Download Cytochrome P450 2D6 (CYP2D6) Genotyping

 201 E. Jefferson Street, Suite 309
Louisville, KY 40202
(502) 569-1584
KY License: 200251
CLIA ID: 18D0983143
Cytochrome P450 2D6 (CYP2D6) Genotyping
General Purpose and Use
CYP2D6 metabolizes more than 25% of all drugs, including
tamoxifen, many antidepressants, antipsychotics, beta-blockers,
and opioids. Detecting variants of the CYP2D6 gene that cause
altered enzymatic activity can identify patients who may be at
increased risk of having adverse drug reactions or therapeutic
failure to standard dosages of CYP2D6 substrates. Medications
which require activation or inactivation by CYP2D6 should be used
with caution in patients with CYP2D6 variants.
Alleles Detected:
Active alleles: *1, *2
Partially active alleles: *9, *10, *17, *29, *41
Inactive alleles: *3, *4, *5 (deletion), *6, *7, *11, *12
Gene Duplication: CYP2D6 *1, *2, *4, *6, *9, *10, *17, *29, *41
Test Code
Cytochrome P450 2D6 (CYP2D6)
CPT Code
81226
Specimen
Whole blood or buccal swabs
Volume
5 mL of whole blood or four buccal swabs
Minimum Volume
3 mL of whole blood or four buccal swabs
Phenotype Categories:
Container
•
Extensive metabolizers (EM) represent the norm for
Lavender-stopper (EDTA) tube or paper
metabolic capacity. Genotypes consistent with the EM
envelope for dried buccal swabs
phenotype include two active CYP2D6 alleles or one active and
one partially active CYP2D6 allele.
Storage Instructions
•
Intermediate metabolizers (IM) represent reduced
Maintain at room temperature or refrigerate
metabolic capacity. Genotypes consistent with the IM
phenotype are those with one active and one inactive CYP2D6
Cause for Rejection
allele, one inactive and one partially active CYP2D6 allele, or
Hemolyzed specimen; quantity not sufficient
two partially active CYP2D6 alleles.
•
Poor metabolizers (PM) are at increased risk of drug-induced
side effects due to diminished drug elimination or lack of
therapeutic effect resulting from failure to generate the active
form of the drug. Genotypes consistent with the PM phenotype are those with no active CYP2D6 genes.
•
Ultra-rapid metabolizers (UM) exhibit higher than average rates of metabolism. UMs are at increased risk of
therapeutic failure due to increased drug elimination and thus may require an increased dosage of medications that
are inactivated by CYP2D6. Alternatively, UMs may also be at increased risk of drug-induced side effects due to
increased exposure to active drug metabolites, in which case they may require lower than average doses.
Genotypes consistent with UM phenotype include three or more active CYP2D6 alleles due to duplication of an active
allele.
Limitations
Other variants of the CYP2D6 gene that are not detected in this assay may influence drug metabolism. CYP2D6
metabolic capacity is also influenced by concomitant medications, inhibitors, inducers, diet and various disease states.
All factors should be considered as part of the overall patient management strategy.
Methodology
Real-time polymerase chain reaction with fluorescence detection. Multiplex polymerase chain reaction and allele-specific
primer extension available with alternate allele coverage.
Informed Consent
Informed consent for CYP2D6 genotyping is required for patients residing in New York State. The informed consent
document is required to be completed along with the test requisition form for these patients.
TD 2D6 031014