IL4 rs11740584: What Your Genotype Means
The rs11740584 variant is a single nucleotide polymorphism located in the region of the IL4 gene. It has been studied for its potential association with the risk of penicillin hypersensitivity and immediate allergic reactions.
What each genotype means
Typical penicillin reaction risk
You carry two copies of the common C allele for this variant in the IL4 gene region. Candidate gene research suggests this genotype is not linked to increased susceptibility to immediate penicillin hypersensitivity relative to the general population. However, genetic markers only explain a very small fraction of drug reactions, so you should always discuss any antibiotic concerns or history of allergic symptoms with your clinician or pharmacist.
Carried by approximately 60% to 75% of individuals across diverse global populations in gnomAD, representing the most common genotype.
Slightly increased allergy risk
You carry one copy of the T risk allele for rs11740584 in the IL4 gene region. Preliminary candidate gene studies have observed a modest statistical association between this allele and self-reported penicillin hypersensitivity, although overall scientific evidence remains limited. Because this marker is not diagnostic and does not guarantee an allergic reaction, always review your medication history and antibiotic choices with your clinician or pharmacist.
Carried by approximately 25% to 35% of individuals across most ancestries in gnomAD.
Elevated penicillin allergy association
You carry two copies of the T risk allele near the IL4 gene. While small candidate gene studies have associated the T allele with a higher likelihood of immediate hypersensitivity to penicillin, evidence across broader populations is limited and clinical testing guidelines do not currently use this variant. Never alter or discontinue prescribed antibiotics on your own; consult your clinician or pharmacist regarding any drug allergy testing or treatment plans.
Carried by roughly 2% to 5% of individuals across global populations in gnomAD.
Understanding the Variant
The variant rs11740584 is a single nucleotide polymorphism (SNP) located on chromosome 5. While it is often discussed in the context of the IL4 gene, it is important to note that this SNP is physically situated within the KIF3A gene region. However, because these genes are located in the same linkage disequilibrium block, they are often inherited together. In genetics, linkage disequilibrium describes a situation where specific alleles at different locations are found together more frequently than would be expected by chance. This means that while the SNP is located in the KIF3A region, its statistical associations are frequently analyzed alongside the IL4 gene, which plays a critical role in the immune system. Researchers use these markers to investigate how variations in our DNA might influence individual differences in immune responses, including how the body reacts to certain medications.
The Role of IL4 in Immunity
The IL4 gene encodes interleukin-4, a vital cytokine secreted primarily by activated T cells, mast cells, and eosinophils. This protein acts as a key regulator of the immune system, particularly in driving humoral responses and immune polarization. During an allergic response, IL-4 is essential for the production of allergen-specific immunoglobulin E (IgE), the antibody responsible for triggering immediate hypersensitivity reactions. By activating the JAK-STAT6 signaling pathway, IL-4 influences how the body differentiates between various immune threats. Because of its central role in promoting Th2-type immune responses, researchers have long hypothesized that variations in the IL4 gene or its regulatory regions could influence an individual's susceptibility to allergic conditions, including reactions to common antibiotics like penicillin.
Research and Evidence Strength
The evidence linking rs11740584 to penicillin hypersensitivity is currently considered limited. Initial research, such as a study published in the Journal of Allergy and Clinical Immunology, identified a statistical association between this SNP and self-reported penicillin allergy in a small cohort of 23 cases and 39 controls. While the study found that the presence of this variant improved the predictive power of clinical models for penicillin allergy, the sample size was quite small. Furthermore, subsequent multivariable analyses often highlight that clinical factors, such as a family history of drug reactions, remain the most significant predictors of allergy. Because the association has not been robustly replicated in large-scale, genome-wide studies, it is not currently used in clinical practice to predict drug reactions. Genetic associations in small studies can sometimes be influenced by population-specific factors or chance, necessitating caution when interpreting these findings.
Population Frequency
The minor allele frequency for rs11740584 varies across different ancestral groups, typically ranging between 0.14 and 0.22 in diverse populations according to gnomAD data. This indicates that the variant is relatively common in the general population. Because it is a common variant, its presence alone is not a definitive indicator of any specific health outcome. Genetic markers like this are often studied to understand the architecture of complex traits, but their frequency suggests that many individuals carry the variant without experiencing the specific allergic reactions being studied. Understanding these frequencies helps researchers determine whether a genetic association is consistent across different global populations or if it is unique to specific ancestral backgrounds.
What This Means for You
It is important to understand that having a specific genotype for rs11740584 does not constitute a medical diagnosis. The association between this variant and penicillin allergy is based on limited research and is not currently used as a diagnostic tool in clinical settings. If you have concerns about a potential penicillin allergy, you should never rely on genetic testing results to guide your medication choices. Instead, consult with your physician or a board-certified allergist. They can perform validated clinical tests, such as skin prick tests or graded challenges, which are the gold standard for diagnosing drug hypersensitivity. Always discuss your medical history and any concerns about medication dosing with your healthcare provider or pharmacist, as they are the only ones qualified to make decisions regarding your clinical care.
How common is this variant?
The minor allele frequency for rs11740584 is approximately 0.14 to 0.22 across diverse populations in gnomAD, making it a relatively common genetic variant.
Frequently asked questions
Can I use this genetic test to see if I am allergic to penicillin?
No. Genetic testing for rs11740584 is not a clinical diagnostic tool for penicillin allergy. If you suspect an allergy, you must consult a doctor for validated clinical testing.
Is rs11740584 located in the IL4 gene?
While often associated with the IL4 gene in research, the SNP is physically located in the KIF3A gene region. These genes are in the same linkage disequilibrium block, meaning they are often inherited together.
What should I do if I have the 'risk' genotype?
You should not change your medical behavior based on this genotype. Always discuss your medication history and any concerns about drug reactions with your healthcare provider.
Why is the evidence for this variant considered limited?
The association was identified in a small study with a limited number of participants. It has not been confirmed by large-scale, genome-wide association studies, which are required to establish strong clinical evidence.
Sources & further reading
Educational information only, last refreshed 10/13/2026. Not medical advice — these associations describe population statistics, not individual predictions.
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