NAT2 rs1799930: Understanding Your Acetylator Status
The rs1799930 variant is a specific change in the NAT2 gene that helps determine how quickly your body processes certain drugs. It is widely studied in pharmacogenomics because it serves as a signature marker for identifying individuals who may be 'slow acetylators' of medications.
What each genotype means
Rapid or intermediate acetylator
This genotype represents the ancestral state of the NAT2 gene. Individuals with this profile typically exhibit higher enzyme activity, which may lead to faster metabolism of drugs like isoniazid. Please discuss your medication dosing and potential treatment efficacy with your clinician or pharmacist.
This genotype is common globally, though its frequency varies significantly depending on ancestral background.
Intermediate acetylator status
This genotype includes one copy of the variant associated with reduced enzyme activity. You may metabolize certain medications, such as isoniazid or hydralazine, at a different rate than those with two ancestral copies. Please consult your healthcare provider or pharmacist regarding how this may influence your specific medication requirements.
This heterozygous genotype is frequently observed across many diverse populations worldwide.
Slow acetylator status
This genotype is associated with the slow acetylator phenotype, which can result in reduced metabolism of drugs like isoniazid and hydralazine. Individuals with this profile may have an increased risk of certain drug-related adverse effects, such as peripheral neuropathy or drug-induced hepatitis. Always discuss your medication management and potential side effects with your clinician or pharmacist.
The frequency of this homozygous genotype varies widely by ethnicity, being more prevalent in certain populations compared to others.
What is the rs1799930 Variant?
The rs1799930 variant, also known as c.590G>A or p.Arg197Gln, is a single nucleotide polymorphism (SNP) located within the NAT2 gene on chromosome 8. In genetic terms, this variant represents a substitution where the nucleotide guanine (G) is replaced by adenine (A). This specific change is a well-documented marker used by researchers to identify the NAT2*6 allelic group. Because the NAT2 gene is responsible for producing an enzyme that breaks down various substances, changes in its DNA sequence can alter the enzyme's efficiency. When this variant is present, it often leads to a reduction in the enzyme's ability to perform its metabolic function, which is why it is frequently categorized as a slow acetylator allele in scientific literature.
The Role of the NAT2 Gene
The NAT2 gene provides instructions for making an enzyme called N-acetyltransferase 2. This enzyme plays a critical role in the phase II metabolism of many drugs and environmental toxins. By adding an acetyl group to these compounds, the enzyme helps the body neutralize and eliminate them. Because individuals inherit two copies of the NAT2 gene—one from each parent—the combination of these copies determines an individual's overall 'acetylator phenotype.' People are generally classified as rapid, intermediate, or slow acetylators based on their genotype. Slow acetylators, who carry variants like rs1799930, process certain medications more slowly than others. This can lead to higher concentrations of the drug remaining in the bloodstream for longer periods, which may increase the risk of side effects or drug-induced liver injury.
Research and Clinical Associations
Research has consistently linked the NAT2 rs1799930 variant to the metabolism of drugs such as isoniazid, a common treatment for tuberculosis, as well as hydralazine. Studies have shown that individuals with genotypes associated with slow acetylation may experience higher serum concentrations of these drugs. While this can sometimes be beneficial for therapeutic efficacy, it also raises the risk of adverse drug reactions. The evidence for this association is strong in the context of pharmacogenomics, though the clinical impact can vary based on the specific drug and the individual's overall genetic profile. It is important to note that while this variant is a significant predictor, it is only one piece of the puzzle; other genetic and environmental factors also influence how a person responds to medication.
Population Frequency
The frequency of the rs1799930 variant varies significantly across different global populations. Data from large-scale genomic databases indicate that the A allele is present at varying frequencies in groups such as Non-Finnish Europeans, South Asians, and Middle Eastern populations. Because the distribution of NAT2 alleles is highly ancestry-specific, the prevalence of the slow acetylator phenotype differs widely between ethnic groups. For example, some populations may have a higher proportion of individuals who are slow acetylators compared to others. Understanding these population-level differences is a key focus of ongoing pharmacogenetic research, as it helps clinicians anticipate potential drug-response patterns in diverse patient groups.
What You Can Do With This Information
If you have information about your NAT2 genotype, it is essential to view it as a tool for conversation rather than a medical diagnosis. Genetic testing can provide insights into how your body might process specific medications, but it does not replace the expertise of a healthcare professional. You should never change your medication dosage or stop taking a prescribed drug based on genetic test results alone. Instead, bring your report to your doctor or pharmacist. They can interpret these results in the context of your overall health, current medications, and medical history to determine if any adjustments to your treatment plan are necessary. Always prioritize professional medical guidance when making decisions about your health.
How common is this variant?
The frequency of the rs1799930 variant is highly variable by ancestry, with the A allele appearing in approximately 29% of Non-Finnish Europeans and 36% of South Asian populations.
Frequently asked questions
What does it mean to be a slow acetylator?
A slow acetylator is someone whose body processes certain drugs more slowly than average due to variations in the NAT2 gene. This can lead to higher levels of the drug in the blood, which may increase the risk of side effects.
Does rs1799930 cause disease?
No, rs1799930 is not a disease-causing mutation. It is a genetic variation that influences how your body metabolizes specific medications, which is a field of study known as pharmacogenomics.
Should I get tested for NAT2 variants?
Genetic testing for NAT2 is generally only performed if a healthcare provider determines it is necessary to guide the dosing of specific medications. You should discuss the necessity of such testing with your doctor.
Can I change my acetylator status?
No, your genetic makeup is inherited and cannot be changed. However, knowing your status can help your doctor make more informed decisions about your medication dosages.
Sources & further reading
Educational information only, last refreshed 10/14/2026. Not medical advice — these associations describe population statistics, not individual predictions.
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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.
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.
Synonymous variant (282C>T) associated with the NAT2*6 allele, contributing to slow acetylator status.
Tag SNP defining the rapid versus slow N-acetyltransferase 2 acetylator phenotype, showing substantial allele frequency divergence across world ancestries.