What is pharmacogenetics?
Pharmacogenetics (PGx) combines the words "pharmacology" (the study of how medications affect the body) and "genetics" (the study of differences between individuals and how these traits are inherited within families). PGx is a type of precision medicine and is the study of how genetic variation can influence an individual’s response to medications.
Does genetic variation affect all medications my child takes now and in the future?
PGx can only inform dosing for certain medications. Genes can affect specific medications similarly to how a key fits into a specific lock. Medications that may be impacted by genetic variation currently fall under the following health specialties:
- Autoimmune disorders (immunology)
- Blood clotting disorders (hematology)
- Cancer treatment (oncology)
- Digestive health (gastroenterology)
- Heart care (cardiology)
- Infectious diseases
- Mental health (psychiatry)
- Neurologic disorders (neurology)
- Pain management
Why do some medications work well for my child but others do not, even if their PGx results do not show genetic variation that influences drug metabolism?
Genes are just one piece of the puzzle. Other factors, like your child’s age, the foods they eat, other medications they take, and their overall health, can also affect how their body handles medications. Even if their PGx results do not indicate genetic variation, these other factors can still make a difference in how well a medication works for your child. Genetic variation in specific genes alone cannot explain everything about your child’s response to medications.
Do I or my child’s siblings have the same genetic make-up?
Genes are passed down from parents, but not always in the exact same way. It is kind of like mixing paint colours—each person can end up with a slightly different shade. So, while you and your child’s siblings may share some variations, they might not all be the same.
Can my child’s PGx variation make them sick?
Variation in specific genes involved in PGx does not make your child sick but can affect how their body responds to certain medications. For example, some variation can cause a medication to be broken down too quickly, while others too slowly. Your child’s health-care team may use this information to choose the right medication and dosage to keep your child safe and healthy.
What is the connection between my child’s PGx results and medication allergies?
Knowing that your child carries specific genetic variation that may affect their response to medication does not mean they are allergic to that medication. Genetic variation and allergies can both explain why people react differently to medications, but they are not the same thing. In PGx, specific genetic variation can provide clues as to how effective a medication might be for your child, while an allergy is a result of the immune system’s overreaction to a substance that is generally not harmful to most people.
Do babies receive PGx testing when they are born?
Newborn babies typically receive a screening test shortly after birth to detect health conditions that require early treatment. However, this is different from PGx testing, which examines how the body processes or interacts with medications. Not all children require PGx testing—only those whose health-care team considers it necessary.
For more information about newborn screening, please see Newborn screening.
Can my family’s background affect my child’s genes?
Yes, it can. People from different parts of the world can have different versions of genes. These genetic differences can sometimes affect how a person’s body responds to certain medications. A gene that is rare in one place might be more common in another.
What can I expect if PGx testing is offered to me or my child?
PGx testing is simple and usually done with a cheek swab. Before the test, the health-care team will have a meeting with you and your child to explain how the test is done. This is a great time to ask any questions you may have. The health-care team will make sure you understand how the test works and why it might be helpful for your child.
What to expect before, during and after PGx testing
- Permission to take a sample from either you or your child will be obtained by the institution providing the testing.
- You will meet the PGx/health-care team conducting the test and have an opportunity to ask any questions you may have.
- A sample will be taken, usually via a cheek swab or a blood draw if necessary.
- The sample will be sent to a lab, where the PGx test is performed. The results usually take about a month to be processed.
- Once the results are received by your or your child’s health-care team, the team will explain what the results mean for you and/or your child.
Is processing (metabolizing) medication the same as metabolizing food?
No, they are different!
Food processing (metabolism) is how your body breaks down the food you eat to get energy and nutrients.
Medication processing (metabolism) is how your body uses and removes medications so they can work properly and stay in the body as they are intended. The body uses different helpers (enzymes) for food and medication metabolism. So, having a fast or slow food metabolism does not mean your child’s body will process medicine the same way.