How Laboratory Developed Tests (LDTs) Work

This material has been reviewed for accuracy by: Renee Albers, PhD

scientist conducting a laboratory developed testLaboratories are the source of many medical advances, from vaccines to medications. The GeneSight® test itself was developed in a clinical laboratory.

The GeneSight test is an example of what are known as Laboratory Developed Tests (LDT) – tests designed, manufactured and used within a single laboratory. Some LDTs are relatively simple tests that measure a single substance, like the level of sodium in a patient’s blood. More complex LDTs may measure or detect more substances or analyze genetic code.

Because these tests are used to provide insight into health issues, they require significant oversight.

LDTs are Overseen by Multiple Government Agencies

Traditionally, LDTs have been regulated by the Centers for Medicare & Medicaid Services (CMS), an agency within the United States Department of Health and Human Services (HHS) that administers the Medicare program and works in partnership with state governments to administer Medicaid.

To ensure quality laboratory testing, CMS enforces the Clinical Laboratory Improvement Amendments (CLIA 1988), which are federal regulatory standards for approximately 260,000 laboratories across the country.  These strict standards include guidelines on personnel, quality control, and proficiency testing. Additionally, CLIA requires laboratories to document the validity of LDTs, participate in proficiency testing and be subject to government inspections.

Button with text "Read our Clinical Studies"State and other entities also oversee LDTs’ laboratories to ensure accurate and reliable test results when laboratories perform the testing on patient specimens. Centers for Medicare and Medicaid Services (CMS) granted the CAP (College of American Pathologists) Laboratory Accreditation Program deeming authority, which allows CAP inspection in lieu of a CMS inspection. In addition, some states may require more extensive accreditation. For example, New York State Department of Health asks that laboratories document analytic and clinical validity of a test prior to introducing it to New York State patients.

FDA’s Role in LDT Oversight

There’s a bit of a gray area on the FDA’s role in regulating LDTs – one that the Agency itself acknowledges. In late 2017, the FDA issued a discussion paper on whether it should consider regulating LDTs.

The FDA has admitted the reason for their increased attention is the dramatic increase in the number and complexity of LDTs, particularly in the field of genetic testing. Accordingly, the Agency is evaluating whether some LDTs need clearance or approval from the FDA prior to being offered to ensure their safe and effective use in patient care.

There is still much debate within the industry on whether the FDA should regulate LDTs. For example, the American Academy of Clinical Chemistry supports the current regulatory model by CMS.

FDA Oversees Direct-to-Consumer Tests

signs labeled Extraction and DNA Stamping within a laboratoryThere are different levels of FDA oversight for Direct to Consumer (DTC) testing dependent on what each test does. In the past, the FDA has sent letters to numerous companies when they think a test that is marketed as DTC requires the involvement of a health care provider. For others, they exercised enforcement discretion without regulating them, saying in effect that these tests are low risk to consumers. The FDA recently granted market authorization to a company to sell their test DTC but the agency cautioned against using this test to make any treatment decisions.

In a statement about the FDA decision, Tim Stenzel, director of the Office of In Vitro Diagnostics and Radiological Health in the FDA’s Center for Devices and Radiological Health warned that:

“Any medical decisions should be made only after discussing the results with a licensed health care provider and results have been confirmed using clinical pharmacogenetic testing.”

GeneSight Complies With All Standards, Laws

GeneSight is a clinical pharmacogenomic test that is processed in the Myriad Neuroscience laboratory, which is accredited by CLIA, CAP, and several State Departments of Health including New York, California, Rhode Island, Maryland, Pennsylvania, and Florida.

scientist conducting a pharmacogenomic test in a laboratoryThe GeneSight test complies with all industry and quality standards, all federal laws, and HIPAA (the Health Insurance Portability and Accountability Act of 1996) and GINA (the Genetic Information Nondiscrimination Act of 2008) regulations.

The GeneSight test must be ordered by a healthcare provider who prescribes medicines based on medical necessity

“While genetics provides an important piece of the puzzle, other factors can influence medication response and susceptibility to side effects, including drug/drug interactions, food/drug interactions, allergies, and environmental factors such as lifestyle,” said Dr. Bryan Dechairo, Ph. D., Executive Vice President, Clinical Development, Myriad Genetics, Inc., the parent company of Myriad Neuroscience.“ Accordingly, a healthcare provider must take into consideration a patient’s entire clinical profile for medication selection and a personalized treatment program.”

Visit our website for more information:

Image instructing clinicians to learn more about the GeneSight test

Our articles are for informational purposes only and are reviewed by our Medical Information team, which includes PharmDs, MDs, and PhDs. Do not make any changes to your current medications or dosing without consulting your healthcare provider.

The GeneSight test must be ordered by and used only in consultation with a healthcare provider who can prescribe medications. As with all genetic tests, the GeneSight test results have limitations and do not constitute medical advice. The test results are designed to be just one part of a larger, complete patient assessment, which would include proper diagnosis and consideration of your medical history, other medications you may be taking, your family history, and other factors.

If you are a healthcare provider and interested in learning more about the GeneSight test, please contact us at 855.891.9415. If you are a patient, please talk with your doctor to see if the GeneSight test may be helpful.

Published: February 20, 2019