Cytochrome P450 3A4 Genotype, Varies
Use
This test aids in determining therapeutic strategies for drugs metabolized by cytochrome P450 3A4, like quetiapine. It helps predict drug response by identifying genetic variations that affect CYP3A4 activity, which metabolizes over 50% of drugs. Variants like CYP3A4*22 reduce expression and activity, impacting drug metabolism. However, it is not useful for drugs metabolized minimally by CYP3A4. Its interpretation assists in understanding pharmacogenomic interactions and potential dose adjustments.
Special Instructions
Not provided.
Limitations
This test doesn't detect all CYP3A4 activity-altering variants. False results may occur due to rare variants or if samples contain donor DNA. It doesn't predict CYP3A4 phenotype where methods differ. Drug interactions and metabolite inhibition affecting CYP3A4 must be considered. Non-detected variants don't exclude altered metabolism risk. The test doesn't determine cis/trans-variant arrangement.
New York Approved
Methodology
PCR-based (PCR)
Biomarkers
LOINC Codes
- 74007-6 - CYP3A4 Mut Anl Bld/T
- 81139-8 - CYP3A4 allele Geno Bld/T
- 81145-5 - CYP3A4 gene prod met act 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 whole blood specimen in original tube without aliquoting.
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 4 days |
| Refrigerated | 4 days |
| Frozen | 4 days |