Monthly Archives: January 2015

Transgender History by Susan Stryker – book recommendation

This is a great book. Read it.

Don’t you wish you could have turned in a book report like that? Sweet and simple.

This blog is about science, but I’ve decided to throw in some occasional book recommendations. I’ll be quoting Stryker’s history from time to time as well.

Meanwhile, other people have already written thorough reviews: C. Riley Snorton at the University of Pennsylvania, A Gender Variance Who’s Who, or plain old GoodReads.

You can buy Transgender History by Susan Stryker:

from Seal Press (support women’s publishing)

from Barnes and Noble (support brick and mortar stores)

from Amazon (support books)

Identical Reared apart Twins Concordant for Transsexuality – Review

This is a brief article about a case of identical twins reared apart who both had gender dysphoria. Unfortunately, it is based on an interview with only one of the twins. This makes it a suggestive report, but not scientific proof.

In addition, one of the twins was born with an intersex condition. This raises the question of whether his gender dysphoria was caused by genes or the prenatal environment.

The twins were born male and separated at birth and raised in different families. They did not meet each other until they were 15. DNA testing confirmed that they were identical twins.

This is only one case, so the conclusions we can draw are limited.

The main weakness of the report, however, is that it is based on the memories of only one of the twins, LT. The authors were able to interview LT in his 50s.* It is possible that his memories of meeting his twin AT 35 years ago would be incorrect or might exaggerate similarities or differences.

According to LT,

“Prior to meeting, by age 8 years both twins experienced gender discomfort, engaged in cross-dressing, and felt that they should have been born as the other gender. Also prior to meeting, both twins experienced unease with the anticipated and actual secondary sexual development of puberty. Furthermore, unbeknownst to his twin, at age 14 years LT was fully committed to undergoing sex reassignment surgery and so convinced his mother that she took him to see a urologist.”

According to the author of the report, this means that both twins met the criteria for gender dysphoria, “persistent cross-gender identification and a strong desire to change the sexual characteristics to those of the other gender.”

I am not comfortable with diagnosing someone you have not interviewed. Clearly, AT had some issues with his gender, but how did he define himself? Did he want to have surgery? Did the twins continue to have contact and did AT’s gender dysphoria persist into adulthood? Did they influence each other after age 15?

This report is also about a tragedy. AT committed suicide at age 35.

The twin’s birth mother had skin cancer and doctors believed she should give one twin up for adoption. AT was therefore put in a state-run institution and then adopted by a less well-to-do family. His parents were “religious, punitive, and rejecting of his cross-gendered behaviors.” (Presumably we know all this from his twin, LT.)

LT was raised by his biological parents. His family was more financially comfortable. His mother and sisters “supported his female identity as it developed and afterward.”

The authors of the study stress the importance of family support in preventing suicide, but there are a number of other factors that might have also influenced AT. Adoptees are more likely to attempt suicide than non-adoptees. It might also be upsetting to learn that you had a twin and your birth parents had kept them, as AT did. Having parents with a lower socio-economic status also increases the risk of suicide. AT was therefore more at risk for suicide to start with, although we also know that family support reduces the risk of suicide for people with gender dysphoria.

An interesting aspect of this study is that LT was a “sickly infant” and had hypospadias, a birth defect in the urethra. The Intersex Society of America lists it as an intersex condition. There is no information in the study as to whether or not AT also had hypospadias or any other intersex condition.

Did the hypospadias contribute to LT’s gender dysphoria? Could having a scar on your penis influence feelings about gender identity?

Could the hypospadias be a sign of something else that also caused LT’s gender dysphoria?

According to Wikipedia, the cause of most cases of hypospadias is unknown, but it may be influenced by: having an older mother, the mother taking progesterone during pregnancy, the fetus not producing enough testosterone or nor responding to it, or genetics. It seems reasonable to ask if these factors might also affect gender identity.

In this case, the mother was 40 when the twins were born, which might have been a factor in LT’s hypospadias. We don’t know about any hormonal factors.

We have no way of knowing what caused LT’s hypospadias, but it does raise the question of whether the twins’ issues with gender were caused by a genetic factor or something to do with the prenatal environment or the genital surgery.

I am frustrated by this study. It seems like a good case for a genetic component to gender dysphoria – twins reared apart are a classic test of genetic effects. Unfortunately, since it is based on the account of one twin, the evidence is not as strong. It might be that the twin who lived developed a narrative to make sense of his twin’s tragic suicide.

In addition, the fact that one twin had an intersex condition at birth might be a sign of something unusual in the twin’s prenatal environment.

Mostly, though, you can’t say you have scientific proof that the twins were alike if you only interview one of the pair of twins.

It is so very hard to get good data on gender dysphoria. People with gender dysphoria are extremely rare and twins with gender dsyphoria are even rarer. Add in a much-too-high suicide rate, and you have even less ability to collect data.

Once again, we need more research in this area. As Heylens et. al said in their review of the literature: “detailed registers of GID twins, preferably on MZ twins discordant for GID and DZ twins are needed, to gain more decisive information about the influence of genetic vs. environmental factors in the development of GID.

Original Case Report:

Identical Reared apart Twins Concordant for Transsexuality by Nancy Segal & Milton Diamond, Letter to the Editor, published in: Journal of Clinical and Experimental Medicine, April 2014 Volume 6, Issue 2, Page 74.

*The article refers to the twins with male pronouns. The article does not make it clear what the twins did when they grew up. LT, if you have transitioned and I am using the wrong pronouns, I apologize.

More about twins and gender dysphoria:

My review of “Gender Identity Disorder in Twins: A Review of the Case Report Literature.”

At the Intersection of Gender and Autism – Part 3

The final part of a great series on gender and autism from the point of view of a woman with autism.

One thing I found interesting was the ways autism may be hidden with girls. For example, the author of the article played with dolls, but she played with them by lining them up.

Musings of an Aspie

The final post of a three part series (read Part 2)

While many of the intersections of autistic and female in my life have been social, there are undeniable physical intersections too.

The arrival of adolescence brought with it hints of what it would mean to be an autistic adult. My first real meltdowns. My first experience with depression. My first confusing encounters with physical intimacy.

With nothing to compare those experiences to, I assumed they were a normal part of being a teenager. Everyone said that being a teenager was hard. I couldn’t dispute that. It didn’t seem necessary to look beyond the explanation of “this is hard for everyone.”

That would become a theme. Pregnancy. Breastfeeding. Postpartum depression. My body’s reaction to birth control pills. Countless books and magazine articles assured me that these things were no walk in the park. Not knowing that I was autistic…

View original post 1,464 more words

Polymicrogyria of the Unilateral Temporal Lobe in a Transsexual Patient-Case Report – a Review

This is an interesting case study about an abnormality in a trans woman’s brain. The trans woman did not have epilepsy or any other neurological condition.

This brain abnormality may or may not be related to gender dysphoria. We only have one case here.

The authors suggest that future studies of people with gender dysphoria should look for “possible brain abnormalities of any kind [in] MRI scans.”

Details of the study:

The trans woman had a condition called polymicrogyria in her left temporal lobe. Polymicrogyria is exactly what it sounds like – if you speak Latin.

Basically we all have ridges or folds in the cerebral cortex of our brains called gyri (one gyrus, two gyri). In polymicrogyria the brain develops many small folds during the prenatal period.

Polymicrogyria can have small or severe effects, depending on where it is in the brain. It is most typically associated with epilepsy.

Polymicrogyria in a larger area of the brain is associated with severe problems like developmental delays, problems with speech and swallowing, muscle weakness or paralysis, and seizures that are difficult to control.

The cause of polymicrogyria is generally unknown. In some cases it is caused by prenatal infections or other problems and in some cases there is a genetic link.

Mild cases of polymicrogyria may be more widespread than we realize.

In this case, the polymicrogyria were in a limited area of the brain and were not causing any problems. The question is, could they be causing gender dysphoria?

At this point, we don’t know, we just have an interesting result to follow up on.

Where exactly is the polymicrogyria in this case study? The English of the study is fairly awkward, but this is what I think they are saying.

The lateral sulcus on the left side is missing the ascending branch. In addition, the posterior branch ends at the preoccipital notch because it is interrupted by the polymicrogyria.

The polymicrogyria are in the parietotemporal region.

This would, I think, be near the temporoparietal junction  (TPJ).*

File:Brain - Lobes - Temporoparietal junction.png

The TPJ integrates information and has many functions, from theory of mind and moral behavior to paying attention. What makes the TPJ interesting in discussing gender dysphoria is that the TPJ also plays a role in integrating multisensory signals from your body. The TPJ may be part of how we experience a sense of body self-consciousness, i.e. identifying with your body, self-location, and first-person perspective.

Stimulating the TPJ can cause an out-of-body experience (OBE). (Fascinating study here.)

This study concludes:

“These results suggest that the TPJ is a crucial structure for the conscious experience of the normal self, mediating spatial unity of self and body, and also suggest that impaired processing at the TPJ may lead to pathological selves such as OBEs.”

So it might be possible that polymicrogyria in the TPJ would cause someone to experience a disconnect from their body. Could that cause or contribute to gender dysphoria?

Polymicrogyria are created during fetal development and are not influenced by the postnatal environment, so dysphoria about the body could not cause polymicrogyria.

In addition, if polymicrogyria plays a role in gender dysphoria, it is not related to sex hormones or normal differences between males and females. Polymicrogyria are not a normal part of the brain.

There might, however, be multiple factors that contribute to developing gender dysphoria. Damage to the TPJ might be just one factor or it might only be a factor in some cases.

Another possibility would be that something happened to this trans woman prenatally that caused her to develop gender dysphoria and to have polymicrogyria.

Interestingly, an earlier study of gynephilic** trans women’s brains found that the trans women had larger gray matter volumes than cis men or women in the “right temporo-parietal junction (around the angular gyrus and in the posterior portion of the superior temporal gyrus).”*** You can read more here. This is not the same as what the current study found – polymicrogyria on the left side of the brain – but it is interesting that the TPJ seems to be involved in both studies.

Obviously without more data, this is all very hypothetical.

It would be useful to have more studies that look at the TPJ in the brains of trans and cis people. As always, controls should include some gay and lesbian cis people.

Original Study:

Polymicrogyria of the Unilateral Temporal Lobe in a Transsexual Patient—Case Report by Starcevic, Ana; Zigic, Dusica Markovic; Filipovic, Branislav in Neuroscience and Medicine4.4 (Dec 2013): 263-266.

For more information on polymicrogyria:

Genetics Home Reference on Polymicrogyria (a service of the National Institutes of Health).

Polymicrogyria Awareness group.

*Parietotemporal region may be another way to say temporoparietal junction, I’m not sure. The translation of the article has a lot of problems.

**Gynephilic = attracted to women. Some studies of brain sex look only at trans women (born male) attracted to men, some look only at trans women attracted to women. Studies comparing trans women attracted to men to cis men attracted to women can’t be sure if their results are due to sexual orientation or gender. However, studies that look only at trans women attracted to women leave out half of trans women and may miss important aspects of gender dysphoria. We need more studies that include cis gay and lesbian controls.

The trans woman in the current study had a wife and an ex-wife. She had experienced gender dysphoria since age four. She had a degree in electrical sciences and was “working two jobs which are not in [her] field of professional interest.”

*** The original text refers to the superior temporal gurus. A cool idea, but probably a typo.

Thanks to Wikipedia for the image.