Genetic tests: clinical validity and clinical utility

Abstract

When evaluating the appropriate use of new genetic tests, clinicians and health care policymakers must consider the accuracy with which a test identifies a patient's clinical status (clinical validity) and the risks and benefits resulting from test use (clinical utility). Genetic tests in current use vary in accuracy and potential to improve health outcomes, and these test properties may be influenced by testing technology and the clinical setting in which the test is used. This unit defines clinical validity and clinical utility, provides examples, and considers the implications of these test properties for clinical practice.

Keywords: clinical utility; clinical validity; penetrance; predictive value.

Figure 1

Family with multiple endocrine neoplasia type 2 (MEN2). A definitive diagnosis of MEN2 can be made in the proband (arrow), on the basis of clinical findings of MEN2 (medullary thyroid cancer and hyperparathyroidism), combined with a family pedigree demonstrating autosomal dominant inheritance of the clinical problems associated with MEN2, including medullary thyroid cancer in the proband’s father, and pheochromocytoma and C-cell hyperplasia (a precursor of medullary thyroid cancer) in the proband’s daughter.