ABCG2 and Medicines

What is ABCG2?

When you take a medicine, your body needs a way to handle it. One way your body does this is by using drug transporters to move medicines into and out of cells. Adenosine triphosphate (ATP)-binding cassette G2, known as ABCG2, helps the body get rid of a medicine called rosuvastatin (Crestor®).

How pharmacogenomic testing works

Each person differs from another at the DNA level. Genes are segments of DNA that act as a set of instructions and tell the body how to work. The ABCG2 gene is a section of DNA that instructs how well ABCG2 transporter will work. 

The study of how genes like ABCG2 affect the way your body interacts with medicines is called pharmacogenomics. Differences in your DNA that make up the ABCG2 gene can affect how well you are able to break down certain medicines. 

If you transport medicine too fast or too slow, the medicine may not work as well, or you may have more side effects. 

A pharmacogenomic test looks for differences that can help your medical team know how well your ABCG2 transporter will work. The test results can help your doctors and pharmacists choose the correct type or dose of medicine to give you.  

Please share your pharmacogenomic test results with all your new doctors and pharmacists. 

After pharmacogenomic testing 

The results of your ABCG2 test will place you into 1 of 4 ABCG2 gene groups: 

• Normal function: People in this group have normal working ABCG2 transporters. About 80% (80 in 100) of people are in this group. 
• Decreased function: People in this group have slightly lower functioning ABCG2 proteins. About 18% (18 in 100) of people are in this group. 
• Poor function: People in this group have very low ABCG2 transporter function. People who are in this group may need lower doses or a different medicine to avoid side effects. About 1% (1 in 100) of people are in this group. 
• Indeterminate phenotype: A small number of people will have unknown function of their ABCG2 transporter based on their test. About 1% (1 in 100) of people are in this group. 

The ABCG2 transporter helps break down a medicine called rosuvastatin. This medicine is used to lower cholesterol levels. Depending on what gene group you are in, you may need a lower dose of rosuvastatin.   

A second transporter called solute carrier organic anion transporter family member 1B1 (SLCO1B1) is important to break down rosuvastatin. You may also be tested for the SLCO1B1 gene. For more information, see SLCO1B1 and Medicines. 

Scientists continue to find new information about which medicines are affected by genes. Talk to your doctor or pharmacist if you have questions about your medicines, side effects, or pharmacogenomic testing. 

Find more information about genes that are being used to make medication therapy decisions for patients at St. Jude. 

If you have questions about pharmacogenomic testing done at St. Jude, you can email the Clinical Pharmacogenomics Program at pharmacogenomics@stjude.org. 

Related content