IL23R rs688783: Understanding Your Genetic Variant
The rs688783 variant is a genetic change located within the IL23R gene, which provides instructions for making a receptor involved in immune system signaling. Research has investigated this variant for its potential role in modulating inflammatory responses and its association with susceptibility to Crohn's disease.
What each genotype means
Typical Crohn's Disease Risk
You carry two copies of the common G allele at rs688783. Research shows this baseline genotype does not alter standard population risk for inflammatory bowel conditions like Crohn's disease, maintaining typical IL-23 receptor signaling.
Carried by approximately 45% to 55% of individuals of European and admixed American ancestries, and more common in African populations.
Slightly Reduced Crohn's Risk
You carry one copy of the C allele associated with modestly reduced IL23R-mediated Th17 pathway inflammatory responses. Published genome-wide association studies suggest this genotype is statistically linked to a minor reduction in relative susceptibility to Crohn's disease.
Found in approximately 40% to 45% of European and admixed American populations.
Moderately Reduced Crohn's Risk
You have two copies of the C allele in the IL23R gene. In epidemiological studies, carrying this homozygous genotype is correlated with lower relative odds of developing Crohn's disease compared to non-carriers, though overall autoimmune risk depends on complex multi-gene and environmental interactions.
Carried by roughly 8% to 10% of individuals of European and admixed American ancestry.
What is the rs688783 Variant?
The rs688783 variant is a single nucleotide polymorphism (SNP) located in the intronic region of the IL23R gene. Introns are non-coding segments of DNA that sit between the exons, which are the parts of the gene that provide the blueprint for proteins. While intronic variants do not change the amino acid sequence of the resulting protein, they often function as regulatory elements. These elements can influence how much of a protein is produced, when it is produced, or in which tissues it is expressed. In the case of rs688783, researchers study it to understand if it alters the regulation of the interleukin-23 receptor, potentially impacting how the body manages inflammation.
The Role of the IL23R Gene
The IL23R gene encodes a subunit of the receptor for interleukin-23 (IL-23), a cytokine that plays a critical role in the immune system. IL-23 is essential for the activation and maintenance of Th17 cells, a subset of T-helper cells that produce pro-inflammatory signals. While this pathway is vital for defending the body against certain infections, an overactive or dysregulated IL-23 pathway is linked to chronic inflammation. Because of this, the IL23R gene has become a major focus in studies of autoimmune and inflammatory conditions, such as Crohn's disease, ulcerative colitis, and psoriasis. Variations in this gene may shift the balance of immune responses, potentially contributing to the development of these complex conditions.
Research and Evidence Strength
The association between IL23R and inflammatory bowel disease (IBD) is well-established in scientific literature, particularly through genome-wide association studies (GWAS). While specific coding variants like Arg381Gln have been heavily studied for their protective effects, non-coding variants like rs688783 are also frequently analyzed to understand the broader genetic architecture of IBD risk. The evidence for rs688783 specifically is considered limited compared to more prominent functional variants. While some studies suggest that various markers within the IL23R region contribute to disease susceptibility, the exact functional impact of this specific intronic SNP remains a subject of ongoing research. It is important to note that genetic associations are statistical in nature and do not imply a direct cause-and-effect relationship for any individual.
What You Can Do With This Information
Understanding your genetic variants can be an educational experience, but it is important to maintain realistic expectations. Genetic testing for variants like rs688783 provides information about statistical predispositions rather than a medical diagnosis. Because complex diseases like Crohn's are influenced by a combination of many genes, environmental factors, and lifestyle choices, a single SNP rarely determines health outcomes. You cannot use this information to diagnose yourself or predict the future development of a disease. If you have concerns about your digestive health or family history of inflammatory conditions, the most effective step is to consult with a healthcare professional or a genetic counselor. They can help interpret your results in the context of your overall health and provide guidance on appropriate screenings or lifestyle adjustments.
How common is this variant?
The rs688783 variant is common, with a minor allele frequency of approximately 0.30 in European and admixed American populations.
Frequently asked questions
Is rs688783 a cause of Crohn's disease?
No, rs688783 is not a direct cause of Crohn's disease. It is a genetic marker that has been statistically associated with susceptibility to the condition in some studies, but complex diseases are influenced by many genetic and environmental factors.
Can I use this result to change my diet?
Genetic results for this variant do not provide specific dietary instructions. You should discuss any significant changes to your diet or health management with a doctor or a registered dietitian.
What does 'intronic' mean for my health?
An intronic variant is located in a non-coding part of a gene. While it does not change the protein structure, it may influence how the gene is regulated, though the clinical significance of such changes is often complex and requires further research.
Should I be worried if I have the risk allele?
Genetic associations are statistical, not diagnostic. Having a specific allele does not mean you will develop a disease, and many people with the same genotype remain healthy.
Sources & further reading
Educational information only, last refreshed 10/18/2026. Not medical advice — these associations describe population statistics, not individual predictions.
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Protective missense variant (p.Arg381Gln) in IL23R associated with decreased risk of Crohn's disease, ulcerative colitis, and ankylosing spondylitis.
Missense variant (p.Arg381Gln) strongly protective against inflammatory bowel disease including Crohn's disease and ulcerative colitis.
Associated with susceptibility to inflammatory bowel disease, including Crohn disease and ulcerative colitis.