I don't know what "You" believe... that's why I tempered it with 'you/they' (they being a non-gendered catch-all pronoun for liberals)...
and "Trans" means to Change... barring high doses of radiation ones 'Biology' does not Change... so NO there is no BIOLOGICAL transgender...
- you can take All the Hormones, until have a higher Estrogen/Testosterone count than the gender you wish you were...
- you can (pay some one to) cut off or attach any appendage you like
You are Still BIOLOGICALLY what you Born as...
and again the rate of NON-XX/XY is such that it is an ANOMALY (one might even say such an occurrence is rather queer, if we use an arcane definition)