Genetic Testing

What is Genetic Testing?

What is genetic testing? Genetic testing is a type of medical test that looks for changes, sometimes called variants or mutations, in your DNA. DNA contains the genetic instructions in all living things. Often, these changes have no effect, but sometimes, even a small change in DNA can cause disease or other health conditions. Genetic tests take a sample of your blood or tissues and check your cells to look for any changes in: Genes are parts of DNA found in your cells that carry information that controls what you look like and how your body works. Many genes tell your body how to make proteins, which are needed for your body to work correctly. Genome sequencing is a process that checks all your DNA. Exome sequencing is a process that only checks the parts of your DNA that provide instructions to make proteins. Proteins do most of the work in your cells. If there are changes in the amount and activity level of proteins, they might be due to changes in the genes that produce those proteins. Chromosomes are thread-like structures in your cells. Each chromosome is made up of DNA tightly packaged around proteins. People usually have 23 pairs of chromosomes that contain all their DNA. What are the different ways to get genetic tests? Most of the time, genetic testing is done through your health care provider. This is called clinical testing. It is done to find out about an inherited disorder (passed down through families) and to help make decisions about your care. Other ways to get genetic testing include: Research-based testing is a genetic test done as part of a research study (clinical trial). Direct-to-consumer (DTC) testing is a genetic test that allows you to send a DNA sample and get the results. You may do this to learn about your ancestry or your risk for certain diseases. Why is genetic testing done? Genetic testing may be done for many different reasons, including to: Find genetic diseases in a fetus. This is a type of prenatal testing. Screen newborn babies for certain treatable conditions. Lower the risk of genetic diseases in embryos that were created using assisted reproductive technology. Find out if you carry a gene for a certain disease that could be passed on to your children. This is called carrier testing. See whether you are at an increased risk of getting a specific disease. This may be done for a disease that runs in your family. Diagnose certain diseases. Identify genetic changes that may be causing or contributing to a disease that you were already diagnosed with. Help guide your provider in deciding the best medicine and dosage for you. This is called pharmacogenomic testing. To check for, monitor, or manage a disease. This is sometimes used to help find the best cancer treatment. To confirm the biological father (paternity) of a child, or how much genetic information is shared with other relatives. To explore the likelihood of having or developing certain physical traits, such as hair color or facial dimples, or to learn about your ancestry. To help advance our understanding of genetic conditions, learn how genes work, and find unknown genes. How is genetic testing done? Genetic tests are often done on a blood or cheek swab sample. But they may also be done on samples of hair, saliva, skin, amniotic fluid (the fluid that surrounds a fetus during pregnancy), or other tissue. The sample is sent to a laboratory. There, a lab technician will use one of several different techniques to look for genetic changes. What are the benefits of genetic testing? The benefits of genetic testing include: Helping your provider make recommendations for the management or monitoring of a genetic condition. Giving you more information for making decisions about your health and your family's health: If you find out that you are at risk for a certain disease, you might take steps to lower that risk. For example, you may find out that you should be screened for a disease earlier and more often. Or you might decide to make health

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