N-Acetyltransferase 2 (NAT2) Genotyping

The enzyme arylamine N-acetyltransferase 2 (NAT2) metabolizes compounds that are foreign to the body (e.g, pesticides, cancer-causing chemicals) as well as therapeutic medications. Mutations in the gene encoding NAT2 cause a decrease in NAT2 activity, resulting in potential adverse effects. In some cases, a decrease in NAT2 activity may increase medication effectiveness (e.g., hydralazine). Isoniazid, hydralazine, and certain sulfonamides have the most evidence for variations in individuals drug response caused by NAT2 polymorphisms. Additionally, mutations in the NAT2 gene are tentatively associated with certain cancers and other disease states, but in most cases more evidence is needed.


Indications for Testing

Individuals who have a personal or family history of adverse effects with medications metabolized by NAT2 or who are currently undergoing or will undergo isoniazid, hydralazine, or sulfonamide (e.g., sulfamethoxazole, sulfasalazine, etc.) therapy should be considered for NAT2 testing. In general, assessment of medical necessity for testing is up to the provider’s clinical judgment.

Insurance Coverage

NAT2 testing is currently not covered by Medicare. Private insurance coverage varies by insurance company. The CPT code for NAT2 testing is 81479 (provided as guidance only).

Specimen Information

Click here to order testing supplies or call Client Services at 800-837–8362. 

  • Buccal Swabs: 4 sterile buccal swabs
  • Blood: 5-10cc whole blood lavender-top EDTA or yellow-top ACD-A tubes

Turnaround Time: 7 business days, faster turnaround available for clinical trials