Today we present the second installment of my interview with medical geneticist Robert Green about the promises and pitfalls that could lie in reading out your full genome. Part one ran yesterday—so if you missed it, click right here. Otherwise, you can press play on the embedded player or pull up the transcript—both of which are below.

In this installment, we discuss why some medical researchers view personal genetic information as a literal toxin. This isn’t strictly out of paternalism (although there are elements of that). A tiny fraction of people might indeed make discoveries that are both horrible and unactionable. A larger fraction could suffer anguish from the sheer ambiguity of what’s divulged. After carefully studying both the psychology and consequences of these situations, Robert is fully convinced that personal genetic information should be made available to any adult who seeks it after being soundly apprised of the ramifications.

We next discuss rare genetic diseases and how incongruously common they are. Robert’s groundbreaking research recently revealed that as much as a fifth of us are recessive carriers of some exotic genetic horror or other. Which brings us to the important notion of partial “penetrance,” or diseases that can slightly (and often mysteriously) manifest in a recessive carrier. High school biology trains us to think of recessive/dominant and afflicted/unafflicted in very binary terms. In reality, there are many gradations between the poles.

Toward the end of today’s installment, we discuss an agonizing instance in which Robert’s team deduced that the mother of a child whose genome they’d sequenced in a study simply had to be carrying a certain dangerous gene—but research protocols from their IRB (institutional review board) forbade them from warning her. This exemplifies the ethical weirdness that can arise when self-knowledge is viewed as “toxic” (in this case, the toxicity of ignorance was greater).

If you enjoy this installment and just can’t wait for part three (which goes up on Ars tomorrow), you can find it in my podcast feed, where it first appeared in September of last year. A full archive of my episodes can be found on my site or via your favorite podcast app by searching for “After On” (the podcast’s title).

There, you’ll find deep-dive interviews with other world-class thinkers, founders, and scientists, tackling subjects including synthetic biology, cryptocurrency, astrophysics, drones, genomics, neuroscience, consciousness, privacy and government hacking, and a whole lot more.

Lastly, if you’re curious about the latest episode in the main After On podcast feed, this week it’s an interview with Yale ornithologist and evolutionary heretic Richard Prum. Rick boldly and brilliant refutes much of the common wisdom about sexual attraction, aesthetics, and more. And the wellspring of his unorthodox ideas is... Charles Darwin himself. Even if you’re not at all into birds, you’ll find this interview intriguing if you’re interested in the deep roots of human behavior and biology.

This special edition of the Ars Technicast podcast can be accessed in the following places:

iTunes:

https://itunes.apple.com/us/podcast/the-ars-technicast/id522504024?mt=2 (Might take several hours after publication to appear.)

RSS:

http://arstechnica.libsyn.com/rss

Stitcher

http://www.stitcher.com/podcast/ars-technicast/the-ars-technicast

Libsyn:

http://directory.libsyn.com/shows/view/id/arstechnica