rs1801020
Variant in the F12 gene (Coagulation Factor XII)
rs1801020 is a single nucleotide polymorphism (SNP) in the F12 gene, involved in contact activation. 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 rs1801020 variant?
rs1801020 is a SNP (single nucleotide polymorphism) in the F12 (Coagulation Factor XII) gene. It belongs to the Coagulation category and is part of the Coagulation & Vascular biological cluster. Factor XII (Hageman factor) initiates contact activation upon binding to negatively charged surfaces (polyphosphate, DNA, RNA, lipid membranes), activating kallikrein and the intrinsic coagulation cascade. It is not required for normal hemostasis but drives immunothrombosis.
Biological role and pathway
This variant sits within the F12 gene, which is involved in the contact activation pathway. Genes within the Coagulation & Vascular 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.
rs1801020 and Long COVID / ME-CFS research
FXII is activated by SARS-CoV-2 RNA and NET components, driving kallikrein-kinin and intrinsic coagulation activation in COVID-19. F12 variants (especially the common Thr328Lys) affect FXII levels and contact activation susceptibility relevant to Long COVID coagulopathy.
This information is based on published research and does not constitute medical advice. See references below.
Parent gene: F12
rs1801020 is one of 3 known variants in the F12 gene. To understand the full biological context of this variant, explore the parent gene page.
View F12 gene page →Conditions studied in relation to rs1801020
Research into F12 variants including rs1801020 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 F12 and the rs1801020 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 F12 gene
The following variants in F12 are also studied in relation to chronic illness and may be analysed together for a more complete picture.
Frequently asked questions
What is the rs1801020 variant in the F12 gene?
rs1801020 is a single nucleotide polymorphism (SNP) located in the F12 (Coagulation Factor XII) gene, which is involved in contact activation. Factor XII (Hageman factor) initiates contact activation upon binding to negatively charged surfaces (polyphosphate, DNA, RNA, lipid membranes), activating kallikrein and the intrinsic coagulation cascade. It is not required for normal hemostasis but drives immunothrombosis.
How may the rs1801020 variant relate to Long COVID or ME/CFS?
FXII is activated by SARS-CoV-2 RNA and NET components, driving kallikrein-kinin and intrinsic coagulation activation in COVID-19. F12 variants (especially the common Thr328Lys) affect FXII levels and contact activation susceptibility relevant to Long COVID coagulopathy.
Can a consumer DNA test detect the rs1801020 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 rs1801020 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 F12 and its variants. This is not an exhaustive literature review.
- [1]PMID: 33508100
- [2]Blood
- [3]Science