NAT2 rs1041983: What Your Genotype Means
The rs1041983 variant is a single nucleotide polymorphism located within the NAT2 gene. It is widely studied as a key marker for predicting how efficiently an individual's body metabolizes certain medications, including the tuberculosis drug isoniazid.
What each genotype means
Rapid acetylator associated
This genotype is a signature component of the NAT2*4 haplotype, which is associated with rapid drug acetylation. Rapid acetylators may clear certain medications, such as isoniazid, more quickly, which can impact treatment efficacy; please discuss your medication dosing with your clinician or pharmacist.
This genotype is commonly found globally as part of the NAT2 haplotype structure.
Intermediate acetylator associated
This genotype is associated with intermediate acetylation capacity, often seen in individuals who carry one rapid and one slow-acting NAT2 haplotype. Your ability to metabolize drugs like isoniazid may be moderate, so please consult your healthcare provider or pharmacist regarding appropriate dosing.
This is a very common genotype observed across diverse global populations.
Slow acetylator associated
This genotype is a signature of the NAT2*13 allelic group and is associated with a slow acetylator phenotype. Slow acetylators may be at an increased risk for side effects from certain medications, such as isoniazid-induced liver injury; always discuss your medication management with your clinician or pharmacist.
This genotype is found globally and is a significant contributor to the slow acetylator phenotype in many populations.
Understanding the NAT2 Gene and rs1041983
The NAT2 gene provides instructions for making an enzyme called N-acetyltransferase 2. This enzyme is responsible for the process of acetylation, a chemical reaction that helps the body break down and eliminate various drugs and environmental toxins. The variant rs1041983, often described as a 282C > T change, is a specific location in the DNA sequence where individuals may have different letters. Because this SNP is frequently inherited alongside other variations in the NAT2 gene, it serves as a signature marker for specific allelic groups. By identifying which version of this SNP a person carries, researchers can categorize individuals into different acetylator phenotypes, such as fast or slow metabolizers. This classification is essential for understanding why people respond differently to the same standard doses of certain medications.
Research and Clinical Associations
Scientific research has consistently associated NAT2 variants with the speed at which the body processes drugs. Individuals classified as slow acetylators, often determined by specific combinations of NAT2 SNPs including rs1041983, may process medications more slowly than others. This can lead to higher concentrations of the drug in the bloodstream, which may increase the risk of side effects or drug-induced liver injury, particularly with treatments like isoniazid. Conversely, fast acetylators may clear drugs from their system more rapidly, which can sometimes lead to lower drug efficacy if the medication is not dosed appropriately. While the evidence linking these genotypes to metabolic rates is strong, it is important to note that individual responses can be influenced by other genetic factors, diet, and environmental exposures. Always consult with your clinician or pharmacist regarding how your genetic profile might influence your specific medication dosing or treatment plan.
Population Frequency and Diversity
The frequency of the rs1041983 variant varies significantly across different global populations. Because NAT2 is a highly polymorphic gene, the distribution of its variants reflects complex patterns of human migration and adaptation. Studies have observed that certain haplotypes containing this SNP are common in some ethnic groups while being rare in others. For example, research in diverse cohorts, such as those in Peru, Kenya, and among various 1000 Genomes project populations, highlights the heterogeneity of NAT2. This diversity underscores the importance of population-specific studies when developing pharmacogenomic tools. Because of this variability, a genotype that is common in one region may not be representative of another, making it difficult to apply a single global frequency statistic to all individuals.
What This Information Means for You
Knowing your genotype for rs1041983 provides insight into your potential metabolic profile, but it is not a diagnostic tool on its own. Genetic testing for pharmacogenomics is intended to help healthcare providers make more informed decisions about medication selection and dosing. It is crucial to understand that your genotype does not dictate your health outcomes; rather, it is one piece of a larger puzzle that includes your medical history, current medications, and lifestyle. You cannot use this information to self-diagnose or adjust your own medication dosages. If you have received genetic testing results, the most appropriate step is to discuss them with a qualified healthcare professional or a genetic counselor. They can help interpret what these findings mean in the context of your overall health and ensure that any necessary adjustments to your treatment are made safely and effectively.
How common is this variant?
The rs1041983 variant is commonly found globally as part of the complex NAT2 haplotype structure, with frequencies varying significantly between different ancestral groups.
Frequently asked questions
What is a slow acetylator?
A slow acetylator is an individual whose body processes certain drugs more slowly due to variations in the NAT2 gene. This can lead to higher levels of the drug in the blood, potentially increasing the risk of side effects.
Can I use this SNP to predict my drug response?
While this SNP is a marker for metabolic phenotype, it is not a standalone predictor of drug response. Always discuss your genetic results with a doctor to understand how they apply to your specific medications.
Is rs1041983 the only SNP that determines my NAT2 status?
No, NAT2 status is determined by a combination of multiple SNPs. Researchers often look at a panel of several variants to accurately predict whether someone is a fast, intermediate, or slow acetylator.
Should I change my medication based on this result?
Never change your medication or dosage based on genetic test results without consulting your healthcare provider. Only a clinician can safely evaluate whether a change in your treatment plan is necessary.
Sources & further reading
Educational information only, last refreshed 11/5/2026. Not medical advice — these associations describe population statistics, not individual predictions.
Curious what your genotype is for rs1041983?
Upload a raw DNA file from 23andMe, AncestryDNA, MyHeritage, or FamilyTreeDNA and see this variant — plus thousands more — interpreted in your full report.
Get my report — $29Related variants in NAT2
Coding variant c.857G>A (p.Gly286Glu) defining the NAT2*14 allele (often associated with slow acetylation).
Coding variant c.481C>T (p.Leu161Leu) serving as a diagnostic marker for several NAT2 slow acetylator haplotypes, including *5.
Synonymous variant (282C>T) associated with the NAT2*6 allele, contributing to slow acetylator status.
Missense variant (590G>A) defining the NAT2*6A allele, associated with slow acetylator phenotype.
Synonymous polymorphism (857G>A) representing the defining mutation of the slow acetylator NAT2*7 allele.
This variant (c.590G>A, p.Arg197Gln) is a well-characterized slow acetylator allele in the NAT2 gene, influencing the metabolism of drugs like isoniazid.