which is that it's likely LOTS of people have sex chromosome abnormalities and we just don't know it, because not everyone gets their chromosomes looked at. And a lot of early assumptions about sex chromosomes--like that it automatically leads to infertility or mental slowness and stuff--is likely biased because the only people getting tested were people who had some kind of health issue prompting the test.
I think it would be interesting if similar tests were done on male athletes and it turns out there's a bunch of XXY or XXXY males.