[Nihilartikel]

I wouldn't say that it has an acute immediate negative effect the gene pool by any measure, but it does certainly have an effect on the slow stochastic process shaping the gene pool. It would make intuitive sense that preventable, fecundity decreasing maladies will increase in frequency over time over many generations. Maybe that's not so much a pejorative effect as a beneficial adaptation to a new, more forgiving environment, if you look at it from the right perspective. Still I think that most people would agree that robust health in a low-tech environment is a nice trait to have in a population. Still, we're arguably pretty irreversibly reliant on fire and cooking.

Cave dwelling fish don't lose their eyes because of any immediate selection counter pressure, but from the slow reversion to the mean from no pressure either way. Or maybe the small pressure of nutrients spent on maintaining a useless organ.

Perhaps my example of my own case was misguided - I was turning blue and rushed to the emergency room as an infant, though. It was a single case provided to demonstrate a point where no single case matters that much.