Wrangle Over DTC Results: Ambry Study Highlights 40% False Positives

May 21, 2018
Wrangle Over DTC Results: Ambry Study Highlights 40% False Positives
A recent study led by Ambry Genetics found that rates of false positives among direct-to-consumer genetic tests was as high as 40%.

Alex Philippidis

A study by Ambry Genetics researchers showed that as much as 40% of the variants in a variety of genes reported in the raw data of direct-to-consumer (DTC) tests were false positives. The researchers, and Ambry itself, said the study findings raise questions about the accuracy of DTC genetic testing—while the largest DTC test provider in turn has raised questions about the study and has defended its testing results. A team of eight Ambry researchers analyzed the raw data of 49 patients who were referred to the clinical diagnostic lab of Ambry Genetics for confirmatory testing of variants previously identified by DTC testing between January 2014 and December 2016.

The patients previously shared these raw test data with their medical providers. The researchers found that two out of every five variants noted in the DTC raw data were incorrectly reported and could not be verified by further diagnostic lab tests. In eight instances, according to the study, the variants that were present were misunderstood by third-party interpretation services.

“While having access to raw genotyping data can be informative and empowering for patients, this type of information can also be inaccurate and misinterpreted,” the researchers concluded in the study “False-positive results released by direct-to-consumer genetic tests highlight the importance of clinical confirmation testing for appropriate patient care,” published in Genetics in Medicine.

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