[blinkedup]

I agree that an XY karyotype isn't conclusive proof that an individual is male, but it's a good heuristic for male physical advantage. In the context of women's sports, and certainly at an elite level, there are very few XY DSDs that don't confer such advantage and would still permit an individual to be competitive.

Like for example, Swyer syndrome is an XY DSD where the individual has a female phenotype (including uterus, fallopian tubes, and vagina) but complete gonadal dysgenesis. No ovaries or testes. Because of oestrogen deficiency, such individuals end up with a very high risk of bone defects including osteopenia and osteoporosis - which is not compatible with competitive sport.

Even with CAIS, an XY DSD where the body cannot process testosterone at all so despite presence of testes the individual develops an otherwise female phenotype, has a curiously higher incidence in athletes competing at an elite level, compared to the average within the general population: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5643412

> although they are likely to be taller than the average 46,XX woman given some height-determining genes on the Y chromosome and perhaps some that increase lean body mass. Mutation of this gene is found in fewer than 1 in 20,000 in the general population but is relatively common in elite female athletes [noted as 1/421 and 1/423 at the 1996 Atlanta Olympic Games].

The case of mosaicism you linked is fascinating but also incredibly rare, even more so than other DSDs. Also it almost certainly doesn't apply to these two boxers because it would have been picked up on the karyotyping, as it was in that paper.

I feel that the BBC article was quite enlightening on the topic of DSDs in general, but not so much on the impact of and presence of specific male DSDs in women's sport at an elite level. Sport provides a selection filter so these skew towards the subset that confer performance advantage. Like, 5-ARD has dominated entire podiums: in the Women's 800m of the 2016 Olympics, every medal was taken by a male.

That said, I see this as a policy failure more than anything. The IOC's policy fails women by not attempting to exclude male physical advantage at all, instead just going by whatever an athlete's identity documents say. They prioritise inclusion of male athletes in the women's category more than fairness and safety for female athletes.

This is in contrast with how they police their other eligibility criteria, like weight classes where this is verified at the event by weigh-ins. It's strict, too: an athlete was disqualified in this Olympics for being 100 grams over.

I believe the IBA's process, even though they prioritised the safety of their female athletes and fairness in competition, was also flawed. They should have taken the XY karyotype results as the start of their investigation instead of the end. Though, neither Khelif nor Lin pursued a case against the the IBA's decision at the CAS. Which says a lot too.

[YeGoblynQueenne]

Note that we don't know what kind of test the IBA used to disqualify the two Olympic boxers. You say "karyotype test" because the sports journalist above reported "male karyotype" as the "interpretation" of the test result, without specifying the test (probably because the sports journalist doesn't realise "chromosome test" is vague and imprecise). That doesn't tell us what kind of test was carried out and there is no official information, because it would be illegal to share it. It seems the IBA was planning to share the results but the two athletes' teams sent legal letters to the IBA reminding it of non-disclosure agreements:

The purpose of the press conference was to double down on the IBA’s claim that the IOC, led by Kremlev’s bete noire, Thomas Bach, is a danger to women’s boxing, among other things.

It had been believed making public the chromosome tests of the boxers would place serious pressure on the Olympic organisers’ position that the fighters were eligible having been registered as women at birth and holding passports as such. But that morning legal letters came in from the Algerian and Taiwanese organising committees warning them not to breach non-disclosure agreements.

https://www.theguardian.com/sport/article/2024/aug/11/gender...

So all we have to go by is, frankly, dodgy tactics by the IBA that seems more interested in kicking up a storm to discredit the IOC, than to protect women's sports. I suggest caution in accepting anything the IBA says.

[blinkedup]

That interpretation was by the laboratory, described verbatim from the reports of the test results.

Abrahamson also reported that the XY chromosomes were depicted photographically. So we know it must have been a karyotype test because that's what those tests show.

Here's an example from Wikipedia: https://commons.m.wikimedia.org/wiki/File:NHGRI_human_male_k...

We can see in this how the sex chromosomes make an asymmetrically sized pair, indicating XY. It's clear from the description of the lab reports that the same was observed for Khelif and Lin.