SLC10A1 rs6088: Understanding the S267F Variant
The rs6088 variant, also known as p.Ser267Phe (S267F), is a genetic change in the SLC10A1 gene that alters the function of a liver protein. It is notably associated with a reduced risk of hepatitis B and D viral infection, while also being linked to elevated levels of bile acids in the blood.
What each genotype means
Typical bile acid transport
This is the common, wild-type genotype for the SLC10A1 gene. Individuals with this genotype possess fully functional sodium taurocholate cotransporting polypeptide (NTCP) transporters, which are responsible for the normal uptake of bile acids into liver cells and serve as the primary entry receptor for hepatitis B and D viruses.
This is the most common genotype globally, found in the vast majority of individuals across all ancestral populations.
Reduced bile acid transport
Carriers of this genotype possess one copy of the p.Ser267Phe variant, which may result in partially reduced NTCP transporter function. While generally asymptomatic, research suggests this genotype may offer a degree of protection against hepatitis B and D viral entry compared to those with the CC genotype.
This genotype is observed with moderate frequency in East Asian populations and is considered very rare in individuals of European ancestry.
Impaired bile acid transport
Individuals with this homozygous genotype have significantly reduced or absent NTCP transporter function, which is associated with elevated plasma bile acid levels (hypercholanemia). Research indicates this genotype confers significant protection against hepatitis B and D viral infection, though it may also be associated with altered lipid profiles or vitamin D levels that warrant clinical monitoring.
This genotype is most frequently identified in East Asian populations, where the T allele is enriched, but remains uncommon overall.
What is the rs6088 Variant?
The rs6088 variant, frequently referred to in scientific literature as p.Ser267Phe or S267F, is a missense mutation located within the SLC10A1 gene. This gene provides instructions for creating the sodium-taurocholate cotransporting polypeptide (NTCP) protein. In this specific variant, a single nucleotide change results in the substitution of the amino acid serine with phenylalanine at position 267 of the protein. This alteration occurs in the fourth exon of the gene. Because this change affects the structure of the NTCP protein, it can influence how the liver interacts with substances circulating in the blood, including bile acids and certain viruses. It is a well-studied example of how a single genetic difference can have distinct physiological impacts, particularly in specific ancestral groups.
The Role of the SLC10A1 Gene
The SLC10A1 gene encodes the NTCP protein, which is primarily expressed in the liver. NTCP acts as a critical transporter, responsible for the uptake of conjugated bile salts from the bloodstream into liver cells (hepatocytes). This process is essential for maintaining bile acid homeostasis in the body. Beyond its role in bile acid metabolism, NTCP has been identified as a high-affinity receptor that allows the hepatitis B virus (HBV) and hepatitis D virus (HDV) to enter and infect liver cells. By facilitating the entry of these viruses, the normal function of the NTCP protein inadvertently provides a gateway for infection. Consequently, variations in the SLC10A1 gene that modify the structure or function of the NTCP protein can significantly alter both the body's ability to process bile acids and its susceptibility to these specific viral infections.
Research Associations and Evidence
Research has consistently associated the S267F variant with a protective effect against chronic hepatitis B and D infection. Studies suggest that the altered NTCP protein structure hampers the ability of these viruses to bind to and enter hepatocytes, effectively reducing the risk of infection and potentially slowing disease progression in those who are already infected. However, this protection comes with a trade-off: the variant also impairs the protein's primary function of transporting bile acids. This can lead to harmlessly elevated levels of bile acids in the plasma, a condition sometimes referred to as NTCP deficiency. While the evidence for its role in viral resistance is strong within East Asian cohorts, the clinical significance of the elevated bile acid levels is generally considered benign. As with all genetic associations, these findings are based on statistical observations in populations and do not predict individual health outcomes with absolute certainty.
Population Frequency
The rs6088 variant is notably ancestry-specific, being found almost exclusively in East Asian populations. It is largely absent in African and European populations. Within East Asian groups, the allele frequency is approximately 0.08, though this can vary by specific region and sub-population. For instance, some studies in China have reported carrier frequencies as high as 1 in 5 individuals in certain provinces. Because of this distribution, the variant is a primary focus of genetic research in East Asian countries, where its impact on liver health and viral susceptibility is most relevant. It is important to note that the absence of this variant in other global populations means that its protective effects against HBV are not a universal genetic trait.
Interpreting Your Genetic Information
Understanding your genotype for rs6088 provides insight into your biological predisposition regarding bile acid transport and viral entry receptors. However, this information should be viewed as a single piece of a much larger health puzzle. Having a specific genotype does not guarantee immunity to hepatitis B, nor does it mean you will experience clinical symptoms related to bile acid levels. If you are concerned about your liver health, hepatitis risk, or blood test results, it is essential to consult with a healthcare professional. They can interpret your results in the context of your overall medical history, lifestyle, and other risk factors. Never use genetic information to make independent medical decisions or to alter any prescribed treatments without first discussing the implications with your clinician or a qualified pharmacist.
How common is this variant?
The rs6088 variant is enriched in East Asian populations with an allele frequency of approximately 0.08, while it is very rare or absent in European and African populations.
Frequently asked questions
Does the S267F variant mean I am immune to hepatitis B?
No, the S267F variant is associated with a reduced risk of infection, but it does not provide complete immunity. You should still follow standard medical advice regarding vaccination and prevention of hepatitis B.
Are elevated bile acid levels caused by this variant dangerous?
In the context of the S267F variant, elevated plasma bile acid levels are generally considered harmless. However, you should discuss any abnormal blood test results with your doctor to rule out other underlying liver conditions.
Is this variant found in all ethnic groups?
No, research indicates that this variant is specific to East Asian populations. It is rarely, if ever, found in individuals of European or African descent.
Should I get tested for this variant?
Genetic testing for this variant is not typically required for routine medical care. If you have specific concerns about liver health or hepatitis risk, speak with your healthcare provider about appropriate diagnostic testing.
Sources & further reading
Educational information only, last refreshed 10/15/2026. Not medical advice — these associations describe population statistics, not individual predictions.
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