In response to other posts insisting that one genetic test and one Y chromosome makes an athlete indisputably male with no room for error, I just want to point out that it not true.
There is always genetic exchange, for example, between a mother and baby, so anyone who has had a son will still have Y chromosomes in some cells in their body, and that will possibly show up in a genetic screening.
I am all for keeping men out of women's sport, and defining them genetically, but please lets not go over the top - one test does not prove you are male