Many transsexuals, therapists, human sexuality researchers, religious liberals, and others believe that transsexuality is determined before birth. Some believe that it is determined by one's DNA at conception. others hold to the theory that it is caused by irregular levels of sex hormones to which the fetus may be subjected. These beliefs are grounded in research into genes and traits of transsexuals.
Cristine Shye
Is transsexualism genetically determined?
As noted elsewhere in this thread a transsexual is a person who experiences Gender Identity Disorder (a.k.a. Gender Dysphoria), Their genetic gender is different from their perceived gender. Some describe themselves as a woman trapped in a man's body, or vice versa.
This disorder is rare. It generally causes serious personal conflicts and depression, often starting in pre-school children. Their level of frustration and anxiety is often so high that many become suicidally depressed. The rate of completed suicide for transsexuals was once believed to be about 50% by age 30. Since then, sex reassignment surgery (SRS) has become more widely accessible. Many transsexuals can now have their physical appearance modified to make them appear more like the gender that they feel they are. This surgery has been shown to be generally effective, and the suicide rate among transsexuals has apparently been greatly reduced.
Religious conservatives generally believe that transsexuality is a chosen lifestyle to which a person can become addicted. The solution is therapy and prayer.
The opinion of some gays, lesbians, and bisexuals towards the causes of transsexuality may be influenced by a desire to support their belief that sexual orientation is similarly genetically determined.
Australian DNA study during 2008:
Australian researcher Professor Vincent Harley has led an Australian-American study of transsexuality. He acknowledges that the cause(s) of transsexuality have been debated for years. He said:
"There is a social stigma that transsexualism is simply a lifestyle choice. However our findings support a biological basis of how gender identity develops."
He was the lead researcher in the an Australian-American genetic study of transsexuals -- the largest to date. Included were several research groups in Melbourne Australia and in the University of California in Los Angeles (UCLA). It was funded by the National Health and Medical Research Council in Australia, and the National Institutes of Health in the U.S.
They compared DNA from 112 MTF (male-to-female) transsexuals with DNA from 250 males who did not experience gender dysphoria. Results of the study were published in the 2008-OCT-27 edition of the journal Biological Psychiatry.
The researchers found that the transsexual subjects were more likely to have a longer version of the androgen receptor gene in their DNA.
Lauren Hare, a researcher at Prince Henry's Institute said:
"We think these genetic differences might reduce testosterone action and under-masculinize the brain during fetal development."
"Studies in cells show the longer version of the androgen receptor gene works less efficiently at communicating the testosterone message to cells. Based on these studies, we speculate the longer version may also work less efficiently in the brain."
Terry Reed from the Gender Identity Research and Education Society said:
"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."
Researcher Trudy Kennedy, director of the Monash Gender Dysphoria Clinic, said the study supported previous evidence that genetics and brain gender were important in transsexuality. She said:
"This is something that people are born with and it's certainly not a lifestyle choice as some have suggested."
Studies of fingerprints, left handedness, and ancestry of transsexuals:
During 2000-JUL, Professor Richard Green, visiting professor of psychiatry at Imperial College in London, UK discussed transsexuality at the annual meeting of the Royal College of Psychiatrists. His presentation was based on a study of 400 male-to-female (MTF) and 100 female-to-male (FTM) transsexuals in the late 1990s at the gender identity clinic in Charing Cross Hospital in London. His group determined that:
Over 50% of transsexuals are left-handed -- many times that of the general population.
Transsexuals had distinctive styles of ridged finger prints, and
Transsexuals had more aunts than uncles on their mother's side.
Male transexuals had more older brothers than average.
Thankyou Tammy.
Obviously I never wrote all of it, presuming you have read my article on the home Page with regards to Reifensteins syndrome, well I'm off back to Addenbrooks, hospital on the 15 November to take part in ongoing research into the above articles. Where the term guinea pig came from I have no idea, but I have always wanted to learn more about my own condition, perhaps one day initial clinical testing of DNA for abnormalites will go some way to establishing and validate ones claims to GD and help the general public to be more accepting of a condition we struggle to understand amongst ourselves.
Thankyou Tammy
Yes it is also thought in some medical circles, that it can be attributed to even minor afflictions like low virility in males the inability to father children, whilst looking and to all intense and purpose being normal males, Its not necessarily congruent with gender identity
disorders either. So it will probably never be know what the true percentage of society is actually affected, its estimated that one in 180 M women carry the gene, and one in 30 odd million of the male children born to those women will inherit the condition.
Crissie
I just found this article, which you were unable to find again, first time I have seen it. Well written and erudite. something worth bringing up again for those just joining. I think your dedication and research is exemplary.
Love you. (biased)
http://www.identitygender.com/2011/02/03/gene-variant-for-enzyme-cytochrome-p17-linked-to-transsexuality.html
Linda Geddes, of New Scientist, cites the research of scientists at Medical University of Vienna, Austria, who discovered a gene variant in the enzyme Cytochrome P17 that controls the metabolism of sex hormones. The presence of the gene variation could "cause higher than average tissue concentrations of male and female sex hormones, which may in turn influence early brain development." The proportion of MtF transsexuals with it was similar to control males, but 44% of FtM transsexuals had it, versus 31% of non-transsexual women.
This variant is insufficient to imply direct causality for transsexualism, but "the finding raises the possibility that the variant makes women more likely to feel their bodies are of the wrong sex." "If other gene variants with a stronger association to transsexuality are identified, establishing a diagnosis might become easier.This might allow gender reassignment surgery or hormone therapy to start earlier in life,
The research by Drs. Hare, Bernard, Sanchez, Baird, Vilain, Kennedy, and Harley in Australia complements the MRI studies taking place at UCLA, indicative of significant brain gray matter activity in pre-hormonally treated male-to-female transsexuals that has similarities to cisgender females. Although there is insufficient data to fully comprehend the phenomena of transgenderism, it is clear that there are significant genetic and brain morphology differences in male-to-female transsexuals, even prior to hormone treatments, that may be significant, if not determinant, antecendants to transsexualism.
Hopefully, in all the studies, discoveries, it will not become a prerequisite for treatment, surgery and all that entails soley on the results of DNA samples and brain scans.
What a fascinating article, and impressive variety of research, obviously science is begining to provide people with clues as to 'how we're made', 'what we are' and 'how we're programmed' ... I can claim it all make sense, but it 'feels' as if the research is producing going along in the right direction. This article does go some way toward explaining why we should avoid 'sex and stick to 'gender' - you can go 'off sex' ... while 'gender' is inescapable!
Forgive me if I pose a dumb question, but does all that research alter how trans-people feel about/percieve themselves? Is research similar to this likely to lead to a change in social attitudes, or even some sort of accomodation/acceptence? On a personal level, I don't think science alone has enough influence to counteract centuries of prejudice, propaganda and fear ... me thinks people are needed to make that seismic shift. Hormones are the engines that drive the bus, but the question remains - who is at the wheel? Mum, dad, SO, god, relatives, peers, perhaps all of the above?
"Je pense donc je suis," to quote Mr. Descates.
Al
Is research similar to this likely to lead to a change in social attitudes, or even some sort of accomodation/acceptence?
I think eventually it will be recognised and ''put up with'' same as Dwarfism, and other birth defects. As far as social acceptance goes, an insight into that is another article I put together Heteronormativity. so these two subjects are congruent with each other, both sides of the coin.
Hi Cristine, sadly I have to agree with you ... the level of tolerance is quite superficial, trending toward shallow.
While I value research and your articles are well thought out, sourced and structured, unfortunately the latest research is almost always behind 'the curve' ... a bit like media reporting.
"Recognition leads to toloration, toloration leads to representation, which in turn leads to taxation, taxation gives way to vexation and frustration, which in turn demands recognition ..."
Very interesting read Cristine. As usual a very informative post from you. I find the statistical studies concerning traits TS often have very interesting . I wish I could get the brain scans just to see where i fall lol. My mother always told me she swore she was having a girl because she said she felt differently while carrying me then when she carried my first 2 brothers. She always told me as a baby my disposition was very calm and I was a sweet baby. Who knows ! :) It sure is interesting. I fit a few of those traits you listed even though I'm a righty. Another trait I have herd that has scientific backing is the index finger length verses ring finger length. Apparently many TS have longer index fingers then rings. My index way outstretch the ring fingers on both hands. Apparently this is a result of prenatel hormones the fetus is bathed in. High levels of androgens and estrogens seem to affect this. http://en.wikipedia.org/wiki/Digit_ratio#Transsexualism One question though. Anyone know what "rigid fingerprints" are?? Neat stuff! xxx Jessica
Definition and Synopsis of the Etiology of Adult Gender Identity Disorder and Transsexualism
1.Gender Identity Disorder is defined as an incongruence between the physical phenotype and the gender identity[1], that is, the self identification as male or female. The experience of this incongruence is termed Gender Dysphoria. The most extreme form, in which individuals need to adapt their phenotype with hormones and surgery to make it congruent with their gender identity, is called transsexualism[2], Those individuals experiencing this condition are referred to as trans people, that is, trans men (female to male) and trans women (male to female).
2.Transsexualism can be considered to be a neuro-developmental condition of the brain. Several sexually dimorphic nuclei have been found in the hypothalamic area of the brain (Allen & Gorski, 1990; Swaab et. al., 2001). Of particular interest is the sexually dimorphic limbic nucleus called the central subdivision of the bed nucleus of the stria terminalis (BSTc) which appears to become fully volumetrically sexually differentiated in the human brain by early adulthood. This nucleus has also been found to be sexually dimorphic in other mammalian and avian species (Miller et. al., 1989; Grossmann et. al., 2002). In human males the volume of this nucleus is almost twice as large as in females and its number of neurons is almost double (P <0.006) (Zhou et. al., 1995; Kruijver et. al., 2000; Chung et. al., 2002).
3. The Kruijver et. al. study, cited above, indicates that in the case of transsexualism this nucleus has a sex-reversed structure. This means that in the case of trans women (n=7), the size of this nucleus and its neuron count was found to be in the same range as that of the female controls (n=13) and, therefore, women in the general population. In the only available brain of a trans man, the volume and structure of this nucleus was found to be in the range of the male controls (n=21) and, therefore, men in the general population. It is hypothesised that this male-like BSTc will be present in other trans men as well. These findings were independent of sexual orientation and of the use of exogenous sex hormones. In the 42 human brains collected for this study, the BSTc was found to have a structure concordant with the psychological identification as male or female. It is inferred that the BSTc is an important part of a sexually dimorphic neural circuit, and that it is involved in the development of gender identity (Kruijver et. al., 2000).
4. Sexual differentiation of the mammalian brain starts during fetal development and continues after birth (Kawata, 1995; Swaab et. al., 2001). It is hypothesised that in humans, in common with all other mammals studied, hormones significantly influence this dimorphic development although, at present, the exact mechanism is incompletely understood. It is also postulated that these hormonal effects occur at several critical periods of development of the sexual differentiation of the brain during which gender identity is established, initially during the fetal period, then around the time of birth; and also post-natally. Factors which may contribute to an altered hormone environment in the brain at the critical moments in its early development might include genetic influences (Landèn, 1999; Coolidge et. al, 2002) and/or medication, environmental influences (Diamond et. al., 1996; Whitten et. al., 2002), stress or trauma to the mother during pregnancy (Ward et. al., 2002; Swaab et. al., 2002).
5. Gender identity usually continues along lines which are consistent with the individual's phenotype, however, a very small number of children experience their gender identity as being incongruent with their phenotype. Adult outcomes in such cases are varied and cannot be predicted with certainty. It is only in a minority of these children that, regardless of phenotypical socialisation and nurture, this incongruence will persist into adulthood and manifest as transsexualism (Green, 1987; Ekins, 1997; Prosser, 1998; Di Ceglie, 2000; Ekins & King, 2001; Bates, 2002).
6. As stated, in trans people, a sex-reversed BSTc has been found. The findings of a specific sex-reversed brain organisation in trans people provides evidence consistent with the concept of a biological element in the etiology of transsexualism. The evidence for an innate biological predisposition is supported by other studies, one example of which, indicates a higher than average correlation with left-handedness (Green & Young, 2001). Where the predisposition for transsexualism exists, psycho-social and other factors may subsequently play a role in the outcome, however, there is no evidence that nurturing and socialisation in contradiction to the phenotype can cause transsexualism, nor that nurture which is entirely consistent with the phenotype can prevent it (Diamond, 1996). There is further clear evidence from the histories of conditions involving anomalies of genitalia, that gender identity may resolve independently of genital appearance, even when that appearance and the assigned identity are enhanced by medical and social interventions (Imperato-McGinley, 1979; Rösler & Kohn, 1983; Diamond, 1997; Diamond & Sigmundson, 1997; Kipnis & Diamond, 1998; Reiner, 1999; Reiner, 2000). It is not possible to identify one single cause for transsexualism: rather, its causality is highly complex and multifactorial. The condition requires a careful diagnostic process, based largely on self-assessment, facilitated by a specialist professional.
7. In conclusion, transsexualism is stongly associated with the neurodevelopment of the brain. (Zhou et. al., 1995; Kruijver et. al., 2000). The condition has not been found to be overcome by contrary socialisation, nor by psychological or psychiatric treatments alone (Green, 1999). Individuals may benefit from an approach that includes a programme of hormones and corrective surgery to achieve realignment of the phenotype with the gender identity, accompanied by well-integrated psychosocial interventions to support the individual and to assist in the adaptation to the appropriate social role (Green and Fleming, 2000). Treatments may vary, and should be commensurate with each individual's particular needs and circumstances.
[1] The term 'gender identity' is used, in the UK, to indicate the self-identification as male or female. However, terminology varies around the world, and the term 'sexual identity' is preferred by many in the US. (pace Professor Milton Diamond). See "Sex and Gender are different: Sexual Identity & Gender Identity are Different", (2000) Clinical Psychology & Psychiatry, Vol 7 (3):320-334.
[2] The transsexual condition is also referred to in various ways (Diamond M, 2002 In Press) "What's In a Name? Some terms used in the discussion of Sex and Gender". Transgender Tapestry.
n.b.The UK government recognises that transsexualism is not a mental illness. See Lord Chancellor's Department - government policy concerning transsexual people.