Abstract
Genetic testing is used for screening, diagnosis, and prognosis of diseases consistent with a genetic cause and to guide drug therapy to improve drug efficacy and avoid adverse effects (pharmacogenomics). This In Practice review aims to inform about DNA-related genetic test availability, interpretation, and recommended clinical actions based on results using evidence from clinical guidelines, when available. We discuss challenges that limit the widespread use of genetic information in the clinical care setting, including a small number of actionable genetic variants with strong evidence of clinical validity and utility, and the need for improving the health literacy of health care providers and the public, including for direct-to-consumer tests. Ethical, legal, and social issues and incidental findings also need to be addressed. Because our understanding of genetic factors associated with disease and drug response is rapidly increasing and new genetic tests are being developed that could be adopted by clinicians in the short term, we also provide extensive resources for information and education on genetic testing.