Test Catalog

Test ID: 2D6Q    
Cytochrome P450 2D6 Comprehensive Cascade, Varies

Useful For Suggests clinical disorders or settings where the test may be helpful

Providing information relevant to tamoxifen, codeine, and tramadol, as well as other medications metabolized by cytochrome P450 2D6


Determining the exact genotype when other methods fail to generate this information or if genotype-phenotype discord is encountered clinically


Identifying precise genotype when required (eg, drug trials, research protocols)


Identifying novel variants that may interfere with drug metabolism (when reflex to sequencing is performed)

Genetics Test Information Provides information that may help with selection of the correct genetic test or proper submission of the test request

Testing is done in 2 tiers when needed. Tier 1 uses a PCR-based 5'-nuclease assay to determine the variants present. All samples also have copy number determined by PCR-based 5'-nuclease assay. Testing in tier 1 allows for the detection of all common CYP2D6 variants (eg, *2, *3, *4, *5, *6, *7, *8, *9, *10, *17, *29, *35, *41) and rarer alleles such as *11, *12, *14, *15, and *114. Duplications and multiplications of alleles are also identified. Unitary and tandem CYP2D7-2D6 (*13) alleles and CYP2D6-2D7 (eg, *4N, *36, and *68) alleles can also be detected. Tier 2 testing involves sequencing using fluorescent dye-terminator chemistry and is only done if tier 1 testing results are ambiguous. Approximately 3% of samples require tier 2 testing.

Reflex Tests Lists tests that may or may not be performed, at an additional charge, depending on the result and interpretation of the initial tests.

Test IDReporting NameAvailable SeparatelyAlways Performed
2D61ZCYP2D6 Full Gene SequenceNo, (Bill Only)No
2D62ZCYP2D6 GEN CYP2D6-2D7 HybridNo, (Bill Only)No
2D63ZCYP2D6 GEN CYP2D7-2D6 HybridNo, (Bill Only)No
2D64ZCYP2D6 Nonduplicated GeneNo, (Bill Only)No
2D65ZCYP2D6 5' Gene DUP/MLTNo, (Bill Only)No
2D66ZCYP2D6 3' Gene DUP/MLTNo, (Bill Only)No

Testing Algorithm Delineates situations when tests are added to the initial order. This includes reflex and additional tests.

Tier 2 testing will be performed only if an ambiguous phenotype is identified by tier 1 testing. The number of sequencing tests needed to determine the phenotype will vary depending on the tier 1 result.


See CYP2D6 Comprehensive Cascade Testing Algorithm in Special Instructions.

Special Instructions Library of PDFs including pertinent information and forms related to the test

Method Name A short description of the method used to perform the test

Tier 1: Real Time Polymerase Chain Reaction (PCR)

Tier 2: Polymerase Chain Reaction (PCR) followed by DNA Sequence Analysis

NY State Available Indicates the status of NY State approval and if the test is orderable for NY State clients.


Reporting Name Lists a shorter or abbreviated version of the Published Name for a test

CYP2D6 Genotype Cascade, V

Aliases Lists additional common names for a test, as an aid in searching

Breast Cancer Therapy
Cytochrome P450 2D6 (CYP2D6) Genotyping
Treatment Resistant Depression