F64 GENDER IDENTITY DISORDERS
F64.0 Transsexualism
A. Desire to live and be accepted as a member of the opposite sex, usually accompanied by the wish to make
one's body as congruent as possible with one's preferred sex through surgery and hormonal treatment.
B. Presence of the transsexual identity for at least two years persistently.
C. Not a symptom of another mental disorder, such as schizophrenia, or associated with chromosome
abnormality

http://www.who.int/classifications/icd/en/GRNBOOK.pdf