Sex determined by chromosomes - exceptions?

In summary they have discovered a family where there appears to be a gene or genes on the X chromosome which prevent 46,XY people from developing as male. The daughter’s Y chromosome came from her father and the disordered sexual development appeared to be in a pattern consistent with an X linked condition.

Simply put the SRY gene (sex determining region on Y) starts off a cascade that produces male development. Lots more genes are involved, hence if other genes are missing or altered then we don’t see normal development.

Interestingly males can lose Y chromosomes as they age. For example when we analyse bone marrow of older men with suspected leukaemia we often see loss of the Y chromosome in some cells. I assume this is not what they see here, but more a true mosaic.

That’s my understanding anyway, but my knowledge is from many years ago.

The genes involved in sex development haven’t all be found and understood as yet! This has nothing to do with more than two sexes though, just a family with a very unusual genetic mutation.

Oddly¹, they almost never bring up fungi. But if they do, it doesn't need a complex, pre-Googled counterargument because humans aren't mushrooms.

¹ Not odd at all, really, because that would require actual scientific knowledge that they generally don't have.

I completely agree that sex is binary in humans and I think all animals. Fungi on the other hand are a different story. If you say sex is obviously binary in a debate then someone will start describing sexual reproduction in fungi so you might want to google it now.

Is this just the clownfish argument by another name?
That other species can change sex and breath underwater means that humans can change sex and breath underwater?

I feel the same way. I recently reread that Nature article, which (come to think of it) the OP will probably have tweeted at her any moment now.

https://www.nature.com/articles/518288a

The title and stand first are completely belied by the content, which describes how every element that makes up a human being (genes, chromosomes, cells, internal and external structures, hormones, developmental pathways) fits into the M/F binary. Someone with a complex DSD might have a mixture of elements, but they're all going to be M or F. None of them will be a hitherto undiscovered Quark. And it's not a spectrum 😡.

The author argues beautifully for children with complex DSDs to choose their own sex, by not operating on them as babies and letting them develop their gender identity (in the child development sense) as they grow. She only muddies the case by mentioning trans and gnc, and by hypothesising the possibility of raising a genderless child.

The final sentence "In other words, if you want to know whether someone is male or female, it may be best just to ask." often gets trotted out.

OP, if that happens to you, just point out that the advice was only intended to relate to complex DSDs.

It’s the difference between ‘defined’ and ‘determined’. Sex is ‘defined’ by gamete type, where as genes ‘determine’ it. This is a better source to explain the difference.

https://www.theparadoxinstitute.com/read/defining-sex-vs-determining-sex

The idiots guide to sex is XX=Female and XY=Male. Delve a little deeper, and you find that it's the SRY gene that equals male.

To most involved in this area, that's where our knowledge ends. I'm sure there are cases that scientists could explain that my mind couldn't grasp.

There will also be cases in which scientists scratch their heads.

This doesn't mean that sex might not be binary. What it means is that our knowledge and understanding are not yet at a level where we can categorise the sex of every living being.

Sex by its very nature, has to binary, as the notion of sexual reproduction is binary. We have sexes because we sexually reproduce, and sexual reproduction requires two sexes.

The case posted shows, to me, that there are genes other than SRY that code a person's sex. Give it time, and humanity will have the knowledge of what each gene does. I sincerely hope I'm not around for the ethical dilemmas that will follow.

I'm meant to be working so don't have time to read the whole paper just now. But I strongly suspect the key lies in the word 'predominantly'. Most of her ovarian (and other) tissue was XY, but some was X and a small amount was XX.

It looks like an incredibly rare genetic difference being studied by very specialised scientists.
Very basically, chromosomes are made up of genes and a specific gene in a chromosome can mutate (using that word, which I know isn't perfect, as a kind of shorthand). That's why specific DSDs are linked to sex (often male rather than female) - because they'll be caused by a particular gene on a particular chromosome.
It is irrelevant to population-level sex differences between males and females.
Although I know it's really disrespectful of TRAs to use these very rare disorders to back up their faith, I think there's a (very small) positive, in that it does make me constantly reappraise my position - and conclude yet again that sex is binary and immutable.

And yes, TRAs using DSDs like this is disgusting.

It's a novel DSD, and they are speculating that it is caused by a mutation in a gene on the X chromosome which, although as yet not identified or sequenced, may control an aspect of male development.

So their sex is determined by their chromosomes, but chromosomes are made of genes and sometimes genes are defective or missing.

The reality is that yes, when it comes to chromosomal and other rare disorders of sexual development, there are a tiny number of edge cases where the situation is unclear.

This does not have any relevance to men who claim they are women and should not be used by those men to claim that sex cannot be defined.

This is something that would need input from a remarkably niche forum of geneticists with hyperspecialisms.

I'd suggest that anyone who wants an understanding of this might explore that avenue if it's consonant with their comfort discussing the medical history of this unique family.

Where’s the dignity for people with DSDs in all of this, as our complex and often emotionally difficult medical conditions are trotted out and prodded by the ignorant, discussed with morbid fascination by people who have no idea about the reality of them?

https://mrkhvoice.com/index.php/2019/12/18/what-is-dignity/

It's a discussion of an extremely rare anomoly, the family being described as "unique".

Fuck all to do with Malaga Airport fans or vulnerable autistic teen girls.