It is rather interesting as to the fact that it was an Indian sprinter's case that actually led to the rule being changed:
http://www.nytimes.com/2015/07/28/sports/international/dutee-chand-female-sprinter-with-high-male-hormone-level-wins-right-to-compete.html?_r=0
In the case of Dutee Chand, nobody is worked up about it, because she did not (and had no chance to) take a medal away from anyone. She did indeed qualify for the Olympic Games in the 100m by running under the standard of 11.30 (her PB is 11.24). But in the opening heat of the 100m at the Games, she ran a disappointing 11.69. When interviewed she said she had a 36 hour flight from India to Brazil and this combined with the grand stage of the Games made her nervous and resulted in a poor performance.
People cheered for her when she qualified (as did I) because it was the first time since 1984 that a woman from India qualified for the Olympic Games in a track event. Yes this is true.
Also Dutee Chand's case of hyperandrogenism is in the category of AIS (Androgen insensitivity syndrome). AIS people have a mutation which prevents testosterone (T) from being absorbed by the body; hence there will be plenty of T in the blood, but virtually none in other cells. Those with AIS usually look like any other woman from the outside. Since there is no T uptake in the body, there is no athletic advantage from the excess T in their blood.
Now lets discuss the official statement released to the press by the Court of Arbitration for Sport :
http://www.tas-cas.org/fileadmin/user_upload/Media_Release_3759_FINAL.pdf
They state:
"In the absence of such evidence, the CAS Panel was unable to conclude that hyperandrogenic female athletes may benefit from such a significant performance advantage".
Well, in my humble opinion, this was a classic case of the Court of Arbitration for Sport 'kicking the can down the road'. They basically are saying 'look we don't know' so lets re-visit this in two years. Or more likely 'we don't want to make a decision on this right now, because this is too controversial to tackle'.
C'mon really? You don't have any qualified Endocrinologist on your panel who can tell you that the OTHER type of Hyperandrogenism is Five alpha reductase deficiency (5-ARD)?
You don't know if higher levels of testosterone improve athletic performance in 5-ARD? Of course they do! What evidence are they requiring? Here is the evidence --> Semenya is runnning 1:55 without his testosterone lowering meds. When he was on them, he was running close to 2:00.
Why?
Because those born with 5-ARD have a mutation which prevents the creation of dihydrotestosterone, or DHT, in the body. DHT is a powerful androgen which triggers the formation of male genitalia. Thus, 5-ARD individuals (like Semenya, Niyonsaba and Wambui) are often assigned female gender. Unlike AIS people, however, those with 5-ARD are affected by the T in their system and become much more masculine at puberty. This can give them a very large athletic advantage over other women.
Caster Semenya chooses to compete, knowing that his higher levels of testosterone are giving him a clear advantage. He has refused to normalise his testosterone levels. That . . . is a clear case of the violation of fair play.