rs733618
Variant in the CTLA4 gene (Cytotoxic T-Lymphocyte Associated Protein 4)
rs733618 is a single nucleotide polymorphism (SNP) in the CTLA4 gene, involved in T cell immune checkpoint / costimulation inhibition. 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 rs733618 variant?
rs733618 is a SNP (single nucleotide polymorphism) in the CTLA4 (Cytotoxic T-Lymphocyte Associated Protein 4) gene. It belongs to the Immune Signaling category and is part of the Immune System & Inflammation biological cluster. CTLA4 encodes a key immune checkpoint protein on T cells and Tregs that dampens T cell activation by competing with CD28 for B7 ligands.
Biological role and pathway
This variant sits within the CTLA4 gene, which is involved in the T cell immune checkpoint / costimulation inhibition pathway. Genes within the Immune System & Inflammation 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.
rs733618 and Long COVID / ME-CFS research
CTLA4-mediated T cell suppression prevents autoimmunity; variants affecting CTLA4 may impair immune tolerance and contribute to the autoimmune features documented in Long COVID.
This information is based on published research and does not constitute medical advice. See references below.
Parent gene: CTLA4
rs733618 is one of 3 known variants in the CTLA4 gene. To understand the full biological context of this variant, explore the parent gene page.
View CTLA4 gene page →Conditions studied in relation to rs733618
Research into CTLA4 variants including rs733618 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 CTLA4 and the rs733618 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 CTLA4 gene
The following variants in CTLA4 are also studied in relation to chronic illness and may be analysed together for a more complete picture.
Frequently asked questions
What is the rs733618 variant in the CTLA4 gene?
rs733618 is a single nucleotide polymorphism (SNP) located in the CTLA4 (Cytotoxic T-Lymphocyte Associated Protein 4) gene, which is involved in T cell immune checkpoint / costimulation inhibition. CTLA4 encodes a key immune checkpoint protein on T cells and Tregs that dampens T cell activation by competing with CD28 for B7 ligands.
How may the rs733618 variant relate to Long COVID or ME/CFS?
CTLA4-mediated T cell suppression prevents autoimmunity; variants affecting CTLA4 may impair immune tolerance and contribute to the autoimmune features documented in Long COVID.
Can a consumer DNA test detect the rs733618 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 rs733618 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 CTLA4 and its variants. This is not an exhaustive literature review.
- [1]PMID: 32296168
- [2]Nature Genetics
- [3]NEJM