UGT1A1 Gene Polymorphism (TA repeat)

UDP Glucuronosyltransferase 1A1 Genotyping, Gilberts, Irinotecan, UGT1A1 Genotyping

Test Codes

EPIC: LAB1231944, Beaker: UGT1A1, Quest: 17813

Department

Send Outs

Specimen Collection Criteria

Collect (preferred specimen): One Lavender-top EDTA tube.
Also acceptable: One Pink-top EDTA tube.

Physician Office/Draw Specimen Preparation

Do not centrifuge. Maintain whole blood in original collection tubes, at room temperature. (20-26°C or 68-78.8°F)

Preparation for Courier Transport

Transport: 5.0 mL whole blood, room temperature (20-26°C or 68-78.8°F). (Minimum: 3.0 mL)

Rejection Criteria

• Gross hemolysis.
• Lipemic specimens.
• Clotted specimens.
• Specimens not collected and processed as indicated.

In-Lab Processing

Do not centrifuge. Maintain whole blood in original collection tubes, room temperature (20-26°C or 68-78.8°F).

Transport: 5.0 mL whole blood, room temperature (20-26°C or 68-78.8°F). (Minimum: 3.0 mL) 

Storage

Specimen Stability for Testing:

Room Temperature (20-26°C or 68-78.8°F): 8 days
Refrigerated (2-8°C or 36-46°F): 8 days
Frozen (-20°C/-4°F or below): Unacceptable

Specimen Storage in Department Prior to Disposal:

Specimen retention time is determined by the policy of the reference laboratory. Contact the Send Outs Laboratory with any questions.

Laboratory

Sent to Quest Diagnostics, Wood Dale, IL.

Performed

Monday, Thursday.
Results available in 6-10 days. 

Reference Range

By report.

Test Methodology

Fluorescent Polymerase Chain Reaction

Interpretation

By report.

Clinical Utility

UGT1A1 Gene Polymorphism (TA Repeat) – This test is intended to identify patients who may have Gilbert syndrome and those who are at increased risk for Irinotecan toxicity.

CPT Codes

81350

Contacts

Last Updated

11/19/2025