Genotype test to assess risk, due to genetics, for severe myelosuppression with standard dosing of thiopurine drugs. Use for individuals being considered for thiopurine therapy or who have had an adverse reaction to thiopurine therapy. Preferred test for patients with recent heterologous blood transfusion. Can be performed irrespective of thiopurine therapy.

Only the targeted TPMT and NUDT15 variants will be detected by this test. Because the complex TPMT*3A allele contains the variants found in the *3B and *3C alleles, this test cannot distinguish the 3A/Negative genotype (intermediate enzyme activity) from the rare *3B/*3C genotype (no or low enzyme activity). Genotyping may reflect donor status in patients who have received allogenic stem cell or bone marrow transplants within 2 weeks of specimen collection. Actual enzyme activity and expression and risk for adverse reactions to thiopurines may be affected by additional genetic and non-genetic factors not evaluated by this test. Diagnostic errors can occur due to rare sequence variations. Genotyping does not replace the need for therapeutic drug monitoring and clinical observation.

Lavender (EDTA), 4mL

Immediately following collection, mix by inverting 8 - 10 times to prevent clotting

Lavender (EDTA), 4mL

Yellow ACD (A or B)

Yellow ACD (A or B)

Molecular Medicare Billing Request

Hospital clients submitting a request for this assay on an outpatient with Medicare should complete and submit a Molecular Medicare billing request form to notify us of the need for Allina Health Laboratory to bill insurance.

Ambient (preferred) - 28 days

Refrigerated - 28 days

Frozen - 2 years

• Hemolyzed specimens
• Quantity not sufficient
• Improper specimen type
• Frozen specimens in glass collection tubes

Polymerase Chain Reaction (RT-PCR)

See report

The exact effect of a particular genotype on individual drugs can vary. In addition to genotype, the metabolism of drugs may be influenced by additional factors that include environmental, dietary and other medications; these factors and others should be considered prior to initiating a new therapy. All results must be interpreted in the context of other test results and clinical findings. Results do not rule out the possibility of other variant alleles in TPMT and NUDT15 or other variant alleles in other drug metabolism pathways. Patients should speak with their health care provider about the individual results of this test.

Medical necessity

Hospital clients submitting a request for this assay on an outpatient with Medicare should complete and submit a Molecular Medicare billing request form to notify us of the need for Allina Health Laboratory to bill insurance.

Molecular Medicare Billing Request