An increasing number of companies offer at-home genetic testing, also known as direct-to-consumer (DTC) genetic testing. People collect a saliva sample or a mouth swab themselves and submit the sample through the mail. They learn about the test results on a secure website, by mail, or over the phone.
The genetic testing for cancer risk that is typically ordered by a doctor involves testing for inherited genetic variants that are associated with a high to moderate increased risk of cancer and are responsible for inherited cancer susceptibility syndromes. By contrast, DTC genetic testing for cancer risk often involves the analysis of common inherited genetic variants that, individually, are generally associated with only a minor increase in risk. Even when added together, all the known common variants associated with a particular cancer type account for only a small portion of a person’s risk of that cancer. Genetic tests based on these common variants have not yet been found to help patients and their care providers make health care decisions and, therefore, they are not a part of recommended clinical practice.
Even when people have DTC genetic tests for gene variants that are known to be associated with inherited cancer susceptibility syndromes, there are potential risks and drawbacks to the use of DTC testing. For instance, some DTC genetic tests look for variants in the BRCA1 and BRCA2 genes that are associated with Hereditary Breast and Ovarian Cancer Syndrome (HBOC). However, this testing looks only for three specific variants out of the thousands that have been identified. Therefore, someone could have a negative result with this kind of test but still have a harmful BRCA1 or BRCA2 gene variant that was just not identified by that test. In particular, without guidance about the most appropriate genetic testing to do and interpretation of the genetic test results from a knowledgeable health care provider, people may experience unneeded anxiety or false reassurance, or they may make important decisions about medical treatment or care based on incomplete information.
The U.S. Federal Trade Commission (FTC) has a fact sheet about at-home genetic tests that offers advice for people who are considering such a test. As part of its mission, FTC investigates complaints about false or misleading health claims in advertisements.
Genetics Home Reference, a consumer health website from the National Library of Medicine at the National Institutes of Health, has information about DTC genetic testing.