Researchers reported that single nucleotide polymorphism (SNP) tests, which are used by DTC tests such as 23andMe, are not reliable in identifying the majority of BRCA1/2 mutations or other inherited cancer gene mutations. The SNP test used by many DTC ancestry and DNA companies is designed to detect common traits many people share. However, when this test is used to identify rare mutations that contribute to disease (e.g., BRCA1/2 mutations), the study found it
identified only 16% of nearly 5,000 rare mutations that could be confirmed by more stringent DNA testing/sequencing tools.
Authors of this study concluded:
- SNP-based tests are very unreliable to detect rare
mutations - These test results need to be confirmed in a clinical lab
before being used to guide health decisions
To raise awareness about this topic, the team at Vanderbilt
(Tuya Pal and Katie Lang) have partnered with MusiCares to
host a free virtual educational session open to the public
entitled 23 and Why Me, on Wednesday, October 6th at
1:30pm CT (11:30am PT, 2:30pm ET). During this 1-hour
session, they will debunk myths related to DTC testing and
other inherited cancer-related topics. Register for this free
event at https://tinyurl.com/MusiCaresOct2021.
Weedon, et al. BMJ. 2021 Mar. PMID: 33589468.