There's no reason to believe this. If genetic abnormalities leading to some sort of brain/body mismatch were possible, we should be seeing a lot more people experiencing dysphoria. Achondroplasia, the most common for of dwarfism (think Peter Dinklage) for example, does not produce intense feelings of dysphoria despite the fact that it has pronounced affects on skeletal development but no effect on the brain. There's just no mechanism that can explain a phenomena where the brains "knows" it should have a different set of organs, or different hormones running through it. Even intersex people who have had medical interventions that forcibly gendered them don't report the specific obsessive need and anguish troons report, even though they should be suffering it the most. Instead, a lot of the strife in their lives comes from trying to force them to conform to a specific social role. There probably is some element of gender role variance in the brains of trans people (autism) that predisposes them to the obession/fetish, but just like with actual intersex people, the idea that the solution then is extreme medical intervention to create pseudoorgans is insane. No other type of body dysmorphic disorder, not Anorexia, muscle dysmorphis, or BIID, would ever be treated by feeding into the distored perception of reality.