CCR3 rs12636651: Understanding Your Genetic Variant
The rs12636651 variant is a genetic change located within the CCR3 gene, which is part of a critical cluster of chemokine receptors. This variant is studied for its potential associations with blood eosinophil levels and the risk of allergic airway inflammation.
What each genotype means
Typical eosinophil count profile
You carry two copies of the major allele at this locus in the CCR3 gene cluster. Genome-wide association studies link this genotype with baseline blood eosinophil levels and typical population-average risks for allergic inflammatory responses. It does not mean you cannot develop allergies or asthma, as these traits are influenced by many other genetic and environmental factors.
Carried by approximately 30% to 40% of individuals across global populations, being most common in European and African ancestries.
Slightly altered eosinophil count profile
You carry one copy of the G allele associated with variation in blood eosinophil counts and chemokine regulation. Large-scale population studies show that heterozygous individuals have modest statistical differences in circulating eosinophil numbers compared to non-carriers. This genotype represents a slight shift in immune cell predisposition rather than a direct cause of disease.
Carried by roughly 45% to 50% of individuals globally, representing the most common genotype in many ancestries.
Elevated eosinophil count predisposition
You carry two copies of the variant allele at rs12636651 near the CCR3 chemokine receptor locus. In published research, this genotype shows the strongest statistical association at this SNP with altered blood eosinophil counts and associated allergic airway traits. However, this is an association from population studies and does not constitute a clinical diagnosis or guarantee allergic disease.
Carried by roughly 12% to 20% of people globally, reflecting an overall minor allele frequency of about 35% to 45%.
What is rs12636651?
The rs12636651 variant is a single nucleotide polymorphism (SNP) located on chromosome 3 within the CCR3 gene. SNPs are the most common type of genetic variation among people, representing a difference in a single DNA building block, or nucleotide. This specific variant sits within a genomic region known as the chemokine receptor gene cluster. This cluster contains several genes that encode proteins responsible for directing the movement of immune cells throughout the body. Because this region is highly involved in immune system regulation, researchers frequently study variants here to understand how subtle genetic differences might influence individual immune responses. While rs12636651 is a well-documented marker in genetic databases, it is important to remember that it is just one of many variations in this complex region of the human genome.
The Role of the CCR3 Gene
The CCR3 gene provides instructions for making the C-C motif chemokine receptor 3 protein. This receptor is primarily found on the surface of specific white blood cells, including eosinophils and basophils, which are key players in the body's allergic and inflammatory responses. By binding to signaling molecules called chemokines, such as eotaxin, the CCR3 receptor acts like a homing beacon, guiding these immune cells to sites of inflammation or allergic reaction. Beyond its role in immunity, CCR3 has also been identified as a potential entry co-receptor for certain viruses, including HIV-1. Because of its central role in recruiting cells to the airways and skin, the CCR3 gene is a major focus of research into conditions like asthma and allergic rhinitis, where the over-accumulation of eosinophils can contribute to tissue damage and airway hyperresponsiveness.
Research and Associations
Scientific research has investigated the link between variants in the CCR3 gene cluster and various health traits. The rs12636651 variant has been noted in the GWAS Catalog for its association with blood eosinophil counts and risks related to allergic airway inflammation. The evidence for these associations is generally considered moderate, meaning that while statistical links have been observed in large population studies, the variant does not act as a sole cause for any specific disease. Instead, it likely contributes to a complex interplay of genetic and environmental factors that influence how an individual's immune system reacts to allergens. Some studies have also explored links between this genomic region and other traits, such as obesity-related markers in specific populations. As with many complex genetic associations, findings can vary between different ancestral groups, and further research is required to fully understand the functional impact of this specific SNP.
Understanding Your Results
If you have received information about your rs12636651 genotype, it is important to interpret it within the context of your overall health. Genetic variants are not diagnostic tools; they represent statistical probabilities rather than certainties. Having a particular genotype does not mean you will develop a specific condition, nor does it guarantee protection from one. This information is intended for educational purposes to help you understand the genetic factors that may influence your biology. You cannot use this information to diagnose yourself or to make changes to your medical treatment. If you have concerns about your respiratory health, allergies, or immune function, the best course of action is to consult with a qualified healthcare professional. They can provide personalized medical advice based on your clinical history, symptoms, and physical examinations, which are far more informative than any single genetic variant.
How common is this variant?
The rs12636651 variant is common, with a minor allele frequency typically ranging between 0.35 and 0.45 across most global populations according to gnomAD data.
Frequently asked questions
Does having the rs12636651 variant mean I have asthma?
No. This variant is associated with immune system markers like eosinophil counts, but it is not a diagnostic test for asthma. Asthma is a complex condition influenced by many genes and environmental factors.
Can I use this genetic information to change my medication?
No. You should never change or stop any medication based on genetic test results. Always discuss your medications and any health concerns with your doctor or pharmacist.
Is this variant considered a 'risk' gene?
It is categorized as a health predisposition variant, meaning it is statistically linked to certain immune traits. However, it is not a 'disease-causing' mutation in the traditional sense.
Where can I find more information about CCR3?
You can visit resources like NCBI Gene or MedlinePlus Genetics for authoritative, peer-reviewed summaries of human genes. These sites provide detailed information on gene function and related research.
Sources & further reading
Educational information only, last refreshed 10/17/2026. Not medical advice — these associations describe population statistics, not individual predictions.
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