How To Use CPT Code 0034U

CPT 0034U describes a specific genetic analysis test known as TPMT and NUDT15 Genotyping. This article will cover the official description, procedure, qualifying circumstances, appropriate usage, documentation requirements, billing guidelines, historical information, and examples of CPT code 0034U.

1. What is CPT Code 0034U?

CPT 0034U is a proprietary laboratory analysis code that represents the Thiopurine Methyltransferase (TPMT) and Nudix Hydrolase (NUDT15) Genotyping test offered by the Mayo Clinic. This test involves analyzing the genes TPMT and NUDT15 for common variants related to thiopurine metabolism. It is used to identify patients who may have a toxic response to thiopurine drugs, such as 6-mercaptopurine, 6-thioguanine, and azathioprine.

2. Official Description

The official description of CPT code 0034U is: ‘TPMT (thiopurine S-methyltransferase), NUDT15 (nudix hydroxylase 15) (eg, thiopurine metabolism) gene analysis, common variants (ie, TPMT *2, *3A, *3B, *3C, *4, *5, *6, *8, *12; NUDT15 *3, *4, *5).’ This code specifically refers to the genetic analysis of the TPMT and NUDT15 genes for common variants related to thiopurine metabolism.

3. Procedure

1. The laboratory analyst performs the TPMT and NUDT15 Genotyping test on either blood or saliva samples provided by the patient.
2. The technical steps involved in the test include extracting the nucleic acids from the samples, amplifying the target genes, and detecting the specific genetic variants using nucleic acid probes.
3. The test specifically looks for common variants in the TPMT gene, including *2, *3A, *3B, *3C, *4, *5, *6, *8, and *12, as well as in the NUDT15 gene, including *3, *4, and *5.
4. The results of the test provide information about the patient’s genetic profile related to thiopurine metabolism, which can help clinicians determine the appropriate use of thiopurine drugs and prevent potential toxic reactions.

4. Qualifying circumstances

CPT code 0034U is used for patients who require genetic analysis of the TPMT and NUDT15 genes to assess their response to thiopurine drugs. This test is particularly relevant for patients who may have a toxic reaction to thiopurine drugs, such as 6-mercaptopurine, 6-thioguanine, and azathioprine. It helps identify individuals with specific genetic variants, such as *2, *3A, *3B, *3C, *4, *5, *6, *8, *12 in the TPMT gene, and *3, *4, *5 in the NUDT15 gene, which may impact their ability to metabolize these drugs effectively.

5. When to use CPT code 0034U

CPT code 0034U should be used when a clinician orders the TPMT and NUDT15 Genotyping test to assess a patient’s genetic profile related to thiopurine metabolism. This test is specifically designed to identify common variants in the TPMT and NUDT15 genes that may impact the patient’s response to thiopurine drugs. It should not be used for any other purpose or genetic analysis.

6. Documentation requirements

To support a claim for CPT code 0034U, the following documentation is required:

• Indication for the TPMT and NUDT15 Genotyping test
• Details of the genetic variants analyzed, including TPMT *2, *3A, *3B, *3C, *4, *5, *6, *8, *12, and NUDT15 *3, *4, *5
• Date of service and the specific laboratory performing the test
• Results of the genetic analysis, including any identified variants
• Signature of the laboratory analyst performing the test

7. Billing guidelines

When billing for CPT code 0034U, ensure that the test is performed by the Mayo Clinic or the specific laboratory offering the TPMT and NUDT15 Genotyping test. Report one unit of this code for each individual specimen analyzed on a single date of service. It is important to note that this code takes precedence over other laboratory/pathology codes for this specific test. Do not report CPT code 0034U with any other codes unless specifically instructed by the payer. Additionally, check with the appropriate payer to determine if separate payment is allowed for specimen collection.

8. Historical information

CPT code 0034U was added to the Current Procedural Terminology system on January 1, 2018. There have been no updates or changes to the code since its addition.

9. Examples

1. A clinician orders the TPMT and NUDT15 Genotyping test for a patient who will be starting thiopurine drug therapy to assess their risk of toxic reactions.
2. A patient with a history of adverse reactions to thiopurine drugs undergoes the TPMT and NUDT15 Genotyping test to determine if specific genetic variants are responsible for their intolerance.
3. A clinician suspects that a patient’s lack of response to thiopurine drugs may be due to genetic factors and orders the TPMT and NUDT15 Genotyping test to investigate further.
4. A patient with a known TPMT genetic variant undergoes the TPMT and NUDT15 Genotyping test to assess their risk of adverse reactions to thiopurine drugs.
5. A clinician orders the TPMT and NUDT15 Genotyping test for a patient with inflammatory bowel disease to guide the appropriate use of thiopurine drug therapy.
6. A patient with a family history of adverse reactions to thiopurine drugs undergoes the TPMT and NUDT15 Genotyping test to assess their genetic risk.
7. A clinician orders the TPMT and NUDT15 Genotyping test for a patient who requires thiopurine drug therapy for a specific medical condition.
8. A patient with a known NUDT15 genetic variant undergoes the TPMT and NUDT15 Genotyping test to assess their risk of adverse reactions to thiopurine drugs.
9. A clinician orders the TPMT and NUDT15 Genotyping test for a patient with a history of abnormal liver function tests while on thiopurine drug therapy.
10. A patient with a known TPMT genetic variant undergoes the TPMT and NUDT15 Genotyping test to assess their risk of adverse reactions to thiopurine drugs.