Isn't this exactly the premise of the movie Gattaca? Great movie, BTW.
IMO Gattaca makes a great case for genetic testing. An idiot with a major heart condition bluffs his way onto a space mission where he's likely to die and endanger the rest of the crew. If the testing had been a bit more thorough (say, if the doctor in charge of testing had done his job) then the mission wouldn't have been endangered. It's strange to see everyone hold up this movie as an argument against this sort of…
I would far rather have Ethan Hawke's character as a coast guard swimmer rescuing me in a storm than his brother, even if his brother had no similar heart defect. I would do that because I saw two instances in the movie of him out-performing his brother in feats of swimming endurance when under pressure.
His character is statistically more likely to die on the mission. Just to get a handle on the numbers let's say that with their filtering a 30 year old has about 1/20,000 chance of dying in a given month, and he might have a 1/1000 chance. We haven't seen anything about how he outperformed other candidates, but we can consider the respect of his peers and that he has succeeded in spite of appreciable time spent on establishing an identity and tracking down his DNA.
It probably doesn't matter if he dies on a routine mission. It is the rare mission with an anomaly where someone who is truly exceptional matters. If he is only 20 times more likely to provide the unusual solution that saves the mission, then it is a wash.
Anyway, my point is that one perspective on filling positions is to develop a long list of dis-qualifiers like health forecasts (and minimum competence). That is different than choosing the most extraordinary people possible (where negatives play a role in that determination). I know there is a tendency toward the former when choosing people for very selective and highly sought after roles, but it probably only appropriate when trying to fill out a large headcount with minimal resources for selecting the people. Those who can excel during crunch time are probably far more important for high level positions that are routine but punctuated requirements for extraordinary performance, than the people who look good to a hiring manager playing it safe and relying on clear but potentially less important signals.