Male-to-female transsexuals are more likely to have a genetic variant that may cause weaker testosterone signals in the brain during early development, according to a new study. Researchers say the finding is another piece of evidence that there is a genetic component to these men’s strong feelings that they’re really women who were born into the wrong body, a theory many experts have long endorsed based on anecdotal evidence. “People who come to our clinic describe how they knew they were different at a very early age, just three or four years old. This is something that people are born with,” Dr [Trudy] Kennedy said [Sydney Morning Herald].
The findings are important, but lead researcher Vincent Harley admits he hasn’t discovered a clear, single cause of transsexualism. While the genetic link was statistically significant, it was weak – 55% of the transsexuals had the [genetic variant], compared with 50% of normal men. Harley agrees that many more genes related to male-to-female transsexualism probably remain to be discovered [New Scientist].
In the study, which will be published in an upcoming issue of Biological Psychiatry, researchers conducted a genetic analysis of 112 male-to-female transsexuals as well as a control group of men. They found that the transsexuals were more likely to have the long version of the androgen receptor gene, which controls how testosterone binds to cells.
It is known that longer versions of the androgen receptor gene are associated with less efficient testosterone signalling. This reduced action of the male sex hormone may have an effect on gender development in the womb, the researchers speculated. “We think that these genetic differences might reduce testosterone action and under masculinise the brain during foetal development,” said researcher Lauren Hare [BBC News].
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Image: Wikimedia Commons
October 27th, 2008 at 2:23 pm
What an amazing discovery!
I wonder how transgender people will feel about this?
October 28th, 2008 at 3:14 am
We think its great, lol
October 28th, 2008 at 8:23 am
I have a transgender child – make to female. Our child was born with birth defects brought on by asthma medicine taken before we knew my wife was pregnant. We didn’t know about the transgender issue until our child was 24 years old. My wife and I both believe the transgender issue was another of the birth defects. This latest research tends to support this idea.
October 28th, 2008 at 12:22 pm
Yes. The research supports the findings, but will health insurance company’s will come around and start covering surgery? We can only hope.
October 28th, 2008 at 8:54 pm
The Atlantic recently published an excellent article on transgender children. Well worth reading.
Ihttp://www.theatlantic.com/doc/200811/transgender-children
October 29th, 2008 at 10:08 am
As Dr Harley himself said: While the genetic link was statistically significant, it was weak …
So, it seems to be important to keep on carrying researches about this topic.
Anyhow, It’s absolutely an evidence that there is a great gap between people who are “born with it” and those who have chosen it as a “way of life”…, maybe more numerous, and certainly often more visible.
Louise, post-op MtF, France
October 29th, 2008 at 5:08 pm
I’m cautiously optimistic about this news, something we in the TG community have been hoping someone would find for a long while. It won’t evaporate the social stigma, but for some of us (like my cloud of family/friends), it might help them to be a bit more comfortable with the idea. At the least, it should help people see this is NOT something we make up – at least those of us who know we were born with it.
October 30th, 2008 at 6:17 am
As a male to female transgender person myself (clinically diagnosed) I am cautiously optimistic about this news as it supports (to me at least) my view of myself. Although I have not transitioned, a strong, innate female self-identity has been part of my being ever since I can remember, and is ever present no matter how I try to deny or bury it. I am sure there are some persons who fall more under the “nurture” umbrella but for me and a great many of us otherwise masculine men, the possibilities of this discovery is that we may finally have an answer to the question of why.