ARUP's Laboratory Test Directory
| 0051232: Cytochrome P450 2D6 (CYP2D6) 17 Mutations |
| Test Mnemonic: CYP 2D6 | |
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Methodology: Polymerase Chain Reaction/Bead Hybridization
Performed: Mon, Thu Reported: 7-10 days |
| Specimen Required: | |
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Collect: One 3 mL lavender (EDTA) or pink (K2EDTA). Also acceptable: lt. blue (sodium citrate) or yellow (ACD Solution A).
Transport: 3 mL whole blood at 2-8°C. Pediatric Collection/Transport: 1 mL whole blood at 2-8°C. Stability: Ambient: 24 hours; Refrigerated: 5 days; Frozen: Unacceptable |
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| Reference Interval: |
| By report |
| Interpretive Data: | |
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Background Information for Cytochrome P450 2D6 (CYP2D6) 17 Mutations: Characteristics: Some CYP2D6 mutations cause impaired drug metabolism, a major cause of 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 Detected: All common and most rare alleles with known clinical significance. Negative: No mutations detected is predictive of *1 alleles. Functional: *2A (-1584C>G), *2 or *35 (-1584C>G + additional mutations defining haplotype assignment 1661G>C/2850C>T/4180G>C). Decreased function: *9 (2613-5delAGA), *10 (100C>T), *17 (1023C>T), *41 (2988G>A). Non-functional: *3 (2549A>del), *4 (1846G>A), *5 (gene deletion),*6 (1707T>del), *7 (2935A>C), *8 (1758G>T), *11 (883G>C), *12 (124G>A), *14 (1758G>A), *15 (138 insT). 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: Unknown; drug dependent. Clinical Sensitivity: Greater than 95 percent of deleterious CYP2D6 mutations are detected in Caucasians; sensitivity is unknown in other ethnicities. Methodology: PCR and allele-specific primer extension (ASPE) by bead array with fluorescence detection. 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. Please refer to Statement C in the Compliance Statements section in the front of the Laboratory Test Directory. |
| CPT Code(s): | |
| 83890 Isolation; 83892 x2 Enzymatic digestion; 83900 Amplification multiplex; 83901 Amplification; 83914 x17 Mutation identification; 83909 Separation and identification; 83912 Interpretation and report - Additional CPT code modifiers may be required for procedures performed to test for oncologic or inherited disorders. |