Gender Dysphoria 457
factors under consideration, especially in indi viduals with late-onset gender dysphoria (ad-
olescence, adulthood), include habitual fetishistic transvesti sm developing into autogyne-
philia (i.e., sexual arousal asso ciated with the thought or imag e of oneself as  a woman) and
other forms of more general social, psychological, or developmental problems.
Genetic and physiological. For individuals with gender dy sphoria without a disorder of
sex development, some genetic contribution is suggested by evidence for (weak) familial-
ity of transsexualism among nontwin siblings, increased concordance for transsexualism
in monozygotic compared with dizygotic same -sex twins, and some degree of heritability
of gender dysphoria. As to endocrine findin gs, no endogenous systemic abnormalities in
sex-hormone levels have been found in 46,XY individuals, whereas there appear to be in-
creased androgen levels (in the range found in hirsute women but far below normal male
levels) in 46,XX individuals. Overall, current evidence is insufficient to label gender dys-
phoria without a disorder of sex development as  a form of intersexuality limited to the cen-
tral nervous system.
In gender dysphoria associated with a disorder of sex development, the likelihood of
later gender dysphoria is increased if pren atal production and utilization (via receptor
sensitivity) of androgens are grossly atypical re lative to what is usually seen in individuals
with the same assigned gender. Examples incl ude 46,XY individuals with a history of nor-
mal male prenatal hormone milieu but inborn nonhormonal genital defects (as in cloacal