Patient Presents with Results of Home Genetics Test

By Charis Eng, MD, PhD, David Flannery, MD, Gary Procop, MD, Jacqueline Riley, MS, LGC, Wilson Tang, MD and Jennifer Hockings, PharmD, PhD

Direct-to-consumer (DTC) genetic testing is now so widely available that a patient can pick up a kit at any big box store or online retailer. These tests have changed a great deal in the last few years, offering information about ancestry and dietary preferences, markers for diseases like cancer and Alzheimer’s, and pharmacogenomics. As a result, more and more physicians will walk into the consult room and be presented with what may look like a clinical laboratory test result.

Important information about DTC genetic tests

When the FDA approved a 23andMe DTC test for genetic health risks in April 2017, it added a caution that DTC results should not be used for health decision-making. The approved test looks for variants associated with Parkinson’s disease, late-onset Alzheimer’s disease, celiac disease, alpha-1 antitrypsin deficiency, early onset primary dystonia, factor XI deficiency, Gaucher disease type 1, glucose-6-phosphate dehydrogenase deficiency, hereditary hemochromatosis and hereditary thrombophilia.

In 2015, the company received its first FDA approval to market a carrier screening test. In 2018, 23andMe received further approvals for a genetic test for three (of more than 1,000 known) BRCA variants that predispose a small percentage of the population to certain cancers, as well as a pharmacogenetic test that detects a limited number of variants affecting drug metabolism. The FDA has remained consistent in its warning that these DTC test results should be confirmed by independent clinical tests.

Not all genes and variants evaluated by DTC tests are clinically relevant. Conversely, DTC tests do not interrogate all medically relevant genes and their variants and thus do not provide comprehensive risk evaluation. Seeking DTC testing or receiving a positive result might inform a patient’s conversation with his or her doctor, but any results should be confirmed in a clinical setting. DTC results alone can neither exclude nor confirm a diagnosis or predict response to medications.

When a patient hands you a report

Be sure that patients who ask questions about their DTC genetic test results know that:

• Test results do not always provide a clear answer.
• Tests may provide useful information for some patients, but the results must be confirmed by a certified clinical laboratory using a compliant process, in the setting of pre- and post-test genetic counseling, prior to relying on them for reassurance, medical management or treatment planning.
• A positive finding — one that identifies a variant — does not necessarily mean they have or will develop the disease, or predict the severity of the disease if it does develop.
• A negative (normal) result for health risks does not mean the disease is not present, or will never develop. Risks for the vast majority of diseases, carrier status or cancer predisposition can be influenced by a wide variety of genetic changes, and DTC tests usually look for only a small number of these changes.
• Detection of pharmacogenomics variants does not necessarily mean medication changes are needed. Drug metabolism may involve multiple genes that are not always included in DTC tests.
• Normal results for pharmacogenomic tests do not necessarily mean they would avoid all adverse effects and tolerate all medications.
• At Cleveland Clinic, genetic counseling and pharmacogenomics consults are available for further interpretation and clarification of DTC test results, if needed.

Indications for follow-up genetic counseling or a pharmacogenomics consult include:

• The clinician and patient agree that the DTC genetic test result may be clinically relevant.
• Management or treatment decisions may be made based on clinical confirmatory test results.
• The patient has a clinical indication, such as symptoms or family history of a condition, even if the DTC genetic test results were normal.
• The patient desires clarification of DTC genetic test results.
• The patient has experienced adverse effects or the lack of efficacy to certain medications, such as thiopurines or antidepressants.

Documentation of DTC results in the EMR

If DTC results are presented or reported by the patient, these should be noted by the provider as unconfirmed information. Any action based on this or any other unconfirmed historical information should be integrated into the decision-making of the provider, in conjunction with other physical examination, historical, radiologic and/or laboratory findings, according to the provider’s best clinical judgment.