CYP2D6 Genotyping

CYP2D6 acts on 25% of all prescription drugs. Approximately 7% of the population has a slow acting form of this enzyme and 7% a super-fast acting form. Thirty-five percent are carriers of a non-functional CYP2D6 allele, which especially elevates the risk of adverse drug reactions when these individuals are taking multiple drugs.

Drugs that CYP2D6 metabolizes include selective serotonin reuptake inhibitors (SSRI), tricylic antidepressants (TCA), beta-blockers, opiates, neuroleptics, antiarrhythmics and a variety of toxic plant substances. Specific notable drugs include Prozac, Zoloft, Paxil, Effexor, hydrocodone, amitriptyline, Claritin, cyclobenzaprine, Haldol, metoprolol, Rythmol, Tagamet, tamoxifen, and the over-the-counter diphenylhydramine drugs, Allegra, Dytuss, and Tusstat. CYP2D6 is also responsible for activating the prodrugs codeine and other opioids into their active forms. The analgesic activity of the drugs is therefore reduced or absent in CYP2D6 poor metabolizers. Refer to list for substrates, inhibitors and inducers of CYP2D6.

Genelex offers improved detection rates using an extended Cytochrome P450 2D6 DNA mutation panel. This test identifies 17 small nucleotide variants and two gene rearrangements in PCR-multiplex format, providing increased sensitivity and quality performance. This CYP2D6 Mutation Detection Panel is the most extensive on the market and covers over 93-97% of poor metabolizer phenotypes. Analytical specificity and sensitivity for detection of these mutations are >99%.

Indication for Testing
For individuals with a personal or family history of adverse drug reactions to medications metabolized by CYP2D6. Confirm presence of genotypes that affect the metabolism of drugs such as tamoxifen that are metabolized by CYP2D6.

Insurance Coverage

CYP2D6 genotyping is covered by most private insurers and by Medicare in specific instances. Visit the Center for Medicare & Medicaid Services’ Local Coverage Determination for CYP2D6 by clicking here (you will be prompted to review and the CMS licensing information before being directed to the LCD).

Specimen Collection

Click here to order testing supplies or call Client Services at 800-837–8362. 

  • Buccal Swabs: 4 sterile buccal swabs
  • Blood: 5-10cc whole blood lavender-top EDTA or yellow-top ACD-A tubes

Turnaround Time: 5 days, 4 day STAT