8
votes
Very rare pathogenic genetic variants detected by SNP-chips are usually false positives: implications for direct-to-consumer genetic testing
Link information
This data is scraped automatically and may be incorrect.
- Published
- Jul 9 2019
- Word count
- 427 words
The technology used in direct-to-consumer genetic testing performs very poorly in the detection of rare pathogenic variants, with postive predictive values for BRCA1 and 2 variants of only 4.2%.
Relevant article from The Guardian, discussing how this is problematic when consumers that may not fully understand the technical limitations see these variants in their raw data.
Yeah, I honestly wouldn't trust consumer genotyping for medical conditions. As far as I'm aware there's also a high likelihood of pathogenic mutations not being detected - I doubt my particular BRCA2 mutation, which has only been detected in a couple different families, would show up, for example. It's just the nature of the test.
It's worth considering that consumer genetic testing is usually not focused on rare diseases. These companies are more interested in either ancestry or layman-accessible genetic information. Something they can sell as a service (or possibly to third-parties).
I'm sure a consumer chip could be built which puts more emphasis on rare disease if that were desired. The technology is also getting better so more SNPs can be recorded.
A few years back I opted for Ancestry, not because I cared about the family tree stuff, but because they had the most-encompassing chip at the time and allowed me to download the raw data. I plugged that data into Promethease which offers a graphical representation and displays data from SNPedia.
But yes, I'd still be skeptical of any rare disease claims.