UDP Glucuronosyltransferase 1A1 (UGT1A1) Genotyping
Also known as: UGT1A1
Use
The UGT1A1 genotyping test is useful for dosage planning in patients who will receive high-dose irinotecan, as well as in patients with a personal or family history of sensitivity to irinotecan or those who have experienced neutropenia while receiving irinotecan. The test also helps confirm a suspected diagnosis of Gilbert syndrome. UGT1A1 is responsible for the clearance of drugs like irinotecan and endobiotic compounds like bilirubin. Variations in the gene affect transcription efficiency and can lead to irinotecan-related toxicities.
Special Instructions
Patient history form for UGT1A1 sequencing must be submitted with the order, and informed consent for genetic testing is required for patients in New York. Specimen collection should be in lavender (EDTA), pink (K2EDTA), or yellow (ACD solution A or B) tubes and transported refrigerated. Stability is 1 week at room temperature and 1 month refrigerated, while frozen specimens are unacceptable.
Limitations
The test detects variations in the UGT1A1 gene specifically targeted. Variations not targeted will not be detected. The clinical significance of rare alleles such as *36 (TA)5 and *37 (TA)8 in predicting irinotecan toxicities is not well established. Other genetic and non-genetic factors may also contribute to irinotecan toxicity and efficacy. Diagnostic errors can occur due to rare sequence variations.
New York Approved
Methodology
PCR-based (PCR)
Biomarkers
LOINC Codes
- 11526-1
- 34509-0
- 51951-2
- 51952-0
- 66746-9
Result Turnaround Time
2-7 days
Related Documents
For more information, please review the documents below
Specimen
Whole Blood
Volume
3 mL
Minimum Volume
1 mL
Container
Lavender (EDTA), pink (K2EDTA), or yellow (ACD solution A or B)
Storage Instructions
Refrigerated. Also acceptable: Ambient.
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 1 week |
| Refrigerated | 1 month |
| Frozen | Unacceptable |