rs2266780
Variant in the FMO3 gene (Flavin Containing Dimethylaniline Monoxygenase 3)
rs2266780 is a single nucleotide polymorphism (SNP) in the FMO3 gene, involved in drug metabolism. 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 rs2266780 variant?
rs2266780 is a SNP (single nucleotide polymorphism) in the FMO3 (Flavin Containing Dimethylaniline Monoxygenase 3) gene. It belongs to the Metabolism category and is part of the Pharmacogenomics biological cluster. FMO3 is the major hepatic flavin monooxygenase that oxidizes nitrogen- and sulfur-containing compounds including drugs, trimethylamine (TMA), and xenobiotics. Loss-of-function causes trimethylaminuria (fish odor syndrome).
Biological role and pathway
This variant sits within the FMO3 gene, which is involved in the drug metabolism pathway. Genes within the Pharmacogenomics 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.
rs2266780 and Long COVID / ME-CFS research
FMO3 metabolizes trimethylamine produced by gut microbiota, linking gut microbiome composition to systemic metabolites. TMA/TMAO dysmetabolism may contribute to cardiovascular risk and immune dysregulation in Long COVID, with FMO3 variants affecting TMAO clearance.
This information is based on published research and does not constitute medical advice. See references below.
Parent gene: FMO3
rs2266780 is one of 3 known variants in the FMO3 gene. To understand the full biological context of this variant, explore the parent gene page.
View FMO3 gene page →Conditions studied in relation to rs2266780
Research into FMO3 variants including rs2266780 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 FMO3 and the rs2266780 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 FMO3 gene
The following variants in FMO3 are also studied in relation to chronic illness and may be analysed together for a more complete picture.
Frequently asked questions
What is the rs2266780 variant in the FMO3 gene?
rs2266780 is a single nucleotide polymorphism (SNP) located in the FMO3 (Flavin Containing Dimethylaniline Monoxygenase 3) gene, which is involved in drug metabolism. FMO3 is the major hepatic flavin monooxygenase that oxidizes nitrogen- and sulfur-containing compounds including drugs, trimethylamine (TMA), and xenobiotics. Loss-of-function causes trimethylaminuria (fish odor syndrome).
How may the rs2266780 variant relate to Long COVID or ME/CFS?
FMO3 metabolizes trimethylamine produced by gut microbiota, linking gut microbiome composition to systemic metabolites. TMA/TMAO dysmetabolism may contribute to cardiovascular risk and immune dysregulation in Long COVID, with FMO3 variants affecting TMAO clearance.
Can a consumer DNA test detect the rs2266780 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 rs2266780 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 FMO3 and its variants. This is not an exhaustive literature review.
- [1]PMID: 27251483
- [2]Cell Metabolism
- [3]Nature Medicine