Women Born Transsexual

Wed, 29/10/2008 – 17:01 — woman network

http://www.w-o-m-a-n.net/home/node/1064

Australian researchers have identified a significant link between a gene involved in testosterone action and male-to-female transsexualism. DNA analysis from 112 male-to-female transsexual volunteers showed they were more likely to have a longer version of the androgen receptor gene.

The genetic difference may cause weaker testosterone signals, the team reported in Biological Psychiatry.
However, other genes are also likely to play a part, they stressed. Increasingly, biological factors are being implicated in gender identity. One study has shown that certain brain structures in male-to-female transsexual people are more “female like”.
In the latest study, researchers looked for potential differences in three genes known to be involved in sex development – coding for the androgen receptor, the oestrogen receptor and an enzyme which converts testosterone to oestrogen.

Comparison of the DNA from the male to female transsexual participants with 258 controls showed a significant link with a long version of the androgen receptor gene and transsexualism.

Testosterone

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 from Prince Henry’s Institute of Medical Research.

Co-author Professor Vincent Harley added: “There is a social stigma that transsexualism is simply a lifestyle choice, however our findings support a biological basis of how gender identity develops.”

Although this is the largest genetic study of transsexualism to date, the researchers now plan to see if the results can be replicated in a larger population. Terry Reed from the Gender Identity Research and Education Society said she was convinced of a biological basis to transsexualism.
“This study appears to reinforce earlier studies which have indicated that, in some trans people, there may be a genetic trigger to the development of an atypical gender identity.
“However, it may be just one of several routes and, although it seems extremely likely that a biological element will always be present in the aetiology of transsexualism, it’s unlikely that developmental pathways will be the same in all individuals.”

27 October 08

http://www.phimr.monash.edu.au/news/media_releases/genetic_link_to_gender_identity.htm

In the largest ever genetic study of male to female transsexuals Australian researchers have found a significant genetic link between gender identity and a gene involved in testosterone action.

From an early age people develop an inner sense of being male or female – their gender identity. Transsexuals however, identify with a physical sex opposite to their perceived biological sex.

DNA samples were collected from 112 male to female transsexuals and researchers compared genetic differences with non transsexuals. The results are published in the high impact journal Biological Psychiatry.

The researchers discovered that male to female transsexuals were more likely to have a longer version of a gene which is known to modify the action of the sex hormone testosterone.

“We think that these genetic differences might reduce testosterone action and under masculinise the brain during foetal development.” said researcher Lauren Hare.

For decades, there has been debate over the causes of transexuality. Early theories included psychosocial factors such as childhood trauma. More recent studies have indicated that family history and genetic aspects are linked to the development of gender identity.

“There is a social stigma that transsexualism is simply a lifestyle choice, however our findings support a biological basis of how gender identity develops.” said study leader Associate Professor Vincent Harley, Head of Molecular Genetics at Prince Henry’s Institute.

“As with all genetic association studies it will be important to replicate these findings in other populations” said Associate Professor Vincent Harley.

Researchers are now planning even larger genetic studies and are investigating a wider range of genes that may be related to gender identity.

Further Information

Androgen Receptor (AR) Repeat Length Polymorphism Associated with Male-to-female Transsexualism. Authors: Lauren Hare, Pascal Bernard, Francisco J. Sanchez, Paul N. Baird, Eric Vilain, Trudy Kennedy and Vincent R. Harley. The research will published in the Jan 2009 edition of Biological Psychiatry. Advance online publication date 27 Oct 2008.

This international study involved researchers at Prince Henry’s Institute, Monash Gender Dysphoria Unit, Monash University, Melbourne University, the University of California, Los Angeles in the USA. The research was funded by the National Health and Medical Research Council Australia and the US National Institutes of Health.

http://pageoneq.com/stories/IOWA_SUPREME_COURT_MARRIAGE_BAN_UNCONSTITUTI_0403.html

The Iowa Supreme Court says the state’s same-sex marriage ban violates the constitutional rights of gay and lesbian couples, making it the third state where gay marriage is legal.

In a unanimous ruling issued Friday, the court upheld a 2007 Polk County District Court judge’s ruling that the law was unconstitutional.

The case stems from a 2005 lawsuit filed by Lambda Legal, a New York-based gay rights organization. The group filed a lawsuit on behalf of six gay and lesbian Iowa couples who were denied marriage licenses.

The suit named then-Polk County recorder and registrar Timothy Brien.

The Polk County attorney’s office claimed that Hanson’s ruling violated the separation of powers and the issue should be left to the Legislature.

THIS IS A BREAKING NEWS UPDATE. Check back soon for further information. AP’s earlier story is below.

DES MOINES, Iowa (AP) — The Iowa Supreme Court says the state’s same-sex marriage ban violates the constitutional rights of gay and lesbian couples, making it the third state where gay marriage is legal.

In a unanimous ruling issued Friday, the court upheld a 2007 Polk County District Court judge’s ruling that the law was unconstitutional.

The case stems from a 2005 lawsuit filed by Lambda Legal, a New York-based gay rights organization. The group filed a lawsuit on behalf of six gay and lesbian Iowa couples who were denied marriage licenses.

The suit named then-Polk County recorder and registrar Timothy Brien.

The Polk County attorney’s office claimed that Hanson’s ruling violated the separation of powers and the issue should be left to the Legislature.

Friday 3 April 2009

by Dick Swaab

http://weblogs3.nrc.nl/swaab/2009/04/03/the-atypical-brain-development-of-transsexuals/#more-52

Transsexuals are convinced that they were born in the body of the opposite gender and would do almost anything to change that fact. This transformation occurs step by step, by first taking on the social role of the other gender, then taking hormones and then undergoing a series of major operations, after which just 0.4 percent express regret later.

The gender team of the Vrije Universiteit Medical Centre in Amsterdam has been a pioneer in this field for many years, initially under the leadership of professor Louis Gooren and now of professor Peggy Cohen-Kettenis. This is unusual because the Bible, on which the VU is founded, states in Deuteronomy 22:5-6: “A woman must not wear men’s clothing, nor a man wear women’s clothing, for the Lord your God detests anyone who does this.”

In the womb

Male-to-female (M2F) transsexuality occurs in 1 in 10,000 men, and female-to-male (F2M) transsexuality in 1 in 30,000 women. Gender problems are often expressed early in development. Mothers describe how from the moment their son could talk, he would wear his mother’s clothes and shoes, he was exclusively interested in girls’ toys and mostly played with girls. But not all children with gender problems want to change gender later. If necessary, puberty can be delayed for a while with a hormone inhibitor to gain additional time to make a decision about whether to undergo treatment or not.

All of the data indicate that gender problems develop in the womb. Small changes have been found in genes involved in the effect of hormones on brain development, which increase the chance of transsexuality developing. Abnormal hormone levels in the fetus in the womb and medicines that the mother takes during pregnancy that disturb the breakdown of sex hormones can increase the chance of transsexuality developing.

Sexual differentiation of our genitalia occurs in the first few months of pregnancy while sexual differentiation of the brain takes place in the second half of pregnancy. As these two processes occur at different times, it is theorised that in transsexuality these processes are influenced independently of each other. If that hypothesis is true, then we would expect female structures in the male brains of M2F transsexuals and vice versa in F2M transsexuals.

Brain and hormones

In 1995 such a reversal of the gender difference was published by us in Nature. It involved the bed nucleus of the stria terminalis (BSTc), a brain structure implicated in sexual behaviour. The BSTc was found to be  twice as large in men and contained double the number of neurons than in women. In M2F transsexuals we found a female BSTc. The only F2M transsexual we  could study did indeed have a male BSTc.

We could exclude the possibility that the reversal of the gender difference in transsexuals was caused by changed hormone levels in adulthood. Reversal must therefore have taken place during development. When a researcher finally does publish something interesting, the nicest comment that colleagues can come up with is: “This must first be confirmed by an independent group.” That can take a while, as it took me 20 years to collect the brain material for this study.

Thus, I was delighted to hear that Ivanka Savic’s research group the Karolinska Institute in Stockholm published a study last year of functional brain scanning of living M2F transsexuals. They had not yet been surgically altered nor had they started taking hormones. They were stimulated with male and female pheromones, scents that you pick up unconsciously. These scents produce different stimulation patterns in the hypothalamus and other brain regions in control men and women. The stimulation pattern in M2F transsexuals lay between that of men and women.

Last year Ramachandran, a psychologist and  neurologist in the United States presented an interesting hypothesis and preliminary results on transsexuality. His idea is that in M2F transsexuals the representation of the penis is lacking in the cerebral cortex and in F2M transsexuals the region for breasts during development is not mapped onto the cerebral cortex, which is why the brain does not consider the organs as its “own” and wants to get rid of them.

Everything indicates that during the early stages of development, the sexual differentiation of the brain occurs atypically in transsexuals, and not that they are “simply” psychotic, as a psychiatrist from Limburg recently dared to assert.