rs868903
Variant in the MUC5B gene (Mucin 5B)
rs868903 is a single nucleotide polymorphism (SNP) in the MUC5B gene, involved in airway mucus production. 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 rs868903 variant?
rs868903 is a SNP (single nucleotide polymorphism) in the MUC5B (Mucin 5B) gene. It belongs to the Respiratory category and is part of the Respiratory & Lung Function biological cluster. MUC5B encodes the dominant mucin in human lung mucus, critical for mucociliary clearance and respiratory tract defense.
Biological role and pathway
This variant sits within the MUC5B gene, which is involved in the airway mucus production pathway. Genes within the Respiratory & Lung Function 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.
rs868903 and Long COVID / ME-CFS research
MUC5B variants are the strongest genetic risk factor for idiopathic pulmonary fibrosis; post-COVID pulmonary fibrosis in Long COVID patients may be influenced by MUC5B genotype.
This information is based on published research and does not constitute medical advice. See references below.
Parent gene: MUC5B
rs868903 is one of 2 known variants in the MUC5B gene. To understand the full biological context of this variant, explore the parent gene page.
View MUC5B gene page →Conditions studied in relation to rs868903
Research into MUC5B variants including rs868903 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 MUC5B and the rs868903 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 MUC5B gene
The following variants in MUC5B are also studied in relation to chronic illness and may be analysed together for a more complete picture.
Frequently asked questions
What is the rs868903 variant in the MUC5B gene?
rs868903 is a single nucleotide polymorphism (SNP) located in the MUC5B (Mucin 5B) gene, which is involved in airway mucus production. MUC5B encodes the dominant mucin in human lung mucus, critical for mucociliary clearance and respiratory tract defense.
How may the rs868903 variant relate to Long COVID or ME/CFS?
MUC5B variants are the strongest genetic risk factor for idiopathic pulmonary fibrosis; post-COVID pulmonary fibrosis in Long COVID patients may be influenced by MUC5B genotype.
Can a consumer DNA test detect the rs868903 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 rs868903 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 MUC5B and its variants. This is not an exhaustive literature review.
- [1]PMID: 33141942
- [2]NEJM
- [3]Nature Genetics