The cytochrome P450 system are a family of enzymes found throughout the body which are responsible for the synthesis and metabolism of various molecules and chemicals within the cell, most notably including the active ingredient of most drugs.
Common variations - known as polymorphisms - in the genes that determine cytochrome P450 enzyme activity may affect the function of the enzymes. These are most commonly seen in the breakdown or metabolism of medication. Drugs may be metabolized quickly or slowly. If a cytochrome P450 enzyme metabolizes a drug slowly, the drug remains active longer and a lower dose is needed to get the desired effect whereas normal doses may cause toxicity. Cytochrome P450 enzymes, particularly CYP2C9, CYP2C19, and CYP2D6, are responsible for approximately 70% of drug metabolism in the body. Additionally, there are other genes outside of the cytochrome-p450 system that affect drug metabolism and as a result - a patient’s response to medications.
Pharmacogenetic testing is primarily concerned with variations in enzymes that affect drug metabolism.
These variations are broken down into four categories based on their expected effect on drug metabolism:
- Rapid / Ultra Rapid
Notes: Doctors' authorization form required.