I know that being left handed is a lot more common among queer people, some statistics say it occurs twice as often which would mean one out of four. That seems a bit much, but I absolutely see a lot of left handed people in trans spaces.

I have no numbers for Adhd except the baseline prevalence being about 2% in adults. I do know that autism has increased incidence among trans people, and the same is suspected for some forms of Ehlers-Danlos syndrome. And I would expect Adhd to also be more common, most of my friends have a diagnosis.