Direct-to-Consumer Genetic Testing: Taking the Trend to the Next Level…Responsibly

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Our DNA tells a story — it tells us who we are. With advancements in genetic testing and an increased awareness in personalized healthcare, interest in direct-to-consumer (DTC) testing is on the rise. DTC genetic testing companies have made limited genetic testing for the general population readily accessible to healthy individuals. However, the U.S. Food and Drug Administration (FDA) have approved only a small subset of health-related results that DTC companies can provide. 

DTC testing is not intended to diagnose medical conditions, but rather provides carrier status and, at most, provides information about the probability of developing some diseases. In addition, guideline-setting genetics professional organizations, such as the American College of Medical Genetics (ACMG) and the American Society of Human Genetics (ASHG) caution individuals when purchasing DTC tests, citing limitations in analytical validity and result interpretation.1,2

While the FDA restricts the type of health-related information DTC companies can report, many DTCs offer consumers the option of purchasing or downloading their raw genotyping data, which include findings in many genes throughout the genome. This may include alterations that occur in genes associated with certain genetic disorders for which there are surgical and other interventions available. The raw data is usually accompanied by a disclaimer that the information is not meant for medical use; however this data can be misinterpreted as a diagnostic finding and individuals may feel a sense of urgency for medical follow-up.

Ambry Genetics often receives clinical confirmation testing of DTC genetic test results. Many of these orders request confirmation of an alteration reported in the raw data, and we frequently observe errors in the DTC results. We investigated how often confirmatory testing at Ambry revealed a false positive within a DTC result. From our internal cohort, we identified 49 patient samples with alterations previously identified by DTC testing. The confirmatory tests were run on Sanger sequencing or Next-generation sequencing (NGS), and 60% of the alterations were confirmed, while 40% were not confirmed. In other words, 40% of the alterations discovered by DTC tests were actually false positives. The majority of the false positive results came from raw data files. In addition, some findings reported by DTC testing were listed as risk-associated variants, which cause false alarms since they are actually classified as benign polymorphisms, or not disease causing by Ambry and other laboratories that perform routine clinical diagnostics for medical professionals. This information was shared in a scientific poster at the 2017 ACMG meeting.3

Genetic testing needs to be interpreted by a qualified healthcare professional within the context of other factors including personal and family medical history.

The limitations in raw genotyping data currently distributed by DTC companies demonstrates the importance of confirming DTC results in a quality clinical laboratory that is well-versed in complex alteration detection and classification. DTC genetic testing can benefit patients by creating awareness of individual and familial genetic risks and by empowering patients to make informed healthcare decisions. While having access to their raw genotyping data can empower patients, this type of information can also be inaccurate and misinterpreted. Genetic testing needs to be interpreted by a qualified healthcare professional within the context of other factors including personal and family medical history.  The bottom line: DTC testing for at-risk patients should be accompanied by confirmatory testing and appropriate clinical management by a qualified healthcare professional.

For more information about our research and collaboration, click here.
 

References:
1. Direct-to-Consumer genetic testing: a revised position statement of the American College of Medical Genetics and Genomics

2. ASHG Statement on Direct-to-Consumer Genetic Testing in the United States

3. False Positive Results Reported by Direct-To-Consumer Genetic Testing Highlight the Importance of Clinical Confirmation Testing for Appropriate Patient Care

 



Author


Co-authors

Jenna Guiltinan, MS, LCGC

Jenna Guiltinan, MS, LCGC

Jenna received her M.S. in Genetic Counseling from the California State University, Stanislaus in 2013 and began her career at Ambry as a Laboratory Genetic Counselor specializing in genetic variant analysis and results reporting. After nearly four years on the hereditary cancer team, Jenna recently transitioned to the Clinical Genomics department to focus on exome and microarray reporting. Jenna loves the outdoors and regularly hikes with her three dogs on mountain trails in and around Los Angeles, California.

Kate Krempley, MS, CGC

Kate Krempley, MS, CGC

Katie received her M.S. in Human Genetics from Sarah Lawrence College. She joined the Ambry Genetics team in 2015 and currently focuses on cancer gene variant assessment and results reporting. Prior to Ambry, she worked as a clinical prenatal genetic counselor. She has special interests in testing technologies, complex splicing alterations, and RNA analysis.

DISCLAIMER: THIS BLOG DOES NOT PROVIDE MEDICAL ADVICE

The information, including but not limited to, text, graphics, images and other material contained on this blog are for informational purposes only. The purpose of this blog is to promote broad understanding and knowledge of various health topics. It is not intended to be a substi- tute for professional medical advice, diagnosis or treatment. Always seek the advice of your physician or other qualified health care provider with any questions you may have regarding a medical condition or treatment and before undertaking a new health care regimen, and never disregard professional medical advice or delay in seeking it because of something you have read on this blog. Ambry Genetics Corporation does not recommend or endorse any specific tests, physicians, products, procedures, opinions or other information that may be mentioned on this blog. Reliance on any information appearing on this blog is solely at your own risk.

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