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Primary topic: POR caffeine metabolism gene

POR Gene and Metabolism: What It Can Mean in a Pathway Report

POR is tracked as supporting context for cytochrome P450 enzyme activity, including caffeine-metabolism biology.

What is the POR gene?

POR provides electrons to microsomal cytochrome P450 enzymes. It is not the main caffeine enzyme, but it can support the broader clearance system.

How POR affects metabolism

POR-linked common variants are interpreted as low-impact caffeine-metabolism context, not as dose guidance.

What happens when POR is altered

A POR signal matters only if caffeine response, sleep, medication context, or other clearance genes point in the same direction.

Curated SNP evidence for POR

These SNPs come from the approved study-level evidence model. Each claim is scored from curated study rows, then gated before it can influence pathway scoring.

Caffeine / stimulant sensitivity

Evidence-backed report connection

POR currently has 1 curated SNPs, 3 claim-level scores, and 2 claims eligible for pathway scoring.

Open the sample report
rs17685POR caffeine metabolism supporting signal3 claims · 11 study rows

biomarker tendency · AA

POR-supported caffeine metabolism tendency

Moderate

rs17685 AA is associated with increased POR-supported caffeine metabolism tendency.

POR rs17685 is scored as a caffeine-metabolism support marker. The A allele is associated with higher coffee consumption and POR-expression context, so A-containing genotypes are scored as a higher POR-supported caffeine-metabolism tendency.

Likely effectHigher biomarker tendency
Signal sizeSmall signal
Evidence supportModerate support
Report useIncluded in pathway scoring
Show study evidence
NCBI RefSNP recordidentity only · unknownNCBI RefSNP identifies rs17685 as a variation record; the scored coffee and caffeine-metabolism literature for this file uses A/G genotype labels.Coffee and Caffeine Genetics Consortium 2015, PMID 25288136gwas · close proxyA large trans-ethnic GWAS meta-analysis identified rs17685 at the POR locus as a coffee-consumption signal. The paper described rs17685 as mapping to the POR 3-prime UTR, with the A variant associated with higher coffee consumption and linked to increased POR expression.Cornelis et al. 2016, PMID 27702941biomarker association · directA GWAS of plasma caffeine metabolites discussed rs17685 in POR as a coffee-consumption locus and noted that the C/G counterpart associated with lower coffee consumption was nominally associated with higher plasma caffeine levels. This supports the A-associated higher-consumption direction as compatible with faster clearance context.Systematic review 2024, PMC11515775review · close proxyA systematic review summarized POR rs17685 as a caffeine-metabolism-related locus and stated that the A variant is associated with larger caffeine intake and higher POR expression. This supports a cautious A-allele score as a supporting caffeine-metabolism tendency.

biomarker tendency · AG

POR-supported caffeine metabolism tendency

Moderate

rs17685 AG is associated with increased POR-supported caffeine metabolism tendency.

POR rs17685 is scored as a caffeine-metabolism support marker. The A allele is associated with higher coffee consumption and POR-expression context, so A-containing genotypes are scored as a higher POR-supported caffeine-metabolism tendency.

Likely effectHigher biomarker tendency
Signal sizeSmall signal
Evidence supportModerate support
Report useIncluded in pathway scoring
Show study evidence
NCBI RefSNP recordidentity only · unknownNCBI RefSNP identifies rs17685 as a variation record; the scored coffee and caffeine-metabolism literature for this file uses A/G genotype labels.Coffee and Caffeine Genetics Consortium 2015, PMID 25288136gwas · close proxyA large trans-ethnic GWAS meta-analysis identified rs17685 at the POR locus as a coffee-consumption signal. The paper described rs17685 as mapping to the POR 3-prime UTR, with the A variant associated with higher coffee consumption and linked to increased POR expression.Cornelis et al. 2016, PMID 27702941biomarker association · directA GWAS of plasma caffeine metabolites discussed rs17685 in POR as a coffee-consumption locus and noted that the C/G counterpart associated with lower coffee consumption was nominally associated with higher plasma caffeine levels. This supports the A-associated higher-consumption direction as compatible with faster clearance context.Systematic review 2024, PMC11515775review · close proxyA systematic review summarized POR rs17685 as a caffeine-metabolism-related locus and stated that the A variant is associated with larger caffeine intake and higher POR expression. This supports a cautious A-allele score as a supporting caffeine-metabolism tendency.

biomarker tendency · GG

POR-supported caffeine metabolism tendency

Not used for pathway scoring

rs17685 GG has no scored directional claim for POR-supported caffeine metabolism tendency.

POR rs17685 is scored as a caffeine-metabolism support marker. The A allele is associated with higher coffee consumption and POR-expression context, so A-containing genotypes are scored as a higher POR-supported caffeine-metabolism tendency.

Likely effectNo clear biomarker tendency
Signal sizeMinimal signal
Evidence supportVery limited support
Report useEvidence only, not scored
Show study evidence
NCBI RefSNP recordidentity only · unknownNCBI RefSNP identifies rs17685 as a variation record; the scored coffee and caffeine-metabolism literature for this file uses A/G genotype labels.Coffee and Caffeine Genetics Consortium 2015, PMID 25288136gwas · close proxyA large trans-ethnic GWAS meta-analysis identified rs17685 at the POR locus as a coffee-consumption signal, with the A variant associated with higher coffee consumption and linked to increased POR expression. This source supports A-containing genotypes rather than GG for the directional claim.Cornelis et al. 2016, PMID 27702941biomarker association · directA GWAS of plasma caffeine metabolites discussed rs17685 in POR as a coffee-consumption locus and noted that the lower-consumption counterpart was nominally associated with higher plasma caffeine levels. This source supports A-containing genotypes rather than GG for the directional claim.

Common symptoms people report

  • caffeine lasting longer than expected
  • jitteriness or sleep disruption after normal caffeine doses
  • clearance questions that involve several genes

Biomarkers to validate

Caffeine response history

Most practical validation for this pathway.

Sleep latency

Shows whether caffeine timing affects sleep onset.

Blood pressure response

Adds context for stimulant reactivity.

Where DNA analysis helps

DNA helps decide whether caffeine clearance context deserves attention alongside CYP1A2 and ADORA2A.

Example interpretation

POR may add useful context when its SNP evidence lines up with the broader pathway signal.

Suggested validation: caffeine response history and sleep latency.

What to do next

  • Track caffeine dose and timing before changing habits.
  • Interpret POR together with CYP1A2.
  • Do not use POR alone for medication or caffeine dosing decisions.

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