Thursday, November 29, 2018

McCRISPR and the Collective Sanctimony of the Scientists Who Made it Happen

I don't want to add too much to the obvious ethical lapse of the recent CRISPR human guinea pig experiment by Chinese genetic scientist, He Jiankui, as there is an endless stream of outraged scientists, exemplified by this article in Nature: CRISPR-baby scientist fails to satisfy criticsI would, however, like to make a point about the collective scientific outrage, exemplified by a few quotes in the article linked above:
“I’m happy he came, but I was really horrified and stunned when he described the process he used,” says Jennifer Doudna, a biochemist at the University of California, Berkeley, and a pioneer of the CRISPR–Cas-9 gene-editing technique that He used. “It was so inappropriate on so many levels.”
So, it was "the process he used" rather than what he did.  If only he had used a more appropriate process.  Let's look at another quote:

Tuesday, November 6, 2018

Longevity "genetics" appears to be strongly inflated due to assortative mating

This study just came out which used the Ancestry database to assess the genetic heritability of longevity, which has been previously formulated as upwards of 15 to 30%.  They found that, in fact, taking away assortative mating it is below 10%.  They used pedigrees and compared the in-law siblings.
A GWAS in such a scenario, then, would pick up a lot of extraneous, noncausal genetic associations that were really just related to commonalities from assortative mating, leading one to believe that these genes had some specific role for longevity and possibly wasting a researcher's time.
I would be interested in seeing a similar study on educational attainment, as I think it might very well show the same thing.  I have, in fact, postulated just this in previous posts on here.

Saturday, November 3, 2018

A Recent Critique of PRS

This preprint (updated) does some mathematical modeling and shows that PRS, even with h2 = 1, is not as useful as previously thought.  I'll spare you the math (which I'm still trying to wrap my head around) and leave you with their conclusion:
"In summary, our investigation clears up some misconceptions on PRS and demonstrates that PRS is not as useful as its name suggests, and as powerful as the genetics community expects neither for predicting polygenic traits. We hope this research will serve as a wake up call to the genetics community in appreciating more about the challenges in studying complex polygenic traits. As such, more resources and efforts can be devoted in performing better experiments and developing better statistical methods."