IL1RL1 rs7707239: Understanding Asthma-Associated Genetic Variation
The rs7707239 variant is a single nucleotide polymorphism located within the IL1RL1 gene, which encodes the ST2 receptor. Research indicates this variant is statistically associated with modifications in ST2 receptor expression and individual susceptibility to allergic sensitization and asthma.
What each genotype means
Typical ST2 expression and baseline asthma risk
You carry two copies of the common C allele at rs7707239 in the IL1RL1 locus. Research indicates that this baseline genotype is associated with normal expression of the soluble ST2 receptor and typical baseline susceptibility to allergic sensitization and asthma. These findings reflect general statistical trends observed in population studies rather than a definitive predictor of respiratory health.
Carried by approximately 40% to 45% of individuals of European ancestry and is the predominant genotype across most global populations.
Modestly altered ST2 expression and intermediate risk
You carry one copy of the T allele at rs7707239 in the IL1RL1 gene. Genetic association studies link this variant to modest alterations in soluble ST2 levels and an intermediate susceptibility to allergic conditions such as asthma. Because this variant exerts only a small regulatory effect, environmental exposures and other genetic factors play a major role in overall allergic risk.
Carried by roughly 40% to 45% of individuals of European descent, with varying frequencies across other ancestral groups.
Altered ST2 expression and modified asthma susceptibility
You carry two copies of the minor T allele at rs7707239 in the IL1RL1 gene. Studies have linked the homozygous T genotype to altered soluble ST2 expression and a statistical shift in susceptibility to allergic sensitization and asthma phenotypes. This genotype alone does not cause or diagnose respiratory disease, and its clinical relevance depends heavily on personal and environmental risk factors.
Carried by approximately 10% to 15% of people of European ancestry and is less frequent in populations where the T allele is rare.
What is the rs7707239 Variant?
The rs7707239 variant is a specific genetic change, known as a single nucleotide polymorphism (SNP), located within the IL1RL1 gene locus. In genetics, a SNP represents a variation at a single position in the DNA sequence among individuals. This particular variant is situated in a region of the genome that has been identified through genome-wide association studies (GWAS) as a hotspot for immune-related traits. While the variant itself is a simple change in the DNA code, its location within the IL1RL1 gene is significant because this gene is a critical component of the body's inflammatory response system. Scientists study such variants to understand how subtle differences in our genetic blueprint can influence the way our immune systems react to environmental triggers, such as allergens or respiratory irritants, which may contribute to the development of complex conditions like asthma.
The Role of the IL1RL1 Gene
The IL1RL1 gene provides instructions for producing the ST2 protein, which functions as a receptor for the cytokine IL-33. This signaling pathway is a central regulator of type 2 inflammation, a type of immune response often involved in allergic conditions. The ST2 receptor exists in two primary forms: a membrane-bound form (ST2L) that transmits signals to promote inflammation, and a soluble form (sST2) that acts as a decoy receptor. By binding to IL-33, the soluble form prevents it from activating the membrane-bound receptor, effectively acting as a natural "brake" on the inflammatory process. Genetic variations in this locus can influence the balance between these two forms of the receptor. When this balance is altered, it can change how an individual's immune system responds to IL-33, potentially impacting the severity or likelihood of inflammatory responses in the lungs and airways.
Research and Evidence Strength
The association between the IL1RL1 locus and asthma is well-documented in scientific literature, with multiple studies identifying this region as a key contributor to asthma susceptibility. Specifically, research has shown that variants in this gene can influence the expression levels of ST2 mRNA and protein in lung tissue and bronchial epithelial cells. However, the evidence for the specific variant rs7707239 is considered limited in terms of its individual functional impact compared to other variants in the same region. While statistical associations have been observed in various cohorts, the exact molecular mechanism by which rs7707239 modifies asthma risk remains a subject of ongoing investigation. It is important to note that asthma is a polygenic and multifactorial condition, meaning it is influenced by many different genes and environmental factors. Therefore, this variant should be viewed as one small piece of a much larger, complex biological puzzle rather than a definitive predictor of disease.
What This Information Means for You
Understanding your genetic profile regarding variants like rs7707239 is an educational exercise in genomics, but it does not provide a medical diagnosis or a prediction of future health. Because the evidence linking this specific SNP to clinical outcomes is limited and context-dependent, it cannot be used to determine your personal risk for asthma or to guide medical treatment. If you have concerns about asthma, allergies, or respiratory health, it is essential to consult with a qualified healthcare professional, such as an allergist or pulmonologist. They can evaluate your symptoms, medical history, and environmental exposures to provide appropriate care. Never make changes to your medications or health management based on genetic data without first discussing these findings with your clinician or pharmacist, as they are the only ones qualified to interpret your health status in the context of your overall medical profile.
How common is this variant?
The minor allele frequency for rs7707239 is approximately 0.35 in European populations, making it a relatively common variant.
Frequently asked questions
Does having the rs7707239 variant mean I will develop asthma?
No. Genetic variants like rs7707239 are associated with statistical trends in populations, not individual outcomes. Asthma is a complex condition influenced by many genes and environmental factors, and this variant is not a diagnostic tool.
Can I use this genetic information to choose asthma medication?
No. You should never use genetic information to guide medication choices. Always discuss your treatment plan and any concerns about your medications with your doctor or pharmacist.
Where can I find more information about the IL1RL1 gene?
You can find reliable information about the IL1RL1 gene and its functions through resources like MedlinePlus Genetics or the NCBI Gene database. These sites provide comprehensive summaries of gene functions and their roles in human health.
Is this variant found in all ethnic groups?
Genetic variants often show different frequencies across various ancestral populations. While the frequency of 0.35 is noted for European populations, frequencies can vary significantly in other global populations.
Sources & further reading
Educational information only, last refreshed 10/10/2026. Not medical advice — these associations describe population statistics, not individual predictions.
Curious what your genotype is for rs7707239?
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 IL1RL1
An intergenic regulatory variant upstream of IL1RL1 that influences circulating soluble ST2 levels and severity of allergic rhinitis.
Intronic regulatory variant in the IL1RL1/IL18R1 cluster modulating ST2 receptor expression and inflammatory disease risk.
ST2/interleukin-1 receptor-like 1 variant associated with altered IL-33 signaling and heightened risk for allergic asthma and atopy.
A regulatory variant within the IL1RL1 (ST2) gene locus associated with allergic rhinitis, eosinophil count regulation, and atopic asthma susceptibility.
Intronic regulatory SNP in IL1RL1/ST2 associated with sST2 expression levels and susceptibility to allergic sensitization and asthma.
Variant in IL1RL1 (ST2) associated with allergic inflammation and cytokine production.