Genetic tests for about 1 000 health conditions have been developed, of which more than 600 are currently available for clinical testing[1]. Many genetic tests identify DNA variants; others measure biochemical markers or analyze chromosomes. Most are used for diagnosis of rare single-gene disorders or chromosome abnormalities, and a few are used for newborn screening[2]. A growing number of genetic tests may have population-based applications. This includes determining the risk of developing a disease or condition in the future (e.g., predictive testing for breast cancer or cardiovascular disease), and recognizing genetic variations that can influence response to medicines (pharmacogenomics). These genetic tests, therefore, have the potential for broad public health impact.