rs3749421
Variant in the GPT gene (Glutamic--Pyruvic Transaminase (ALT))
rs3749421 is a single nucleotide polymorphism (SNP) in the GPT gene, involved in alanine aminotransferase / liver function. 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 rs3749421 variant?
rs3749421 is a SNP (single nucleotide polymorphism) in the GPT (Glutamic--Pyruvic Transaminase (ALT)) gene. It belongs to the Metabolic category and is part of the Metabolic Regulation biological cluster. GPT encodes alanine aminotransferase (ALT), which catalyzes the reversible transfer of an amino group from alanine to alpha-ketoglutarate.
Biological role and pathway
This variant sits within the GPT gene, which is involved in the alanine aminotransferase / liver function pathway. Genes within the Metabolic Regulation 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.
rs3749421 and Long COVID / ME-CFS research
Elevated ALT/GPT is a common finding in COVID-19 liver involvement; GPT variants affecting baseline ALT levels may influence liver injury biomarker interpretation in Long COVID.
This information is based on published research and does not constitute medical advice. See references below.
Parent gene: GPT
rs3749421 is one of 2 known variants in the GPT gene. To understand the full biological context of this variant, explore the parent gene page.
View GPT gene page →Conditions studied in relation to rs3749421
Research into GPT variants including rs3749421 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 GPT and the rs3749421 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 GPT gene
The following variants in GPT are also studied in relation to chronic illness and may be analysed together for a more complete picture.
Frequently asked questions
What is the rs3749421 variant in the GPT gene?
rs3749421 is a single nucleotide polymorphism (SNP) located in the GPT (Glutamic--Pyruvic Transaminase (ALT)) gene, which is involved in alanine aminotransferase / liver function. GPT encodes alanine aminotransferase (ALT), which catalyzes the reversible transfer of an amino group from alanine to alpha-ketoglutarate.
How may the rs3749421 variant relate to Long COVID or ME/CFS?
Elevated ALT/GPT is a common finding in COVID-19 liver involvement; GPT variants affecting baseline ALT levels may influence liver injury biomarker interpretation in Long COVID.
Can a consumer DNA test detect the rs3749421 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 rs3749421 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 GPT and its variants. This is not an exhaustive literature review.
- [1]PMID: 33153018
- [2]Nature Genetics
- [3]Hepatology