23andMe currently uses a genotyping chip, not gene sequencing. So, this article is misleading at the top (but gets more accurate at the bottom).
Early variant discovery suffers from the winner's curse phenomenon: we overestimate the effect of newly discovered mutations.
As time has gone on, it has become clear that even for many Mendelian diseases, the genetic background plays a significant role in terms of who will develop the disease (or how early they will do so). The estimates of "penetrance" have fallen as we have obtained more data.
This affects clinical genetic interpretation as well as the automated stuff that 23andMe is doing.
This is our biggest gripe with the service. We have a lot of consumers that ask us to perform gene sequencing for them expecting to get something similar to 23andMe. It's always a hurdle to explain the difference between what we do (targeted gene sequencing) and genotyping chip. They're a worlds difference and requires some reading.
Early variant discovery suffers from the winner's curse phenomenon: we overestimate the effect of newly discovered mutations.
As time has gone on, it has become clear that even for many Mendelian diseases, the genetic background plays a significant role in terms of who will develop the disease (or how early they will do so). The estimates of "penetrance" have fallen as we have obtained more data.
This affects clinical genetic interpretation as well as the automated stuff that 23andMe is doing.