Home genetic tests: how accurate are they?

Researchers at Ambry Genetics Corp analyzed how accurate direct-to-consumer genetic tests are in highlighting specific genetic variants. They found test raw data was incorrectly reported and could not be verified by further diagnostic laboratory tests in around 40% of the cases. These findings based on a small sample of 49 patients are reported in journal Genetics in Medicine.

Direct-to-consumer genetic tests (DTC) or home genetic tests are not diagnostic but are usually available to uncover information about ancestry, the risk of developing certain conditions and to check if they are a carrier to specific autosomal recessive conditions.  Home genetic tests are regulated by Food and Drug Administration, which currently prohibit these companies from offering diagnostic genetic tests. While they are not diagnostic some of the companies can provide raw data that can be interpreted by the third party for a fee.

Research led by Tandy-Connor and her colleagues set out to assess how accurate home genetic tests were in highlighting the presence of specific genetic variants. They analyzed the raw data of 49 patients that were referred to Ambry Genetics Corp for confirmatory testing, after sharing their home genetic tests raw data results with their medical providers. They found that two out of every five results were incorrectly reported and could not be further verified.

“Such a high rate of a false positives in this particular study was unexpected,” says Tandy-Connor, who believes that some of the discrepancies in the results can be explained by technical differences between the various testing methods used. “While direct-to-consumer genetic test results may lead to healthy changes in lifestyle or diet, these could also result in unwarranted emotions, including anxiety when someone obtains unexpected information, inaccurate information, or disappointment when receiving a lack of comprehensive diagnostic analysis.”

“The relatively small cohort simply reflects the reality that most people who get such direct-to-consumer genetic test results don’t seek confirmatory testing,” says Tandy-Connor. “People may assume that they are being provided accurate medical grade testing, so understandably do not go to the trouble and expense of seeking confirmation.”

Reference: Tandy-Connor, Stephany, Jenna Guiltinan, Kate Krempely, Holly Laduca, Patrick Reineke, Stephanie Gutierrez, Phillip Gray, and Brigette Tippin Davis. “False-positive Results Released by Direct-to-consumer Genetic Tests Highlight the Importance of Clinical Confirmation Testing for Appropriate Patient Care.” GENETICS in MEDICINE, 2018. doi:10.1038/gim.2018.38.

Adapted from press release by Springer.