OAS1 rs10774671: What Your Genotype Means
The rs10774671 variant is a genetic change located in the OAS1 gene that influences how the body produces specific immune-related proteins. It has been studied for its potential role in modulating the body's innate antiviral response and susceptibility to severe respiratory viral infections.
What each genotype means
Enhanced antiviral enzyme activity
This genotype is associated with the production of a longer, more active form of the OAS1 enzyme. Research suggests this variant may support more effective innate immune responses to certain viral infections, including SARS-CoV-2, compared to the A allele.
The G allele is common in many populations, though its frequency varies significantly by ancestry.
Intermediate antiviral enzyme activity
Carrying one copy of each allele results in a mixed expression profile of OAS1 isoforms. You may have intermediate levels of the more active enzyme compared to individuals with the GG genotype.
This heterozygous genotype is frequently observed in diverse populations where both alleles are present.
Reduced antiviral enzyme activity
This genotype is associated with altered splicing of the OAS1 gene, leading to lower levels of the highly active enzyme isoform. Some studies suggest this may be linked to a higher risk of severe outcomes from certain respiratory viral infections, though individual health outcomes are influenced by many factors beyond this single genetic variant.
The A allele is common globally, and this genotype is found at significant frequencies across many continental ancestries.
Understanding the rs10774671 Variant
The rs10774671 variant is a single-nucleotide polymorphism (SNP) located on chromosome 12 within the OAS1 gene. Specifically, this variant is an A/G substitution situated at a splice acceptor site where the fifth intron meets the sixth exon. Because this location is critical for the proper processing of genetic instructions, the variant can influence how the cell splices the OAS1 messenger RNA. This splicing process determines which protein isoforms are created. Research indicates that the presence of different alleles at this position can lead to the production of distinct protein versions, which may have varying levels of biological activity. Because this SNP sits in a region that regulates gene expression, it is often categorized as a cis-expression quantitative trait locus (cis-eQTL), meaning it directly influences the transcript levels of the gene in which it resides.
The Role of the OAS1 Gene
The OAS1 gene encodes the 2'-5'-oligoadenylate synthetase 1 protein, which is a key component of the innate immune system. When a cell detects a viral infection, it produces type I interferons, which in turn trigger the expression of OAS1. Once activated, the OAS1 protein synthesizes molecules that activate an enzyme called RNase L. This enzyme then degrades viral and cellular RNA, effectively halting viral replication and preventing the spread of the infection to neighboring cells. The efficiency of this antiviral pathway depends heavily on the specific isoforms of OAS1 that are produced. By altering the splicing of the gene, variants like rs10774671 can shift the balance between different protein isoforms, potentially impacting the speed and effectiveness of the immune system's initial response to viral threats.
Research Associations and Evidence Strength
Scientific research has investigated the association between rs10774671 and various health conditions, most notably severe respiratory viral infections and autoimmune disorders like Sjögren's syndrome. Studies have suggested that the A allele may be associated with reduced OAS1 enzymatic activity and a diminished ability to clear certain viral infections compared to the G allele. During the COVID-19 pandemic, this variant was identified as a potential factor in the severity of the disease, with some research linking specific genotypes to altered inflammatory responses. However, the evidence strength for these associations is currently considered limited. Many studies note that the variant is in strong linkage disequilibrium with other nearby genetic markers, making it difficult to determine if rs10774671 is the direct cause of these clinical outcomes or simply a marker for other functional changes in the region. Further research is required to fully disentangle these complex genetic relationships.
Population Frequency
The rs10774671 variant is common across diverse continental ancestries, with a minor allele frequency typically ranging between 0.35 and 0.45. The distribution of the G and A alleles varies by population, and some research suggests that the G allele may be enriched in European populations, potentially originating from ancestral haplotypes. Because this variant is widespread, it is found in a significant portion of the global population, though the specific frequency of each genotype (AA, AG, or GG) can differ significantly depending on the ancestral background of the group being studied.
What This Information Means for You
It is important to understand that genetic variants like rs10774671 represent only one small piece of a much larger biological puzzle. While research has identified statistical associations between this variant and immune-related outcomes, these findings do not constitute a medical diagnosis or a prediction of how your body will respond to any specific virus. Many factors, including age, overall health, environmental exposures, and the rest of your genetic makeup, play a much larger role in determining your health outcomes. You cannot use this information to make decisions about your medical care or to predict your personal risk for specific diseases. If you have questions about your immune health or concerns about your risk for infections, the best course of action is to consult with a qualified healthcare professional who can evaluate your complete medical history and provide personalized guidance.
How common is this variant?
The rs10774671 variant is common across diverse continental ancestries, with a minor allele frequency typically ranging between 0.35 and 0.45.
Frequently asked questions
Is rs10774671 a diagnostic test for COVID-19?
No, rs10774671 is not a diagnostic test for COVID-19 or any other infection. It is a genetic variant that has been studied for its potential influence on immune response, but it cannot be used to determine if you have an infection or how you will react to one.
Does my genotype for rs10774671 mean I have a weak immune system?
No, having a specific genotype for this variant does not mean you have a weak immune system. Immune function is highly complex and influenced by thousands of genes, as well as your environment and lifestyle.
Can I change my OAS1 expression through diet or supplements?
There is no established scientific evidence that specific diets or supplements can meaningfully alter the expression of OAS1 isoforms based on your genotype. Always consult with a doctor before making significant changes to your health regimen.
Why do different studies show different results for this variant?
Genetic associations can vary between studies due to differences in population ancestry, sample sizes, and the specific diseases being investigated. Additionally, because this variant is often linked to other nearby genetic changes, it can be difficult to isolate its specific effects.
Sources & further reading
Educational information only, last refreshed 9/27/2026. Not medical advice — these associations describe population statistics, not individual predictions.
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This splice-acceptor variant regulates alternative splicing of OAS1, modulating enzymatic activity and host susceptibility to viral infections.
Splice-acceptor site polymorphism controlling expression of active OAS1 isoforms and modulating susceptibility to severe viral respiratory infections.