UGT1A1 TA Repeat Genotype (Sendout)
General Information
- Lab Name
- UGT1A1 TA Repeat Genotype (Sendout)
- Lab Code
- RU1A1G
- Epic Name
- UGT1A1 TA Repeat Genotype (Sendout)
- External Test Id
- U1A1Q
- Description
Useful For:
- Identifying individuals who are at increased risk of adverse drug reactions with drugs that are metabolized by UGT1A1; especially irinotecan but also atazanavir, nilotinib, pazopanib, and belinostat
- Identifying individuals with Gilbert syndrome due to the presence of homozygous UGT1A1*6 (NM_000463.2:c.211G>A) allele, TA7, homozygous TA8, or compound heterozygous *6, TA7 or TA8
- Identifying individuals who are carriers of Gilbert syndrome due to the presence of heterozygous TA7 or TA8
- This test is not useful for assessment of Crigler-Najjar syndrome.
- References
- Mayo Clinical & Interpretive Information: UDP-Glucuronosyltransferase 1A1 TA Repeat Genotype, UGT1A1
- Synonyms
- GNT1, Irinotecan metabolism, Phenol/Bilirubin UDP-Glucuronosyltransferase, U1A1Q, UDP-Glucosyltransferase 1, UGT1A1, UGT1A1 Genotype, Uracil Glucuronyl transferase, Uridine Diphosphate Glucosyltransferase 1
- Components
-
Code Name RU1A1T UGT1A1 Genotype RU1A1P UGT1A1 Phenotype RU1A1I UGT1A1 Interpretation RU1A1A UGT1A1 Additional Information RU1A1M UGT1A1 Method RU1A1D UGT1A1 Disclaimer RU1A1R UGT1A1 Reviewed By
Interpretation
- Method
Real-Time Polymerase Chain Reaction (PCR) with Allelic Discrimination Analysis
- Reference Range
- See individual components
- Ref. Range Notes
An interpretive report will be provided.
- Interferences and Limitations
Advisory: This test does not detect or report variants other than the *1 (TA6), *28 (TA7), *36 (TA5), and *6 (NM_000463.2:c.211G>A) alleles. The *37 (TA8) allele cannot be distinguished from *28 (TA7) and will be reported as *28 (TA7) by this methodology. Numerous variants outside of the TA repeat region have been described that impair UGT1A1 activity.
Cautions: Samples may contain donor DNA if obtained from patients who received non-leukoreduced blood transfusions or allogeneic hematopoietic stem cell transplantation. Results from samples obtained under these circumstances may not accurately reflect the recipient's genotype. For individuals who have received blood transfusions, the genotype usually reverts to that of the recipient within 6 weeks. For individuals who have received allogeneic hematopoietic stem cell transplantation, a pretransplant DNA specimen is recommended for testing.
UGT1A1 genetic test results in patients who have undergone liver transplantation may not accurately reflect the patient's UGT1A1 status.
Liver or renal dysfunction may result in adverse drug reactions with irinotecan independently of thymine-adenine (TA)-repeat variants.
Ordering & Collection
- Specimen Type
- Blood
- Collection
-
3 mL blood in LAVENDER TOP (EDTA) tube
- Handling Instructions
Outside Laboratories: Transport whole blood at room temperature.
Stability: Ambient (Preferred): 9 days; Refrigerated: 30 days; Frozen: Unacceptable.
- Quantity
-
Requested: 3 mL EDTA whole blood
Minimum: 0.4 mL EDTA whole blood
Processing
- Receiving Instructions
Store whole blood at room temperature in Sendouts ambient rack.
Sendouts:
- Order Test: U1A1Q.
- Interfaced: Yes.
Stability: Ambient (Preferred): 9 days; Refrigerated: 30 days; Frozen: Unacceptable.
- Misc Sendout
Performance
- Lab Department
- Sendouts Mayo Lab (AB)(MAAB)
- Frequency
- Performed: Monday - Friday. Report available: 3-6 days.
- Available STAT?
- No
- Performing Location(s)
-
Sendout Mayo Clinic Laboratories
800-533-1710200 First Street Southwest
Rochester, MN 55901
Billing & Coding
- CPT Codes
- 81350
- LOINC
- 34509-0