased Risk | - |
| COMT | rs4680A/rs4680G | Intermediate Function | - | |
| CYP1A2 | *1/*30 | Rapid Metabolizer | - | |
| CYP2A6 | *1/*1 | Normal Metabolizer | - | |
| CYP2B6 | *1/*1 | Normal Metabolizer | - |
Score: gene activity score, where defined. Glyph fill shows each copy’s function; color shows the overall phenotype. Full explanations and typical activity ranges are in the detailed report.
Color shows the overall gene result. Dot fill shows each copy’s function; lettered dots show your DNA letters where copy function isn’t defined.
- Normal / typical / favorable
- Intermediate / decreased
- Poor / increased risk
- Rapid / increased
- Not determined
All substances
Summaries describe the report’s overall guidance. “Use as directed” does not guarantee effectiveness or freedom from side effects. Brand names are shown where available.
Summaries use Gene2Rx wording. Summary sources: CPIC = Clinical Pharmacogenetics Implementation Consortium; DPWG = Dutch Pharmacogenetics Working Group; FDA = U.S. Food and Drug Administration drug information; Gene2Rx = research summary. “Report note” is a report explanation without a source summary. See the detailed report for all sources and recommendations.
Arrays test selected positions; imputation helps fill gaps but can still miss rare variants.
Other substances 4
| Medication | Guidance | Genes | Summary |
|---|---|---|---|
| Alcohol | Use as directed | ADH1BALDH2 | Your genes have little effect on how your body handles alcohol. (Summarized from Gene2Rx) |
| CaffeineCoffee, Tea | Use with caution | CYP1A2 | Caffeine may wear off slightly sooner for you than average. The usual advice on caffeine limits applies. (Summarized from Gene2Rx) |
| KetamineKetalar | Use as directed | CYP2B6 | Your body processes ketamine at the usual rate. (Summarized from Gene2Rx) |
| NicotineCigarettes, Zyn | Use with caution | CHRNA5COMTCYP2A6 | 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. (Summarized from Gene2Rx) |
Coverage depends on your data and report tier. A medication missing here may still have pharmacogenetic guidance. Full source text and references are in the detailed report. Questions: contact@gene2rx.com.