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HelpTest ID 2D6Q Cytochrome P450 2D6 Comprehensive Cascade, Varies
Ordering Guidance
This test is not for use in assessing for autoimmune hepatitis. Autoantibodies for the CYP2D6 enzyme are found in many cases of autoimmune hepatitis; order LKM / Liver/Kidney Microsome Type 1 Antibodies, Serum for autoimmune hepatitis assessment.
Testing is available as the single gene assay (this test) and as a part of a psychotropic or focused pharmacogenomics panel.
If multiple pharmacogenomic genotype testing is desired, order PGXQP / Focused Pharmacogenomics Panel, Varies.
If genotype testing for psychotropic medications is desired, order PSYQP / Psychotropic Pharmacogenomics Gene Panel, Varies.
Specimen Required
Multiple genotype tests can be performed on a single specimen after a single extraction. See Multiple Genotype Test List for a list of tests that can be ordered together.
Submit only 1 of the following specimens:
Specimen Type: Whole blood
Container/Tube: Lavender top (EDTA)
Specimen Volume: 3 mL
Collection Instructions:
1. Invert several times to mix blood.
2. Send whole blood specimen in original tube. Do not aliquot.
Specimen Stability Information: Ambient (preferred) 9 days/Refrigerated 30 days
Specimen Type: Saliva
Patient Preparation: Patient should not eat, drink, smoke, or chew gum 30 minutes prior to collection.
Supplies: Saliva Swab Collection Kit (T786)
Specimen Volume: 1 swab
Collection Instructions: Collect and send specimen per kit instructions.
Additional Information: Due to lower concentration of DNA yielded from saliva, testing cannot proceed to tier 2 sequencing and will stop after tier 1 testing is complete.
Specimen Stability Information: Ambient 30 days
Specimen Type: Extracted DNA
Container/Tube: 2 mL screw top tube
Specimen Volume: 100 mcL (microliters)
Collection Instructions:
1. The preferred volume is 100 mcL at a concentration of 75 ng/mcL.
2. Include concentration and volume on tube.
Specimen Stability Information: Frozen (preferred) 1 year/Ambient/Refrigerated
Forms
1. New York Clients-Informed consent is required. Document on the request form or electronic order that a copy is on file. The following documents are available:
-Informed Consent for Genetic Testing (T576)
-Informed Consent for Genetic Testing-Spanish (T826)
2. If not ordering electronically, complete, print, and send 1 of the following forms with the specimen:
-Cardiovascular Test Request (T724)
-Neurology Specialty Testing Client Test Request (T732)
-Therapeutics Test Request (T831)
Useful For
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
Testing is done in 2 tiers when needed. Tier 1 uses a polymerase chain reaction (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, *59) 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.
Testing Algorithm
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.
For more information see CYP2D6 Comprehensive Cascade Testing Algorithm.
Special Instructions
Method Name
Tier 1: Real Time Polymerase Chain Reaction (PCR)
Tier 2: Polymerase Chain Reaction (PCR) followed by DNA Sequence Analysis
Reporting Name
CYP2D6 Genotype Cascade, VSpecimen Type
VariesSpecimen Minimum Volume
Blood: 1 mL
Saliva: 1 swab
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Varies | Varies | ||
Reference Values
A comprehensive interpretive report will be provided.
Day(s) Performed
Monday through Thursday
Report Available
3 to 16 daysPerforming Laboratory
Mayo Clinic Laboratories in Rochester
Test Classification
This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. It has not been cleared or approved by the US Food and Drug Administration.CPT Code Information
0070U
0071U (if appropriate)
0076U (if appropriate)
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| 2D6Q | CYP2D6 Genotype Cascade, V | 47403-1 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| 610103 | CYP2D6 Genotype | 40425-1 |
| 610104 | CYP2D6 Phenotype | 79715-9 |
| 610569 | CYP2D6 Activity Score | 104669-7 |
| 610105 | Interpretation | 69047-9 |
| 610106 | Additional Information | 48767-8 |
| 610107 | Method | 85069-3 |
| 610108 | Disclaimer | 62364-5 |
| 610109 | Reviewed by | 18771-6 |
NY State Approved
YesReflex Tests
| Test ID | Reporting Name | Available Separately | Always Performed |
|---|---|---|---|
| 2D61Z | CYP2D6 Full Gene Sequence | No, (Bill Only) | No |
| 2D62Z | CYP2D6 GEN CYP2D6-2D7 Hybrid | No, (Bill Only) | No |
| 2D63Z | CYP2D6 GEN CYP2D7-2D6 Hybrid | No, (Bill Only) | No |
| 2D64Z | CYP2D6 Nonduplicated Gene | No, (Bill Only) | No |
| 2D65Z | CYP2D6 5' Gene DUP/MLT | No, (Bill Only) | No |
| 2D66Z | CYP2D6 3' Gene DUP/MLT | No, (Bill Only) | No |