rs4148323
Variant in the UGT1A1 gene (UDP Glucuronosyltransferase Family 1 Member A1)
rs4148323 is a single nucleotide polymorphism (SNP) in the UGT1A1 gene, involved in bilirubin glucuronidation / drug conjugation. 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 rs4148323 variant?
rs4148323 is a SNP (single nucleotide polymorphism) in the UGT1A1 (UDP Glucuronosyltransferase Family 1 Member A1) gene. It belongs to the Pharmacogenomics category and is part of the Detox & Medication Sensitivity biological cluster. UGT1A1 encodes UDP-glucuronosyltransferase 1A1, which conjugates bilirubin and many drugs for biliary or renal excretion.
Biological role and pathway
This variant sits within the UGT1A1 gene, which is involved in the bilirubin glucuronidation / drug conjugation pathway. Genes within the Detox & Medication Sensitivity 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.
rs4148323 and Long COVID / ME-CFS research
UGT1A1*28 (*6) reduces bilirubin and drug glucuronidation; Gilbert syndrome from UGT1A1 variants is common and may affect drug metabolism in Long COVID treatment.
This information is based on published research and does not constitute medical advice. See references below.
Parent gene: UGT1A1
rs4148323 is one of 2 known variants in the UGT1A1 gene. To understand the full biological context of this variant, explore the parent gene page.
View UGT1A1 gene page →Conditions studied in relation to rs4148323
Research into UGT1A1 variants including rs4148323 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 UGT1A1 and the rs4148323 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 UGT1A1 gene
The following variants in UGT1A1 are also studied in relation to chronic illness and may be analysed together for a more complete picture.
Frequently asked questions
What is the rs4148323 variant in the UGT1A1 gene?
rs4148323 is a single nucleotide polymorphism (SNP) located in the UGT1A1 (UDP Glucuronosyltransferase Family 1 Member A1) gene, which is involved in bilirubin glucuronidation / drug conjugation. UGT1A1 encodes UDP-glucuronosyltransferase 1A1, which conjugates bilirubin and many drugs for biliary or renal excretion.
How may the rs4148323 variant relate to Long COVID or ME/CFS?
UGT1A1*28 (*6) reduces bilirubin and drug glucuronidation; Gilbert syndrome from UGT1A1 variants is common and may affect drug metabolism in Long COVID treatment.
Can a consumer DNA test detect the rs4148323 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 rs4148323 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.
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References
The following publications were used in compiling the research context for UGT1A1 and its variants. This is not an exhaustive literature review.
- [1]PMID: 32296168
- [2]Nature Genetics
- [3]Clinical Pharmacology and Therapeutics