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Test ID U1A1O UDP-Glucuronosyl Transferase 1A1 TA Repeat Genotype, UGT1A1, Saliva

Useful For

Identifying individuals who are at increased risk of adverse drug reactions with drugs that are metabolized by UGT1A1; especially irinotecan, but also including nilotinib, pazopanib, and belinostat

 

Identifying individuals with Gilbert syndrome due to the presence of homozygous TA7, homozygous TA8, or compound heterozygous TA7/TA8

 

Identifying individuals who are carriers of Gilbert syndrome due to the presence of heterozygous TA7 or TA8

 

Genotyping patients who prefer not to have venipuncture done

Genetics Test Information

This genetic test interrogates the thymine-adenine (TA) repeat in the TATA-box of the promoter region of UGT1A1. Repeat number may vary from 5 to 8 TA repeats, with 6 TA repeats representing the most common (normal) number of repeats. Individuals with more than 6 TA repeats may have an increased risk for adverse drug reactions to drugs metabolized by UGT1A1, especially irinotecan, nilotinib, pazopanib, and belinostat. Homozygosity for TA7, TA8, or compound heterozygosity for TA7/TA8 is also consistent with a diagnosis of Gilbert syndrome. Heterozygosity for TA7 or TA8 is consistent with carrier status for Gilbert syndrome.

Method Name

Polymerase Chain Reaction (PCR) with Fragment Analysis by Capillary Gel Electrophoresis

Reporting Name

UGT1A1 TA Repeat Genotype, Saliva

Specimen Type

Saliva

Specimen Required

Multiple saliva genotype tests can be performed on a single specimen after a single extraction. See Multiple Saliva Genotype Tests in Special Instructions for a list of tests that can be ordered together.

 

Supplies: DNA Saliva Collection Kit (T651)

Container/Tube: Oragene DNA Self-Collection Kit (T651: fees apply)

Specimen Volume: Full tube

Collection Instructions:

1. Fill tube to line.

2. Send specimen in original container per kit instructions.


Advisory Information:

This test does not detect or report variants other than the *28 (TA7), *36 (TA5), and *37 (TA8) alleles. Numerous variants outside of the TA repeat region have been described that impair UGT1A1 activity. Sequencing of the full gene is also available for detection of variants outside of the TA repeat region. Order UGT1 / UDP-Glucuronosyl Transferase 1A1 (UGT1A1), Full Gene Sequencing, Irinotecan Hypersensitivity when evaluating risk for irinotecan toxicity. Order UGT2 / UDP-Glucuronosyl Transferase 1A1 (UGT1A1), Full Gene Sequencing, Hyperbilirubinemia, if evaluation for Gilbert syndrome or Crigler-Najjar syndrome type I or type II is desired.


Specimen Minimum Volume

1 mL

Specimen Stability Information

Specimen Type Temperature Time
Saliva Ambient

Reference Values

An interpretive report will be provided.

Day(s) and Time(s) Performed

Monday, Wednesday, Friday; Varies

Performing Laboratory

Mayo Medical Laboratories in Rochester

CPT Code Information

81350-UGT1A1 (UDP glucuronosyltransferase 1 family, polypeptide AI) (eg, irinotecan metabolism), gene analysis, common variants (eg, *28, *36, *37)

LOINC Code Information

Test ID Test Order Name Order LOINC Value
U1A1O UGT1A1 TA Repeat Genotype, Saliva In Process

 

Result ID Test Result Name Result LOINC Value
32979 TA/TA In Process
32980 Reviewed by No LOINC Needed
32981 UGT1A1 TA Repeat Genotype In Process

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.

Testing Algorithm

See UGT1A1 Test-Ordering Algorithm in Special Instructions.

Forms

New York Clients-Informed consent is required. Please document on the request form or electronic order that a copy is on file. An Informed Consent for Genetic Testing (T576) is available in Special Instructions.