rs4253313
Variant in the KLKB1 gene (Kallikrein B1)
rs4253313 is a single nucleotide polymorphism (SNP) in the KLKB1 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 rs4253313 variant?
rs4253313 is a SNP (single nucleotide polymorphism) in the KLKB1 (Kallikrein B1) gene. It belongs to the Coagulation category and is part of the Coagulation & Vascular biological cluster. Plasma kallikrein (KLKB1) is activated by factor XIIa to generate bradykinin from high-molecular-weight kininogen (HK) and activates the intrinsic coagulation pathway. It is a key mediator of contact activation and vascular permeability.
Biological role and pathway
This variant sits within the KLKB1 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.
rs4253313 and Long COVID / ME-CFS research
The contact activation pathway (factor XII/kallikrein/bradykinin) is activated in COVID-19 contributing to edema and inflammation. KLKB1 variants affecting kallikrein activity may influence bradykinin storm severity and the vascular permeability and hypotension relevant to Long COVID POTS.
This information is based on published research and does not constitute medical advice. See references below.
Parent gene: KLKB1
rs4253313 is one of 3 known variants in the KLKB1 gene. To understand the full biological context of this variant, explore the parent gene page.
View KLKB1 gene page →Conditions studied in relation to rs4253313
Research into KLKB1 variants including rs4253313 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 KLKB1 and the rs4253313 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 KLKB1 gene
The following variants in KLKB1 are also studied in relation to chronic illness and may be analysed together for a more complete picture.
Frequently asked questions
What is the rs4253313 variant in the KLKB1 gene?
rs4253313 is a single nucleotide polymorphism (SNP) located in the KLKB1 (Kallikrein B1) gene, which is involved in contact activation. Plasma kallikrein (KLKB1) is activated by factor XIIa to generate bradykinin from high-molecular-weight kininogen (HK) and activates the intrinsic coagulation pathway. It is a key mediator of contact activation and vascular permeability.
How may the rs4253313 variant relate to Long COVID or ME/CFS?
The contact activation pathway (factor XII/kallikrein/bradykinin) is activated in COVID-19 contributing to edema and inflammation. KLKB1 variants affecting kallikrein activity may influence bradykinin storm severity and the vascular permeability and hypotension relevant to Long COVID POTS.
Can a consumer DNA test detect the rs4253313 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 rs4253313 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 KLKB1 and its variants. This is not an exhaustive literature review.
- [1]PMID: 32826326
- [2]Blood
- [3]Science