"The South African Govt have decided this is a racist issue because naturally high T-Levels is a very rare thing but more common in Africa than elsewhere/"
To be clear, 'naturally high' means 'has testes'.
Various different things have happened, such as:
- intersex (XY) athlete has internal testes but no DHT so genitalia that appear female at birth. In some cases have had testes removed (in last couple of decades)
- intersex (XY) athlete has internal testes but is partially or completely insensitive to testosterone. In this case the issues is there is no way to quantify your sensitivity to testosterone. The vast majority of athletes who have AIS are not completely insensitive - only partly. Essentially a doctor would examine you and say 'you are somewhat virilized' or 'you have no virilization at all'. The latter case is relatively uncontroversial in that they have a female phenotype, but the former case is more so in that if your PAIS is sufficiently weak then you are unambiguously male and have male fertility. But the examining doctors in these cases of athletes with PAIS were basically unwilling to say 'you don't meet the cut-off to be female'.
As I understand it those two DSDs specifically affecting individuals with XY chromosomes constitute all or nearly all of the intersex cases in female sport.
There are many other DSDs, some of which result in 'naturally high testosterone', such as CAH and PCOS, both of which affect people with XX chromosomes, but there is no evidence that either condition is consistent with athletic success.
So basically: yes, we did have chromosome testing in the past (actually NOT for XY, but for the SRY gene, which is a gene on the Y chromosome that can rarely be transposed to the X chromosome, and which is the basic male/female gene), but they were uncovering people who had a female phenotype, but who had XY chromosomes and either infertility, or male fertility.
I don't think there was any desire to kick them out, especially when they did not appear masculine, or were not dominating sport.
The issue currently with the 800m is there are some very XY athletes who are not only not phenotypically female, but also are dominating, and the reaction is not 'oh well, let them compete', but 'we need to do something about it'.
It may be possible to hold that (for example),
- someone who is completely 'immune' to testosterone should be treated as female, despite XY chromosomes, based on their female phenotype, lack of testosterone in their brain, etc.
- but that they should not be allowed to compete in female sport because the Y chromosome carries other genes relating to height etc.
However I don't think we are at that position. What the IAAF are trying to do is something with testosterone levels, in order to avoid making such judgements, but with the goal of excluding non-phenotypically-female athletes from female sport.