Drug-Gene Testing

Drug-gene testing is also called pharmacogenomics, or pharmacogenetics. All terms characterize the study of how your genes affect your body’s response to medications. The word “pharmacogenomics” is combined from the words pharmacology (the study of the uses and effects of medications) and genomics (the study of genes and their functions).

Your body has thousands of genes that you inherited from your parents. Genes determine which characteristics you have, such as eye color and blood type. Some genes are responsible for how your body processes medications. Pharmacogenomic tests look for changes or variants in these genes that may determine whether a medication could be an effective treatment for you or whether you could have side effects to a specific medication.

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Animation: Right Drug, Right Patient, Right Dose

The Pharmacogenomics Program investigates how variations in genes affect response to medications, thereby using a patient's genetic profile to predict a drug's efficacy, guide dosage and improve patient safety.

Patient Information: Pharmacogenomics – Finding the Right Medication for You

Pharmacogenomic testing is one tool that can help your health care provider determine the best medication for you. Your health care provider also considers other factors such as your age, lifestyle, other medications you are taking and your overall health when choosing the right treatment for you.

What Pharmacogenomics Testing Does

The purpose of pharmacogenomic testing is to find out if a medication is right for you. A small blood or saliva sample can help determine:

  • Whether a medication may be an effective treatment for you
  • What the best dose of a medication is for you
  • Whether you could have serious side effects from a medication

The laboratory looks for changes or variants in one or more genes that can affect your response to certain medications.

Genomic Sequencing Animation

Animation: Genome Sequencing

Genomic sequencing is a process for analyzing a sample of DNA taken from your blood. In the lab, technicians extract DNA and prepare it for sequencing.
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Video: Andrew's Story

Applied pharmacogenomics resolves patient's lifelong anxiety and depression.

Each person would need to have the same specific pharmacogenomic test only once because your genetic makeup does not change over time. However, you may need other pharmacogenomics tests if you take another medication. Each medication is associated with a different pharmacogenomics test. Keep track of all your test results and share them with your health care providers.

The need for pharmacogenomics testing is determined on an individual basis. If your pharmacogenomic test results suggest you may not have a good response to a medication, your family members may have a similar response. Mayo Clinic recommends you share this information with your family members. Your health care provider can also provide recommendations for family members who may benefit from having testing.

Current Limitations of Pharmacogenomics Tests

Current limitations of pharmacogenomics testing include:

  • One single pharmacogenomic test cannot be used to determine how you will respond to all medications. You may need more than one pharmacogenomic test if you are taking more than one medication.
  • Pharmacogenomic tests are not available for all medications. Because pharmacogenomic tests are available only for certain medications, your health care provider determines if you need to have a pharmacogenomic test prior to beginning a specific treatment.
  • There are currently no pharmacogenomic tests for aspirin and many over-the-counter pain relievers.

Pharmacogenomics Testing Costs and Coverage

The cost of pharmacogenomics testing varies depending on which test is ordered and your health insurance coverage. To help you determine test costs and coverage:

  • Mayo Clinic’s Patient Account Services may be able to provide an estimate by phone.
  • Some insurance companies may cover pharmacogenomic testing, depending on the policy and reasons for testing.
  • Contact your insurance provider about coverage prior to testing if cost and coverage are concerns.
  • It may be helpful to get the ICD-9/ICD-10 procedure and CPT billing codes for the specific lab tests from your health care provider before calling the insurance company.

A federal law called the Genetic Information Nondiscrimination Act (GINA) generally makes it illegal for health insurance companies to discriminate against you based on your genetic information. This federal law does not protect you against genetic discrimination by life insurance, disability insurance or long-term care insurance companies. Some states have laws in this area.