Precision Medicine & Pharmacogenetics

What is precision medicine?

Precision medicine is also called "personalized medicine" or "genomic medicine." It uses your child's genes, environment, and lifestyle to help pick the right treatment.

If your child needs certain medications for treatment, the doctor can request a genetic test. The test looks at specific genes to help predict how your child's body will respond to the treatment. This helps doctors prescribe the right medication at the correct dose to help avoid the drug's side effects or select an alternative option.

Everyone is genetically unique. That is why one medication might work well for one child, but not for another. For more information, please visit the National Institute of Health (NIH) website.

Why do we need a sample of your child's DNA?

DNA (or deoxyribonucleic acid) is the genetic material found in the cells of our body that makes each person unique. It provides instructions to cells on how to function, what to do, and when to do it.

Healthcare providers will use your child’s DNA to run a genetic test to help make treatment decisions to provide the best care possible for your child by:

• Helping select the best medicine for your child
• Helping decide which medications to avoid
• Helping determine the best-individualized dose
• Helping monitor any side effects of the medicine

How do we take a sample of DNA?

A DNA sample is taken by either a small blood sample (less than one teaspoon) or a cheek swab. The sample is sent to the lab, where the DNA is extracted.

All DNA samples and test results are treated with patient confidentiality. We do not share test results with insurance companies, organizations, or non-hospital employees.

Are there costs associated with a DNA test?

There is a cost for this test. Your insurance will be billed, and the patient/parent will be responsible for any payment not covered by insurance.

• Check your insurance policy for more information about insurance coverage.
• Ask your doctor if a precision medicine test is an option for your child.

Which medications are covered under the Arkansas Children’s Pharmacogenetic test?

Below is a list of current medications covered by the test. The list will continue to grow as we learn more - additional medications will be added in the future.

How is the Pharmacogenetic (PGx) testing performed?

The Arkansas Children's molecular pathology laboratory will use the DNA from the child's blood or buccal sample. The DNA sample is used to run on our internal custom-designed genotyping panel.  Our panel analyzes the following genes: ACYP2, CACNA1S, CEP72, CYP3A4, CYP3A5, CYP2C Cluster, CYP2C9, CYP2C19, CYP4F2, CYP2D6, DPYD, G6PD, NUDT15, RARG, RYR1, SLC28A3, SLCO1B1, TPMT, UGT1A1, UGT1A6, and VKORC1. The results are translated into genotypes and phenotypes. Genotypes consist of two results, one from each parent passed on to the child. The combination of the two results translates into a phenotype.

Who interprets the Pharmacogenetic (PGx) test?

The results are interpreted by our Board-certified team members (insert link to meet the team).  Test results are then uploaded into the electronic health record. A clinical pharmacist specializing in pharmacogenomics will provide clinical recommendations using available, peer-reviewed literature and guidelines (i.e., Clinical Pharmacogenetics Implementation Consortium (CPIC)) for medications that are influenced by your genetic results.

What does metabolizer phenotype mean?

Some results on this test will have metabolizer phenotypes. These phenotypes tell you how fast or how slow certain proteins involved in medication metabolism are functioning in your body. These proteins may include enzymes that activate or break down medications, as well as transporters or targets responsible for removing them from the body. Each medication is uniquely metabolized by specific genes, which can vary greatly between individuals.

We use five different metabolizer phenotypes to describe the activity of proteins involved in medication metabolism: poor metabolizer, intermediate metabolizer, normal metabolizer, rapid metabolizer, and ultrarapid metabolizer.

• Poor Metabolizer metabolizes medications very slowly. Medications have a higher risk of not working or have an increased risk of side effects. Medications are typically avoided or given at lower doses if you have this phenotype.
• Intermediate Metabolizer metabolizes medications slowly but faster than poor metabolizers. Medications have a higher risk of not working or have an increased risk of side effects, but less risk compared to poor metabolizers. Medications are typically given at lower doses if you have this phenotype.
• Normal Metabolizer metabolizes medications as expected. Medications have the standard risk of not working or developing side effects. Medications are typically prescribed at standard (normal) dosing.
• Rapid Metabolizer metabolizes medications quickly. Medications have a higher risk of not working or have an increased risk of side effects, but less risk compared to ultrarapid metabolizers. Medications are typically prescribed at standard (normal) dosing, and some medications are avoided if you have this phenotype.
• Ultrarapid Metabolizer metabolizes medications very quickly. Medications have a higher risk of not working or have an increased risk of side effects. Medications are typically avoided or prescribed at a higher dose if you have this phenotype.

How long does it take to get my Pharmacogenetic (PGx) test results?

After obtaining the DNA sample, it usually takes up to three weeks to get your child’s test results.

What happens to the DNA sample?

Each DNA sample is kept unless requested to be destroyed by the patient or patient's legal guardian.  Stored DNA can be used for additional genetic testing that may be ordered by your healthcare provider in the future.  Stored DNA can also be used for research purposes, but ONLY if consent is provided by the patient or the patient's legal guardian.

How will I receive the PGx test results?

Your pharmacogenetic test results will be uploaded into the electronic health record, currently Epic, and will be viewable in MyChart.