Cytochrome P450 3A5 Genotype, Varies
Use
CYP3A5 genotyping aids in optimizing treatment with tacrolimus and other drugs metabolized by cytochrome P450 3A5. It identifies individuals who may require adjustments in drug dosage to achieve therapeutic drug levels, especially for individuals with differing alleles that affect enzyme activity. This test may predict dose requirements for tacrolimus but does not replace the need for therapeutic drug monitoring.
Special Instructions
Not provided.
Limitations
This test may not detect all variants affecting CYP3A5 activity. Rare variants can lead to false results. In cases of blood transfusions or stem cell transplants, results may not accurately reflect the patient's genotype. Further testing might be necessary if allele results do not match clinical phenotypes. Maternal cell contamination testing may be required for umbilical cord specimens.
New York Approved
Methodology
PCR-based
Biomarkers
No genes
Gene
LOINC Codes
- 81140-6 - CYP3A5 allele Geno Bld/T
- 81140-6 - CYP3A5 allele Geno Bld/T
- 79717-5 - CYP3A5 gene prod met act imp Bld/T-Imp
- 69047-9 - Geneticist review
- 48767-8 - Annotation comment Imp
- 85069-3 - Lab test method
- 62364-5 - Test performance info Spec
- 18771-6 - Provider signing name
Result Turnaround Time
3-8 days
Related Documents
For more information, please review the documents below
Specimen
Whole Blood
Volume
3 mL
Minimum Volume
Not provided
Container
Lavender top (EDTA) or yellow top (ACD)
Collection Instructions
Invert several times to mix blood. Send in original tube. Do not aliquot. Umbilical cord collections are acceptable.
Patient Preparation
A previous hematopoietic stem cell or liver transplant will interfere with testing. Call for more information.
Storage Instructions
Send at ambient temperature within 4 days.
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 4 days |
| Refrigerated | 4 days |
| Frozen | 4 days |