Before undergoing genetic testing, it is important to be sure that the test is valid and useful. A genetic test is valid if it provides an accurate result. Two main measures of accuracy apply to genetic tests: analytical validity and clinical validity. Another measure of the quality of a genetic test is its usefulness, or clinical utility.
Analytical validity refers to how well the test predicts the presence or absence of a particular gene or genetic change. In other words, can the test accurately detect whether a specific genetic variant is present or absent?
Clinical validity refers to how well the genetic variant being analyzed is related to the presence, absence, or risk of a specific disease.
Clinical utility refers to whether the test can provide helpful information about diagnosis, treatment, management, or prevention of a disease.
All laboratories that perform health-related testing for disease prevention, diagnosis, or treatment, including genetic testing, are subject to federal regulatory standards called the Clinical Laboratory Improvement Amendments (CLIA) or even stricter state requirements. CLIA standards cover how tests are performed, the qualifications of laboratory personnel, and quality control and testing procedures for each laboratory. By controlling the quality of laboratory practices, CLIA standards are designed to ensure the analytical validity of genetic tests.
CLIA standards do not address the clinical validity or clinical utility of genetic tests. The Food and Drug Administration (FDA) requires information about clinical validity for some genetic tests, particularly those tests that can influence a person's medical care. Additionally, states may require additional information on clinical validity for laboratory tests performed for people living in that state. Test takers, health care providers, and health insurance companies are often the ones who determine the clinical utility of a genetic test.
It can be difficult to determine the quality of genetic tests sold directly to the public. Some providers of direct-to-consumer genetic tests are not CLIA-certified, and many direct-to-consumer genetic tests are not regulated by the FDA, so it can be difficult to tell whether the tests are valid. If providers of direct-to-consumer genetic tests offer easy-to-understand information about the scientific basis of their tests, it can help people make more informed decisions. It may also be helpful to discuss any concerns with a health care provider before ordering a direct-to-consumer genetic test and after receiving test results.