Source: The Scientist 

Recent study released January 13, 2021 by the BMJ proves SNP chip testing produce false positives for rare pathogenic variants such as those found in breast cancer.

Direct to consumer home base genetic testing kits have been gaining popularity over the years as they encourage more awareness among consumers about genetic diseases. However, these tests kids have been a subject of scrutiny as they have been many reports of there in accuracies. The danger of these test kids comes in when consumers take their results too medical practitioners in order to seek out treatment for genetic disorders they may not have. The study released by the BMJ found that “SNP chips are extremely unreliable for genotyping very rare pathogenic variants and should not be used to guide health decisions without validation.”

However, this is not the first time that these genetic test kits have been proven to be inaccurate. An article published by The Scientist in 2019 found that direct to consumer (DTC) genetic testing kits displayed false positives of up to 85% when testing for rare [genetic] variants. Dr Chimuka Mbala, a researcher at CIDRZ (Center for Infectious Disease Research in Zambia), says that it is generally not encouraged for the public to do any form of self-testing especially when it comes to serious conditions such as genetic disorders. “Given the fact that there is so much evidence that these genetic tests kits are dysfunctional, it is also irresponsible of medical practitioners to take the results of these tests from patients without conducting or encouraging further testing themselves.” Another article published by Nature.com in 2018 40% of variants in a variety of genes were false positives in direct-to-consumer testing. The article concluded that the “Results demonstrate the importance of confirming DTC raw data variants in a clinical laboratory that is well versed in both complex variant detection and classification.”

Yet another article published by Science Magazine in 2010 found results similar to those in  the study by the BMJ. According to the article, the article found the test results of the small group of patients differed from the patients’ calculated family history half the time. According to Mbala, “This is just the downside of science sometimes you try things, and they don’t work. It can take a while until there is proper research to back up certain theories. Science is always a trial-and-error process.”