I found an article in the publication Science Daily describing a promising hypothesis concerning the incongruity found in transgender individuals of having a brain sex and gender opposite their body’s sex resulting in gender dysphoria. Research done at the Medical College of Georgia at Augusta in an article dated February 5, 2020 reports findings that brain / body incongruence causes “may have been found in estrogen receptor pathways in the brain of 30 transgender individuals.”
The full text of the Science Daily Article appears in it’s February 5, 2020 issue. Medical College of Georgia at Augusta University. “Gene variants provide insight into brain, body incongruence in transgender.” ScienceDaily. ScienceDaily, 5 February 2020.
(http://www.sciencedaily.com/releases/2020/02/200205084203.htm).
The cite from the scientific paper that the article is drawn from is:
J. Graham Theisen, Viji Sundaram, Mary S. Filchak, Lynn P. Chorich, Megan E. Sullivan, James Knight, Hyung-Goo Kim, Lawrence C. Layman. The Use of Whole Exome Sequencing in a Cohort of Transgender Individuals to Identify Rare Genetic Variants. Scientific Reports, 2019; 9 (1) DOI: 10.1038/s41598-019-53500-y
This is a quote from a relevant part of the article:
“Basically — and perhaps counterintuitively — these genes are primarily involved in estrogen’s critical sprinkling of the brain right before or after birth, which is essential to masculinization of the brain.”
“Variants investigators identified may mean that in natal males (people whose birth sex is male) this critical estrogen exposure doesn’t happen or the pathway is altered so the brain does not get masculinized. In natal females, it may mean that estrogen exposure happens when it normally wouldn’t, leading to masculinization.”
Both could result in an incongruence between a person’s internal gender and their external sex. The negative emotional experience associated with this incongruence is called gender dysphoria.
The exact cause in human development for mind/body incongruence in transgendered individuals has long been a mystery. Perhaps with the new research which is continuing may provide a satisfying answer at long last.