CYP2D6 rs369177208: Understanding This Pharmacogenetic Variant
The rs369177208 variant is a specific genetic change located within the CYP2D6 gene, which plays a critical role in how the body processes many common medications. This variant is currently being studied for its potential impact on drug metabolism and individual responses to therapeutic treatments.
What each genotype means
Typical enzyme activity
This genotype represents the most common genetic state for this specific position in the CYP2D6 gene. Research on this specific variant is limited, and it is not currently classified as a primary driver of drug metabolism changes. You should discuss any concerns regarding medication response with your clinician or pharmacist.
This is the most frequently observed genotype across global populations.
Uncertain metabolic impact
Carrying one copy of the G allele at this position means you have a variation that is not well-characterized in clinical literature. Because evidence for this specific variant is limited, it is unclear if this change affects how your body processes medications. Please consult your healthcare provider or pharmacist before making any changes to your prescribed treatments.
This genotype is rare and observed at very low frequencies in most population databases.
Uncertain metabolic impact
This genotype indicates you carry two copies of the G allele at this position. Current scientific evidence for this variant is limited, and it is not known to significantly alter the function of the CYP2D6 enzyme. Always discuss your genetic results and medication management with your doctor or pharmacist.
This genotype is extremely rare and is not commonly found in general population studies.
What is the rs369177208 Variant?
The rs369177208 variant is a single nucleotide polymorphism (SNP) found within the CYP2D6 gene. In genetic terms, this variant represents a specific change at a precise location on the DNA sequence. This particular change results in an amino acid substitution known as p.Arg450His, where the amino acid arginine is replaced by histidine at position 450 of the protein. Because the CYP2D6 gene is highly polymorphic, meaning it contains many different variations across the human population, researchers track specific markers like rs369177208 to understand how these structural changes might alter the function of the resulting enzyme. While many variants in this gene are well-characterized, rs369177208 is categorized as having limited evidence regarding its specific clinical impact, making it a subject of ongoing investigation in the field of pharmacogenomics.
The Role of the CYP2D6 Gene
The CYP2D6 gene provides instructions for making an enzyme that is a member of the cytochrome P450 family. This enzyme is primarily expressed in the liver and is responsible for the metabolism of approximately 25% of all clinically used drugs. It acts as a biological catalyst, breaking down or activating a wide array of substances, including antidepressants, antipsychotics, opioids, and certain cancer therapies like tamoxifen. Because this enzyme is so central to drug processing, variations in the CYP2D6 gene can lead to significant differences in how individuals respond to medication. Some people may metabolize drugs very quickly, while others may process them much more slowly. Understanding these genetic differences is the foundation of pharmacogenomics, which aims to tailor medical treatments to an individual's unique genetic profile to maximize efficacy and minimize the risk of adverse drug reactions.
Research and Clinical Evidence
Current research into rs369177208 is categorized as having limited evidence strength. While the CYP2D6 gene itself is one of the most extensively studied pharmacogenes, not every individual variant within it has been fully mapped to a specific clinical outcome. Scientific studies often focus on how variants affect the enzyme's ability to process substrates, but for many rare or less-studied variants like rs369177208, the data remains preliminary. Researchers use large-scale genomic studies to look for associations between this variant and drug response, but it is important to distinguish between a statistical association and a proven clinical effect. Because the evidence is currently limited, clinicians do not typically use this specific variant to make routine prescribing decisions. Ongoing research continues to evaluate whether this variant contributes to the variability in drug metabolism observed in diverse patient populations.
Navigating Your Genetic Information
If you have received information about your rs369177208 genotype, it is essential to understand that this information should not be used to make independent medical decisions. Genetic testing results for pharmacogenomic variants are complex and must be interpreted within the context of your overall health, other medications you may be taking, and your clinical history. You cannot diagnose a condition or determine your drug response based on this single variant alone. If you are concerned about how your body processes a specific medication, the most appropriate step is to discuss your genetic report with your healthcare provider or a clinical pharmacist. They are trained to integrate genetic data with clinical guidelines to ensure that your treatment plan is safe and effective. Always consult with a professional before making any changes to your prescribed medication regimen.
How common is this variant?
There is currently no specific population frequency data recorded for the rs369177208 variant in major public databases.
Frequently asked questions
What does it mean if I have the rs369177208 variant?
Having this variant means you have a specific change in your DNA sequence within the CYP2D6 gene. Because the evidence for this variant is limited, it is not currently used to predict how you will respond to specific medications.
Should I change my medication based on this result?
No. You should never change your medication based on a genetic test result without consulting your doctor. Only a healthcare professional can determine if your genetic profile is relevant to your current treatment plan.
Is CYP2D6 testing standard for all patients?
CYP2D6 testing is not standard for everyone. It is typically ordered by clinicians when there is a specific need to understand why a patient is not responding to a medication or is experiencing unexpected side effects.
Where can I find more information about my CYP2D6 status?
You can discuss your genetic report with your primary care physician or a clinical pharmacist. They can help interpret your results in the context of your medical history and current clinical guidelines.
Sources & further reading
Educational information only, last refreshed 9/22/2026. Not medical advice — these associations describe population statistics, not individual predictions.
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Get my report — $29Related variants in CYP2D6
This missense variant (A237S) is a known marker used in the definition of specific CYP2D6 star alleles, which influence the metabolism of various drugs including antidepressants and opioids.
This stop-gain variant (R378X) results in a non-functional CYP2D6 enzyme, contributing to a poor metabolizer phenotype that necessitates dosage adjustments for affected medications.
This variant is a key marker for the CYP2D6*10 allele, which results in reduced enzymatic activity and altered metabolism of various psychiatric and analgesic medications.
This variant defines the CYP2D6*4 non-functional allele, which causes impaired metabolism of numerous clinically prescribed medications including antidepressants, tamoxifen, and codeine.
Defines the CYP2D6*17 allele (p.Thr107Ile), which exhibits reduced enzyme activity towards substrates like codeine and certain antidepressants.
Defines the CYP2D6*29 variant (p.Val338Met) conferring decreased metabolic capacity, primarily observed in populations of African descent.