Just because you can conduct at-home DNA testing without the advice of a doctor doesn’t mean you should.
As people take a more proactive role in their healthcare, direct-to-consumer (DTC) kits have become increasingly popular.
Companies like 23andMe and DNA Direct make it easy to determine bloodlines and diagnose vulnerabilities to inherited diseases like breast cancer and cystic fibrosis.
But with great power comes great risk: A new study released by diagnostics company Ambry Genetics highlights the perils of these tests—false positives.
“The explosion of direct-to-consumer genetic testing over the last few years has created a ton of buzz, beyond just ancestry, health traits, and wine preferences,” Ambry genetic counselor Stephany Tandy-Connor wrote in a recent blog post.
Think of your genome as a book about you, with each gene a separate chapter (a long book, indeed); your DNA sequence is the letters that make up the words.
A clinical lab will read each word in a requested chapter, making sure large sections are not missing or duplicated. DTCs, on the other hand, use a method called SNP array, which reads only specific letters, but not the whole chapter (or even a full sentence).
“Many of these DTC labs also release raw data to the consumer,” Tandy-Connor continued. “This often leaves many individuals interested in what these findings mean and their potential impact on their healthcare management.”
Ambry’s research, published in the journal Genetics in Medicine, revealed a 40% false-positive rate, highlighting the importance of confirming DTC raw data before making any medical decisions.
The latest trend in DIY DNA looks for the BRCA gene, which increases the chance of developing breast and ovarian cancer.
23andMe is FDA-approved to report on three specific alterations in BRCA1 and BRCA2 genes, which together contain roughly 16,000 letters (sticking with the book analogy). Only four of those 16,000, however, are analyzed and reported by direct-to-consumer kits.
