Cytochrome P450 2D6 Comprehensive Cascade, Varies
Use
This test provides vital information on the metabolism of various medications through the cytochrome P450 2D6 enzyme. It facilitates precision in drug therapies, particularly for medications such as tamoxifen, codeine, and tramadol. The test is instrumental when typical genotyping methods fail or if there is a discord between genotype and phenotype. It is also crucial for drug trials, research protocols, and in identifying novel variants impacting drug metabolism through sequencing reflex tests.
Special Instructions
The testing involves two tiers, with Tier 1 employing PCR-based 5'-nuclease assay for identifying common CYP2D6 variants and copy numbers. If Tier 1 results remain ambiguous, Tier 2 sequencing is undertaken. The reflex testing strategy isn't standalone billable but part of the cascade process to clarify genotype.
Limitations
Approximately 3% of cases proceed to Tier 2 testing due to ambiguous Tier 1 results. This test focuses on the CYP2D6 gene and may not detect all genetic factors influencing drug metabolism. Rare alleles and complex loci duplications like CYP2D7-2D6 and CYP2D6-2D7 hybrids present challenges in interpretation without full sequencing.
New York Approved
Methodology
PCR-based (qPCR)
Biomarkers
Result Turnaround Time
Not provided.
Related Documents
For more information, please review the documents below
Specimen
Whole Blood
Volume
Not provided
Minimum Volume
Not provided