How do genes shape transgender people?


Mahrael Boutros

People whose gender identity differs from their biological gender are called transgender , and they were once subject to discrimination. In recent years, there has been a movement to advocate for LGBT rights, with Apple CEO Tim Cook revealing he is gay, same-sex marriage now legal in some countries and states, and transgender Understanding of gender is deepening. Jenny Graves , an Australian geneticist, explains, ``Transgender is not shaped by the environment, but is likely inherited by genetics.''

How genes and evolution shape gender – and transgender – identity

During early childhood, it is not uncommon for boys to wear cute clothes and act like girls, and for girls to be enthusiastic about boyish activities. However, as boys grow up, if they don't act like boys and girls don't act like girls, they will be bullied by their classmates and rejected by their families, who will tell them to stop doing that.

Not being able to behave as they like causes great stress and pain for children, and the suicide rate among transgender children is extremely high . Even as adults, many people feel that they were born with the wrong sex, and some choose to change their gender by undergoing hormone therapy or gender reassignment surgery. In recent years, many people who have changed their gender from male to female or female to male have spoken out about their experiences, but discrimination has not completely disappeared, and there is still a deep-seated feeling of rejection towards transgender people. There are many people who have it.

Transgender people have existed in all cultures around the world since ancient times, but in most societies, transgender people have been subject to rejection and discrimination. Much of this discrimination is based on the awareness that ``transgender people are acquired for some reason, and that something is wrong with such people.'' However, according to Graves, research on transgender has progressed in recent decades, and much evidence has been discovered that transgender is caused by biological rather than psychological factors.



In 1988, Graves' laboratory was visited by psychiatrist Herbert Bower . Mr. Bower was a person who approved of gender reassignment surgery, which was controversial at the time, and was said to be a person respected by the gay community. Mr. Bower also believes that ``transgender may be caused by biological factors,'' and visited Mr. Graves, a geneticist, to explore this possibility.

Bower focused on the SRY gene , a gene on the Y chromosome that controls male development. The SRY gene has the function of guiding undifferentiated gonads to the testes, and the hormones produced in the testes promote sexual differentiation into males. Mr. Bower thought that the SRY gene might not work properly in transgender men, but unfortunately the SRY gene was not directly involved in transgender men.

It is true that there are mutations in which the SRY gene does not work properly, but if the SRY gene does not work, the person will be biologically female even if they have a Y chromosome. Subsequent research did not prove that mutations in genes involved in sex determination create transgender people, but a series of developments led to the conclusion that transgender people are not created by environmental factors, but by the action of some kind of gene. According to Graves, the idea that 'Is this true?' has become widespread.


Jonas Mohamadi

All genetic research often begins by studying twins. A 2011 study found that identical twins, who have essentially the same genetic information, have a higher chance of both being transgender or having the same biological and psychological sex. It was revealed that this was higher than that of siblings and fraternal twins. This result suggests that genes influence transgender people.

A 2018 study looked closely at genes involved in hormone pathways in a sample of 380 transgender women who had undergone or were planning gender reassignment surgery. The researchers found that transgender women frequently have a specific gene type that is involved in hormone pathways that are developing in the womb.

Graves believes that in addition to the genes revealed in this study, many other genes influence male and female gender identity. Graves said there may be hundreds of genes working to create a wide range of transgender people.


Quintin Gellar

In addition, research to date has shown that genes related to transgender do not need to be present on sex chromosomes, and that transgender is likely to be separable, occurring without any connection to biological sex.

The fact that biological sex and spiritual sex are unrelated suggests that ``masculine gender identity'' and ``feminine gender identity'' are widespread among biological men and women. In other words, there is a wide range of men, from ``masculine men'' to ``feminine men,'' and there are also women, from ``masculine women'' to ``feminine women.''

Graves considers these different identities to be 'the same height and all.' Men tend to be about a dozen centimeters taller than women on average, but there are also taller women, and of course there are shorter men as well. Graves believes the transgender issue is similar.

by Kaique Rocha

A topic that comes up in the discussion that transgender is based on genetic factors is that ``If transgender is hereditary, then transgender people whose biological sex and psychological sex do not match would be unable to reproduce.'' The counterargument is, 'Wouldn't it be that they are at a disadvantage in the field, so they will disappear over the course of generations?'

In this regard, Graves believes that ``genes that affect transgender people may have positive effects on other genders.'' In other words, ``feminine women'' and ``masculine men'' may have more children, but the hypothesis is that if the gene that makes them femininize affects a man, he will become transgender.

Graves believes that gay men have a ``gene that loves men,'' and that their female relatives must also have the same ``gene that loves men.'' In fact, past research (PDF file) has revealed that women who have gay men as relatives tend to have more women.

Graves pointed out that many genetic variants related to sexual identity are called sexual antagonisms, and that genetic variants have different values for men and women. Graves says that transgender is not a unique or strange phenomenon, but just a type of diversity such as being tall or short.

by Marcelo Chagas

in Science,   , Posted by log1h_ik