CYP 1A2

Cytochrome P450 1A2 (CYP1A2) Genotyping

Test Code
Cytochrome P450 1A2 (CYP1A2)

CPT Code
81479 

Specimen
Whole blood or buccal swabs 

Volume
5 mL of whole blood or four buccal swabs 

Minimum Volume
3 mL of whole blood or four buccal swabs 

Container
Lavender-stopper (EDTA) tube or paper envelope for dried buccal swabs 

Storage Instructions
Maintain at room temperature or refrigerate 

Cause for Rejection
Hemolyzed specimen; quantity not sufficient

General Purpose and Use
CYP1A2 metabolizes many medications, including theophylline, diazepam, caffeine, and amitriptyline.  CYP1A2 can be induced by several medications, substrates, and constituents of tobacco smoke.  CYP1A2 can also be inhibited by several medications.  Basal metabolic capacity remains relatively consistent among the different genotypes in the absence of an inducer.  Detecting variants of the CYP1A2 gene that cause altered enzymatic induction in the presence of an inducer can identify patients who may be at increased risk of having adverse drug reactions or therapeutic failure to standard dosages of CYP1A2 substrates.

Alleles Detected
CYP1A2*1A, *1C, *1E, *1F, *1J, *1K, *1L 

Limitations
Other variants of the CYP1A2 gene that are not detected in this assay may influence drug metabolism.  CYP1A2 metabolic capacity is also influenced by concomitant medications, inhibitors, inducers, diet and various disease states.  All factors should be considered as part of the overall patient management strategy.

Methodology
Real-time polymerase chain reaction with fluorescence detection.

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