Transsexualism ("gender identity disorder") - A CNS-limited form of intersexuality?

Abstract

In terms of their gender-related behavior, persons with (non-intersex) gender identity disorder (GID; aka transsexualism) of early onset resemble patients with somatic intersexuality who request a change of gender. However, there is currently no known intersex analog for GID of late onset. Neuroanatomy studies of somatic intersex are too few for providing any guidance on what brain effects to expect in a putative CNS-limited form of intersexuality as the basis for (non-intersex) GID. Findings in GID patients of atypical androgen levels apply only to about one-third of female-to-male transsexuals and not at all to male-to-female transsexuals. Sex steroid-related findings of genetic polymorphisms are weak, inconsistent, and largely unreplicated. Neuroanatomic findings are few and also largely unreplicated; distributions for patients with GID overlap with those of controls and are therefore of questionable utility for GID diagnosis. Given the complexity of gendered behavior and identity, the neuroanatomic basis of GID is likely to be neural networks rather than individual brain nuclei or regions. Findings on neurofunction in persons with GID are few and unreplicated. In summary, the emerging data are interesting, but at this time insufficient to constitute a firm basis for the recategorization of GID as a form of CNS-limited intersexuality. © 2011 Springer Science+Business Media, LLC.