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POR Genotype

Published: July 27, 2026Updated: August 25, 2026

The POR genotype measures variations in the cytochrome P450 oxidoreductase (POR) gene, which affects the activity of several drug-metabolizing enzymes.

Quick summary

POR genotype predicts individual response to drugs metabolized by POR-dependent enzymes.

Medically reviewed by WellAlly Editorial TeamLast reviewed August 25, 2026Editorial policy

Key facts at a glance

Units
genotype
Clinical utility
predictive
Result kind
qualitative
FDA-cleared
Roche POR Genotype, AutoGenomics POR
interpretation: {"text":"Individuals with the normal POR genotype are expected to have typical drug metabolism rates.","label":"Normal Activity"}; {"text":"A variant POR genotype may indicate reduced enzyme activity, necessitating dose adjustments for affected drugs.","label":"Reduced Activity"}

The POR gene encodes the cytochrome P450 oxidoreductase enzyme, which is crucial for the functioning of many drug-metabolizing enzymes in the cytochrome P450 family.

Variations in the POR genotype can lead to altered enzyme activity, impacting the metabolism of drugs such as warfarin, tamoxifen, and some steroid hormones.

Understanding an individual's POR genotype can help tailor drug dosages and improve treatment outcomes by predicting drug metabolism efficiency.

Frequently asked questions

How is the POR genotype test performed?
The test is typically done using a blood or saliva sample, which is then analyzed in a laboratory to identify specific genetic variations.
Can the POR genotype change over time?
No, the POR genotype is determined at birth and remains constant throughout a person's life.
  1. 1
    Cytochrome P450 Oxidoreductase: Structure, Function, and Role in Drug MetabolismSource
  2. 2
    Pharmacogenomics of Cytochrome P450 Oxidoreductase: Implications for Drug Metabolism and TherapySource

Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 25, 2026. · Read our editorial policy