Sign in →

Test Code TPNUV Thiopurine Methyltransferase (TPMT) and Nudix Hydrolase (NUDT15) Genotyping, Varies

Reporting Name

TPMT and NUDT15 Genotype

Useful For

Predicting potential for toxicity to thiopurine drugs (6-mercaptopurine, 6-thioguanine, and azathioprine)

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Specimen Type

Varies


Advisory Information


For thiopurine methyltransferase (TPMT) enzyme activity testing, order TPMT3 / Thiopurine Methyltransferase (TPMT) Activity Profile, Erythrocytes.



Specimen Required


Multiple genotype tests can be performed on a single specimen after a single extraction. See Multiple Genotype Test List in Special Instructions 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 specimen in original tube.

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: One swab

Collection Instructions: Collect and send specimen per kit instructions.

Specimen Stability Information: Ambient 30 days

 

Specimen Type: DNA

Container/Tube: 2 mL screw top tube

Specimen Volume: 100 mcL

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


Specimen Minimum Volume

Blood: 0.4 mL
Saliva: 1 swab

Specimen Stability Information

Specimen Type Temperature Time Special Container
Varies Varies

Reference Values

An interpretive report will be provided.

Day(s) and Time(s) Performed

Monday through Friday; 8 a.m.

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

0034U

LOINC Code Information

Test ID Test Order Name Order LOINC Value
TPNUV TPMT and NUDT15 Genotype 93193-1

 

Result ID Test Result Name Result LOINC Value
BA0211 TPMT Genotype 41048-0
BA0212 TPMT Phenotype 79713-4
BA0213 NUDT15 Genotype 93194-9
BA0214 NUDT15 Phenotype 93195-6
BA0215 Interpretation 69047-9
BA0216 Additional Information 48767-8
BA0217 Method 49549-9
BA0218 Disclaimer 62364-5
BA0219 Reviewed by 18771-6

Clinical Reference

1. TPMT nomenclature committee. Available at www.imh.liu.se/tpmtalleles

2. Moriyama T, Nishii R, Perez-Andreu V, et al: NUDT15 polymorphisms alter thiopurine metabolism and hematopoietic toxicity. Nat Genet 2016;48:367-373

3. Appell ML, Berg J, Duley J, et al: Nomenclature for alleles of the thiopurine methyltransferase gene. Pharmacogenet Genomics 2013;23(4):242-248

4. Nguyen CM, Mendes MA, Ma JD: Thiopurine methyltransferase (TPMT) genotyping to predict myelosuppression risk. PLoS Curr 2011;3:RRN1236

5. Relling MV, Gardner EE, Sandborn WJ, et al: Clinical Pharmacogenetics Implementation Consortium guidelines for thiopurine methyltransferase genotype and thiopurine dosing. Clin Pharmacol Ther 2011;89(3):387-391

6. Weinshilboum R: Thiopurine pharmacogenetics clinical and molecular studies of thiopurine methyltransferase. Drug Metab Dispos 2001 Apr;29(4 Pt 2):601-605

7. Zaza G, Cheok M, Krynetskaia N, et al: Thiopurine pathway. Pharmacogenet Genomics 2010 Sep;20(9):573-574

Method Description

Genomic DNA is extracted from whole blood. Genotyping for the TPMT and NUDT15 alleles is performed using a PCR-based 5'-nuclease assay. Fluorescently labeled detection probes anneal to the target DNA. PCR is used to amplify the segment of DNA that contains the polymorphism. If the detection probe is an exact match to the target DNA, the 5'-nuclease polymerase degrades the probe, the reporter dye is released from the effects of the quencher dye, and a fluorescent signal is detected. Genotypes are assigned based on the allele-specific fluorescent signals that are detected.(Instruction manual: TaqMan SNP Genotyping Assay, Applied Biosystems Revision A.0 January 2014)

Analytic Time

1 day (not reported on Saturday or Sunday)

Reject Due To

All specimens will be evaluated at Mayo Clinic Laboratories for test suitability.

Method Name

Real-Time Polymerase Chain Reaction (PCR) With Allelic Discrimination 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 1 of the following forms with the specimen:

-Neurology Specialty Testing Client Test Request (T732)

-Gastroenterology and Hepatology Client Test Request (T728)

-Therapeutics Test Request (T831)

Secondary ID

65160