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Test Code NAT2 N-Acetyltransferase 2 Gene (NAT2), Full Gene Sequence, Whole Blood

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Method Name

Polymerase Chain Reaction (PCR) Followed by DNA Sequence Analysis

Reporting Name

NAT2, Full Gene Sequence

Specimen Required

Multiple whole blood EDTA genotype tests can be performed on a single specimen after a single extraction. See Multiple Whole Blood EDTA Genotype Tests in Special Instructions for a list of tests that can be ordered together.


Container/Tube: Lavender top (EDTA)

Specimen Volume: 3 mL

Collection Instructions: Send specimen in original tube.

Specimen Type

Whole Blood EDTA

Specimen Minimum Volume

0.3 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Whole Blood EDTA Ambient (preferred)

Reject Due To

No specimen should be rejected.

Reference Values

An interpretive report will be provided.

Day(s) and Time(s) Performed


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
NAT2 NAT2, Full Gene Sequence 90259-3


Result ID Test Result Name Result LOINC Value
NAT2S NAT2, Gene Sequencing 90259-3
57009 NAT2 Full Gene Interpretation 69047-9
57010 Haplotype 1 84414-2
57011 Haplotype 2 84414-2
57012 Haplotype 3 84414-2
57013 Haplotype 4 84414-2
57014 111T>C 82939-0
57015 190C>T 82939-0
57016 191G>A 82939-0
57017 282C>T 82939-0
57018 341T>C 82939-0
57019 364G>A 82939-0
57020 411T>A 82939-0
57021 434A>C 82939-0
57022 481C>T 82939-0
57023 499G>A 82939-0
57024 590G>A 82939-0
57025 759C>T 82939-0
57026 803A>G 82939-0
57027 845A>C 82939-0
57028 857G>A 82939-0
57029 859T>C/del 82939-0
57031 Reviewed By 18771-6

Useful For

Identifying patients who may require isoniazid dosing adjustments

Profile Information

Test ID Reporting Name Available Separately Always Performed
NAT2F NAT2, Full Gene Sequence No Yes
NAT2S NAT2, Gene Sequencing No Yes


The wild-type (normal) genotype for NAT2 is *4. This is the most commonly occurring allele in some, but not all, ethnic groups.(5)


Individuals are classified as being slow, intermediate, or fast acetylators depending on their diplotypes. Slow acetylators have 2 slow haplotypes, fast acetylators have 2 fast haplotypes, and intermediate acetylators have 1 of each.


Slow acetylators receiving isoniazid therapy should be monitored for signs of toxicity.


Dose reductions may be considered for both slow and intermediate acetylators. However, it should be verified that the reduced isoniazid dose produces serum levels within the therapeutic range.


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 1 of the following forms with the specimen:

-Pharmacogenomics Test Request (T797)

-Therapeutics Test Request (T831)