23/04/2025
In the FB group International Transgender Health Kristine Theresa C***s writes along piece on chromosomes, s*x, gender and why current anti-trans politics is scientifically bu****it. Because of its importance we re-post it her in its entirety.
Koons writes:
I spend a lot of time with the "chromosomes" crowd. It's kinda fun to mess with them bit. When I started this deep dive into the literature starting about 3 years ago, I noticed we needed a better foundation for describing s*x than the current executive order paradigm being parroted right now.
It required me to sit back and rework the fundamentals and start addressing some of the discrepancies between the socially accepted viewpoints and current medical data. It took some time to get past the prior medical school learning, which, looking back, is now a source of frustration.
The Executive Order model clearly makes a lot of erroneous assumptions and bases them on social systems mixed with historical perspective.
Basically, our Western culture started with a s*x binary that was further cemented when we discovered early Mendelian genetics and s*x chromosomes in 1906. Reginald Punnett's book "Mendelism" still echos in textbooks today.
The 1950s brought us to the next steps of looking at variations of s*x development but was premised under the guise (and still is) of social norms, which led to the s*x-normalizing surgeries that are still prevalent and should be abolished. The 1970s and 80s brought us the works of Benjamin, Money and Kinsey, which were still cemented in social norms.
From the "executive order" perspective, "males" and "females" develop along two completely different and parallel lines that never meet. Hence, the false belief of s*x determination at conception and unchanging through life. To them, inters*x is so far out there that it gets ignored or frequently challenged. It's too frustrating for them to comprehend of acknowledge because it is disruptive to their paradigm.
Most clinical textbooks and even a lot of inters*x websites still anchor around s*x determination at conception, and we still get super excited about chromosomes.
S*x is not determined at conception because the foundational frameworks of development have not occurred. The first thing an embryo is interested in is not reproduction but making it to implantation in the uterus. The next is directionality. A developing fetus needs to know up, down, left, right, front and back. Even then, the foundational work is incomplete because nutrition is next, not reproduction. This is seen in gastrulation. Only when the foundational work of development is done, then comes the undifferentiated stage of s*x development.
During early embryology, both male and female designated primordial structures present. Yes, at the same time. These structures are called the mesonephros and paramesonephros. This doesn't even include the gonadal cells which arrive later as undifferentiated cells from the developing mesoderm. Every developing fetus is "poly"-potential and determinant is not the Y chromosome or SRY. It actually comes down to the collection genes surrounding SOX9 and it remains suppressed or activated.
SOX9 is situated on chromosome 17 and, when activated or released, is the primary driving force to male development. SOX9 has a positive feedback mechanism that causes it to go into overdrive. Consequently, under normal conditions, it is repressed and held under tension. If that tension is maintained, then male development remains suppressed and female development occurs. As male development moves forward, it must repress female development. As female development occurs, it must repress male development. The process is extremely variable and there are hundreds of genes involved that must coordinate a complex set of developing systems. Variations of perceived s*xual development occurs because of the inherent variability of these systems.
Of note, this is only discussing gonadal, internal and external organ development. These structures develop independently, but related to brain development with s*xual orientation and gender identity.
There is no "y chromosome" activation in brain development. There is a very slight representation in the midbrain, but the SRY gene is not present in how the brain develops orientation, identity or expression. There is, however, a ton of estrogen AND androgen receptors, which means a driving force to how the brain develops orientation, identity and expression is related to hormones. Hormones are inherently significantly variable especially how they influence developing neural pathways (Hormones are likely not the only influencer).
Hormones, by definition, are secreted by an organ to have a distant effect on other organ systems. Consequently, variabilities exist in how much produced, how much is secreted, the rate of secretion, the pattern of secretion, the distribution in blood, the number of receptors at receiving site, the function of those receptors, the distribution of those receptors and how DNA/genes are activated or suppressed.
Like many regions of the brain, there are specialized regions devoted to certain responsibilities. We're typically familiar with things like the occipital lobe where vision is processed or cerebellum for balance. Notice these regions are close together and linked because we use vision, the inner and body coordination to allow us to move through space and time. Gender identity and s*xual orientation or situated in the limbic system, but as expected, have various interconnects to other regions of the brain. For example, they are related to vision (creating romantic interests or body recognition), the hypothalamus/pituitary gland (s*x arousal and s*x development), smell and other sensory connections.
There are a few take aways from these paragraphs.
1) Humans are dynamic.
2) S*x is fundamentally complicated and nonbinary
3) there are clear medical and scientific reasons for variations of s*x development, identity, orientation and expression. Not only are they allowed, they are expected.
4) Genetic testing is not appropriate to confirm "maleness" or "femaleness"
5) Chromosomes are nothing more than carrier structures of the genetic code and don't determine how development occurs. The underlying genes do that.
6) 1% of the genome is devoted to protein-encoding genes - about 21,000 of them. Hardly sufficient to explain full human development. About 25% of the genome functions as the regulatory system, what we term as epigenetics.
7) There are genetic and biologic reasons for every letter of LGBTQIA+ based on the above. You don't have to prove anything. You are allowed to be and exist. You are not a mistake.
