Genes tested in pharmacogenetics
Genes serve as the instructions our bodies use to develop, grow and function throughout our life. In pharmacogenetics (PGx), genes are tested for their association with predicted medication response. Most genes analyzed in PGx testing provide instructions for enzymes. Enzymes are proteins in the body that help process medications. Genetic variations found in these genes can affect how the body responds to certain medications, influencing the medication’s effectiveness and potential side effects.
What is VKORC1?
VKORC1 is a gene that provides instructions for making the VKORC1 enzyme, which plays a key role in blood clotting. This enzyme is mainly found in the liver where it interacts with certain medications inside of the body, affecting how well they work.
PGx testing of VKORC1
Genetic variation—the natural differences in DNA sequences between individuals—can affect how different people process the same medication.
The results of VKORC1 PGx testing can predict how your child responds to the anticoagulant warfarin—a medication that helps prevent blood clotting—which can help their health-care team adjust their dosage of the medication.
Medications affected by VKORC1
Currently, there is one medication affected by genetic variation in VKORC1. If your child has a genetic variation in their VKORC1 gene, it may affect how this medication works:
- Warfarin, an anticoagulant medication that helps prevent blood clotting
The medications listed above are referred to by their generic names. You may hear your child’s medication called by a different brand name. Generic medicines and brand-name medicines share the same active ingredient and offer the same performance, safety and effectiveness. This medication list is also subject to change with increasing research on VKORC1.
VKORC1 warfarin sensitivity status
The results of a genetic test of VKORC1 are categorized by sensitivity to warfarin. There are two different statuses for VKORC1:
- Increased warfarin sensitivity – your child’s VKORC1 genetic variants show they may be more sensitive to warfarin.
- Your child may require a lower dose of warfarin compared to an individual with no warfarin sensitivity
- Your child may require a lower dose of warfarin compared to an individual with no warfarin sensitivity
- Normal warfarin sensitivity – your child’s VKORC1 genetic variants show they may have normal sensitivity to warfarin.
- Your child can be prescribed the average warfarin dose, as their test results do not indicate an increased sensitivity to warfarin.
- Your child can be prescribed the average warfarin dose, as their test results do not indicate an increased sensitivity to warfarin.
These statuses are not an indicator of your child’s health—they simply predict whether your child might need a different dose of medication. In addition to PGx test results, your child’s health-care team will still consider medical history and other factors to ensure the best treatment for your child.
To learn more about how genes relate to medication use, see Genetics basics for pharmacogenetics.