the fact of not having your gender match the physical body you were born with

In the therapeutic clinic, transsexuality is usually considered a medical condition. 在治疗诊所，变性通常被认为是一种病症。

the fact of having had medical treatment to change your sex

The applicant requested a change in the legislation so that his transsexuality could remain secret. 申请人要求修改立法，这样他做过变性手术的事就可以保密。