rs901865
Variant in the HRH1 gene (Histamine Receptor H1)
rs901865 is a single nucleotide polymorphism (SNP) in the HRH1 gene, involved in histamine signaling. 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 rs901865 variant?
rs901865 is a SNP (single nucleotide polymorphism) in the HRH1 (Histamine Receptor H1) gene. It belongs to the Pharmacology category and is part of the Adaptive Immunity biological cluster. HRH1 mediates most of histamine's inflammatory and allergic actions including vasodilation, bronchoconstriction, pruritus, and CNS arousal. It is the target of first and second-generation antihistamines.
Biological role and pathway
This variant sits within the HRH1 gene, which is involved in the histamine signaling pathway. Genes within the Adaptive Immunity 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.
rs901865 and Long COVID / ME-CFS research
Antihistamines have shown benefit in some Long COVID patients, suggesting H1 receptor-mediated histamine signaling contributes to symptoms. HRH1 variants affecting receptor expression or sensitivity may modulate histamine-driven Long COVID manifestations.
This information is based on published research and does not constitute medical advice. See references below.
Parent gene: HRH1
rs901865 is one of 3 known variants in the HRH1 gene. To understand the full biological context of this variant, explore the parent gene page.
View HRH1 gene page →Conditions studied in relation to rs901865
Research into HRH1 variants including rs901865 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 HRH1 and the rs901865 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 HRH1 gene
The following variants in HRH1 are also studied in relation to chronic illness and may be analysed together for a more complete picture.
Frequently asked questions
What is the rs901865 variant in the HRH1 gene?
rs901865 is a single nucleotide polymorphism (SNP) located in the HRH1 (Histamine Receptor H1) gene, which is involved in histamine signaling. HRH1 mediates most of histamine's inflammatory and allergic actions including vasodilation, bronchoconstriction, pruritus, and CNS arousal. It is the target of first and second-generation antihistamines.
How may the rs901865 variant relate to Long COVID or ME/CFS?
Antihistamines have shown benefit in some Long COVID patients, suggesting H1 receptor-mediated histamine signaling contributes to symptoms. HRH1 variants affecting receptor expression or sensitivity may modulate histamine-driven Long COVID manifestations.
Can a consumer DNA test detect the rs901865 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 rs901865 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 HRH1 and its variants. This is not an exhaustive literature review.
- [1]PMID: 33017536
- [2]Frontiers in Pharmacology
- [3]Journal of Allergy and Clinical Immunology