CYP2D6 rs1049432: Understanding Your Pharmacogenetic Profile
The rs1049432 variant is a common genetic change located within the CYP2D6 gene, which plays a critical role in how the body metabolizes many prescription drugs. Variations in this gene can influence whether an individual processes certain medications faster or slower than average, potentially impacting drug efficacy and safety.
What each genotype means
Normal enzyme activity
This genotype is typically associated with normal CYP2D6 enzyme function, often categorized as a normal metabolizer. Because CYP2D6 processes many psychiatric and cardiovascular medications, your ability to clear these drugs is generally expected to be within the standard range. Please discuss your specific medication needs and potential dosing requirements with your clinician or pharmacist.
This is a common genotype found across most global populations, though exact frequencies vary by ancestry.
Possible altered enzyme activity
Carrying one copy of the T allele may be associated with altered CYP2D6 enzyme activity compared to the C/C genotype. The clinical significance of this specific variant can be variable, and your actual metabolic rate may be influenced by other genetic factors or concurrent use of medications that inhibit the enzyme. Consult with your healthcare provider or a pharmacist to understand how this might affect your response to specific drug therapies.
This heterozygous genotype is frequently observed in diverse populations, often appearing in a significant portion of the general public.
Potential reduced enzyme activity
This genotype is associated with the presence of the variant allele on both chromosomes, which may lead to reduced or altered CYP2D6 enzyme activity. Individuals with this profile might experience different drug clearance rates for medications metabolized by this pathway, such as certain antidepressants or beta-blockers. You should share this information with your doctor or pharmacist to ensure any prescribed treatments are appropriately managed.
This genotype is less common than the homozygous reference state but is present at varying frequencies across different ancestral groups.
What is the rs1049432 Variant?
The rs1049432 variant is a single nucleotide polymorphism (SNP) situated within the CYP2D6 gene. In genetics, a SNP represents a variation at a single position in the DNA sequence. This specific variant is categorized as a coding variant, meaning it occurs in a region of the gene that provides instructions for building a protein. Because CYP2D6 is highly polymorphic—meaning it has many different versions across the human population—researchers study specific SNPs like rs1049432 to understand how these small changes in the genetic code translate into differences in enzyme function. By identifying these variants, scientists aim to map how individual genetic differences contribute to the wide range of responses people have to the same standard doses of medication.
The Role of the CYP2D6 Gene
The CYP2D6 gene encodes the cytochrome P450 2D6 enzyme, which is primarily produced in the liver. This enzyme is a workhorse of the body's detoxification system, responsible for metabolizing approximately 20% to 25% of all commonly prescribed medications. This includes a broad spectrum of drugs used in psychiatry, such as antidepressants and antipsychotics, as well as cardiovascular medications like beta-blockers. When the CYP2D6 enzyme functions normally, it breaks down these drugs at a predictable rate, allowing them to reach the appropriate concentration in the bloodstream. However, because the gene is highly variable, some individuals produce an enzyme that is less active, inactive, or even hyperactive. These differences can lead to 'metabolizer' phenotypes, where a person might clear a drug too quickly, leading to reduced effectiveness, or too slowly, which may increase the risk of side effects.
Research and Clinical Evidence
Research into CYP2D6 is extensive, yet the evidence for any single SNP like rs1049432 is often considered limited in isolation because the gene's overall function is determined by the combination of many variants, often referred to as star alleles. While the GWAS Catalog and other databases track associations between CYP2D6 variants and drug responses, clinical guidelines from organizations like the Clinical Pharmacogenetics Implementation Consortium (CPIC) typically focus on diplotypes—the combined genetic profile from both parents—rather than single SNPs. Studies have shown that altered CYP2D6 function is linked to clinical outcomes, such as the need for dose adjustments in heart failure patients taking beta-blockers. However, because of the complexity of the gene, clinicians generally require a comprehensive genotype report to make informed decisions. The evidence suggests that while rs1049432 is a piece of the puzzle, it should be interpreted within the context of a full pharmacogenetic assessment.
Navigating Your Genetic Information
If you have received information about your rs1049432 status, it is important to understand that this data is not a medical diagnosis. Genetic variants are only one factor among many—including age, weight, liver function, and other medications—that influence how your body responds to drugs. You should never change your medication dosage or stop taking a prescribed drug based on genetic test results without consulting your healthcare provider. A doctor or pharmacist can interpret your specific genetic profile in the context of your overall health and current treatment plan. They are the only ones qualified to determine if a dosage adjustment is necessary or if an alternative medication might be more appropriate for your unique genetic makeup. Always bring your pharmacogenetic reports to your appointments to facilitate an informed discussion about your care.
How common is this variant?
The rs1049432 variant is a common pharmacogenetic marker found across diverse global populations, with minor allele frequencies frequently exceeding 0.20 in many ancestral groups.
Frequently asked questions
Does having a specific CYP2D6 genotype mean I will have side effects?
Not necessarily. While your genotype influences how your body processes drugs, it is only one of many factors that determine your risk of side effects. Other variables like your diet, other medications, and overall health also play significant roles.
Can I use this information to choose my own medication dose?
No. You should never adjust your medication dosage based on genetic test results alone. Always consult with your physician or pharmacist, as they must consider your full clinical history before making any changes to your treatment.
Is CYP2D6 testing standard for all patients?
CYP2D6 testing is not currently standard for everyone. It is typically ordered by specialists when a patient is not responding to a medication as expected or is experiencing unexpected side effects from drugs known to be metabolized by this enzyme.
What is the difference between a SNP and a star allele?
A SNP is a single change in the DNA sequence, while a star allele is a specific combination of multiple SNPs and structural changes that define the overall function of the gene. Pharmacogenetic guidelines usually rely on star allele definitions rather than single SNPs.
Sources & further reading
Educational information only, last refreshed 9/24/2026. Not medical advice — these associations describe population statistics, not individual predictions.
Curious what your genotype is for rs1049432?
Upload a raw DNA file from 23andMe, AncestryDNA, MyHeritage, or FamilyTreeDNA and see this variant — plus thousands more — interpreted in your full report.
Get my report — $29Related variants in CYP2D6
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.
Promoter variant defining the CYP2D6*41 allele, associated with reduced enzyme expression and decreased metabolic capacity for various drugs.
Defines the CYP2D6*6 deletion variant (1707delT) leading to a premature stop codon and loss of enzyme function.