So that raises a bunch of questions about genetic testing that I want to touch on. The most obvious, to begin with, is who should be tested. By the way, I need to draw a distinction fairly early on between screening and testing.
Testing has to do with individuals.
Screening refers to whole populations. There are diseases for which we now screen routinely. Dietary changes can prevent the onset of this otherwise terrible disorder. So, screening is effective when it's cheap and when there is something that can be done effectively to remedy the condition. I think that the consensus that is now emerging is that we shouldn't even begin to think of genetic screening for a whole range of issues and that we should limit testing to those who are in high risk categories.