Test Code NAT2O N-Acetyltransferase 2 Gene (NAT2), Full Gene Sequence, Saliva
Reporting Name
NAT2 Full Gene Sequence, SalivaUseful For
Identifying patients who may require isoniazid dosing adjustments
Genotyping patients who prefer not to have venipuncture done
Profile Information
Test ID | Reporting Name | Available Separately | Always Performed |
---|---|---|---|
NT2FO | NAT2, Full Gene Sequence | No | Yes |
NAT2S | NAT2, Gene Sequencing | No | Yes |
Performing Laboratory

Specimen Type
SalivaSpecimen Required
Multiple saliva genotype tests can be performed on a single specimen after a single extraction. See Multiple Saliva Genotype Tests in Special Instructions for a list of tests that can be ordered together.
Container/Tube: Oragene DNA Self-Collection Kit (T651: fees apply)
Specimen Volume: Full tube
Collection Instructions:
1. Fill tube to line.
2. Send specimen in original container per kit instructions.
Specimen Minimum Volume
1 mL
Specimen Stability Information
Specimen Type | Temperature | Time | Special Container |
---|---|---|---|
Saliva | Ambient |
Special Instructions
Reference Values
An interpretive report will be provided.
Day(s) and Time(s) Performed
Varies
Test Classification
This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the U.S. Food and Drug Administration.CPT Code Information
81479-Unlisted molecular pathology procedure
LOINC Code Information
Test ID | Test Order Name | Order LOINC Value |
---|---|---|
NAT2O | NAT2 Full Gene Sequence, Saliva | 90259-3 |
Result ID | Test Result Name | Result LOINC Value |
---|---|---|
NAT2S | NAT2, Gene Sequencing | 90259-3 |
32985 | Haplotype 1 | 84414-2 |
32986 | Haplotype 2 | 84414-2 |
32987 | Haplotype 3 | 84414-2 |
32988 | Haplotype 4 | 84414-2 |
32989 | 111T>C | 82939-0 |
32990 | 190C>T | 82939-0 |
32991 | 191G>A | 82939-0 |
32992 | 282C>T | 82939-0 |
32993 | 341T>C | 82939-0 |
32994 | 364G>A | 82939-0 |
32995 | 411T>A | 82939-0 |
32996 | 434A>C | 82939-0 |
32997 | 481C>T | 82939-0 |
32998 | 499G>A | 82939-0 |
32999 | 590G>A | 82939-0 |
33000 | 759C>T | 82939-0 |
33001 | 803A>G | 82939-0 |
33002 | 845A>C | 82939-0 |
33003 | 857G>A | 82939-0 |
33004 | 859T>C/del | 82939-0 |
33005 | Reviewed By | 18771-6 |
33006 | NAT2 Full Gene Interpretation | 69047-9 |
Clinical Information
Arylamine N-acetyltransferase type 2 (NAT2) is a highly polymorphic phase 2 metabolic enzyme that conjugates hydrazine derivatives and aromatic amine drugs with acetyl-groups. NAT2 also is involved in the acetylation and activation of some procarcinogens.(1)
Individuals acetylate drugs at different rates by NAT2, and are described as having slow, intermediate, or fast acetylator phenotypes. A gradient exists in which the prevalence of slow acetylator phenotypes increases with decreasing distance to the equator. Near the equator, up to 80% of individuals may be slow acetylators, while in some more northern countries, as few as 10% of the population may have the slow acetylator phenotype.
A number of drugs are metabolized by NAT2 including procainamide, dapsone, nitrazepam, hydralazine, zonisamide, and isoniazid. Isoniazid is used to treat and prevent tuberculosis, and is still used as a primary treatment agent. Adverse reactions with isoniazid, which include nausea, drug-induced hepatitis, peripheral neuropathy, and sideroblastic anemia, are associated more often with a slow NAT2 acetylator phenotype. These individuals may require a lower dose to avoid adverse reactions.
The NAT2 gene contains a single intronless exon of 870 base pairs and encodes 290 amino acids. NAT2 is highly polymorphic and contains 16 known single nucleotide polymorphisms and 1 single base-pair deletion. These polymorphisms are combined into 36 known haplotype alleles. Each individual haplotype is predictive of either a fast or slow acetylator phenotype. Individuals with 2 fast haplotypes are predicted to be extensive (normal) metabolizers, while those with 1 fast and 1 slow haplotype are intermediate metabolizers, and those with 2 slow haplotypes are poor metabolizers.(2,3) Studies with patients who have different acetylator haplotypes have correlated the ratio of plasma N-acetylisoniazid/isoniazid drug concentrations with haplotypes, with slow and intermediate acetylators having lower ratios than fast acetylators.(4)
NAT2 Allele |
Nucleotide Change |
Amino Acid Change |
Predicted Acetylator Phenotype |
*4 |
None |
None |
Fast |
*5A |
341T->C |
I114T |
Slow |
*5B |
341T->C |
I114T |
Slow |
*5C |
341T->C |
I114T |
Slow |
*5D |
341T->C |
I114T |
Slow |
*5E |
341T->C |
I114T |
Slow |
*5F |
341T->C |
I114T |
Slow |
*5G |
282C->T |
I114T K268R |
Slow |
*5H |
341T->C 481C->T 803A->G 859Del |
I114T S287 Frameshift |
Slow |
*5I |
341T->C 411A->T 481C->T 803A->G |
I114T |
Slow |
*5J |
282C->T |
I114T R197Q |
Slow |
*6A |
282C->T |
R197Q |
Slow |
*6B |
590G->A |
R197Q |
Slow |
*6C |
282C->T |
R197Q |
Slow |
*6D |
111T->C |
R197Q |
Slow |
*6E |
481C->T |
R197Q |
Slow |
*7A |
857G->A |
G286E |
Slow |
*7B |
282C->T |
G286E |
Slow |
*10 |
499G->A |
E167K |
Undetermined |
*11A |
481C->T |
None |
Undetermined |
*11B |
481C->T 859Del |
S287 Frameshift |
Undetermined |
*12A |
803A->G |
K268R |
Fast |
*12B |
282C->T |
K268R |
Fast |
*12C |
481C->T |
K268R |
Fast |
*12D |
364G->A |
D122N |
Undetermined |
*13 |
282C->T |
None |
Fast |
*14A |
191G->A |
R64Q |
Slow |
*14B |
191G->A |
R64Q |
Slow |
*14C |
191G->A |
R64Q |
Slow |
*14D |
191G->A |
R64Q |
Slow |
*14E |
191G->A |
R64Q |
Slow |
*14F |
191G->A |
R64Q |
Slow |
*14G |
191G->A |
R64Q |
Slow |
*17 |
434A->C |
Q145P |
Undetermined |
*18 |
845A->C |
K282T |
Undetermined |
*19 |
190C->T |
R64W |
Undetermined |
Analytic Time
7 days (not reported on Saturday or Sunday)Reject Due To
No specimen should be rejected.NY State Approved
YesMethod Name
Polymerase Chain Reaction (PCR) Followed by DNA Sequence Analysis
Forms
1. New York Clients-Informed consent is required. Document on the request form or electronic order that a copy is on file. The following documents are available in Special Instructions:
-Informed Consent for Genetic Testing (T576)
-Informed Consent for Genetic Testing-Spanish (T826)
2. If not ordering electronically, complete, print, and send a Therapeutics Test Request (T831) form with the specimen.