It was just the comorbidities that tipped me off. Well, that and the added clue that you are here specifically. ED+ADHD+autism+lemmy is an almost guaranteed hit for also having gender fuckery.

ED alters collagen, a key brain component. This can cause the system responsible for gender congruency to get incorrect, or no feedback at a key stage in development. It can cause other systems to get incorect feedback too, leading to autism.

Gender dysphoria can cause childhood cptsd, which presents as autism or ADHD as the brain grows wonky.

Having a differently connected, autistic network can cause the system responsible for gender congruency to get the wrong, or no signals at all during that key stage in development.

So, I don't think it's one thing really. It's just a bunch of stuff that triggers eachother.