Last fall, the Food and Drug Administration (FDA) finally took steps toward an action that it had been publicly considering for over four years: the regulation of laboratory-developed tests (LDTs). The FDA defines LDTs as tests which are “designed, manufactured, and used within a single laboratory.”
This definition encompasses a wide range of diagnostics, including complex multigene panels that are performed in just a single laboratory in the United States, and basic diagnostic tests like a complete blood count, which are performed in thousands of laboratories nationwide.
As long as a manufacturer does not make and sell a kit for use in other laboratories, its test can be provided as an LDT. Estimates suggest that tens of thousands of diagnostic tests, including the majority of genetic tests, are currently available as LDTs.
