IL33 rs3939286: Understanding Genetic Associations with Nasal Polyposis
The rs3939286 variant is a single nucleotide polymorphism located near the IL33 gene. Research has associated this variant with an increased risk of developing nasal polyposis, particularly in individuals with eosinophilia.
What each genotype means
Baseline risk profile
This genotype represents the non-risk version of this variant. Research indicates that individuals with this genotype do not carry the specific genetic association with nasal polyposis linked to the A-allele of this variant.
This is the most common genotype, found in the majority of the global population.
Slightly increased risk
Carrying one copy of the A-allele is associated with a statistically higher risk of developing nasal polyposis compared to those without the allele. This association is particularly noted in individuals who also exhibit eosinophilia, though this genetic factor is only one of many potential contributors to the condition.
This heterozygous genotype is found in a significant portion of the population, consistent with the reported global minor allele frequency of approximately 24%.
Increased risk profile
Carrying two copies of the A-allele is associated with an increased susceptibility to nasal polyposis. Studies suggest that each A-allele contributes to this risk, particularly in patients with eosinophilia, but this does not mean the condition is inevitable; please discuss any concerns about nasal health with your clinician.
This homozygous genotype is the least common of the three, occurring in a smaller subset of the population compared to the G/G and A/G genotypes.
What is rs3939286?
The variant rs3939286 is a single nucleotide polymorphism (SNP) located on chromosome 9. In genetics, a SNP represents a variation at a single position in the DNA sequence among individuals. This specific variant is situated in a non-coding region near the IL33 gene. Because it is located in a regulatory area, researchers study it to understand how it might influence the expression of nearby genes. Genetic variants like rs3939286 are often identified through genome-wide association studies (GWAS), which compare the DNA of people with a specific condition to those without it to find statistical patterns. It is important to note that being a carrier of a specific allele does not mean an individual will develop a condition; rather, it indicates a statistical association observed in large population studies.
The Role of the IL33 Gene
The IL33 gene provides instructions for making a protein called interleukin-33. This protein is a member of the cytokine family, which are signaling molecules that play a critical role in the immune system. Interleukin-33 acts as an 'alarmin,' a molecule released by cells in response to damage or stress to alert the immune system to potential threats. It is particularly involved in type 2 inflammatory pathways, which are associated with allergic responses and the recruitment of eosinophils—a type of white blood cell. Because of its role in inflammation, variations in or near the IL33 gene are frequently studied in the context of respiratory and allergic conditions, such as asthma and chronic rhinosinusitis with nasal polyposis.
Research and Associations
Scientific research has identified rs3939286 as a susceptibility factor for nasal polyposis. Studies have observed that the A-allele of this variant is associated with an increased risk of the condition, especially in patients who also exhibit eosinophilia. While the association is statistically significant, the evidence is considered moderate, as genetic risk is often complex and influenced by multiple factors, including other genes and environmental exposures. Some research suggests that this variant may be in linkage disequilibrium with other causal variants in the region, meaning it is often inherited alongside other genetic changes that might directly influence IL33 expression. Ongoing studies continue to refine our understanding of how these specific genomic regions contribute to the development of inflammatory airway diseases.
Interpreting Your Genetic Information
Understanding your genetic profile can be an educational experience, but it is important to maintain a balanced perspective. Genetic associations identified in research studies describe trends across large populations, not individual medical outcomes. If you have concerns about nasal polyposis, asthma, or other inflammatory conditions, the most important step is to consult with a healthcare professional, such as an otolaryngologist or an allergist. They can provide a clinical evaluation based on your symptoms, medical history, and physical examination. Genetic information should never be used to self-diagnose or make medical decisions. Always discuss any health-related questions with a qualified clinician who can provide personalized guidance based on your specific health needs.
How common is this variant?
The frequency of the A-allele is variable across different ancestral populations. According to public databases, the Global Minor Allele Frequency (GMAF) is approximately 0.24.
Frequently asked questions
Does having the A-allele mean I will get nasal polyps?
No. A genetic association indicates a statistical trend in a population, not a certainty for an individual. Many people with the A-allele do not develop nasal polyps, and many people without it do.
Is rs3939286 a diagnostic test?
No. This variant is a research finding used to study disease mechanisms. It is not a clinical diagnostic tool for identifying or predicting nasal polyposis.
Can I change my genetic risk?
You cannot change your DNA sequence. However, you can manage your health by working with a doctor to address environmental triggers and symptoms related to inflammation.
Where can I learn more about my specific results?
If you have received genetic testing results, consult with a certified genetic counselor. They can help you interpret your data in the context of your personal and family health history.
Sources & further reading
Educational information only, last refreshed 10/12/2026. Not medical advice — these associations describe population statistics, not individual predictions.
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An intronic regulatory polymorphism in IL33 that influences expression levels and predisposes carriers to allergic rhinitis and atopic sensitization.
Interleukin-33 promoter variant modulating cytokine expression and predisposition to environmental allergies.
A regulatory SNP near the IL33 locus linked to enhanced IL-33 alarmin expression and risk of allergic rhinitis, peanut allergy, and atopic dermatitis.
The G allele of this IL33 variant is associated with a reduced risk of asthma and allergic sensitization in mixed-ancestry populations.
Upstream noncoding regulatory variant altering IL-33 alarmin expression in epithelial barriers, impacting early-onset atopic phenotypes.