ARUP's Laboratory Test Directory

Cytochrome P450 2D6 (CYP2D6) 14 Mutations and Gene Duplication : 0051232
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Additional Technical Information
  


Mnemonic: CYP 2D6

Ordering Recommendation: May aid in dose planning for tamoxifen and other drugs metabolized by CYP2D6.
Methodology: Polymerase Chain Reaction/Primer Extension
Performed: Mon, Thu
Reported: 7-14 days
Specimen Required: Collect: Lavender (EDTA), pink (K2EDTA), or yellow (ACD Solution A or B).

Specimen Preparation: Transport 3 mL whole blood. (Min: 1 mL)

Storage/Transport Temperature: Refrigerated.

Stability (collection to initiation of testing): Ambient: 72 hours; Refrigerated: 1 week; Frozen: Unacceptable
Reference Interval:
By report
Interpretive Data: Interpretive Data:
Background Information for Cytochrome P450 2D6 (CYP2D6) 14 Mutations and Gene Duplication:
Characteristics: Impaired drug metabolism causing adverse drug reactions or lack of drug response. Drugs metabolized by CYP2D6 include antiestrogens (tamoxifen), alpha-blockers, analgesics, anticonvulsives, antidepressants, antidiabetics, antihypertensives, antipsychotics, antitussives, beta blockers, cardioactives, norepinephrine reuptake inhibitors, and stimulants. Additionally, many drugs inhibit CYP2D6 activity, and may affect drug response.
Inheritance: Autosomal recessive.
Cause: CYP2D6 gene mutations.
Mutations Tested: All common and most rare alleles with known clinical significance.
Negative: No mutations detected is predictive of *1 functional alleles.
Functional: *2 (2850C>T), *2A (-1584C>G).
Decreased function: *9 (2613-5delAGA), *10 (100C>T), *17 (1023C>T), *29 (1659G>A) *41 (2988G>A).
Non-functional: *3 (2549A>del), *4 (1846G>A), *5 (gene deletion),*6 (1707T>del), *7 (2935A>C), *8 (1758G>T), *12 (124G>A), *14 (1758G>A).
Increased function: Duplicated functional alleles.
Incidence of Poor Metabolizer Phenotype: 10 percent of Caucasians and Hispanics, 2 percent of African Americans, and 1 percent of Asians.
Penetrance: Drug dependent.
Clinical Sensitivity: Greater than 95 percent of deleterious CYP2D6 mutations are detected in Caucasians; sensitivity is unknown in other ethnicities.
Methodology: Multiplex PCR and Detection Primer Extension.
Analytical Sensitivity and Specificity: Greater than 99 percent.
Limitations: Only the targeted CYP2D6 mutations will be detected. Mutations in other genes will not be detected. Rare diagnostic errors can occur due to primer site mutations. Mutation detection is not a substitute for therapeutic drug monitoring. Non-genetic factors may also affect drug metabolism



Counseling and informed consent are recommended for genetic testing. Consent forms are available online at www.aruplab.com.

See Compliance Statement C: www.aruplab.com/CS
CPT Code(s): 81226
Cross References: CYP2D6 ( Cytochrome P450 2D6 (CYP2D6) 14 Mutations & Gene Duplication) , Cytochrome P450 2D6 Genotype for Tamoxifen Hormonal Therapy, Saliva (Cytochrome P450 2D6 (CYP2D6) 14 Mutations & Gene Duplication) , Tamoxifin Drug Metabolism ( Cytochrome P450 2D6 (CYP2D6) 14 Mutations & Gene Duplication)