SLC28A3 rs4792343: Anthracycline Cardiotoxicity Risk
The rs4792343 variant is a single-nucleotide polymorphism located in the SLC28A3 gene on chromosome 9. In pharmacogenomic research, this genetic variant has been studied for its association with a decreased likelihood of anthracycline-induced cardiotoxicity in cancer patients receiving agents such as doxorubicin. However, evidence remains limited and observational, meaning it cannot be used in isolation to guide chemotherapy treatment.
What each genotype means
Typical anthracycline response
This genotype represents the most common form of the SLC28A3 gene in many populations. Research suggests that individuals with this genotype may not have the specific genetic protection against anthracycline-induced cardiotoxicity associated with the variant allele. Please discuss your treatment plan and any concerns regarding medication side effects with your oncologist or pharmacist.
This is the most common genotype, found in the majority of individuals across most global populations.
Potential reduced cardiotoxicity risk
Carrying one copy of the variant allele has been associated in some studies with a reduced risk of developing heart-related side effects when treated with anthracycline chemotherapy. Because the evidence for this association is considered limited and may vary by ancestry, this information should be used only as a supportive tool. Always consult your healthcare provider regarding your specific treatment risks and monitoring.
This genotype is relatively common, appearing in a significant portion of the population depending on ethnic background.
Likely reduced cardiotoxicity risk
Individuals with two copies of the variant allele have been observed in some clinical studies to have a lower risk of anthracycline-induced cardiotoxicity compared to those without the variant. This association is based on limited evidence and should not be used to alter clinical care without professional guidance. Please discuss your personalized risk profile and any necessary cardiac monitoring with your medical team.
This genotype is less common than the others, with its frequency varying significantly across different global populations.
What Is rs4792343 and Where Is It Located?
The single nucleotide polymorphism rs4792343 is an intronic variant located within the SLC28A3 gene on chromosome 9. In dbSNP and genomic reference databases, the major allele is typically represented as cytosine (C), while the minor alternative allele is thymine (T). As an intronic variation, rs4792343 does not alter the primary amino acid sequence of the resulting protein directly. Instead, it is hypothesized to either act as an expression quantitative trait locus (eQTL) modifying gene regulation or serve as a linkage disequilibrium marker tagged to functional variants in nearby regulatory elements. Pharmacogenomic researchers evaluate such non-coding single-nucleotide polymorphisms because subtle alterations in transporter expression can significantly affect how specialized tissues, like cardiac muscle cells, interact with circulating antineoplastic agents.
The Biological Role of the SLC28A3 Gene
The SLC28A3 gene encodes human Concentrative Nucleoside Transporter 3 (hCNT3), a membrane transport protein belonging to the solute carrier family 28. Expressed in various tissues, CNT3 functions as a sodium- and proton-dependent concentrative transporter responsible for importing natural pyrimidine and purine nucleosides into cells. Beyond endogenous metabolic building blocks, CNT3 plays a recognized role in handling pharmacological substrates, notably nucleoside analogues utilized in oncology and antiviral therapies. While anthracyclines such as doxorubicin and daunorubicin are structurally distinct from conventional nucleosides, mechanistic and functional investigations suggest that SLC28A3-associated transport pathways influence drug uptake, cellular drug retention, or indirect cardioprotective signaling networks within the myocardium, which helps explain its emergence in drug toxicity research.
Association with Anthracycline Cardiotoxicity and Evidence Quality
Anthracycline chemotherapy medications are standard backbone treatments for solid tumors and hematologic malignancies, but their clinical utility is limited by dose-dependent cardiotoxicity, which can lead to cardiomyopathy and congestive heart failure. Candidate gene studies and pediatric oncology cohorts identified rs4792343 and adjacent SLC28A3 variants as statistically significant markers for cardioprotection, where carriers of the minor T allele exhibited lower rates of cardiac injury. Despite these promising statistical signals, the overarching clinical evidence level remains classified as limited according to pharmacogenomic curators such as PharmGKB. Effect sizes have shown inconsistency across adult cohorts versus pediatric populations, and replication studies have produced mixed findings. As a result, the variant is considered an active research target rather than an actionable clinical predictor.
Global Frequency Across Diverse Populations
The rs4792343 variant is relatively common worldwide, with the minor T allele frequency generally ranging between 0.25 and 0.45 across broad population groups. Data from large-scale population reference sets such as gnomAD show that the alternative allele occurs in substantial frequencies across European, American, and Asian ancestries, although exact proportions fluctuate. Because both the ancestral and variant alleles are widespread, heterozygous and homozygous carriers form a notable segment of the global population. This high baseline frequency makes the locus attractive for large-scale association studies, though it also implies that presence of the protective allele alone does not entirely prevent drug-related toxicity in real-world clinical settings.
Interpreting Genetic Results in a Medical Context
Learning that you carry one or two copies of the rs4792343 alternative allele does not guarantee immunity from chemotherapy side effects, nor does an ancestral genotype confirm that heart damage will occur. Clinical anthracycline-induced cardiotoxicity is a complex, multifactorial outcome governed heavily by cumulative drug dosage, patient age, preexisting cardiovascular disease, combination radiation therapy, and other physiological factors. Professional clinical guidelines, including those from the Clinical Pharmacogenetics Implementation Consortium (CPIC), do not currently endorse dose adjustments based on SLC28A3 status alone. Patients undergoing or preparing for cancer treatment should never alter treatment protocols based on consumer genetic tests and should discuss any cardiovascular risks directly with their oncologist or clinical pharmacist.
How common is this variant?
The minor allele frequency for rs4792343 ranges between approximately 0.25 and 0.45 across global populations, meaning both the ancestral and variant genotypes are commonly encountered across diverse ancestries.
Frequently asked questions
What is rs4792343?
The rs4792343 marker is a naturally occurring single-nucleotide variant found in the SLC28A3 gene. It has been examined in pharmacogenomics because certain alleles appear to track with reduced cardiac damage after chemotherapy.
Does having the protective rs4792343 genotype prevent chemotherapy heart damage?
No, carrying the protective T allele does not guarantee protection against chemotherapy-induced heart injury. Heart toxicity depends strongly on the cumulative dose of anthracycline received, patient age, preexisting health conditions, and overall medical history.
Should my oncologist change my chemotherapy dose based on rs4792343?
No, current oncology and pharmacogenomic guidelines do not recommend altering chemotherapy dosages based on rs4792343. You should discuss your cardiovascular history and treatment monitoring plans directly with your oncologist and pharmacist.
How common is the rs4792343 variant?
The variant is very common globally, with the alternative allele occurring at a frequency of approximately 25% to 45% across most major world populations.
Sources & further reading
Educational information only, last refreshed 9/8/2026. Not medical advice — these associations describe population statistics, not individual predictions.
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