[Little Ray]

There are two sexes - XX and XY - Female and Male.
Everything else is varying degrees and flavors of mental illness.

[AustinBill]

There are rare chromosomal variants other than XX and XY. In non-PC days they were referred to as "birth defects". People with such rare medical conditions should be treated compassionately, but you don't upend society to pretend that they are normal.

But the vast majority of "trans" people have perfectly normal XX or XY chromosomes. Their problem is a society unmoored from any moral grounding that coddles their delusions.