I spent a couple minutes searching just now.

It looks as though Klobukowska was trisomatic X (ie XXX chromosomes vs the typical XX for women) which apparently something like 1 in 1,000 women are.

Among the consequences of this disorder are extra height, which is an advantage in running and "subtle physical and skeletal anomalies" which I haven't seen explained but could also contribute to athletic performance.

Obviously if you just let everyone compete the winners will typically be men at the far end of the bell curve. If you try to create a restricted category for some group the winners will be at the far end of the bell curve inside of that group. For women's sports, this is going to mean cross-dressing men (who should probably be excluded) but also people with masculinizing genetic disorders like Klobukowsky and Semenya, as well as women with disorders of a non-genetic nature which promote testosterone (or other beneficial hormones for the competition in question).

In an unrestricted competition you will obviously have "gifted" men competing alongside performance-enhancing drug use, but at least everyone belongs in the competition and you don't have these edge cases.

All in all, this is another reminder that women's sports should be discontinued.