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HelpTest Code NAT2Q N-Acetyltransferase 2 (NAT2) Genotype, Varies
Specimen Required
Multiple genotype tests can be performed on a single specimen after a single extraction. See Multiple Genotype Test List for a list of tests that can be ordered together.
Submit only 1 of the following specimens:
Specimen Type: Whole blood
Container/Tube: Lavender top (EDTA)
Specimen Volume: 3 mL
Collection Instructions:
1. Invert several times to mix blood.
2. Send whole blood specimen in original tube. Do not aliquot.
Specimen Stability Information: Ambient (preferred) 9 days/Refrigerated 30 days
Specimen Type: Saliva
Patient Preparation: Patient should not eat, drink, smoke, or chew gum 30 minutes prior to collection.
Supplies: Saliva Swab Collection Kit (T786)
Specimen Volume: 1 Swab
Collection Instructions: Collect and send specimen per kit instructions.
Specimen Stability Information: Ambient 30 days
Specimen Type: Extracted DNA
Container/Tube: 2 mL screw top tube
Specimen Volume: 100 mcL (microliters)
Collection Instructions:
1. The preferred volume is 100 mcL at a concentration of 50 ng/mcL.
2. Include concentration and volume on tube.
Specimen Stability Information: Frozen (preferred)/Ambient/Refrigerated
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:
-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 with the specimen:
-Neurology Specialty Testing Client Test Request (T732)
-Therapeutics Test Request (T831)
Useful For
Identifying patients who may be at risk for altered metabolism of drugs that are substrates of arylamine N-acetyltransferase type 2 (NAT2), including isoniazid
Special Instructions
Method Name
Real-Time Polymerase Chain Reaction (PCR) with Allelic Discrimination Analysis
Reporting Name
NAT2 Genotype, VSpecimen Type
VariesSpecimen Minimum Volume
Blood: 0.4 mL
Saliva: 1 swab
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Varies | Varies | ||
Reject Due To
All specimens will be evaluated at Mayo Clinic Laboratories for test suitability.Reference Values
An interpretive report will be provided.
Interpretation
An interpretive report will be provided. The wild-type (normal) genotype for NAT2 is *4. This is the most commonly occurring allele in some, but not all, ethnic groups.(8)
Individuals are classified as being slow, intermediate, or rapid (fast) acetylators depending on their diplotypes. Slow acetylators have 2 slow haplotypes, rapid acetylators have 2 rapid (fast, normal) haplotypes, and intermediate acetylators have one of each.
The genotype, with associated star alleles, is assigned using standard allelic nomenclature as described by the Human NAT2 Alleles (Haplotypes) Database (http://nat.mbg.duth.gr/Human%20NAT2%20alleles_2013.htm).
For additional information regarding pharmacogenomic genes and their associated drugs, see Pharmacogenomic Associations Tables. This resource also includes information regarding enzyme inhibitors and inducers, as well as potential alternate drug choices.
Drug-drug interactions and drug-metabolite inhibition must be considered when adjusting medication dosage. It is important to interpret the results of testing and dose adjustments in the context of hepatic and renal function and patient age. For applicable medications, therapeutic drug monitoring is useful to verify that the drug concentration is within the therapeutic range.
Day(s) Performed
Monday through Friday
Report Available
3 to 8 daysPerforming Laboratory
Mayo Clinic Laboratories in Rochester
Test Classification
This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. It has not been cleared or approved by the US Food and Drug Administration.CPT Code Information
81479-Unlisted molecular pathology procedure
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| NAT2Q | NAT2 Genotype, V | 101141-0 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| 616425 | NAT2 Genotype | 101142-8 |
| 616426 | NAT2 Phenotype | 101143-6 |
| 616427 | Interpretation | 69047-9 |
| 616428 | Additional Information | 48767-8 |
| 616430 | Method | 85069-3 |
| 616429 | Disclaimer | 62364-5 |
| 616431 | Reviewed By | 18771-6 |