GPR35 rs3749171: What Your Genotype Means
The rs3749171 variant is a common genetic change in the GPR35 gene that has been significantly associated with an increased susceptibility to inflammatory bowel disease, including ulcerative colitis. This variant is a missense mutation that alters the protein structure, potentially affecting how the body regulates intestinal inflammation.
What each genotype means
Typical GPR35 profile
This genotype represents the common version of the GPR35 gene, which does not include the specific threonine-to-methionine substitution associated with increased disease risk. Research indicates that individuals with this genotype do not carry the variant linked to higher susceptibility for inflammatory bowel disease or primary sclerosing cholangitis. This is considered the baseline genetic state for this position.
This is the most common genotype found across most global populations.
Increased inflammatory risk
This genotype includes one copy of the variant allele, which results in a threonine-to-methionine (T108M) amino acid change in the GPR35 protein. Studies suggest this variant may alter receptor signaling and is statistically associated with a higher risk of developing inflammatory bowel disease and primary sclerosing cholangitis. This association is based on population-level data and does not mean you will develop these conditions.
This genotype is observed at varying frequencies depending on ancestry, appearing in a significant portion of the population.
Elevated inflammatory risk
This genotype consists of two copies of the variant allele, leading to the T108M substitution in the GPR35 protein. Research has linked this variant to an increased statistical risk for inflammatory bowel disease and primary sclerosing cholangitis, potentially due to changes in how the GPR35 receptor functions. Please discuss any concerns regarding your digestive health or family history with your clinician.
This genotype is less common than the heterozygous state but is present in many populations.
What is the rs3749171 Variant?
The rs3749171 variant is a single nucleotide polymorphism (SNP) located within the GPR35 gene on chromosome 2. This genetic change involves the substitution of one DNA nucleotide for another, resulting in the replacement of the amino acid threonine with methionine at position 108 of the GPR35 protein, often denoted as T108M. Because it is a missense variant, it alters the protein's amino acid sequence, which can change its physical shape and biological function. Scientists study this location because it is a known hotspot for genetic research into chronic inflammatory conditions. By observing how this change correlates with health outcomes in large groups of people, researchers have been able to link this specific variation to the body's inflammatory pathways in the gastrointestinal tract. It serves as a marker for understanding how subtle changes in protein structure can influence complex physiological responses.
The Role of the GPR35 Gene
The GPR35 gene provides instructions for making a G protein-coupled receptor (GPCR). GPCRs act like cellular mailboxes that receive signals from outside the cell and trigger a specific response inside the cell. GPR35 is found in high concentrations in the cells lining the intestines and in certain immune cells. Research suggests that GPR35 plays a protective role in maintaining the gut barrier, which helps keep harmful bacteria and substances from causing inflammation. When this receptor is functioning properly, it helps the gut maintain homeostasis. However, studies have shown that the rs3749171 variant can lead to a hypermorphic receptor, which is essentially overactive. This heightened activity can disrupt the delicate balance of the intestinal environment, potentially triggering the inflammatory processes seen in conditions like ulcerative colitis. Understanding this mechanism is a key focus for researchers investigating the molecular basis of gut health.
Research and Evidence Strength
The association between rs3749171 and inflammatory bowel disease is well-documented in scientific literature, particularly through genome-wide association studies (GWAS). These studies compare the genomes of thousands of people with and without IBD to identify common genetic markers. The evidence strength for this association is considered limited regarding clinical predictability, meaning that having the variant does not guarantee the development of a disease. While the statistical association is strong and replicable across many populations, IBD is a complex, polygenic condition. This means it is influenced by many genes, environmental factors, and gut microbiome composition, not just a single SNP. Scientists view rs3749171 as one piece of a much larger puzzle, providing important clues about the biological mechanisms of gut inflammation rather than acting as a standalone diagnostic tool. It is essential to interpret these findings as part of a broader genetic and environmental context.
What You Can and Cannot Do
Understanding your genotype can provide insight into your genetic profile, but it is not a medical diagnosis. You cannot change your genetics, but you can focus on overall gut health through lifestyle choices. Research into GPR35 suggests it is a potential therapeutic target, but there is no specific SNP-based diet or supplement regimen validated by medical research for this variant. Genetic testing results for single SNPs like rs3749171 are not used for clinical screening or diagnosing IBD. If you have concerns about your digestive health, such as persistent abdominal pain, changes in bowel habits, or unexplained weight loss, please consult a healthcare professional. They can provide appropriate clinical evaluations that go beyond genetic markers. Remember that over 300 genetic loci have been associated with IBD risk, and this variant is only one small contributor to the total genetic architecture of the disease.
How common is this variant?
The rs3749171 variant is common across many human populations. The minor allele (the T allele) has an allele frequency of approximately 15%, though this varies depending on ancestral background.
Frequently asked questions
Does having the T allele mean I will get ulcerative colitis?
No. Having the T allele at rs3749171 is associated with a statistically higher risk, but the vast majority of people with this genotype will never develop the disease. IBD is caused by a complex interaction between genetics, diet, the environment, and the gut microbiome.
Can I change my risk based on this result?
You cannot change your genetics, but you can focus on overall gut health. Research into GPR35 suggests it is a potential therapeutic target, but there is no specific SNP-based diet or supplement regimen validated by medical research for this variant.
Should I be screened for IBD if I have the T allele?
Genetic testing results for single SNPs like rs3749171 are not used for clinical screening or diagnosing IBD. Always consult your doctor if you are experiencing symptoms like persistent abdominal pain, changes in bowel habits, or unexplained weight loss.
Is this the only gene involved in IBD?
Far from it. Over 300 genetic loci have been associated with IBD risk. This variant is only one small contributor to the total genetic architecture of the disease.
Sources & further reading
Educational information only, last refreshed 10/3/2026. Not medical advice — these associations describe population statistics, not individual predictions.
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