rs3894220
Variant in the TBX21 gene (T-Box Transcription Factor 21)
rs3894220 is a single nucleotide polymorphism (SNP) in the TBX21 gene, involved in Th1 differentiation. Variants at this position have been studied in relation to immune function, metabolism, and chronic illness.
This page is for educational and informational purposes only. Not a diagnostic tool. Always consult a qualified healthcare provider.
What is the rs3894220 variant?
rs3894220 is a SNP (single nucleotide polymorphism) in the TBX21 (T-Box Transcription Factor 21) gene. It belongs to the Adaptive Immunity category and is part of the Adaptive Immunity biological cluster. TBX21 (T-bet) is the master transcription factor for Th1 cell differentiation, driving IFN-γ production, NK cell cytotoxicity, and antiviral immunity. It antagonizes GATA3 to suppress Th2 responses.
Biological role and pathway
This variant sits within the TBX21 gene, which is involved in the Th1 differentiation pathway. Genes within the Adaptive Immunity cluster work together to maintain balanced function across interconnected biological systems.
Variants in genes within this pathway may influence an individual's predisposition to altered function — particularly under conditions of physiological stress such as viral infection or prolonged illness.
rs3894220 and Long COVID / ME-CFS research
T-bet-driven Th1 responses are essential for effective antiviral immunity. TBX21 variants affecting IFN-γ production may influence both initial SARS-CoV-2 control and the subsequent immune resolution relevant to Long COVID development. T-bet is also expressed in innate NK cells.
This information is based on published research and does not constitute medical advice. See references below.
Parent gene: TBX21
rs3894220 is one of 3 known variants in the TBX21 gene. To understand the full biological context of this variant, explore the parent gene page.
View TBX21 gene page →Conditions studied in relation to rs3894220
Research into TBX21 variants including rs3894220 has explored associations with the following conditions. These are areas of scientific investigation and do not imply causation.
Genetic insights from DNA data
Consumer DNA files from 23andMe, AncestryDNA, and MyHeritage contain raw SNP data. When you upload your file to ChronicDNA, the analysis engine checks your genotype against a curated panel of 80+ genes selected for their relevance to Long COVID, ME/CFS, and connected biological pathways - some of which may include TBX21 and the rs3894220 variant.
The report is educational - it explains which variants you carry, what the research says about them, and how they fit into the biological pathways most relevant to chronic illness. Results are presented in plain English with appropriate scientific context, no medical jargon, no scare tactics. All results should be discussed with a qualified healthcare provider.
Other variants in the TBX21 gene
The following variants in TBX21 are also studied in relation to chronic illness and may be analysed together for a more complete picture.
Frequently asked questions
What is the rs3894220 variant in the TBX21 gene?
rs3894220 is a single nucleotide polymorphism (SNP) located in the TBX21 (T-Box Transcription Factor 21) gene, which is involved in Th1 differentiation. TBX21 (T-bet) is the master transcription factor for Th1 cell differentiation, driving IFN-γ production, NK cell cytotoxicity, and antiviral immunity. It antagonizes GATA3 to suppress Th2 responses.
How may the rs3894220 variant relate to Long COVID or ME/CFS?
T-bet-driven Th1 responses are essential for effective antiviral immunity. TBX21 variants affecting IFN-γ production may influence both initial SARS-CoV-2 control and the subsequent immune resolution relevant to Long COVID development. T-bet is also expressed in innate NK cells.
Can a consumer DNA test detect the rs3894220 variant?
Many consumer DNA tests such as 23andMe, AncestryDNA, and MyHeritage genotype common SNPs. ChronicDNA analyses your raw DNA file and reports on variants studied in relation to chronic illness, immune function, and metabolism. This is not a diagnostic service — results are informational and educational only.
Find out if you carry the rs3894220 variant
Upload your DNA data from 23andMe, AncestryDNA, or MyHeritage and receive a personalised report covering >80 genes relevant to Long COVID and ME/CFS.
Get Your Personalised DNA ReportInformational and educational only · Not a diagnostic tool · GDPR compliant
References
The following publications were used in compiling the research context for TBX21 and its variants. This is not an exhaustive literature review.
- [1]PMID: 26779607
- [2]Nature Immunology
- [3]Cell