A question about chromosomes

[PlanetJanette]

The furore over the olympics raises some odd conclusions.

Various folk saying that the fact that someone has XY chromosomes means they are a man. But these are the same people who say that men can’t get pregnant, men can’t have a cervix, can’t menstruate etc.

But of course people with DSDs that involve having XY chromosomes can get pregnant, in at least some cases. They can have cervices in some cases. They can menstruate in some cases.

So a question for those who insist on a black and white claim that those with XY chromosomes are men - do they think those with Swyer Syndrome who get pregnant are pregnant men? Or menstruating men? Or men with cervices?

I would think they are the exception that proves the rule. An extremely rare health condition that puts them in a category of their own.

More to the point I wouldn’t have any opinion on their personal medical history, unless they were attempting to claim something they were not entitled to.

This doesn’t really answer the question.

If they are men - then they must be men with cervixes, men who menstruate, men who get pregnant? However exceptional.

Lots.of people on both sides confuse sex determination with sex identification.

In humans, XY usually but not quite universally gives rise to a male phenotype (sex determination).

We can identify a male in lots of ways. It was done very reliably from anatomy long before chromosomes were discovered. For athletics categories, karyotype from a cheek swab is a good start but if it conflicts with other evidence then more investigation might be needed.

And in case you're wondering, female is defined as "belonging to the sex class that produces large immotile gametes". That of course does not mean that every member of the sex class does so.

Geneticist here. These extremely rare conditions have nothing to do with transgenderism. They are medical conditions and have no connection whatsoever with the belief that people have an innate gender identity that may or may not match with with biological reality. Stop co- opting people with distressing medical conditions in a weak attempt to win an argument.

Men as a class don’t do any of those things.

Men as a class have two legs.
Just as man with one leg doesn’t contradict that, a man with an anomalous internal reproduction structure doesn’t contradict the fact that men as a class don’t have a uterus.

Men with swyer carry a pregnancy only with massive medical intervention. I’m surprised it’s ethical, given the increased risk to the child. It’s a variation on the idea of men receiving a uterus transplant and being able to carry a pregnancy.

It’s achieved with massive medical intervention.
It doesn’t alter the facts.

The existence of a tiny handful of people with a rare chromosome disorder does not change the fact that women and girls need single sex spaces in certain situations.

Girls with Swyer's syndrome don't have ovaries, so don't go through puberty unless they get given female hormones (and can't produce eggs). It's a failure to develop male characteristics due to other gene mutations. I assume they would be no stronger than females because they don't go through male puberty or produce testosterone. There would be no problem treating these potential males as women.

Where did I mention transgender people or co-opt anyone.

This forum is filled with threads calling some athletes men on the sole basis that they have XY chromosomes.

I am simply asking if people believe they are men, does that mean they also think that some men can menstruate, get pregnant etc.

XX/XY is a shorthand for female/male because it's true almost all of the time, but it's not 100%.

The SRY gene is what triggers male development, and this is almost always located on the Y chromosome. Sometimes it's not, it's and located elsewhere, so you can find XX men because they still have an active SRY triggering male development.

There are also cases where there is an SRY gene on the Y chromosome but it doesn't activate properly and male development doesn't begin, male puberty doesn't happen etc. and there isn't the male level of testosterone produced.

Whether someone with XY chromosomes but without an active SRY gene is male or female is, I suppose academic, and I'm open as to how a person might be classified.

But relating this to the Algerian boxer Khelif, or Caster Semenya, both have clearly undergone male puberty and are absolutely swimming in testosterone so can't have Swyer syndrome (XY female)

No

Why not?

So in your view what makes them men is not XY chromosomes but their level of testosterone?

The boxers clearly don’t have swyer syndrom.

XY = man is an oversimplification, which explains over 99% of the population.

It's the SRY that matters in most cases, which is usually found on the Y chromosome but can sometimes transpose onto the X chromosome.

No man can ever get pregnant and give birth. It is impossible. Just as it is impossible for a woman to father a child. That is the basics of human sexual reproduction and what it means to be male or female.

Can humans make a mistake? Sure. Do humans fully understand the complexities of genetics? No. As our understanding increases, the number of people being incorrectly sexed gets lower and lower.

Was this a response to my post?

In which case no, it's not testosterone that determines sex, but high testosterone levels are evidence that they don't have a female XY condition, but have instead developed as male, because someone with Swyer syndrome wouldn't produce that much testosterone.

This is a really cogent explanation

What's a woman Planet?

The XY females are really only potential males that failed to developed male characteristics, they don't develop full female characteristics either, but because the male characteristics don't develop and particularly if visible genitalia are female it's fair enough to call them female. In fact they never develop properly as males or females, even with hormone treatment.

It answers the question well enough for everyday purposes, and I shouldn’t have bothered expanding on it.

I sympathise with your determination to ignore what anyone else thinks about the subject. I’m also not persuaded to change my mind by the determination of someone who disagrees, when I know they are wrong.

People with Swyer syndrome don't have functional ovaries. Left untreated, they don't go through puberty. So they don't naturally menstruate or get pregnant. They could potentially become pregnant with a donated egg, they don't produce their own eggs.

It's an interesting condition that takes us to the edges of all these questions. In a sports setting, due to the above it would likely not impact sports, unless the person had male hormone therapy, as they won't experience male puberty and the advantages it gives. Generally those with Swyer are raised female and have female hormone therapy.

Can you link to an example of an XY person becoming pregnant without significant medical
intervention (including donated eggs?).

It's my understanding that at the most basic level, it's the potential production of gametes that determines sex.

Someone with swyer syndrome does not have ovaries. So cannot produce eggs.

I think they could be pregnant if a fertilised egg from elsewhere was implanted in the womb though. But they can't get pregnant spontaneously, if you see what I mean.

That's my loose understanding.

Hopefully all this discussion about DSDs is going to make people a lot more informed.

And one thing is for sure, the DSD that these two boxers have is male specific. It's colloquially called penis at 12, which is something of a clue!

It almost never happens, so it's irrelevant.

Not interested in bad faith questions.

Somebody with the VSD of Swyer syndrome does not produce eggs (ova), but, with support and a sufficiently assessed uterus, it may be feasible to carry an implanted embryo.

This is the case study of a very rare assisted pregnancy with donor eggs.

She was compliant with HRT to prevent further uterine hypoplasia in order to carry a pregnancy when ready.

Taneja J, Ogutu D, Ah-Moye M. Rare successful pregnancy in a patient with Swyer Syndrome. Case Rep Womens Health. 2016 Oct 18;12:1-2. doi: 10.1016/j.crwh.2016.10.001. PMID: 29629300; PMCID: PMC5885995.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5885995/