rs2227981
Variant in the PDCD1 gene (Programmed Cell Death 1 (PD-1))
rs2227981 is a single nucleotide polymorphism (SNP) in the PDCD1 gene, involved in T cell co-inhibitory signaling. 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 rs2227981 variant?
rs2227981 is a SNP (single nucleotide polymorphism) in the PDCD1 (Programmed Cell Death 1 (PD-1)) gene. It belongs to the Immune Checkpoint category and is part of the Immune Checkpoints biological cluster. PDCD1 encodes PD-1, an inhibitory receptor on T cells that suppresses immune activation when engaged by PD-L1 or PD-L2.
Biological role and pathway
This variant sits within the PDCD1 gene, which is involved in the T cell co-inhibitory signaling pathway. Genes within the Immune Checkpoints 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.
rs2227981 and Long COVID / ME-CFS research
PD-1 upregulation on T cells reflects T cell exhaustion, a hallmark of persistent antigen stimulation associated with Long COVID immune dysfunction.
This information is based on published research and does not constitute medical advice. See references below.
Parent gene: PDCD1
rs2227981 is one of 2 known variants in the PDCD1 gene. To understand the full biological context of this variant, explore the parent gene page.
View PDCD1 gene page →Conditions studied in relation to rs2227981
Research into PDCD1 variants including rs2227981 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 PDCD1 and the rs2227981 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 PDCD1 gene
The following variants in PDCD1 are also studied in relation to chronic illness and may be analysed together for a more complete picture.
Frequently asked questions
What is the rs2227981 variant in the PDCD1 gene?
rs2227981 is a single nucleotide polymorphism (SNP) located in the PDCD1 (Programmed Cell Death 1 (PD-1)) gene, which is involved in T cell co-inhibitory signaling. PDCD1 encodes PD-1, an inhibitory receptor on T cells that suppresses immune activation when engaged by PD-L1 or PD-L2.
How may the rs2227981 variant relate to Long COVID or ME/CFS?
PD-1 upregulation on T cells reflects T cell exhaustion, a hallmark of persistent antigen stimulation associated with Long COVID immune dysfunction.
Can a consumer DNA test detect the rs2227981 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 rs2227981 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.
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References
The following publications were used in compiling the research context for PDCD1 and its variants. This is not an exhaustive literature review.
- [1]PMID: 34316049
- [2]Nature Genetics
- [3]Journal of Clinical Investigation