Genetic testing is a type of medical examination that looks for changes in genes, chromosomes, or proteins. It can uncover mutations in DNA that can cause a disease or illness. Currently, more than 77,000 genetic tests are available and new ones are being developed. The process is done with a blood or saliva sample and the results are usually ready within a few weeks. Genetic testing can provide a diagnosis of a genetic condition, such as the fragile X chromosome, or information about the risk of developing cancer.
Panel genetic tests can be grouped into genes related to an increased risk of developing certain types of cancer, such as breast cancer or colorectal (colon) cancer. Diagnostic genetic tests are often used during pregnancy, but they can be used at any time to confirm a diagnosis if you have symptoms of a certain disease. Large-scale genomic testing is also used in research to learn more about the genetic causes of conditions. If you test positive for a genetic condition or you find that you have a higher risk of developing a disease, you should contact your healthcare provider. These types of tests can help your healthcare provider choose medications that best fit your genetic makeup. Because genetic testing provides information about DNA, which is shared with other family members, sometimes the result of a genetic test can have implications for the blood relatives of the person who was tested.
The approach to genetic testing is individualized based on your medical and family history and the condition you are being tested for. Genetic counseling before and after genetic testing can help ensure that you are the right person in your family to have a genetic test, that you have the right genetic test, and that you understand the results. If you're concerned about a pattern of cancer in your family, cancer you've had in the past, or other risk factors for cancer, it may be beneficial to talk to a healthcare provider about whether genetic counseling and testing might be an option for you. Genetic test results can be difficult to comprehend, but specialists such as geneticists and genetic counselors can help explain what the results may mean for you and your family.