Cancer Genetics Risk Assessment and Counseling (PDQ®): Genetics - Health Professional Information [NCI] - The Option of Genetic Testing
Table 1. Clinical Utility of Genetic/Genomic Testsa continued...
In regard to analytic validity, genetic tests fall into two primary categories; test kits and laboratory-developed tests (previously called home brews). Test kits are manufactured for use in laboratories performing the test and include all the reagents necessary to complete the analysis, instructions, performance outcomes, and details about which mutations can be detected. The U.S. Food and Drug Administration (FDA) regulates test kits as medical devices; however, despite more than 1,000 available genetic tests, there are fewer than ten FDA-approved test kits. Laboratory-developed tests are performed in a laboratory that assembles its own testing materials in-house;  this category represents the most common form of genetic testing. Laboratory-developed tests are subject to the least amount of oversight, as neither CLIA nor the FDA evaluate the laboratories' proficiency in performing the test or clinical validity relative to the accuracy of the test to predict a clinical outcome.[10,12] The FDA does regulate manufactured analyte-specific reagents (ASRs) as medical devices. These small molecules are used to conduct laboratory-developed tests but can also be made by the laboratory. ASRs made in the laboratory are not subject to FDA oversight. For laboratory-developed tests utilizing manufactured commercially available ASRs, the FDA requires that the test be ordered by a health professional or other individual authorized to order the test by state law. However, this regulation does not distinguish between health providers caring for the patient or health providers who work for the laboratory offering the test.
In addition to classical clinical genetic tests is the regulatory oversight of research genetic testing. Laboratories performing genetic testing on a research basis are exempt from CLIA oversight if the laboratory does not report patient-specific results for the diagnosis, prevention, or treatment of any disease or impairment or the assessment of the health of individual patients. However, there are anecdotal reports of research laboratories providing test results for clinical purposes with the caveat that the laboratory recommends that testing be repeated in a clinical CLIA-approved laboratory. In addition, there is no established mechanism that determines when a test has sufficient analytic and clinical validity to be offered clinically. Currently, the decision to offer a genetic test clinically is at the discretion of the laboratory director.