I always feel weird to think just how common a 0.1% is actually on any slightly bigger population. It is 1 in 1000. Or 100 in 100k and in this case 300... Which

I always feel weird to think just how common a 0.1% is actually on any slightly bigger population. It is 1 in 1000. Or 100 in 100k and in this case 300... Which isn't actually so many. And then you start listing up these sort of "rare" conditions and wonder where do we actually end up and how much overlap there is.