PTGDR2 rs634681: Understanding Your Genetic Variant
The rs634681 variant is a single nucleotide polymorphism located within the PTGDR2 gene. It has been studied for its potential associations with allergic inflammation and Th2-mediated immune responses.
What each genotype means
Typical PTGDR2 genotype
This genotype represents the most common genetic sequence at this location in the PTGDR2 gene. Research into this variant focuses on its potential role in allergic inflammation and asthma susceptibility, though carrying the common sequence does not imply an absence of these conditions. As with all genetic traits, environmental factors and other genes play a significant role in your overall health.
This is the most frequent genotype observed across most global populations.
Variant-associated genotype
Carrying one copy of the T allele at this position has been studied in the context of allergic inflammation and immune response pathways. While some research links variations in the PTGDR2 gene to asthma susceptibility or altered inflammatory markers, these associations are complex and influenced by many other factors. This result should not be used for medical diagnosis; please consult with a healthcare provider regarding any concerns about allergic conditions.
This heterozygous genotype is found at varying frequencies depending on ancestry, appearing in a minority of individuals in most studied populations.
Variant-associated genotype
Carrying two copies of the T allele at this position is associated with the variant being studied for its role in Th2-mediated immune responses and allergic inflammation. Scientific literature suggests that genetic variability in this region may influence susceptibility to conditions like asthma, though the clinical impact for any specific individual remains uncertain. Please discuss any health symptoms or concerns with your clinician.
This homozygous genotype is relatively rare and its frequency varies significantly across different ancestral groups.
What is the rs634681 Variant?
The rs634681 variant is a specific change in the DNA sequence, known as a single nucleotide polymorphism (SNP), located within the PTGDR2 gene. This gene is situated on chromosome 11 in the human genome. SNPs like rs634681 represent common variations where a single building block of DNA—a nucleotide—differs between individuals. While many such variations have no observable effect on health, researchers study them to understand how subtle differences in our genetic code might influence biological processes. In the case of rs634681, scientists are particularly interested in its location and potential impact on the regulation of the PTGDR2 gene, which plays a significant role in the body's immune system. By mapping these variations, researchers aim to build a clearer picture of the genetic architecture underlying complex traits and immune-related conditions.
The Role of the PTGDR2 Gene
The PTGDR2 gene encodes a protein known as the Prostaglandin D2 receptor 2, often referred to as CRTH2 or CD294. This protein functions as a G-protein-coupled receptor that is primarily expressed on the surface of specific immune cells, including Th2 lymphocytes, eosinophils, and basophils. When activated by prostaglandin D2, a lipid mediator, the receptor triggers signaling pathways that promote the movement and activation of these cells. This process is a critical component of the body's inflammatory response, particularly in allergic reactions. Because these cells are central to the development of allergic inflammation, the PTGDR2 gene is a subject of intense interest in immunology. Understanding how this receptor functions helps scientists explain how the body coordinates its defense mechanisms and why these responses sometimes become overactive in conditions like asthma or other allergic diseases.
Research and Evidence
Research into rs634681 has primarily focused on its association with allergic inflammation and asthma susceptibility. Studies have suggested that variations in the PTGDR2 gene, particularly those in the 3' untranslated region (UTR), may influence how the receptor is expressed or regulated. The evidence linking this specific SNP to these traits is generally considered moderate, meaning that while statistical associations have been observed in various studies, the biological mechanism is complex and influenced by many other genetic and environmental factors. It is important to note that genetic associations are not diagnostic; having a particular genotype does not guarantee the development of any condition. Current research continues to explore how this variant interacts with other genes and environmental triggers to influence immune health. As with all genetic research, these findings represent population-level trends rather than individual medical predictions.
Population Frequency and Interpretation
The frequency of the rs634681 variant varies significantly across different ancestral populations. Genetic databases indicate that the distribution of the alleles for this SNP is not uniform globally, which is a common feature of human genetic variation. Because of this, the prevalence of specific genotypes can differ depending on an individual's genetic background. When interpreting this information, it is essential to recognize that genetic data provides only one piece of a much larger puzzle. Factors such as lifestyle, environment, and other genetic markers play substantial roles in health outcomes. Readers should view this information as educational rather than clinical. If you have concerns about your health, such as symptoms related to allergies or asthma, it is best to consult with a healthcare professional who can provide personalized medical advice based on your clinical history and physical examination.
How common is this variant?
The frequency of the rs634681 variant varies by ancestry, with different populations showing distinct patterns of allele distribution across the globe.
Frequently asked questions
Does having the rs634681 variant mean I have asthma?
No. Genetic variants like rs634681 are associated with susceptibility, not a diagnosis. Many factors, including environment and other genes, contribute to the development of asthma.
Can I use this information to change my medication?
No. You should never change your medication based on genetic information alone. Always discuss your treatment plan and any concerns with your clinician or pharmacist.
What is the function of the PTGDR2 gene?
The PTGDR2 gene encodes a receptor that helps regulate immune cells involved in allergic inflammation. It plays a role in how the body responds to certain inflammatory signals.
Where can I find more information about this SNP?
You can find more information through reputable scientific databases like the NCBI SNP database, the GWAS Catalog, or by speaking with a genetic counselor.
Sources & further reading
Educational information only, last refreshed 9/19/2026. Not medical advice — these associations describe population statistics, not individual predictions.
Curious what your genotype is for rs634681?
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 PTGDR2
Variant in the PTGDR2 (CRTH2) gene associated with allergic disease susceptibility.
Regulatory polymorphism in PTGDR2 (CRTH2) associated with allergic inflammation, eosinophilic airway activation, and asthma susceptibility.
A polymorphism in the CRTh2 gene linked to various allergic phenotypes in diverse populations.
This variant in the CRTh2 receptor gene is associated with susceptibility to allergic asthma and altered receptor expression levels.