FADS1 rs174548: What Your Genotype Means
The rs174548 variant is a common genetic change located within the FADS1 gene, which plays a critical role in how the body processes fats. It is statistically associated with variations in the levels of circulating polyunsaturated fatty acids, such as arachidonic acid, in the blood.
What each genotype means
Higher fatty acid conversion
This genotype is associated with higher estimated activity of the delta-5 desaturase enzyme, which helps convert dietary fatty acids into long-chain polyunsaturated fatty acids. Research suggests individuals with this profile may have different circulating levels of arachidonic acid compared to those with the T allele. This is a statistical association observed in population studies and does not constitute a medical diagnosis.
This genotype is common in many populations, though its prevalence varies significantly by ancestry, being more frequent in European populations compared to South Asian populations.
Intermediate fatty acid conversion
Carrying one copy of the T allele is associated with intermediate levels of delta-5 desaturase enzyme activity compared to the CC genotype. Studies indicate that T-allele carriers may show differences in plasma fatty acid profiles, including variations in oleic and linoleic acid levels. Please consult with a healthcare provider or registered dietitian if you have concerns regarding your nutritional status or lipid metabolism.
This heterozygous genotype is frequently observed across diverse global populations, reflecting the common nature of both the C and T alleles.
Lower fatty acid conversion
This genotype is associated with lower estimated delta-5 desaturase enzyme activity, which can influence the efficiency of converting dietary fats into long-chain polyunsaturated fatty acids. Some research links this genotype to altered plasma lipid profiles, including lower levels of certain cholesterol markers. These findings are based on population-level statistical associations; please discuss your metabolic health and dietary needs with a qualified clinician.
The T allele is highly prevalent in many regions, particularly in South Asian populations where this genotype is common, while it is less frequent in European populations.
Understanding the rs174548 Variant
The rs174548 variant is a single nucleotide polymorphism (SNP) located on chromosome 11 within the FADS1 gene cluster. In genetics, a SNP represents a variation at a single position in the DNA sequence. This specific variant is situated in an intronic region, meaning it does not code for the protein itself but is thought to influence how the FADS1 gene is regulated and expressed. Research has identified rs174548 as a functional expression quantitative trait locus (eQTL), particularly in liver tissue, suggesting it can modulate the activity levels of the FADS1 and FADS2 genes. Because it sits within a cluster of genes involved in fatty acid processing, it is frequently studied alongside neighboring variants that are in high linkage disequilibrium, meaning they are often inherited together as a block.
The Role of the FADS1 Gene
The FADS1 gene encodes the enzyme fatty acid desaturase 1, also known as delta-5 desaturase. This enzyme is a key player in the biosynthesis of highly unsaturated fatty acids (HUFA). Specifically, it catalyzes the rate-limiting step of converting dihomo-gamma-linolenic acid (DGLA) into arachidonic acid (AA), and eicosatetraenoic acid into eicosapentaenoic acid (EPA). These fatty acids are essential components of cell membranes and serve as precursors for important signaling molecules in the body. By regulating the conversion of these fats, the FADS1 enzyme helps maintain the balance of fatty acid composition in the blood and tissues. Variations in the FADS1 gene can alter the efficiency of this conversion process, potentially leading to differences in the circulating proportions of these specific fatty acids between individuals.
Research Associations and Evidence
Scientific research has consistently linked the FADS1 gene cluster, including rs174548, to variations in blood lipid profiles. Studies have observed significant associations between this variant and levels of arachidonic acid, as well as other polyunsaturated fatty acids. Furthermore, the FADS1 locus has been associated with markers of cardiovascular health, such as HDL cholesterol and triglyceride levels, in large-scale genome-wide association studies. While these statistical associations are robust, the evidence regarding the clinical impact of these variations remains limited. It is important to note that while genetics influence fatty acid metabolism, dietary intake and other environmental factors also play a major role. Current research is ongoing to determine how these genetic differences might interact with diet, such as fish oil supplementation, to influence individual health outcomes.
Population Frequency
The rs174548 variant is common across global populations, though its frequency varies significantly by ancestry. In European populations, the minor allele frequency is approximately 0.30, while in South Asian populations, it is often observed at frequencies greater than 0.50. These differences in allele distribution are thought to reflect historical evolutionary adaptations to varying dietary patterns across different regions of the world. Because the variant is so common, it is considered a normal part of human genetic diversity rather than a rare mutation. Understanding these frequency differences is essential for researchers studying how genetic background influences metabolic traits across diverse groups.
Interpreting Your Genetic Information
Information about your FADS1 genotype provides insight into your biological predisposition for fatty acid metabolism, but it should not be used for medical diagnosis or to guide personal health decisions without professional input. Genetic associations are statistical in nature and describe trends across large populations, not individual outcomes. If you are concerned about your lipid levels, cardiovascular health, or the potential impact of dietary supplements like omega-3s, it is essential to discuss these topics with a qualified clinician or a registered dietitian. They can evaluate your overall health, including blood work and lifestyle factors, to provide personalized guidance. Never make changes to your diet or medication regimen based solely on genetic test results without consulting a healthcare professional.
How common is this variant?
The rs174548 variant is a common allele globally, with a minor allele frequency of approximately 0.30 in Europeans and greater than 0.50 in South Asian populations.
Frequently asked questions
What does the FADS1 gene do?
The FADS1 gene provides instructions for making an enzyme called delta-5 desaturase. This enzyme is responsible for converting certain fatty acids into more complex forms, such as arachidonic acid, which are important for cell membrane structure and signaling.
Is rs174548 associated with a specific disease?
While the FADS1 gene has been studied in relation to cardiovascular health and lipid levels, rs174548 is a marker of metabolic variation rather than a direct cause of disease. Statistical associations exist, but they do not imply a diagnosis.
Should I take omega-3 supplements based on my FADS1 genotype?
Genetic research into FADS1 and omega-3 supplementation is ongoing and complex. You should discuss your specific health needs and any potential supplementation with your doctor or a registered dietitian.
How common is the rs174548 variant?
This variant is very common in the human population. Its frequency varies by ancestry, with the minor allele appearing in about 30% of Europeans and over 50% of South Asians.
Sources & further reading
Educational information only, last refreshed 9/23/2026. Not medical advice — these associations describe population statistics, not individual predictions.
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Key regulatory polymorphism governing the efficiency of dietary polyunsaturated fatty acid (PUFA) conversion to arachidonic and eicosapentaenoic acids.
Variant in the FADS gene cluster associated with plasma levels of long-chain polyunsaturated fatty acids.
Regulates fatty acid desaturase expression, altering conversion efficiency of dietary alpha-linolenic acid to EPA and DHA.
The ancestral C allele of this FADS1 variant influences blood fatty acid profiles, specifically reducing arachidonic acid.
Influences the efficiency of processing plant-based Omega-3 into EPA/DHA.
This variant in the FADS1 gene influences how efficiently the body converts plant-based fats into essential Omega-3 and Omega-6 fatty acids.