CYP2D6 (Cytochrome P450 2D6)

Test Mnemonic


CPT Codes

  • 81226 - QTY (1)
  • if reflexed, add 81479 - QTY (1)


  • 2D6
  • P450 2D6 Genotype


  • Interpretation
  • CYP2D6 Genotype
  • CYP2D6 Phenotype
  • EER CYP2D6
  • 2D6GENO Specimen

Performing Laboratory


Specimen Requirements

Volume Type Container Collect Temperature Transport Temperature Special Instructions
3 mLWhole bloodEDTA (Lavender) Refrigerated 

Alternate Specimen Requirements

Volume Type Container Collect Temperature Transport Temperature Special Instructions
3 mLWhole bloodACD A or B (Yellow) Refrigerated 
N/ASalivaSee note AmbientCollect using Saliva Collection Device by DNA Genotek (OCD-100, ARUP Supply #49295)

Minimum Specimen Requirements

Volume Type Container Collect Temperature Transport Temperature Special Instructions
1 mL    Whole blood


Environmental Condition Description
RefrigeratedWhole blood: 1 week; Saliva: Unacceptable
AmbientWhole blood: 72 hours; Saliva: 2 weeks
FrozenWhole blood: 1 month; Saliva: Unacceptable

Days Performed


Turnaround Time

6 - 11 days


Name Description
Fluorescence Monitoring 
Polymerase Chain Reaction (PCR) 

Special Info

Plasma, serum and frozen specimens in glass collection tubes will be rejected. Specimens collected in sodium heparin or lithium heparin are unacceptable. Whole blood is the preferred specimen type. Saliva samples that yield inadequate DNA quality and/or quantity will be reported as inconclusive if test performance does not meet laboratory-determined criteria for reporting. Saliva is only validated for the OpenArray and CNV portions of testing and not the long-range PCR/duplication testing. Long-range PCR/duplication testing will not be performed for saliva samples. If long-range PCR/duplication testing is performed, additional charges will apply and TAT will be extended by five to seven days. Approximately less than 5% of samples require 2D6 copy number determination. This test is New York DOH approved.

Clinical Info

Background: Characteristics: The cytochrome P450 (CYP) isozyme 2D6 is involved in the metabolism of many drugs. Variants in the gene that codes for CYP2D6 may influence pharmacokinetics of CYP2D6 substrates, and may predict or explain non-standard dose requirement, therapeutic failure or adverse reactions. Inheritance: Autosomal co-dominant. Cause: CYP2D6 gene variants and copy number affect enzyme function. Variants tested: Negative: No variants detected is predictive of the *1 functional allele. *2 (rs16947, c.2850C>T; rs1135840, c.4180G>C), *2A (rs1080985, c.-1584C>G; rs16947, c.2850C>T; rs1135840, c.4180G>C), *3 (rs35743686, c.2549delA), *4 (rs1065852, c.100C>T; rs3892097, c.1846G>A; rs1135840, c.4180G>C), *5 (gene deletion), *6 (rs5030655, c.1707delT; rs1135840, c.4180G>C), *7 (rs5030867, c.2935A>C), *8 (rs5030865, c.1758G>T; rs16947, c.2850C>T; rs1135840, c.4180G>C), *9 (rs5030656, c.2615_2617delAAGA), *10 (rs1065852, c.100C>T; rs1135840, c.4180G>C), *11 (rs1080985, c.-1584C>G; rs201377835, c.883G>C; rs16947, c.2850C>T; rs1135840, c.4180G>C), *12 (rs5030862, c.124G>A; rs16947, c.2850C>T; rs1135840, c.4180G>C), *13 (a CYP2D7-derived exon 1 conversion), *14 (rs5030865, c.1758G>A; rs16947, c.2850C>T; rs1135840, c.4180G>C), *15 (rs774671100, c.137_138insT), *17 (rs28371706, c.1023C>T; rs16947, c.2850C>T; rs1135840, c.4180G>C), *29 (rs16947, c.2850C>T; rs59421388, c.3183G>A; rs1135840, c.4180G>C), *35 (rs769258, c.31G>A; rs16947, c.2850C>T; rs1135840, c.4180G>C), *36 (a CYP2D6*10 carrying a CYP2D7-derived exon 9 conversion), *36-*10 ( a CYP2D6*36 and a CYP2D6*10 in tandem, *41 (rs16947, c.2850C>T; rs28371725, c.2988G>A; rs1135840, c.4180G>C), *45 (rs28371710, c.1716G>A; rs16947, c.2850C>T; rs1135840, c.4180G>C), *46 (rs28371696, c.77G>A; rs28371710, c.1716G>A; rs16947, c.2850C>T; rs1135840, c.4180G>C), *49 (rs1065852, c.100C>T; rs1135822, c.1611T>A; rs1135840, c.4180G>C), *53 (rs1135822, c.1611T>A), *69 (rs1065852, c.100C>T; rs16947, c.2850C>T; rs28371725, c.2988G>A; rs1135840, c.4180G>C), *114 (rs1065852, c.100C>T; rs5030865, c.1758G>A; rs16947, c.2850C>T; rs1135840, c.4180G>CDUP: complete gene duplications) Clinical Sensitivity: Drug-dependent. Methodology: Polymerase chain reaction (PCR) and fluorescence monitoring. Sequencing is only performed if needed to characterize a duplicated CYP2D6 gene. Analytical Sensitivity and Specificity: Greater than 99%

Clinical Limitation

Only the targeted CYP2D6 variants will be detected by this panel, and assumptions about phase and content are made to assign alleles. Publicly available sources such as the or provide guidance on phenotype predictions and allele frequencies. A combination of the *5 (gene deletion) and a gene duplication cannot be specifically identified. This combination is not expected to adversely affect the phenotype prediction. Diagnostic errors can occur due to rare sequence variations. Risk of therapeutic failure or adverse reactions with CYP2D6 substrates may be affected by genetic and non-genetic factors that are not detected by this test. This result does not replace the need for therapeutic drug or clinical monitoring.