NOS2 rs2297518: Understanding This Genetic Variant
The rs2297518 variant is a single nucleotide polymorphism located within the NOS2 gene, which encodes the inducible nitric oxide synthase enzyme. This variant has been studied for its potential associations with systemic inflammation, nitric oxide levels, and hypertension risk.
What each genotype means
Baseline enzyme activity
This genotype represents the most common version of the NOS2 gene in many populations. Research suggests this version is associated with standard levels of nitric oxide production compared to the A allele. This is considered the baseline profile for this variant.
Carried by approximately 70% of the global population.
Increased enzyme activity
Carrying one copy of the A allele may lead to increased activity of the NOS2 enzyme and higher nitric oxide production. Some studies have linked this variant to an increased risk of inflammatory conditions, though the evidence remains limited and may vary by ancestry. Please discuss any health concerns with your clinician.
This heterozygous genotype is found in a significant portion of the population, consistent with the reported minor allele frequency of 0.15 to 0.25.
Higher enzyme activity
This genotype is associated with higher NOS2 enzyme activity and increased nitric oxide production compared to the GG genotype. Research has explored associations between this genotype and an increased incidence of inflammatory conditions, such as inflammatory bowel disease, particularly in pediatric populations. These associations are based on statistical observations and do not constitute a medical diagnosis.
This is the least common genotype, occurring less frequently than the GG or AG combinations.
What is rs2297518?
The rs2297518 variant is a specific genetic change, or single nucleotide polymorphism (SNP), found within the human NOS2 gene. Located on chromosome 17 at position 17q11.2, this SNP represents a variation in the DNA sequence where one nucleotide is substituted for another. In the context of genetic research, SNPs like rs2297518 are used by scientists to study how small differences in our genetic code might influence biological processes or susceptibility to certain health conditions. This particular variant is cataloged in major genomic databases, including dbSNP, which track its position and frequency across different human populations. Because it sits within the NOS2 gene, researchers are interested in whether this specific change alters the function or expression of the protein that the gene produces.
The Role of the NOS2 Gene
The NOS2 gene provides instructions for creating an enzyme called inducible nitric oxide synthase (iNOS). This enzyme plays a critical role in the body's immune response. Unlike other forms of nitric oxide synthase that are constantly active, iNOS is typically 'inducible,' meaning its production is triggered by specific signals, such as exposure to inflammatory cytokines or bacterial components. Once activated, the enzyme produces nitric oxide, a molecule that acts as a signaling agent and a defense mechanism against pathogens. Because of its involvement in inflammation and immune defense, the NOS2 gene is a frequent subject of study in conditions where the immune system is overactive or dysregulated. Understanding how variants like rs2297518 might influence this enzyme's activity is a key area of ongoing research into inflammatory health.
Research and Evidence
Research into rs2297518 has explored its potential links to systemic inflammation, hypertension, and variations in nitric oxide metabolite levels. However, it is important to note that the current evidence strength for these associations is considered limited. While some studies have suggested that variants in the NOS2 gene may influence how the body manages inflammation or blood pressure, these findings are often mixed or require further validation in larger, more diverse cohorts. Genetic associations are complex, and a single SNP rarely acts in isolation; rather, it often works in concert with other genetic factors and environmental influences. Consequently, while rs2297518 is a recognized marker in the scientific literature, it is not currently used as a definitive diagnostic tool for any specific medical condition.
What This Information Means for You
If you have encountered information about your rs2297518 genotype, it is essential to view it within the context of current scientific understanding. This variant is a subject of academic research rather than clinical practice. Because the evidence linking this SNP to specific health outcomes is limited and often ancestry-specific, it cannot be used to predict your personal health or diagnose a condition. You should never use genetic data to make decisions about your health, such as starting or stopping medications or changing your diet, without consulting a qualified healthcare professional. If you have concerns about inflammation, blood pressure, or other health traits, speak with your doctor or a pharmacist. They can provide guidance based on your full medical history and established clinical standards, rather than relying on individual genetic markers.
How common is this variant?
The rs2297518 variant is relatively common, with a minor allele frequency (MAF) typically ranging between 0.15 and 0.25 in European and East Asian populations.
Frequently asked questions
Is rs2297518 a cause of high blood pressure?
No, rs2297518 is not considered a direct cause of high blood pressure. While some research has explored potential associations between NOS2 variants and hypertension, the evidence is limited and does not establish a causal relationship.
Can I use this SNP to predict my inflammation risk?
No, you cannot use this SNP to predict your risk of inflammation. Genetic associations with complex traits like inflammation are influenced by many genes and environmental factors, and this variant's role is not well-defined enough for clinical prediction.
Should I change my diet based on my NOS2 genotype?
No, you should not change your diet based on your genotype for this variant. Always consult with a registered dietitian or your physician before making significant changes to your nutrition or lifestyle.
Where can I find more information about NOS2?
You can find reliable information about the NOS2 gene through resources like the NCBI Gene database or MedlinePlus Genetics. These sites provide comprehensive, peer-reviewed summaries of gene functions and their roles in human health.
Sources & further reading
Educational information only, last refreshed 9/21/2026. Not medical advice — these associations describe population statistics, not individual predictions.
Curious what your genotype is for rs2297518?
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 NOS2
This variant in the inducible nitric oxide synthase gene alters NO production and has been associated with protection against severe malaria and altered inflammatory responses.
Variant in the nitric oxide synthase 2 gene associated with altered susceptibility to age-related macular degeneration (AMD).
Functional polymorphism interacting with environmental factors such as smoking to modify the risk of age-related macular degeneration.